13 files changed, 223 insertions, 1860 deletions

diff --git a/erts/emulator/beam/arith_instrs.tab b/erts/emulator/beam/arith_instrs.tab
index b828e86788..574fceec5b 100644
--- a/erts/emulator/beam/arith_instrs.tab
+++ b/erts/emulator/beam/arith_instrs.tab
@@ -19,21 +19,22 @@
 // %CopyrightEnd%
 //
 
-OUTLINED_ARITH_2(Fail, Live, Name, BIF, Op1, Op2, Dst) {
+OUTLINED_ARITH_2(Fail, Name, BIF, Op1, Op2, Dst) {
     Eterm result;
-    Uint live = $Live;
-    HEAVY_SWAPOUT;
-    reg[live] = $Op1;
-    reg[live+1] = $Op2;
-    result = erts_gc_$Name (c_p, reg, live);
-    HEAVY_SWAPIN;
+#ifdef DEBUG
+    Eterm* orig_htop = HTOP;
+    Eterm* orig_stop = E;
+#endif
+    DEBUG_SWAPOUT;
+    result = erts_$Name (c_p, $Op1, $Op2);
+    DEBUG_SWAPIN;
+    ASSERT(orig_htop == HTOP && orig_stop == E);
     ERTS_HOLE_CHECK(c_p);
     if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
         $Dst = result;
         $NEXT0();
     }
-    $BIF_ERROR_ARITY_2($Fail, $BIF, reg[live], reg[live+1]);
+    $BIF_ERROR_ARITY_2($Fail, $BIF, $Op1, $Op2);
 }
 
 
@@ -48,7 +49,7 @@ plus.fetch(Op1, Op2) {
     PlusOp2 = $Op2;
 }
 
-plus.execute(Fail, Live, Dst) {
+plus.execute(Fail, Dst) {
     if (ERTS_LIKELY(is_both_small(PlusOp1, PlusOp2))) {
         Sint i = signed_val(PlusOp1) + signed_val(PlusOp2);
         if (ERTS_LIKELY(IS_SSMALL(i))) {
@@ -56,7 +57,7 @@ plus.execute(Fail, Live, Dst) {
             $NEXT0();
         }
     }
-    $OUTLINED_ARITH_2($Fail, $Live, mixed_plus, BIF_splus_2, PlusOp1, PlusOp2, $Dst);
+    $OUTLINED_ARITH_2($Fail, mixed_plus, BIF_splus_2, PlusOp1, PlusOp2, $Dst);
 }
 
 i_minus := minus.fetch.execute;
@@ -70,7 +71,7 @@ minus.fetch(Op1, Op2) {
     MinusOp2 = $Op2;
 }
 
-minus.execute(Fail, Live, Dst) {
+minus.execute(Fail, Dst) {
     if (ERTS_LIKELY(is_both_small(MinusOp1, MinusOp2))) {
         Sint i = signed_val(MinusOp1) - signed_val(MinusOp2);
         if (ERTS_LIKELY(IS_SSMALL(i))) {
@@ -78,7 +79,7 @@ minus.execute(Fail, Live, Dst) {
             $NEXT0();
         }
     }
-    $OUTLINED_ARITH_2($Fail, $Live, mixed_minus, BIF_sminus_2, MinusOp1, MinusOp2, $Dst);
+    $OUTLINED_ARITH_2($Fail, mixed_minus, BIF_sminus_2, MinusOp1, MinusOp2, $Dst);
 }
 
 i_increment := increment.fetch.execute;
@@ -91,9 +92,8 @@ increment.fetch(Src) {
     increment_reg_val = $Src;
 }
 
-increment.execute(IncrementVal, Live, Dst) {
+increment.execute(IncrementVal, Dst) {
     Eterm increment_val = $IncrementVal;
-    Uint live;
     Eterm result;
 
     if (ERTS_LIKELY(is_small(increment_reg_val))) {
@@ -103,15 +103,9 @@ increment.execute(IncrementVal, Live, Dst) {
             $NEXT0();
         }
     }
-    live = $Live;
-    HEAVY_SWAPOUT;
-    reg[live] = increment_reg_val;
-    reg[live+1] = make_small(increment_val);
-    result = erts_gc_mixed_plus(c_p, reg, live);
-    HEAVY_SWAPIN;
+    result = erts_mixed_plus(c_p, increment_reg_val, make_small(increment_val));
     ERTS_HOLE_CHECK(c_p);
     if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
         $Dst = result;
         $NEXT0();
     }
@@ -119,19 +113,19 @@ increment.execute(IncrementVal, Live, Dst) {
     goto find_func_info;
 }
 
-i_times(Fail, Live, Op1, Op2, Dst) {
+i_times(Fail, Op1, Op2, Dst) {
     Eterm op1 = $Op1;
     Eterm op2 = $Op2;
-    $OUTLINED_ARITH_2($Fail, $Live, mixed_times, BIF_stimes_2, op1, op2, $Dst);
+    $OUTLINED_ARITH_2($Fail, mixed_times, BIF_stimes_2, op1, op2, $Dst);
 }
 
-i_m_div(Fail, Live, Op1, Op2, Dst) {
+i_m_div(Fail, Op1, Op2, Dst) {
     Eterm op1 = $Op1;
     Eterm op2 = $Op2;
-    $OUTLINED_ARITH_2($Fail, $Live, mixed_div, BIF_div_2, op1, op2, $Dst);
+    $OUTLINED_ARITH_2($Fail, mixed_div, BIF_div_2, op1, op2, $Dst);
 }
 
-i_int_div(Fail, Live, Op1, Op2, Dst) {
+i_int_div(Fail, Op1, Op2, Dst) {
     Eterm op1 = $Op1;
     Eterm op2 = $Op2;
     if (ERTS_UNLIKELY(op2 == SMALL_ZERO)) {
@@ -144,7 +138,7 @@ i_int_div(Fail, Live, Op1, Op2, Dst) {
             $NEXT0();
         }
     }
-    $OUTLINED_ARITH_2($Fail, $Live, int_div, BIF_intdiv_2, op1, op2, $Dst);
+    $OUTLINED_ARITH_2($Fail, int_div, BIF_intdiv_2, op1, op2, $Dst);
 }
 
 i_rem := rem.fetch.execute;
@@ -158,7 +152,7 @@ rem.fetch(Src1, Src2) {
     RemOp2 = $Src2;
 }
 
-rem.execute(Fail, Live, Dst) {
+rem.execute(Fail, Dst) {
     if (ERTS_UNLIKELY(RemOp2 == SMALL_ZERO)) {
         c_p->freason = BADARITH;
         $BIF_ERROR_ARITY_2($Fail, BIF_rem_2, RemOp1, RemOp2);
@@ -166,7 +160,7 @@ rem.execute(Fail, Live, Dst) {
         $Dst = make_small(signed_val(RemOp1) % signed_val(RemOp2));
         $NEXT0();
     } else {
-        $OUTLINED_ARITH_2($Fail, $Live, int_rem, BIF_rem_2, RemOp1, RemOp2, $Dst);
+        $OUTLINED_ARITH_2($Fail, int_rem, BIF_rem_2, RemOp1, RemOp2, $Dst);
     }
 }
 
@@ -181,7 +175,7 @@ band.fetch(Src1, Src2) {
     BandOp2 = $Src2;
 }
 
-band.execute(Fail, Live, Dst) {
+band.execute(Fail, Dst) {
     if (ERTS_LIKELY(is_both_small(BandOp1, BandOp2))) {
         /*
          * No need to untag -- TAG & TAG == TAG.
@@ -189,10 +183,10 @@ band.execute(Fail, Live, Dst) {
         $Dst = BandOp1 & BandOp2;
         $NEXT0();
     }
-    $OUTLINED_ARITH_2($Fail, $Live, band, BIF_band_2, BandOp1, BandOp2, $Dst);
+    $OUTLINED_ARITH_2($Fail, band, BIF_band_2, BandOp1, BandOp2, $Dst);
 }
 
-i_bor(Fail, Live, Src1, Src2, Dst) {
+i_bor(Fail, Src1, Src2, Dst) {
     if (ERTS_LIKELY(is_both_small($Src1, $Src2))) {
         /*
          * No need to untag -- TAG | TAG == TAG.
@@ -200,10 +194,10 @@ i_bor(Fail, Live, Src1, Src2, Dst) {
         $Dst = $Src1 | $Src2;
         $NEXT0();
     }
-    $OUTLINED_ARITH_2($Fail, $Live, bor, BIF_bor_2, $Src1, $Src2, $Dst);
+    $OUTLINED_ARITH_2($Fail, bor, BIF_bor_2, $Src1, $Src2, $Dst);
 }
 
-i_bxor(Fail, Live, Src1, Src2, Dst) {
+i_bxor(Fail, Src1, Src2, Dst) {
     if (ERTS_LIKELY(is_both_small($Src1, $Src2))) {
         /*
          * TAG ^ TAG == 0.
@@ -214,7 +208,7 @@ i_bxor(Fail, Live, Src1, Src2, Dst) {
         $Dst = ($Src1 ^ $Src2) | make_small(0);
         $NEXT0();
     }
-    $OUTLINED_ARITH_2($Fail, $Live, bxor, BIF_bxor_2, $Src1, $Src2, $Dst);
+    $OUTLINED_ARITH_2($Fail, bxor, BIF_bxor_2, $Src1, $Src2, $Dst);
 }
 
 i_bsl := shift.setup_bsl.execute;
@@ -265,7 +259,7 @@ shift.setup_bsl(Src1, Src2) {
     }
 }
 
-shift.execute(Fail, Live, Dst) {
+shift.execute(Fail, Dst) {
     Uint big_words_needed;
 
     if (ERTS_LIKELY(is_small(Op1))) {
@@ -320,7 +314,9 @@ shift.execute(Fail, Live, Dst) {
         }
         {
             Eterm tmp_big[2];
-            Sint big_need_size = BIG_NEED_SIZE(big_words_needed+1);
+            Sint big_need_size = 1 + BIG_NEED_SIZE(big_words_needed+1);
+            Eterm* hp;
+            Eterm* hp_end;
 
             /*
              * Slightly conservative check the size to avoid
@@ -331,15 +327,16 @@ shift.execute(Fail, Live, Dst) {
             if (big_need_size-8 > BIG_ARITY_MAX) {
                 $SYSTEM_LIMIT($Fail);
             }
-            $GC_TEST_PRESERVE(big_need_size+1, $Live, Op1);
+            hp = HeapFragOnlyAlloc(c_p, big_need_size);
             if (is_small(Op1)) {
                 Op1 = small_to_big(signed_val(Op1), tmp_big);
             }
-            Op1 = big_lshift(Op1, shift_left_count, HTOP);
+            Op1 = big_lshift(Op1, shift_left_count, hp);
+            hp_end = hp + big_need_size;
             if (is_big(Op1)) {
-                HTOP += bignum_header_arity(*HTOP) + 1;
+                hp += bignum_header_arity(*hp) + 1;
             }
-            HEAP_SPACE_VERIFIED(0);
+            HRelease(c_p, hp_end, hp);
             if (ERTS_UNLIKELY(is_nil(Op1))) {
                 /*
                  * This result must have been only slighty larger
@@ -349,7 +346,6 @@ shift.execute(Fail, Live, Dst) {
                 $SYSTEM_LIMIT($Fail);
             }
             ERTS_HOLE_CHECK(c_p);
-            $REFRESH_GEN_DEST();
             $Dst = Op1;
             $NEXT0();
         }
@@ -366,31 +362,28 @@ shift.execute(Fail, Live, Dst) {
         reg[0] = Op1;
         reg[1] = Op2;
         SWAPOUT;
-        if (IsOpCode(I[0], i_bsl_ssjtd)) {
+        if (IsOpCode(I[0], i_bsl_ssjd)) {
             I = handle_error(c_p, I, reg, &bif_export[BIF_bsl_2]->info.mfa);
         } else {
-            ASSERT(IsOpCode(I[0], i_bsr_ssjtd));
+            ASSERT(IsOpCode(I[0], i_bsr_ssjd));
             I = handle_error(c_p, I, reg, &bif_export[BIF_bsr_2]->info.mfa);
         }
         goto post_error_handling;
     }
 }
 
-i_int_bnot(Fail, Src, Live, Dst) {
+i_int_bnot(Fail, Src, Dst) {
     Eterm bnot_val = $Src;
+    Eterm result;
+
     if (ERTS_LIKELY(is_small(bnot_val))) {
-        bnot_val = make_small(~signed_val(bnot_val));
+        result = make_small(~signed_val(bnot_val));
     } else {
-        Uint live = $Live;
-        HEAVY_SWAPOUT;
-        reg[live] = bnot_val;
-        bnot_val = erts_gc_bnot(c_p, reg, live);
-        HEAVY_SWAPIN;
+        result = erts_bnot(c_p, bnot_val);
         ERTS_HOLE_CHECK(c_p);
-        if (ERTS_UNLIKELY(is_nil(bnot_val))) {
-            $BIF_ERROR_ARITY_1($Fail, BIF_bnot_1, reg[live]);
+        if (ERTS_UNLIKELY(is_nil(result))) {
+            $BIF_ERROR_ARITY_1($Fail, BIF_bnot_1, bnot_val);
         }
-        $REFRESH_GEN_DEST();
     }
-    $Dst = bnot_val;
+    $Dst = result;
 }
diff --git a/erts/emulator/beam/beam_debug.c b/erts/emulator/beam/beam_debug.c
index b33aab7eee..f71efd708f 100644
--- a/erts/emulator/beam/beam_debug.c
+++ b/erts/emulator/beam/beam_debug.c
@@ -558,23 +558,6 @@ print_op(fmtfn_t to, void *to_arg, int op, int size, BeamInstr* addr)
 	case 'I':
         case 'W':
 	    switch (op) {
-	    case op_i_gc_bif1_jWstd:
-	    case op_i_gc_bif2_jWtssd:
-	    case op_i_gc_bif3_jWtssd:
-		{
-		    const ErtsGcBif* p;
-		    BifFunction gcf = (BifFunction) *ap;
-		    for (p = erts_gc_bifs; p->bif != 0; p++) {
-			if (p->gc_bif == gcf) {
-			    print_bif_name(to, to_arg, p->bif);
-			    break;
-			}
-		    }
-		    if (p->bif == 0) {
-			erts_print(to, to_arg, "%d", (Uint)gcf);
-		    }
-		    break;
-		}
 	    case op_i_make_fun_Wt:
                 if (*sign == 'W') {
                     ErlFunEntry* fe = (ErlFunEntry *) *ap;
diff --git a/erts/emulator/beam/beam_emu.c b/erts/emulator/beam/beam_emu.c
index 2e4d1f8f48..6b34024a5a 100644
--- a/erts/emulator/beam/beam_emu.c
+++ b/erts/emulator/beam/beam_emu.c
@@ -206,8 +206,12 @@ void** beam_ops;
 #ifdef DEBUG
 #  /* The stack pointer is used in an assertion. */
 #  define LIGHT_SWAPOUT SWAPOUT
+#  define DEBUG_SWAPOUT SWAPOUT
+#  define DEBUG_SWAPIN  SWAPIN
 #else
 #  define LIGHT_SWAPOUT HEAP_TOP(c_p) = HTOP
+#  define DEBUG_SWAPOUT
+#  define DEBUG_SWAPIN
 #endif
 
 /*
@@ -386,7 +390,6 @@ do {                                            \
  */
 static void init_emulator_finish(void) NOINLINE;
 static ErtsCodeMFA *ubif2mfa(void* uf) NOINLINE;
-static ErtsCodeMFA *gcbif2mfa(void* gcf) NOINLINE;
 static BeamInstr* handle_error(Process* c_p, BeamInstr* pc,
 			       Eterm* reg, ErtsCodeMFA* bif_mfa) NOINLINE;
 static BeamInstr* call_error_handler(Process* p, ErtsCodeMFA* mfa,
@@ -1301,18 +1304,6 @@ void erts_dirty_process_main(ErtsSchedulerData *esdp)
 }
 
 static ErtsCodeMFA *
-gcbif2mfa(void* gcf)
-{
-    int i;
-    for (i = 0; erts_gc_bifs[i].bif; i++) {
-	if (erts_gc_bifs[i].gc_bif == gcf)
-	    return &bif_export[erts_gc_bifs[i].exp_ix]->info.mfa;
-    }
-    erts_exit(ERTS_ERROR_EXIT, "bad gc bif");
-    return NULL;
-}
-
-static ErtsCodeMFA *
 ubif2mfa(void* uf)
 {
     int i;
@@ -1320,7 +1311,7 @@ ubif2mfa(void* uf)
 	if (erts_u_bifs[i].bif == uf)
 	    return &bif_export[erts_u_bifs[i].exp_ix]->info.mfa;
     }
-    erts_exit(ERTS_ERROR_EXIT, "bad u bif");
+    erts_exit(ERTS_ERROR_EXIT, "bad u bif: %p\n", uf);
     return NULL;
 }
 
diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index c28a5c57e6..400a58a75c 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -3580,38 +3580,36 @@ gen_skip_bits2(LoaderState* stp, GenOpArg Fail, GenOpArg Ms,
 }
 
 static GenOp*
-gen_increment(LoaderState* stp, GenOpArg Reg, GenOpArg Integer,
-	      GenOpArg Live, GenOpArg Dst)
+gen_increment(LoaderState* stp, GenOpArg Reg,
+              GenOpArg Integer, GenOpArg Dst)
 {
     GenOp* op;
 
     NEW_GENOP(stp, op);
-    op->op = genop_i_increment_4;
-    op->arity = 4;
+    op->op = genop_i_increment_3;
+    op->arity = 3;
     op->next = NULL;
     op->a[0] = Reg;
     op->a[1].type = TAG_u;
     op->a[1].val = Integer.val;
-    op->a[2] = Live;
-    op->a[3] = Dst;
+    op->a[2] = Dst;
     return op;
 }
 
 static GenOp*
-gen_increment_from_minus(LoaderState* stp, GenOpArg Reg, GenOpArg Integer,
-			 GenOpArg Live, GenOpArg Dst)
+gen_increment_from_minus(LoaderState* stp, GenOpArg Reg,
+                         GenOpArg Integer, GenOpArg Dst)
 {
     GenOp* op;
 
     NEW_GENOP(stp, op);
-    op->op = genop_i_increment_4;
-    op->arity = 4;
+    op->op = genop_i_increment_3;
+    op->arity = 3;
     op->next = NULL;
     op->a[0] = Reg;
     op->a[1].type = TAG_u;
     op->a[1].val = -Integer.val;
-    op->a[2] = Live;
-    op->a[3] = Dst;
+    op->a[2] = Dst;
     return op;
 }
 
@@ -4300,98 +4298,6 @@ gen_make_fun2(LoaderState* stp, GenOpArg idx)
 }
 
 static GenOp*
-translate_gc_bif(LoaderState* stp, GenOp* op, GenOpArg Bif)
-{
-    const ErtsGcBif* p;
-    BifFunction bf;
-
-    bf = stp->import[Bif.val].bf;
-    for (p = erts_gc_bifs; p->bif != 0; p++) {
-	if (p->bif == bf) {
-	    op->a[1].type = TAG_u;
-	    op->a[1].val = (BeamInstr) p->gc_bif;
-	    return op;
-	}
-    }
-
-    op->op = genop_unsupported_guard_bif_3;
-    op->arity = 3;
-    op->a[0].type = TAG_a;
-    op->a[0].val = stp->import[Bif.val].module;
-    op->a[1].type = TAG_a;
-    op->a[1].val = stp->import[Bif.val].function;
-    op->a[2].type = TAG_u;
-    op->a[2].val = stp->import[Bif.val].arity;
-    return op;
-}
-
-/*
- * Rewrite gc_bifs with one parameter (the common case).
- */
-static GenOp*
-gen_guard_bif1(LoaderState* stp, GenOpArg Fail, GenOpArg Live, GenOpArg Bif,
-	      GenOpArg Src, GenOpArg Dst)
-{
-    GenOp* op;
-
-    NEW_GENOP(stp, op);
-    op->next = NULL;
-    op->op = genop_i_gc_bif1_5;
-    op->arity = 5;
-    op->a[0] = Fail;
-    /* op->a[1] is set by translate_gc_bif() */
-    op->a[2] = Src;
-    op->a[3] = Live;
-    op->a[4] = Dst;
-    return translate_gc_bif(stp, op, Bif);
-}
-
-/*
- * This is used by the ops.tab rule that rewrites gc_bifs with two parameters.
- */
-static GenOp*
-gen_guard_bif2(LoaderState* stp, GenOpArg Fail, GenOpArg Live, GenOpArg Bif,
-	      GenOpArg S1, GenOpArg S2, GenOpArg Dst)
-{
-    GenOp* op;
-
-    NEW_GENOP(stp, op);
-    op->next = NULL;
-    op->op = genop_i_gc_bif2_6;
-    op->arity = 6;
-    op->a[0] = Fail;
-    /* op->a[1] is set by translate_gc_bif() */
-    op->a[2] = Live;
-    op->a[3] = S1;
-    op->a[4] = S2;
-    op->a[5] = Dst;
-    return translate_gc_bif(stp, op, Bif);
-}
-
-/*
- * This is used by the ops.tab rule that rewrites gc_bifs with three parameters.
- */
-static GenOp*
-gen_guard_bif3(LoaderState* stp, GenOpArg Fail, GenOpArg Live, GenOpArg Bif,
-	      GenOpArg S1, GenOpArg S2, GenOpArg S3, GenOpArg Dst)
-{
-    GenOp* op;
-
-    NEW_GENOP(stp, op);
-    op->next = NULL;
-    op->op = genop_ii_gc_bif3_7;
-    op->arity = 7;
-    op->a[0] = Fail;
-    /* op->a[1] is set by translate_gc_bif() */
-    op->a[2] = Live;
-    op->a[3] = S1;
-    op->a[4] = S2;
-    op->a[5] = S3;
-    op->a[6] = Dst;
-    return translate_gc_bif(stp, op, Bif);
-}
-
-static GenOp*
 tuple_append_put5(LoaderState* stp, GenOpArg Arity, GenOpArg Dst,
 		  GenOpArg* Puts, GenOpArg S1, GenOpArg S2, GenOpArg S3,
 		  GenOpArg S4, GenOpArg S5)
diff --git a/erts/emulator/beam/bif.tab b/erts/emulator/beam/bif.tab
index 35e10f3e63..f141407c0e 100644
--- a/erts/emulator/beam/bif.tab
+++ b/erts/emulator/beam/bif.tab
@@ -41,7 +41,7 @@
 #
 
 
-gcbif erlang:abs/1
+ubif erlang:abs/1
 bif erlang:adler32/1
 bif erlang:adler32/2
 bif erlang:adler32_combine/3
@@ -66,7 +66,7 @@ bif erlang:exit/2
 bif erlang:exit_signal/2
 bif erlang:external_size/1
 bif erlang:external_size/2
-gcbif erlang:float/1
+ubif erlang:float/1
 bif erlang:float_to_list/1
 bif erlang:float_to_list/2
 bif erlang:fun_info/2
@@ -84,7 +84,7 @@ bif erlang:phash2/2
 ubif erlang:hd/1
 bif erlang:integer_to_list/1
 bif erlang:is_alive/0
-gcbif erlang:length/1
+ubif erlang:length/1
 bif erlang:link/1
 bif erlang:list_to_atom/1
 bif erlang:list_to_binary/1
@@ -133,10 +133,10 @@ bif erlang:processes/0
 bif erlang:put/2
 bif erlang:register/2
 bif erlang:registered/0
-gcbif erlang:round/1
+ubif erlang:round/1
 ubif erlang:self/0
 bif erlang:setelement/3
-gcbif erlang:size/1
+ubif erlang:size/1
 bif erlang:spawn/3
 bif erlang:spawn_link/3
 bif erlang:split_binary/2
@@ -146,7 +146,7 @@ bif erlang:term_to_binary/2
 bif erlang:throw/1
 bif erlang:time/0
 ubif erlang:tl/1
-gcbif erlang:trunc/1
+ubif erlang:trunc/1
 bif erlang:tuple_to_list/1
 bif erlang:universaltime/0
 bif erlang:universaltime_to_localtime/1
@@ -481,8 +481,8 @@ bif erlang:list_to_existing_atom/1
 #
 ubif erlang:is_bitstring/1
 ubif erlang:tuple_size/1
-gcbif erlang:byte_size/1
-gcbif erlang:bit_size/1
+ubif erlang:byte_size/1
+ubif erlang:bit_size/1
 bif erlang:list_to_bitstring/1
 bif erlang:bitstring_to_list/1
 
@@ -534,8 +534,8 @@ bif erlang:binary_to_term/2
 #
 # The searching/splitting/substituting thingies
 #
-gcbif erlang:binary_part/2
-gcbif erlang:binary_part/3
+ubif erlang:binary_part/2
+ubif erlang:binary_part/3
 
 bif binary:compile_pattern/1
 bif binary:match/2
@@ -623,7 +623,7 @@ bif io:printable_range/0
 bif re:inspect/2
 
 ubif erlang:is_map/1
-gcbif erlang:map_size/1
+ubif erlang:map_size/1
 bif maps:find/2
 bif maps:get/2
 bif maps:from_list/1
@@ -671,8 +671,8 @@ bif maps:take/2
 # New in 20.0
 #
 
-gcbif erlang:floor/1
-gcbif erlang:ceil/1
+ubif erlang:floor/1
+ubif erlang:ceil/1
 bif math:floor/1
 bif math:ceil/1
 bif math:fmod/2
diff --git a/erts/emulator/beam/bif_instrs.tab b/erts/emulator/beam/bif_instrs.tab
index 00854471a9..3abd062552 100644
--- a/erts/emulator/beam/bif_instrs.tab
+++ b/erts/emulator/beam/bif_instrs.tab
@@ -31,13 +31,20 @@
 
 CALL_GUARD_BIF(BF, TmpReg, Dst) {
     Eterm result;
+#ifdef DEBUG
+    Eterm* orig_htop = HTOP;
+    Eterm* orig_stop = E;
+#endif
 
     ERTS_DBG_CHK_REDS(c_p, FCALLS);
     c_p->fcalls = FCALLS;
     PROCESS_MAIN_CHK_LOCKS(c_p);
     ASSERT(!ERTS_PROC_IS_EXITING(c_p));
     ERTS_CHK_MBUF_SZ(c_p);
+    DEBUG_SWAPOUT;
     result = (*$BF)(c_p, $TmpReg, I);
+    DEBUG_SWAPIN;
+    ASSERT(orig_htop == HTOP && orig_stop == E);
     ERTS_CHK_MBUF_SZ(c_p);
     ASSERT(!ERTS_PROC_IS_EXITING(c_p) || is_non_value(result));
     ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
@@ -55,7 +62,7 @@ CALL_GUARD_BIF(BF, TmpReg, Dst) {
 // to the code for the next clause.  We don't support tracing
 // of guard BIFs.
 
-bif1(Fail, Bif, Src, Dst) {
+i_bif1(Fail, Bif, Src, Dst) {
     ErtsBifFunc bf;
     Eterm tmp_reg[1];
 
@@ -70,7 +77,7 @@ bif1(Fail, Bif, Src, Dst) {
 // Guard BIF in body.  It can fail like any BIF.  No trace support.
 //
 
-bif1_body(Bif, Src, Dst) {
+i_bif1_body(Bif, Src, Dst) {
     ErtsBifFunc bf;
     Eterm tmp_reg[1];
 
@@ -118,154 +125,38 @@ i_bif2_body(Bif, Src1, Src2, Dst) {
     goto post_error_handling;
 }
 
-//
-// Garbage-collecting BIF with one argument in either guard or body.
-//
-
-i_gc_bif1(Fail, Bif, Src, Live, Dst) {
-    typedef Eterm (*GcBifFunction)(Process*, Eterm*, Uint);
-    GcBifFunction bf;
-    Eterm result;
-    Uint live = (Uint) $Live;
-
-    x(live) = $Src;
-    bf = (GcBifFunction) $Bif;
-    ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    c_p->fcalls = FCALLS;
-    SWAPOUT;
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    ERTS_UNREQ_PROC_MAIN_LOCK(c_p);
-    ERTS_CHK_MBUF_SZ(c_p);
-    result = (*bf)(c_p, reg, live);
-    ERTS_CHK_MBUF_SZ(c_p);
-    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
-    ERTS_REQ_PROC_MAIN_LOCK(c_p);
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    SWAPIN;
-    ERTS_HOLE_CHECK(c_p);
-    FCALLS = c_p->fcalls;
-    ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
-        $Dst = result;
-        $NEXT0();
-    }
-    if (ERTS_LIKELY($Fail != 0)) { /* Handle error in guard. */
-        $JUMP($Fail);
-    }
-
-    /* Handle error in body. */
-    x(0) = x(live);
-    I = handle_error(c_p, I, reg, gcbif2mfa((void *) bf));
-    goto post_error_handling;
-}
-
-//
-// Garbage-collecting BIF with two arguments in either guard or body.
-//
-
-i_gc_bif2(Fail, Bif, Live, Src1, Src2, Dst) {
-    typedef Eterm (*GcBifFunction)(Process*, Eterm*, Uint);
-    GcBifFunction bf;
-    Eterm result;
-    Uint live = (Uint) $Live;
-
-    /*
-     * XXX This calling convention does not make sense. 'live'
-     * should point out the first argument, not the second
-     * (i.e. 'live' should not be incremented below).
-     */
-    x(live) = $Src1;
-    x(live+1) = $Src2;
-    live++;
+// Guard BIF in head (binary_part/3).  On failure, ignore the error
+// and jump to the code for the next clause.  We don't support tracing
+// of guard BIFs.
 
-    bf = (GcBifFunction) $Bif;
-    ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    c_p->fcalls = FCALLS;
-    SWAPOUT;
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    ERTS_UNREQ_PROC_MAIN_LOCK(c_p);
-    ERTS_CHK_MBUF_SZ(c_p);
-    result = (*bf)(c_p, reg, live);
-    ERTS_CHK_MBUF_SZ(c_p);
-    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
-    ERTS_REQ_PROC_MAIN_LOCK(c_p);
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    SWAPIN;
-    ERTS_HOLE_CHECK(c_p);
-    FCALLS = c_p->fcalls;
-    ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
-        $Dst = result;
-        $NEXT0();
-    }
+i_bif3(Fail, Bif, Src1, Src2, Src3, Dst) {
+    ErtsBifFunc bf;
+    Eterm tmp_reg[3];
 
-    if (ERTS_LIKELY($Fail != 0)) { /* Handle error in guard. */
-        $JUMP($Fail);
-    }
+    tmp_reg[0] = $Src1;
+    tmp_reg[1] = $Src2;
+    tmp_reg[2] = $Src3;
+    bf = (BifFunction) $Bif;
+    $CALL_GUARD_BIF(bf, tmp_reg, $Dst);
 
-    /* Handle error in body. */
-    live--;
-    x(0) = x(live);
-    x(1) = x(live+1);
-    I = handle_error(c_p, I, reg, gcbif2mfa((void *) bf));
-    goto post_error_handling;
+    $FAIL($Fail);
 }
 
-//
-// Garbage-collecting BIF with three arguments in either guard or body.
-//
-
-i_gc_bif3(Fail, Bif, Live, Src2, Src3, Dst) {
-    typedef Eterm (*GcBifFunction)(Process*, Eterm*, Uint);
-    GcBifFunction bf;
-    Eterm result;
-    Uint live = (Uint) $Live;
+// Guard BIF in body with three arguments (binary_part/3).
 
-    /*
-     * XXX This calling convention does not make sense. 'live'
-     * should point out the first argument, not the third
-     * (i.e. 'live' should not be incremented below).
-     */
-    x(live) = x(SCRATCH_X_REG);
-    x(live+1) = $Src2;
-    x(live+2) = $Src3;
-    live += 2;
+i_bif3_body(Bif, Src1, Src2, Src3, Dst) {
+    ErtsBifFunc bf;
+    Eterm tmp_reg[3];
 
-    bf = (GcBifFunction) $Bif;
-    ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    c_p->fcalls = FCALLS;
+    tmp_reg[0] = $Src1;
+    tmp_reg[1] = $Src2;
+    tmp_reg[2] = $Src3;
+    bf = (BifFunction) $Bif;
+    $CALL_GUARD_BIF(bf, tmp_reg, $Dst);
+    reg[0] = tmp_reg[0];
+    reg[1] = tmp_reg[1];
     SWAPOUT;
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    ERTS_UNREQ_PROC_MAIN_LOCK(c_p);
-    ERTS_CHK_MBUF_SZ(c_p);
-    result = (*bf)(c_p, reg, live);
-    ERTS_CHK_MBUF_SZ(c_p);
-    ERTS_VERIFY_UNUSED_TEMP_ALLOC(c_p);
-    ERTS_REQ_PROC_MAIN_LOCK(c_p);
-    PROCESS_MAIN_CHK_LOCKS(c_p);
-    SWAPIN;
-    ERTS_HOLE_CHECK(c_p);
-    FCALLS = c_p->fcalls;
-    ERTS_DBG_CHK_REDS(c_p, FCALLS);
-    if (ERTS_LIKELY(is_value(result))) {
-        $REFRESH_GEN_DEST();
-        $Dst = result;
-        $NEXT0();
-    }
-
-    /* Handle error in guard. */
-    if (ERTS_LIKELY($Fail != 0)) {
-        $JUMP($Fail);
-    }
-
-    /* Handle error in body. */
-    live -= 2;
-    x(0) = x(live);
-    x(1) = x(live+1);
-    x(2) = x(live+2);
-    I = handle_error(c_p, I, reg, gcbif2mfa((void *) bf));
+    I = handle_error(c_p, I, reg, ubif2mfa((void *) bf));
     goto post_error_handling;
 }
 
diff --git a/erts/emulator/beam/erl_arith.c b/erts/emulator/beam/erl_arith.c
index 144fb56ea5..68d1cd989e 100644
--- a/erts/emulator/beam/erl_arith.c
+++ b/erts/emulator/beam/erl_arith.c
@@ -52,19 +52,11 @@ static ERTS_INLINE void maybe_shrink(Process* p, Eterm* hp, Eterm res, Uint allo
     Uint actual;
 
     if (is_immed(res)) {
-	if (p->heap <= hp && hp < p->htop) {
-	    p->htop = hp;
-	}
-	else {
-	    erts_heap_frag_shrink(p, hp);
-	}
+        ASSERT(!(p->heap <= hp && hp < p->htop));
+        erts_heap_frag_shrink(p, hp);
     } else if ((actual = bignum_header_arity(*hp)+1) < alloc) {
-	if (p->heap <= hp && hp < p->htop) {
-	    p->htop = hp+actual;
-	}
-	else {
-	    erts_heap_frag_shrink(p, hp+actual);
-	}
+        ASSERT(!(p->heap <= hp && hp < p->htop));
+        erts_heap_frag_shrink(p, hp+actual);
     }
 }
 
@@ -246,7 +238,7 @@ shift(Process* p, Eterm arg1, Eterm arg2, int right)
 		    BIF_ERROR(p, SYSTEM_LIMIT);
 		}
 		need = BIG_NEED_SIZE(ires+1);
-		bigp = HAlloc(p, need);
+		bigp = HeapFragOnlyAlloc(p, need);
 		arg1 = big_lshift(arg1, i, bigp);
 		maybe_shrink(p, bigp, arg1, need);
 		if (is_nil(arg1)) {
@@ -298,7 +290,7 @@ BIF_RETTYPE bnot_1(BIF_ALIST_1)
 	ret = make_small(~signed_val(BIF_ARG_1));
     } else if (is_big(BIF_ARG_1)) {
 	Uint need = BIG_NEED_SIZE(big_size(BIF_ARG_1)+1);
-	Eterm* bigp = HAlloc(BIF_P, need);
+	Eterm* bigp = HeapFragOnlyAlloc(BIF_P, need);
 
 	ret = big_bnot(BIF_ARG_1, bigp);
 	maybe_shrink(BIF_P, bigp, ret, need);
@@ -343,7 +335,7 @@ erts_mixed_plus(Process* p, Eterm arg1, Eterm arg2)
 		    if (IS_SSMALL(ires)) {
 			return make_small(ires);
 		    } else {
-			hp = HAlloc(p, 2);
+			hp = HeapFragOnlyAlloc(p, 2);
 			res = small_to_big(ires, hp);
 			return res;
 		    }
@@ -400,7 +392,7 @@ erts_mixed_plus(Process* p, Eterm arg1, Eterm arg2)
 		    sz2 = big_size(arg2);
 		    sz = MAX(sz1, sz2)+1;
 		    need_heap = BIG_NEED_SIZE(sz);
-		    hp = HAlloc(p, need_heap);
+		    hp = HeapFragOnlyAlloc(p, need_heap);
 		    res = big_plus(arg1, arg2, hp);
 		    maybe_shrink(p, hp, res, need_heap);
 		    if (is_nil(res)) {
@@ -446,7 +438,7 @@ erts_mixed_plus(Process* p, Eterm arg1, Eterm arg2)
 		do_float:
 		    f1.fd = f1.fd + f2.fd;
 		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    hp = HAlloc(p, FLOAT_SIZE_OBJECT);
+		    hp = HeapFragOnlyAlloc(p, FLOAT_SIZE_OBJECT);
 		    res = make_float(hp);
 		    PUT_DOUBLE(f1, hp);
 		    return res;
@@ -488,7 +480,7 @@ erts_mixed_minus(Process* p, Eterm arg1, Eterm arg2)
 		    if (IS_SSMALL(ires)) {
 			return make_small(ires);
 		    } else {
-			hp = HAlloc(p, 2);
+			hp = HeapFragOnlyAlloc(p, 2);
 			res = small_to_big(ires, hp);
 			return res;
 		    }
@@ -534,7 +526,7 @@ erts_mixed_minus(Process* p, Eterm arg1, Eterm arg2)
 		    sz2 = big_size(arg2);
 		    sz = MAX(sz1, sz2)+1;
 		    need_heap = BIG_NEED_SIZE(sz);
-		    hp = HAlloc(p, need_heap);
+		    hp = HeapFragOnlyAlloc(p, need_heap);
 		    res = big_minus(arg1, arg2, hp);
                     maybe_shrink(p, hp, res, need_heap);
 		    if (is_nil(res)) {
@@ -589,7 +581,7 @@ erts_mixed_minus(Process* p, Eterm arg1, Eterm arg2)
 		do_float:
 		    f1.fd = f1.fd - f2.fd;
 		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    hp = HAlloc(p, FLOAT_SIZE_OBJECT);
+		    hp = HeapFragOnlyAlloc(p, FLOAT_SIZE_OBJECT);
 		    res = make_float(hp);
 		    PUT_DOUBLE(f1, hp);
 		    return res;
@@ -657,7 +649,7 @@ erts_mixed_times(Process* p, Eterm arg1, Eterm arg2)
 			    hdr = big_res[0];
 			    arity = bignum_header_arity(hdr);
 			    ASSERT(arity == 1 || arity == 2);
-			    hp = HAlloc(p, arity+1);
+			    hp = HeapFragOnlyAlloc(p, arity+1);
 			    res = make_big(hp);
 			    *hp++ = hdr;
 			    *hp++ = big_res[1];
@@ -726,7 +718,7 @@ erts_mixed_times(Process* p, Eterm arg1, Eterm arg2)
 
 		do_big:
 		    need_heap = BIG_NEED_SIZE(sz);
-                    hp = HAlloc(p, need_heap);
+                    hp = HeapFragOnlyAlloc(p, need_heap);
 		    res = big_times(arg1, arg2, hp);
 
 		    /*
@@ -779,7 +771,7 @@ erts_mixed_times(Process* p, Eterm arg1, Eterm arg2)
 		do_float:
 		    f1.fd = f1.fd * f2.fd;
 		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    hp = HAlloc(p, FLOAT_SIZE_OBJECT);
+		    hp = HeapFragOnlyAlloc(p, FLOAT_SIZE_OBJECT);
 		    res = make_float(hp);
 		    PUT_DOUBLE(f1, hp);
 		    return res;
@@ -905,7 +897,7 @@ erts_mixed_div(Process* p, Eterm arg1, Eterm arg2)
 		do_float:
 		    f1.fd = f1.fd / f2.fd;
 		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    hp = HAlloc(p, FLOAT_SIZE_OBJECT);
+		    hp = HeapFragOnlyAlloc(p, FLOAT_SIZE_OBJECT);
 		    PUT_DOUBLE(f1, hp);
 		    return make_float(hp);
 		default:
@@ -957,7 +949,7 @@ erts_int_div(Process* p, Eterm arg1, Eterm arg2)
 
 	    ires = big_size(arg2);
 	    need = BIG_NEED_SIZE(i-ires+1) + BIG_NEED_SIZE(i);
-	    hp = HAlloc(p, need);
+	    hp = HeapFragOnlyAlloc(p, need);
 	    arg1 = big_div(arg1, arg2, hp);
 	    maybe_shrink(p, hp, arg1, need);
 	    if (is_nil(arg1)) {
@@ -1004,7 +996,7 @@ erts_int_rem(Process* p, Eterm arg1, Eterm arg2)
 	    arg1 = SMALL_ZERO;
 	} else if (ires > 0) {
 	    Uint need = BIG_NEED_SIZE(big_size(arg1));
-	    Eterm* hp = HAlloc(p, need);
+	    Eterm* hp = HeapFragOnlyAlloc(p, need);
 
 	    arg1 = big_rem(arg1, arg2, hp);
 	    maybe_shrink(p, hp, arg1, need);
@@ -1041,7 +1033,7 @@ Eterm erts_band(Process* p, Eterm arg1, Eterm arg2)
 	return THE_NON_VALUE;
     }
     need = BIG_NEED_SIZE(MAX(big_size(arg1), big_size(arg2)) + 1);
-    hp = HAlloc(p, need);
+    hp = HeapFragOnlyAlloc(p, need);
     arg1 = big_band(arg1, arg2, hp);
     ASSERT(is_not_nil(arg1));
     maybe_shrink(p, hp, arg1, need);
@@ -1069,7 +1061,7 @@ Eterm erts_bor(Process* p, Eterm arg1, Eterm arg2)
 	return THE_NON_VALUE;
     }
     need = BIG_NEED_SIZE(MAX(big_size(arg1), big_size(arg2)) + 1);
-    hp = HAlloc(p, need);
+    hp = HeapFragOnlyAlloc(p, need);
     arg1 = big_bor(arg1, arg2, hp);
     ASSERT(is_not_nil(arg1));
     maybe_shrink(p, hp, arg1, need);
@@ -1097,7 +1089,7 @@ Eterm erts_bxor(Process* p, Eterm arg1, Eterm arg2)
 	return THE_NON_VALUE;
     }
     need = BIG_NEED_SIZE(MAX(big_size(arg1), big_size(arg2)) + 1);
-    hp = HAlloc(p, need);
+    hp = HeapFragOnlyAlloc(p, need);
     arg1 = big_bxor(arg1, arg2, hp);
     ASSERT(is_not_nil(arg1));
     maybe_shrink(p, hp, arg1, need);
@@ -1110,7 +1102,7 @@ Eterm erts_bnot(Process* p, Eterm arg)
 
     if (is_big(arg)) {
 	Uint need = BIG_NEED_SIZE(big_size(arg)+1);
-	Eterm* bigp = HAlloc(p, need);
+	Eterm* bigp = HeapFragOnlyAlloc(p, need);
 
 	ret = big_bnot(arg, bigp);
 	maybe_shrink(p, bigp, ret, need);
@@ -1125,924 +1117,6 @@ Eterm erts_bnot(Process* p, Eterm arg)
     return ret;
 } 
 
-#define ERTS_NEED_GC(p, need) ((HEAP_LIMIT((p)) - HEAP_TOP((p))) <= (need))
-
-static ERTS_INLINE void
-trim_heap(Process* p, Eterm* hp, Eterm res)
-{
-    if (is_immed(res)) {
-	ASSERT(p->heap <= hp && hp <= p->htop);
-	p->htop = hp;
-    } else {
-	Eterm* new_htop;
-	ASSERT(is_big(res));
-	new_htop = hp + bignum_header_arity(*hp) + 1;
-	ASSERT(p->heap <= new_htop && new_htop <= p->htop);
-	p->htop = new_htop;
-    }
-    ASSERT(p->heap <= p->htop && p->htop <= p->stop);
-}
-
-/*
- * The functions that follow are called from the emulator loop.
- * They are not allowed to allocate heap fragments, but must do
- * a garbage collection if there is insufficient heap space.
- */
-
-#define erts_heap_frag_shrink horrible error
-#define maybe_shrink horrible error
-
-Eterm
-erts_gc_mixed_plus(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    Eterm res;
-    Eterm hdr;
-    FloatDef f1, f2;
-    dsize_t sz1, sz2, sz;
-    int need_heap;
-    Eterm* hp;
-    Sint ires;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    ERTS_FP_CHECK_INIT(p);
-    switch (arg1 & _TAG_PRIMARY_MASK) {
-    case TAG_PRIMARY_IMMED1:
-	switch ((arg1 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    ires = signed_val(arg1) + signed_val(arg2);
-		    if (IS_SSMALL(ires)) {
-			return make_small(ires);
-		    } else {
-			if (ERTS_NEED_GC(p, 2)) {
-			    erts_garbage_collect(p, 2, reg, live);
-			}
-			hp = p->htop;
-			p->htop += 2;
-			res = small_to_big(ires, hp);
-			return res;
-		    }
-		default:
-		badarith:
-		    p->freason = BADARITH;
-		    return THE_NON_VALUE;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    if (arg1 == SMALL_ZERO) {
-			return arg2;
-		    }
-		    arg1 = small_to_big(signed_val(arg1), tmp_big1);
-		    goto do_big;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	default:
-	    goto badarith;
-	}
-    case TAG_PRIMARY_BOXED:
-	hdr = *boxed_val(arg1);
-	switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-	case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if (arg2 == SMALL_ZERO) {
-			return arg1;
-		    }
-		    arg2 = small_to_big(signed_val(arg2), tmp_big2);
-		    goto do_big;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		do_big:
-		    sz1 = big_size(arg1);
-		    sz2 = big_size(arg2);
-		    sz = MAX(sz1, sz2)+1;
-		    need_heap = BIG_NEED_SIZE(sz);
-		    if (ERTS_NEED_GC(p, need_heap)) {
-			erts_garbage_collect(p, need_heap, reg, live+2);
-			if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-			    arg1 = reg[live];
-			}
-			if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-			    arg2 = reg[live+1];
-			}
-		    }
-		    hp = p->htop;
-		    p->htop += need_heap;
-		    res = big_plus(arg1, arg2, hp);
-		    trim_heap(p, hp, res);
-		    if (is_nil(res)) {
-			p->freason = SYSTEM_LIMIT;
-			return THE_NON_VALUE;
-		    }
-		    return res;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    GET_DOUBLE(arg2, f2);
-
-		do_float:
-		    f1.fd = f1.fd + f2.fd;
-		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-			erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live);
-		    }
-		    hp = p->htop;
-		    p->htop += FLOAT_SIZE_OBJECT;
-		    res = make_float(hp);
-		    PUT_DOUBLE(f1, hp);
-		    return res;
-		default:
-		    goto badarith;
-		}
-	    default:
-		goto badarith;
-	    }
-	}
-    default:
-	goto badarith;
-    }
-}
-
-Eterm
-erts_gc_mixed_minus(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    Eterm hdr;
-    Eterm res;
-    FloatDef f1, f2;
-    dsize_t sz1, sz2, sz;
-    int need_heap;
-    Eterm* hp;
-    Sint ires;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    ERTS_FP_CHECK_INIT(p);
-    switch (arg1 & _TAG_PRIMARY_MASK) {
-    case TAG_PRIMARY_IMMED1:
-	switch ((arg1 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    ires = signed_val(arg1) - signed_val(arg2);
-		    if (IS_SSMALL(ires)) {
-			return make_small(ires);
-		    } else {
-			if (ERTS_NEED_GC(p, 2)) {
-			    erts_garbage_collect(p, 2, reg, live);
-			}
-			hp = p->htop;
-			p->htop += 2;
-			res = small_to_big(ires, hp);
-			return res;
-		    }
-		default:
-		badarith:
-		    p->freason = BADARITH;
-		    return THE_NON_VALUE;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    arg1 = small_to_big(signed_val(arg1), tmp_big1);
-		    goto do_big;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	default:
-	    goto badarith;
-	}
-    case TAG_PRIMARY_BOXED:
-	hdr = *boxed_val(arg1);
-	switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-	case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if (arg2 == SMALL_ZERO) {
-			return arg1;
-		    }
-		    arg2 = small_to_big(signed_val(arg2), tmp_big2);
-
-		do_big:
-		    sz1 = big_size(arg1);
-		    sz2 = big_size(arg2);
-		    sz = MAX(sz1, sz2)+1;
-		    need_heap = BIG_NEED_SIZE(sz);
-		    if (ERTS_NEED_GC(p, need_heap)) {
-			erts_garbage_collect(p, need_heap, reg, live+2);
-			if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-			    arg1 = reg[live];
-			}
-			if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-			    arg2 = reg[live+1];
-			}
-		    }
-		    hp = p->htop;
-		    p->htop += need_heap;
-		    res = big_minus(arg1, arg2, hp);
-                    trim_heap(p, hp, res);
-		    if (is_nil(res)) {
-			p->freason = SYSTEM_LIMIT;
-			return THE_NON_VALUE;
-		    }
-		    return res;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    goto do_big;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    GET_DOUBLE(arg2, f2);
-
-		do_float:
-		    f1.fd = f1.fd - f2.fd;
-		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-			erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live);
-		    }
-		    hp = p->htop;
-		    p->htop += FLOAT_SIZE_OBJECT;
-		    res = make_float(hp);
-		    PUT_DOUBLE(f1, hp);
-		    return res;
-		default:
-		    goto badarith;
-		}
-	    default:
-		goto badarith;
-	    }
-	}
-    default:
-	goto badarith;
-    }
-}
-
-Eterm
-erts_gc_mixed_times(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    Eterm hdr;
-    Eterm res;
-    FloatDef f1, f2;
-    dsize_t sz1, sz2, sz;
-    int need_heap;
-    Eterm* hp;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    ERTS_FP_CHECK_INIT(p);
-    switch (arg1 & _TAG_PRIMARY_MASK) {
-    case TAG_PRIMARY_IMMED1:
-	switch ((arg1 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if ((arg1 == SMALL_ZERO) || (arg2 == SMALL_ZERO)) {
-			return(SMALL_ZERO);
-		    } else if (arg1 == SMALL_ONE) {
-			return(arg2);
-		    } else if (arg2 == SMALL_ONE) {
-			return(arg1);
-		    } else {
-			DeclareTmpHeap(big_res,3,p);
-			UseTmpHeap(3,p);
-
-			/*
-			 * The following code is optimized for the case that
-			 * result is small (which should be the most common case
-			 * in practice).
-			 */
-			res = small_times(signed_val(arg1), signed_val(arg2),
-					  big_res);
-			if (is_small(res)) {
-			    UnUseTmpHeap(3,p);
-			    return res;
-			} else {
-			    /*
-			     * The result is a a big number.
-			     * Allocate a heap fragment and copy the result.
-			     * Be careful to allocate exactly what we need
-			     * to not leave any holes.
-			     */
-			    Uint arity;
-			    Uint need;
-			    
-			    ASSERT(is_big(res));
-			    hdr = big_res[0];
-			    arity = bignum_header_arity(hdr);
-			    ASSERT(arity == 1 || arity == 2);
-			    need = arity + 1;
-			    if (ERTS_NEED_GC(p, need)) {
-				erts_garbage_collect(p, need, reg, live);
-			    }
-			    hp = p->htop;
-			    p->htop += need;
-			    res = make_big(hp);
-			    *hp++ = hdr;
-			    *hp++ = big_res[1];
-			    if (arity > 1) {
-				*hp = big_res[2];
-			    }
-			    UnUseTmpHeap(3,p);
-			    return res;
-			}
-		    }
-		default:
-		badarith:
-		    p->freason = BADARITH;
-		    return THE_NON_VALUE;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    if (arg1 == SMALL_ZERO)
-			return(SMALL_ZERO);
-		    if (arg1 == SMALL_ONE)
-			return(arg2);
-		    arg1 = small_to_big(signed_val(arg1), tmp_big1);
-		    sz = 2 + big_size(arg2);
-		    goto do_big;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	default:
-	    goto badarith;
-	}
-    case TAG_PRIMARY_BOXED:
-	hdr = *boxed_val(arg1);
-	switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-	case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if (arg2 == SMALL_ZERO)
-			return(SMALL_ZERO);
-		    if (arg2 == SMALL_ONE)
-			return(arg1);
-		    arg2 = small_to_big(signed_val(arg2), tmp_big2);
-		    sz = 2 + big_size(arg1);
-		    goto do_big;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    sz1 = big_size(arg1);
-		    sz2 = big_size(arg2);
-		    sz = sz1 + sz2;
-
-		do_big:
-		    need_heap = BIG_NEED_SIZE(sz);
-		    if (ERTS_NEED_GC(p, need_heap)) {
-			erts_garbage_collect(p, need_heap, reg, live+2);
-			if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-			    arg1 = reg[live];
-			}
-			if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-			    arg2 = reg[live+1];
-			}
-		    }
-		    hp = p->htop;
-		    p->htop += need_heap;
-		    res = big_times(arg1, arg2, hp);
-		    trim_heap(p, hp, res);
-
-		    /*
-		     * Note that the result must be big in this case, since
-		     * at least one operand was big to begin with, and
-		     * the absolute value of the other is > 1.
-		     */
-
-		    if (is_nil(res)) {
-			p->freason = SYSTEM_LIMIT;
-			return THE_NON_VALUE;
-		    }
-		    return res;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    GET_DOUBLE(arg2, f2);
-
-		do_float:
-		    f1.fd = f1.fd * f2.fd;
-		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-			erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live);
-		    }
-		    hp = p->htop;
-		    p->htop += FLOAT_SIZE_OBJECT;
-		    res = make_float(hp);
-		    PUT_DOUBLE(f1, hp);
-		    return res;
-		default:
-		    goto badarith;
-		}
-	    default:
-		goto badarith;
-	    }
-	}
-    default:
-	goto badarith;
-    }
-}
-
-Eterm
-erts_gc_mixed_div(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    FloatDef f1, f2;
-    Eterm* hp;
-    Eterm hdr;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    ERTS_FP_CHECK_INIT(p);
-    switch (arg1 & _TAG_PRIMARY_MASK) {
-    case TAG_PRIMARY_IMMED1:
-	switch ((arg1 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		badarith:
-		    p->freason = BADARITH;
-		    return THE_NON_VALUE;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    f1.fd = signed_val(arg1);
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	default:
-	    goto badarith;
-	}
-    case TAG_PRIMARY_BOXED:
-	hdr = *boxed_val(arg1);
-	switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-	case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-	case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0 ||
-			big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    if (big_to_double(arg1, &f1.fd) < 0) {
-			goto badarith;
-		    }
-		    GET_DOUBLE(arg2, f2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    }
-	case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-	    switch (arg2 & _TAG_PRIMARY_MASK) {
-	    case TAG_PRIMARY_IMMED1:
-		switch ((arg2 & _TAG_IMMED1_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_IMMED1_SMALL >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    f2.fd = signed_val(arg2);
-		    goto do_float;
-		default:
-		    goto badarith;
-		}
-	    case TAG_PRIMARY_BOXED:
-		hdr = *boxed_val(arg2);
-		switch ((hdr & _TAG_HEADER_MASK) >> _TAG_PRIMARY_SIZE) {
-		case (_TAG_HEADER_POS_BIG >> _TAG_PRIMARY_SIZE):
-		case (_TAG_HEADER_NEG_BIG >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    if (big_to_double(arg2, &f2.fd) < 0) {
-			goto badarith;
-		    }
-		    goto do_float;
-		case (_TAG_HEADER_FLOAT >> _TAG_PRIMARY_SIZE):
-		    GET_DOUBLE(arg1, f1);
-		    GET_DOUBLE(arg2, f2);
-
-		do_float:
-		    f1.fd = f1.fd / f2.fd;
-		    ERTS_FP_ERROR(p, f1.fd, goto badarith);
-		    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-			erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live);
-		    }
-		    hp = p->htop;
-		    p->htop += FLOAT_SIZE_OBJECT;
-		    PUT_DOUBLE(f1, hp);
-		    return make_float(hp);
-		default:
-		    goto badarith;
-		}
-	    default:
-		goto badarith;
-	    }
-	}
-    default:
-	goto badarith;
-    }
-}
-
-Eterm
-erts_gc_int_div(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    int ires;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    switch (NUMBER_CODE(arg1, arg2)) {
-    case SMALL_SMALL:
-	/* This case occurs if the most negative fixnum is divided by -1. */
-	ASSERT(arg2 == make_small(-1));
-	arg1 = small_to_big(signed_val(arg1), tmp_big1);
-	/*FALLTHROUGH*/
-    case BIG_SMALL:
-	arg2 = small_to_big(signed_val(arg2), tmp_big2);
-	goto L_big_div;
-    case SMALL_BIG:
-	if (arg1 != make_small(MIN_SMALL)) {
-	    return SMALL_ZERO;
-	}
-	arg1 = small_to_big(signed_val(arg1), tmp_big1);
-	/*FALLTHROUGH*/
-    case BIG_BIG:
-    L_big_div:
-	ires = big_ucomp(arg1, arg2);
-	if (ires < 0) {
-	    arg1 = SMALL_ZERO;
-	} else if (ires == 0) {
-	    arg1 = (big_sign(arg1) == big_sign(arg2)) ?
-		SMALL_ONE : SMALL_MINUS_ONE;
-	} else {
-	    Eterm* hp;
-	    int i = big_size(arg1);
-	    Uint need;
-
-	    ires = big_size(arg2);
-	    need = BIG_NEED_SIZE(i-ires+1) + BIG_NEED_SIZE(i);
-	    if (ERTS_NEED_GC(p, need)) {
-		erts_garbage_collect(p, need, reg, live+2);
-		if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-		    arg1 = reg[live];
-		}
-		if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-		    arg2 = reg[live+1];
-		}
-	    }
-	    hp = p->htop;
-	    p->htop += need;
-	    arg1 = big_div(arg1, arg2, hp);
-	    trim_heap(p, hp, arg1);
-	    if (is_nil(arg1)) {
-		p->freason = SYSTEM_LIMIT;
-		return THE_NON_VALUE;
-	    }
-	}
-	return arg1;
-    default:
-	p->freason = BADARITH;
-	return THE_NON_VALUE;
-    }
-}
-
-Eterm
-erts_gc_int_rem(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg1;
-    Eterm arg2;
-    DECLARE_TMP(tmp_big1,0,p);
-    DECLARE_TMP(tmp_big2,1,p);
-    int ires;
-
-    arg1 = reg[live];
-    arg2 = reg[live+1];
-    switch (NUMBER_CODE(arg1, arg2)) {
-    case BIG_SMALL:
-	arg2 = small_to_big(signed_val(arg2), tmp_big2);
-	goto L_big_rem;
-    case SMALL_BIG:
-	if (arg1 != make_small(MIN_SMALL)) {
-	    return arg1;
-	} else {
-	    Eterm tmp;
-	    tmp = small_to_big(signed_val(arg1), tmp_big1);
-	    if ((ires = big_ucomp(tmp, arg2)) == 0) {
-		return SMALL_ZERO;
-	    } else {
-		ASSERT(ires < 0);
-		return arg1;
-	    }
-	}
-	/* All paths returned */
-    case BIG_BIG:
-    L_big_rem:
-	ires = big_ucomp(arg1, arg2);
-	if (ires == 0) {
-	    arg1 = SMALL_ZERO;
-	} else if (ires > 0) {
-	    Eterm* hp;
-	    Uint need = BIG_NEED_SIZE(big_size(arg1));
-
-	    if (ERTS_NEED_GC(p, need)) {
-		erts_garbage_collect(p, need, reg, live+2);
-		if (ARG_IS_NOT_TMP(arg1,tmp_big1)) {
-		    arg1 = reg[live];
-		}
-		if (ARG_IS_NOT_TMP(arg2,tmp_big2)) {
-		    arg2 = reg[live+1];
-		}
-	    }
-	    hp = p->htop;
-	    p->htop += need;
-	    arg1 = big_rem(arg1, arg2, hp);
-	    trim_heap(p, hp, arg1);
-	    if (is_nil(arg1)) {
-		p->freason = SYSTEM_LIMIT;
-		return THE_NON_VALUE;
-	    }
-	}
-	return arg1;
-    default:
-	p->freason = BADARITH;
-	return THE_NON_VALUE;
-    }
-}
-
-#define DEFINE_GC_LOGIC_FUNC(func)						\
-Eterm erts_gc_##func(Process* p, Eterm* reg, Uint live)				\
-{										\
-    Eterm arg1;									\
-    Eterm arg2;									\
-    DECLARE_TMP(tmp_big1,0,p);							\
-    DECLARE_TMP(tmp_big2,1,p);							\
-    Eterm* hp;									\
-    int need;									\
-										\
-    arg1 = reg[live];								\
-    arg2 = reg[live+1];								\
-    switch (NUMBER_CODE(arg1, arg2)) {						\
-    case SMALL_BIG:								\
-	arg1 = small_to_big(signed_val(arg1), tmp_big1);			\
-	need = BIG_NEED_SIZE(big_size(arg2) + 1);				\
-	if (ERTS_NEED_GC(p, need)) {						\
-	    erts_garbage_collect(p, need, reg, live+2);				\
-	    arg2 = reg[live+1];							\
-	}									\
-	break;									\
-    case BIG_SMALL:								\
-	arg2 = small_to_big(signed_val(arg2), tmp_big2);			\
-	need = BIG_NEED_SIZE(big_size(arg1) + 1);				\
-	if (ERTS_NEED_GC(p, need)) {						\
-	    erts_garbage_collect(p, need, reg, live+2);				\
-	    arg1 = reg[live];							\
-	}									\
-	break;									\
-    case BIG_BIG:								\
-	need = BIG_NEED_SIZE(MAX(big_size(arg1), big_size(arg2)) + 1);		\
-	if (ERTS_NEED_GC(p, need)) {						\
-	    erts_garbage_collect(p, need, reg, live+2);				\
-	    arg1 = reg[live];							\
-	    arg2 = reg[live+1];							\
-	}									\
-	break;									\
-    default:									\
-	p->freason = BADARITH;							\
-	return THE_NON_VALUE;							\
-    }										\
-    hp = p->htop;								\
-    p->htop += need;								\
-    arg1 = big_##func(arg1, arg2, hp);						\
-    trim_heap(p, hp, arg1);							\
-    return arg1;								\
-}
-
-DEFINE_GC_LOGIC_FUNC(band)
-DEFINE_GC_LOGIC_FUNC(bor)
-DEFINE_GC_LOGIC_FUNC(bxor)
-
-Eterm erts_gc_bnot(Process* p, Eterm* reg, Uint live)
-{
-    Eterm result;
-    Eterm arg;
-    Uint need;
-    Eterm* bigp;
-
-    arg = reg[live];
-    if (is_not_big(arg)) {
-	p->freason = BADARITH;
-	return NIL;
-    } else {
-	need = BIG_NEED_SIZE(big_size(arg)+1);
-	if (ERTS_NEED_GC(p, need)) {
-	    erts_garbage_collect(p, need, reg, live+1);
-	    arg = reg[live];
-	}
-	bigp = p->htop;
-	p->htop += need;
-	result = big_bnot(arg, bigp);
-	trim_heap(p, bigp, result);
-	if (is_nil(result)) {
-	    p->freason = SYSTEM_LIMIT;
-	    return NIL;
-	}
-    }
-    return result;
-} 
-
 /* Needed to remove compiler optimization */
 double erts_get_positive_zero_float() {
     return 0.0f;
diff --git a/erts/emulator/beam/erl_bif_binary.c b/erts/emulator/beam/erl_bif_binary.c
index d465f6c6b9..ca1ba55b22 100644
--- a/erts/emulator/beam/erl_bif_binary.c
+++ b/erts/emulator/beam/erl_bif_binary.c
@@ -1970,9 +1970,7 @@ BIF_RETTYPE erts_binary_part(Process *p, Eterm binary, Eterm epos, Eterm elen)
 	goto badarg;
     }
 
-
-
-    hp = HAlloc(p, ERL_SUB_BIN_SIZE);
+    hp = HeapFragOnlyAlloc(p, ERL_SUB_BIN_SIZE);
 
     ERTS_GET_REAL_BIN(binary, orig, offset, bit_offset, bit_size);
     sb = (ErlSubBin *) hp;
@@ -1990,100 +1988,6 @@ BIF_RETTYPE erts_binary_part(Process *p, Eterm binary, Eterm epos, Eterm elen)
     BIF_ERROR(p, BADARG);
 }
 
-#define ERTS_NEED_GC(p, need) ((HEAP_LIMIT((p)) - HEAP_TOP((p))) <= (need))
-
-BIF_RETTYPE erts_gc_binary_part(Process *p, Eterm *reg, Eterm live, int range_is_tuple)
-{
-    Uint pos;
-    Sint len;
-    size_t orig_size;
-    Eterm orig;
-    Uint offset;
-    Uint bit_offset;
-    Uint bit_size;
-    Eterm* hp;
-    ErlSubBin* sb;
-    Eterm binary;
-    Eterm *tp;
-    Eterm epos, elen;
-    int extra_args;
-
-
-    if (range_is_tuple) {
-	Eterm tpl = reg[live];
-	extra_args = 1;
-	if (is_not_tuple(tpl)) {
-	    goto badarg;
-	}
-	tp = tuple_val(tpl);
-	if (arityval(*tp) != 2) {
-	    goto badarg;
-	}
-
-	epos = tp[1];
-	elen = tp[2];
-    } else {
-	extra_args = 2;
-	epos = reg[live-1];
-	elen = reg[live];
-    }
-    binary = reg[live-extra_args];
-
-    if (is_not_binary(binary)) {
-	goto badarg;
-    }
-    if (!term_to_Uint(epos, &pos)) {
-	goto badarg;
-    }
-    if (!term_to_Sint(elen, &len)) {
-	goto badarg;
-    }
-    if (len < 0) {
-	Uint lentmp = -(Uint)len;
-	/* overflow */
-	if ((Sint)lentmp < 0) {
-	    goto badarg;
-	}
-	len = lentmp;
-	if (len > pos) {
-	    goto badarg;
-	}
-	pos -= len;
-    }
-    /* overflow */
-    if ((pos + len) < pos || (len > 0 && (pos + len) == pos)) {
-	goto badarg;
-    }
-    if ((orig_size = binary_size(binary)) < pos ||
-	orig_size < (pos + len)) {
-	goto badarg;
-    }
-
-    if (ERTS_NEED_GC(p, ERL_SUB_BIN_SIZE)) {
-	erts_garbage_collect(p, ERL_SUB_BIN_SIZE, reg, live+1-extra_args); /* I don't need the tuple
-									      or indices any more */
-	binary = reg[live-extra_args];
-    }
-
-    hp = p->htop;
-    p->htop += ERL_SUB_BIN_SIZE;
-
-    ERTS_GET_REAL_BIN(binary, orig, offset, bit_offset, bit_size);
-
-    sb = (ErlSubBin *) hp;
-    sb->thing_word = HEADER_SUB_BIN;
-    sb->size = len;
-    sb->offs = offset + pos;
-    sb->orig = orig;
-    sb->bitoffs = bit_offset;
-    sb->bitsize = 0;
-    sb->is_writable = 0;
-
-    BIF_RET(make_binary(sb));
-
- badarg:
-    BIF_ERROR(p, BADARG);
-}
 /*************************************************************
  * The actual guard BIFs are in erl_bif_guard.c
  * but the implementation of both the non-gc and the gc
diff --git a/erts/emulator/beam/erl_bif_guard.c b/erts/emulator/beam/erl_bif_guard.c
index 8a5c6ada6c..84783e71a0 100644
--- a/erts/emulator/beam/erl_bif_guard.c
+++ b/erts/emulator/beam/erl_bif_guard.c
@@ -19,7 +19,12 @@
  */
 
 /*
- * Numeric guard BIFs.
+ * This file implements the former GC BIFs. They used to do a GC when
+ * they needed heap space. Because of changes to the implementation of
+ * literals, those BIFs are now allowed to allocate heap fragments
+ * (using HeapFragOnlyAlloc()). Note that they must NOT call HAlloc(),
+ * because the caller does not do any SWAPIN / SWAPOUT (that is,
+ * HEAP_TOP(p) and HEAP_LIMIT(p) contain stale values).
  */
 
 #ifdef HAVE_CONFIG_H
@@ -36,15 +41,8 @@
 #include "erl_binary.h"
 #include "erl_map.h"
 
-static Eterm gc_double_to_integer(Process* p, double x, Eterm* reg, Uint live);
-
 static Eterm double_to_integer(Process* p, double x);
 
-/*
- * Guard BIFs called using apply/3 and guard BIFs that never build
- * anything on the heap.
- */
-
 BIF_RETTYPE abs_1(BIF_ALIST_1)
 {
     Eterm res;
@@ -56,7 +54,7 @@ BIF_RETTYPE abs_1(BIF_ALIST_1)
 	i0 = signed_val(BIF_ARG_1);
 	i = ERTS_SMALL_ABS(i0);
 	if (i0 == MIN_SMALL) {
-	    hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
+	    hp = HeapFragOnlyAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
 	    BIF_RET(uint_to_big(i, hp));
 	} else {
 	    BIF_RET(make_small(i));
@@ -68,7 +66,7 @@ BIF_RETTYPE abs_1(BIF_ALIST_1)
 	    int sz = big_arity(BIF_ARG_1) + 1;
 	    Uint* x;
 
-	    hp = HAlloc(BIF_P, sz);	/* See note at beginning of file */
+	    hp = HeapFragOnlyAlloc(BIF_P, sz);	/* See note at beginning of file */
 	    sz--;
 	    res = make_big(hp);
 	    x = big_val(BIF_ARG_1);
@@ -83,7 +81,7 @@ BIF_RETTYPE abs_1(BIF_ALIST_1)
 
 	GET_DOUBLE(BIF_ARG_1, f);
 	if (f.fd < 0.0) {
-	    hp = HAlloc(BIF_P, FLOAT_SIZE_OBJECT);
+	    hp = HeapFragOnlyAlloc(BIF_P, FLOAT_SIZE_OBJECT);
 	    f.fd = fabs(f.fd);
 	    res = make_float(hp);
 	    PUT_DOUBLE(f, hp);
@@ -116,7 +114,7 @@ BIF_RETTYPE float_1(BIF_ALIST_1)
     } else if (big_to_double(BIF_ARG_1, &f.fd) < 0) {
 	goto badarg;
     }
-    hp = HAlloc(BIF_P, FLOAT_SIZE_OBJECT);
+    hp = HeapFragOnlyAlloc(BIF_P, FLOAT_SIZE_OBJECT);
     res = make_float(hp);
     PUT_DOUBLE(f, hp);
     BIF_RET(res);
@@ -229,7 +227,7 @@ BIF_RETTYPE size_1(BIF_ALIST_1)
 	if (IS_USMALL(0, sz)) {
 	    return make_small(sz);
 	} else {
-	    Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
+	    Eterm* hp = HeapFragOnlyAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
 	    BIF_RET(uint_to_big(sz, hp));
 	}
     }
@@ -252,12 +250,12 @@ BIF_RETTYPE bit_size_1(BIF_ALIST_1)
 	    if (IS_USMALL(0,low_bits)) {
 		BIF_RET(make_small(low_bits));
 	    } else {
-		Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
+		Eterm* hp = HeapFragOnlyAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
 		BIF_RET(uint_to_big(low_bits, hp));
 	    }
 	} else {
 	    Uint sz = BIG_UINT_HEAP_SIZE+1;
-	    Eterm* hp = HAlloc(BIF_P, sz);
+	    Eterm* hp = HeapFragOnlyAlloc(BIF_P, sz);
 	    hp[0] = make_pos_bignum_header(sz-1);
 	    BIG_DIGIT(hp,0) = low_bits;
 	    BIG_DIGIT(hp,1) = high_bits;
@@ -281,7 +279,7 @@ BIF_RETTYPE byte_size_1(BIF_ALIST_1)
 	if (IS_USMALL(0, bytesize)) {
 	    BIF_RET(make_small(bytesize));
 	} else {
-	    Eterm* hp = HAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
+	    Eterm* hp = HeapFragOnlyAlloc(BIF_P, BIG_UINT_HEAP_SIZE);
 	    BIF_RET(uint_to_big(bytesize, hp));
 	}
     } else {
@@ -325,7 +323,7 @@ double_to_integer(Process* p, double x)
     }
     sz = BIG_NEED_SIZE(ds);          /* number of words including arity */
 
-    hp = HAlloc(p, sz);
+    hp = HeapFragOnlyAlloc(p, sz);
     res = make_big(hp);
     xp = (ErtsDigit*) (hp + 1);
 
@@ -371,389 +369,3 @@ BIF_RETTYPE binary_part_2(BIF_ALIST_2)
  badarg:
    BIF_ERROR(BIF_P,BADARG);
 }
-
-
-/*
- * The following code is used when a guard that may build on the
- * heap is called directly. They must not use HAlloc(), but must
- * do a garbage collection if there is insufficient heap space.
- *
- * Important note: All error checking MUST be done before doing
- * a garbage collection. The compiler assumes that all registers
- * are still valid if a guard BIF generates an exception.
- */
-
-#define ERTS_NEED_GC(p, need) ((HEAP_LIMIT((p)) - HEAP_TOP((p))) <= (need))
-
-Eterm erts_gc_length_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm list = reg[live];
-    int i;
-
-    if (is_nil(list)) 
-	return SMALL_ZERO;
-    i = 0;
-    while (is_list(list)) {
-	i++;
-	list = CDR(list_val(list));
-    }
-    if (is_not_nil(list))  {
-	BIF_ERROR(p, BADARG);
-    }
-    return make_small(i);
-}
-
-Eterm erts_gc_size_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg = reg[live];
-    if (is_tuple(arg)) {
-	Eterm* tupleptr = tuple_val(arg);
-	return make_small(arityval(*tupleptr));
-    } else if (is_binary(arg)) {
-	Uint sz = binary_size(arg);
-	if (IS_USMALL(0, sz)) {
-	    return make_small(sz);
-	} else {
-	    Eterm* hp;
-	    if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-		erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live);
-	    }
-	    hp = p->htop;
-	    p->htop += BIG_UINT_HEAP_SIZE;
-	    return uint_to_big(sz, hp);
-	}
-    }
-    BIF_ERROR(p, BADARG);
-}
-
-Eterm erts_gc_bit_size_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg = reg[live];
-    if (is_binary(arg)) {
-	Uint low_bits;
-	Uint bytesize;
-	Uint high_bits;
-	bytesize = binary_size(arg);
-	high_bits = bytesize >>  ((sizeof(Uint) * 8)-3);
-	low_bits = (bytesize << 3) + binary_bitsize(arg);
-	if (high_bits == 0) {
-	    if (IS_USMALL(0,low_bits)) {
-		return make_small(low_bits);
-	    } else {
-		Eterm* hp; 
-		if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-		    erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live);
-		}
-		hp = p->htop;
-		p->htop += BIG_UINT_HEAP_SIZE;
-		return uint_to_big(low_bits, hp);
-	    }
-	} else {
-	    Uint sz = BIG_UINT_HEAP_SIZE+1;
-	    Eterm* hp;
-	    if (ERTS_NEED_GC(p, sz)) {
-		erts_garbage_collect(p, sz, reg, live);
-	    }
-	    hp = p->htop;
-	    p->htop += sz;
-	    hp[0] = make_pos_bignum_header(sz-1);
-	    BIG_DIGIT(hp,0) = low_bits;
-	    BIG_DIGIT(hp,1) = high_bits;
-	    return make_big(hp);
-	}
-    } else {
-	BIF_ERROR(p, BADARG);
-    }
-}
-
-Eterm erts_gc_byte_size_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg = reg[live];
-    if (is_binary(arg)) {
-	Uint bytesize = binary_size(arg);
-	if (binary_bitsize(arg) > 0) {
-	    bytesize++;
-	}
-	if (IS_USMALL(0, bytesize)) {
-	    return make_small(bytesize);
-	} else {
-	    Eterm* hp;
-	    if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-		erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live);
-	    }
-	    hp = p->htop;
-	    p->htop += BIG_UINT_HEAP_SIZE;
-	    return uint_to_big(bytesize, hp);
-	}
-    } else {
-	BIF_ERROR(p, BADARG);
-    }
-}
-
-Eterm erts_gc_map_size_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg = reg[live];
-    if (is_flatmap(arg)) {
-	flatmap_t *mp = (flatmap_t*)flatmap_val(arg);
-        return make_small(flatmap_get_size(mp));
-    } else if (is_hashmap(arg)) {
-        Eterm* hp;
-        Uint size;
-	size = hashmap_size(arg);
-        if (IS_USMALL(0, size)) {
-            return make_small(size);
-        }
-        if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-            erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live);
-        }
-        hp = p->htop;
-        p->htop += BIG_UINT_HEAP_SIZE;
-        return uint_to_big(size, hp);
-    }
-    p->fvalue = arg;
-    BIF_ERROR(p, BADMAP);
-}
-
-Eterm erts_gc_abs_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    Eterm res;
-    Sint i0, i;
-    Eterm* hp;
-
-    arg = reg[live];
-
-    /* integer arguments */
-    if (is_small(arg)) {
-	i0 = signed_val(arg);
-	i = ERTS_SMALL_ABS(i0);
-	if (i0 == MIN_SMALL) {
-	    if (ERTS_NEED_GC(p, BIG_UINT_HEAP_SIZE)) {
-		erts_garbage_collect(p, BIG_UINT_HEAP_SIZE, reg, live+1);
-		arg = reg[live];
-	    }
-	    hp = p->htop;
-	    p->htop += BIG_UINT_HEAP_SIZE;
-	    return uint_to_big(i, hp);
-	} else {
-	    return make_small(i);
-	}
-    } else if (is_big(arg)) {
-	if (!big_sign(arg)) {
-	    return arg;
-	} else {
-	    int sz = big_arity(arg) + 1;
-	    Uint* x;
-
-	    if (ERTS_NEED_GC(p, sz)) {
-		erts_garbage_collect(p, sz, reg, live+1);
-		arg = reg[live];
-	    }
-	    hp = p->htop;
-	    p->htop += sz;
-	    sz--;
-	    res = make_big(hp);
-	    x = big_val(arg);
-	    *hp++ = make_pos_bignum_header(sz);
-	    x++;                          /* skip thing */
-	    while(sz--)
-		*hp++ = *x++;
-	    return res;
-	}
-    } else if (is_float(arg)) {
-	FloatDef f;
-
-	GET_DOUBLE(arg, f);
-	if (f.fd < 0.0) {
-	    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-		erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live+1);
-		arg = reg[live];
-	    }
-	    hp = p->htop;
-	    p->htop += FLOAT_SIZE_OBJECT;
-	    f.fd = fabs(f.fd);
-	    res = make_float(hp);
-	    PUT_DOUBLE(f, hp);
-	    return res;
-	}
-	else
-	    return arg;
-    }
-    BIF_ERROR(p, BADARG);
-}
-
-Eterm erts_gc_float_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    Eterm res;
-    Eterm* hp;
-    FloatDef f;
-     
-    /* check args */
-    arg = reg[live];
-    if (is_not_integer(arg)) {
-	if (is_float(arg))  {
-	    return arg;
-	} else {
-	badarg:
-	    BIF_ERROR(p, BADARG);
-	}
-    }
-    if (is_small(arg)) {
-	Sint i = signed_val(arg);
-	f.fd = i;		/* use "C"'s auto casting */
-    } else if (big_to_double(arg, &f.fd) < 0) {
-	goto badarg;
-    }
-    if (ERTS_NEED_GC(p, FLOAT_SIZE_OBJECT)) {
-	erts_garbage_collect(p, FLOAT_SIZE_OBJECT, reg, live+1);
-	arg = reg[live];
-    }
-    hp = p->htop;
-    p->htop += FLOAT_SIZE_OBJECT;
-    res = make_float(hp);
-    PUT_DOUBLE(f, hp);
-    return res;
-}
-
-Eterm erts_gc_round_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    FloatDef f;
-     
-    arg = reg[live];
-    if (is_not_float(arg)) {
-	if (is_integer(arg))  {
-	    return arg;
-	}
-	BIF_ERROR(p, BADARG);
-    }
-    GET_DOUBLE(arg, f);
-
-    return gc_double_to_integer(p, round(f.fd), reg, live);
-}
-
-Eterm erts_gc_trunc_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    FloatDef f;
-     
-    arg = reg[live];
-    if (is_not_float(arg)) {
-	if (is_integer(arg))  {
-	    return arg;
-	}
-	BIF_ERROR(p, BADARG);
-    }
-    /* get the float */
-    GET_DOUBLE(arg, f);
-
-    /* truncate it and return the resultant integer */
-    return gc_double_to_integer(p, (f.fd >= 0.0) ? floor(f.fd) : ceil(f.fd),
-				reg, live);
-}
-
-Eterm erts_gc_floor_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    FloatDef f;
-
-    arg = reg[live];
-    if (is_not_float(arg)) {
-	if (is_integer(arg))  {
-	    return arg;
-	}
-	BIF_ERROR(p, BADARG);
-    }
-    GET_DOUBLE(arg, f);
-    return gc_double_to_integer(p, floor(f.fd), reg, live);
-}
-
-Eterm erts_gc_ceil_1(Process* p, Eterm* reg, Uint live)
-{
-    Eterm arg;
-    FloatDef f;
-
-    arg = reg[live];
-    if (is_not_float(arg)) {
-	if (is_integer(arg))  {
-	    return arg;
-	}
-	BIF_ERROR(p, BADARG);
-    }
-    GET_DOUBLE(arg, f);
-    return gc_double_to_integer(p, ceil(f.fd), reg, live);
-}
-
-static Eterm
-gc_double_to_integer(Process* p, double x, Eterm* reg, Uint live)
-{
-    int is_negative;
-    int ds;
-    ErtsDigit* xp;
-    int i;
-    Eterm res;
-    size_t sz;
-    Eterm* hp;
-    double dbase;
-
-    if ((x < (double) (MAX_SMALL+1)) && (x > (double) (MIN_SMALL-1))) {
-	Sint xi = x;
-	return make_small(xi);
-    }
-
-    if (x >= 0) {
-	is_negative = 0;
-    } else {
-	is_negative = 1;
-	x = -x;
-    }
-
-    /* Unscale & (calculate exponent) */
-    ds = 0;
-    dbase = ((double)(D_MASK)+1);
-    while(x >= 1.0) {
-	x /= dbase;         /* "shift" right */
-	ds++;
-    }
-    sz = BIG_NEED_SIZE(ds);          /* number of words including arity */
-    if (ERTS_NEED_GC(p, sz)) {
-	erts_garbage_collect(p, sz, reg, live);
-    }
-    hp = p->htop;
-    p->htop += sz;
-    res = make_big(hp);
-    xp = (ErtsDigit*) (hp + 1);
-
-    for (i = ds-1; i >= 0; i--) {
-	ErtsDigit d;
-
-	x *= dbase;      /* "shift" left */
-	d = x;            /* trunc */
-	xp[i] = d;        /* store digit */
-	x -= d;           /* remove integer part */
-    }
-    while ((ds & (BIG_DIGITS_PER_WORD-1)) != 0) {
-	xp[ds++] = 0;
-    }
-
-    if (is_negative) {
-	*hp = make_neg_bignum_header(sz-1);
-    } else {
-	*hp = make_pos_bignum_header(sz-1);
-    }
-    return res;
-}
-
-/********************************************************************************
- * binary_part guards. The actual implementation is in erl_bif_binary.c
- ********************************************************************************/
-Eterm erts_gc_binary_part_3(Process* p, Eterm* reg, Uint live)
-{
-    return erts_gc_binary_part(p,reg,live,0);
-}
-
-Eterm erts_gc_binary_part_2(Process* p, Eterm* reg, Uint live)
-{
-    return erts_gc_binary_part(p,reg,live,1);
-}
diff --git a/erts/emulator/beam/erl_binary.h b/erts/emulator/beam/erl_binary.h
index 08edb43c49..4bf77988f7 100644
--- a/erts/emulator/beam/erl_binary.h
+++ b/erts/emulator/beam/erl_binary.h
@@ -278,7 +278,6 @@ Eterm erts_bin_bytes_to_list(Eterm previous, Eterm* hp, byte* bytes, Uint size,
  */
 
 BIF_RETTYPE erts_list_to_binary_bif(Process *p, Eterm arg, Export *bif);
-BIF_RETTYPE erts_gc_binary_part(Process *p, Eterm *reg, Eterm live, int range_is_tuple);
 BIF_RETTYPE erts_binary_part(Process *p, Eterm binary, Eterm epos, Eterm elen);
 
 
diff --git a/erts/emulator/beam/erl_map.c b/erts/emulator/beam/erl_map.c
index 3d6c9eb43f..93816542cd 100644
--- a/erts/emulator/beam/erl_map.c
+++ b/erts/emulator/beam/erl_map.c
@@ -125,15 +125,20 @@ BIF_RETTYPE map_size_1(BIF_ALIST_1) {
 	flatmap_t *mp = (flatmap_t*)flatmap_val(BIF_ARG_1);
 	BIF_RET(make_small(flatmap_get_size(mp)));
     } else if (is_hashmap(BIF_ARG_1)) {
-	Eterm *head, *hp, res;
-	Uint size, hsz=0;
+	Eterm *head;
+	Uint size;
 
 	head = hashmap_val(BIF_ARG_1);
 	size = head[1];
-	(void) erts_bld_uint(NULL, &hsz, size);
-	hp = HAlloc(BIF_P, hsz);
-	res = erts_bld_uint(&hp, NULL, size);
-	BIF_RET(res);
+
+        /*
+         * As long as a small has 28 bits (on a 32-bit machine) for
+         * the integer itself, it is impossible to build a map whose
+         * size would not fit in a small. Add an assertion in case we
+         * ever decreases the number of bits in a small.
+         */
+        ASSERT(IS_USMALL(0, size));
+        BIF_RET(make_small(size));
     }
 
     BIF_P->fvalue = BIF_ARG_1;
diff --git a/erts/emulator/beam/erl_vm.h b/erts/emulator/beam/erl_vm.h
index 4089fac48e..fd46a804d3 100644
--- a/erts/emulator/beam/erl_vm.h
+++ b/erts/emulator/beam/erl_vm.h
@@ -146,6 +146,21 @@
       (HEAP_TOP(p) = HEAP_TOP(p) + (sz), HEAP_TOP(p) - (sz))))
 #endif
 
+/*
+ * Always allocate in a heap fragment, never on the heap.
+ */
+#if defined(VALGRIND)
+/* Running under valgrind, allocate exactly as much as needed.*/
+#  define HeapFragOnlyAlloc(p, sz)              \
+  (ASSERT((sz) >= 0),                           \
+   ErtsHAllocLockCheck(p),                      \
+   erts_heap_alloc((p),(sz),0))
+#else
+#  define HeapFragOnlyAlloc(p, sz)              \
+  (ASSERT((sz) >= 0),                           \
+   ErtsHAllocLockCheck(p),                      \
+   erts_heap_alloc((p),(sz),512))
+#endif
 
 /*
  * Description for each instruction (defined here because the name and
diff --git a/erts/emulator/beam/ops.tab b/erts/emulator/beam/ops.tab
index 349034e8ac..fbed2e56e1 100644
--- a/erts/emulator/beam/ops.tab
+++ b/erts/emulator/beam/ops.tab
@@ -1002,10 +1002,11 @@ bif1 Fail Bif=u$bif:erlang:get/1 Src=s Dst=d => gen_get(Src, Dst)
 
 bif2 Jump=j u$bif:erlang:element/2 S1=s S2=xy Dst=d => gen_element(Jump, S1, S2, Dst)
 
-bif1 p Bif S1 Dst => bif1_body Bif S1 Dst
+bif1 p Bif S1 Dst         => i_bif1_body Bif S1 Dst
+bif1 Fail=f Bif S1 Dst    => i_bif1 Fail Bif S1 Dst
 
-bif2 p Bif S1 S2 Dst => i_bif2_body Bif S1 S2 Dst
-bif2 Fail Bif S1 S2 Dst => i_bif2 Fail Bif S1 S2 Dst
+bif2 p Bif S1 S2 Dst      => i_bif2_body Bif S1 S2 Dst
+bif2 Fail=f Bif S1 S2 Dst => i_bif2 Fail Bif S1 S2 Dst
 
 i_get_hash c I d
 i_get s d
@@ -1023,10 +1024,12 @@ i_fast_element xy j? I d
 
 i_element xy j? s d
 
-bif1 f? b s d
-bif1_body b s d
+i_bif1 f? b s d
+i_bif1_body b s d
 i_bif2 f? b s s d
 i_bif2_body b s s d
+i_bif3 f? b s s s d
+i_bif3_body b s s s d
 
 #
 # Internal calls.
@@ -1499,80 +1502,80 @@ gc_bif2 Fail Live u$bif:erlang:sminus/2 S1 S2 Dst => \
 
 #
 # Optimize addition and subtraction of small literals using
-# the i_increment/4 instruction (in bodies, not in guards).
+# the i_increment/3 instruction (in bodies, not in guards).
 #
 
 gen_plus p Live Int=i Reg=d Dst => \
-	gen_increment(Reg, Int, Live, Dst)
+	gen_increment(Reg, Int, Dst)
 gen_plus p Live Reg=d Int=i Dst => \
-	gen_increment(Reg, Int, Live, Dst)
+	gen_increment(Reg, Int, Dst)
 
 gen_minus p Live Reg=d Int=i Dst | negation_is_small(Int) => \
-	gen_increment_from_minus(Reg, Int, Live, Dst)
+	gen_increment_from_minus(Reg, Int, Dst)
 
 #
-# GCing arithmetic instructions.
+# Arithmetic instructions.
 #
 
-gen_plus Fail Live S1 S2 Dst => i_plus S1 S2 Fail Live Dst
+gen_plus Fail Live S1 S2 Dst => i_plus S1 S2 Fail Dst
 
-gen_minus Fail Live S1 S2 Dst => i_minus S1 S2 Fail Live Dst
+gen_minus Fail Live S1 S2 Dst => i_minus S1 S2 Fail Dst
 
 gc_bif2 Fail Live u$bif:erlang:stimes/2 S1 S2 Dst => \
-  i_times Fail Live S1 S2 Dst
+  i_times Fail S1 S2 Dst
 
 gc_bif2 Fail Live u$bif:erlang:div/2 S1 S2 Dst => \
-  i_m_div Fail Live S1 S2 Dst
+  i_m_div Fail S1 S2 Dst
 gc_bif2 Fail Live u$bif:erlang:intdiv/2 S1 S2 Dst => \
-  i_int_div Fail Live S1 S2 Dst
+  i_int_div Fail S1 S2 Dst
 
 gc_bif2 Fail Live u$bif:erlang:rem/2 S1 S2 Dst => \
-  i_rem S1 S2 Fail Live Dst
+  i_rem S1 S2 Fail Dst
 
 gc_bif2 Fail Live u$bif:erlang:bsl/2 S1 S2 Dst => \
-  i_bsl S1 S2 Fail Live Dst
+  i_bsl S1 S2 Fail Dst
 gc_bif2 Fail Live u$bif:erlang:bsr/2 S1 S2 Dst => \
-  i_bsr S1 S2 Fail Live Dst
+  i_bsr S1 S2 Fail Dst
 
 gc_bif2 Fail Live u$bif:erlang:band/2 S1 S2 Dst => \
-  i_band S1 S2 Fail Live Dst
+  i_band S1 S2 Fail Dst
 
 gc_bif2 Fail Live u$bif:erlang:bor/2 S1 S2 Dst => \
-  i_bor Fail Live S1 S2 Dst
+  i_bor Fail S1 S2 Dst
 
 gc_bif2 Fail Live u$bif:erlang:bxor/2 S1 S2 Dst => \
-  i_bxor Fail Live S1 S2 Dst
+  i_bxor Fail S1 S2 Dst
 
-gc_bif1 Fail I u$bif:erlang:bnot/1 Src Dst=d => i_int_bnot Fail Src I Dst
+gc_bif1 Fail Live u$bif:erlang:bnot/1 Src Dst=d => i_int_bnot Fail Src Dst
 
-i_increment rxy W t d
+i_increment rxy W d
 
-i_plus x xy j? t d
-i_plus s s  j? t d
+i_plus x xy j? d
+i_plus s s  j? d
 
-i_minus x x j? t d
-i_minus s s j? t d
+i_minus x x j? d
+i_minus s s j? d
 
-i_times j? t s s d
+i_times j? s s d
 
-i_m_div j? t s s d
-i_int_div j? t s s d
+i_m_div j? s s d
+i_int_div j? s s d
 
-i_rem x x j? t d
-i_rem s s j? t d
+i_rem x x j? d
+i_rem s s j? d
 
-i_bsl s s j? t d
-i_bsr s s j? t d
+i_bsl s s j? d
+i_bsr s s j? d
 
-i_band x c j? t d
-i_band s s j? t d
+i_band x c j? d
+i_band s s j? d
 
-i_bor j? I s s d
-i_bxor j? I s s d
+i_bor j? s s d
+i_bxor j? s s d
 
-i_int_bnot Fail Src=c Live Dst => move Src x | i_int_bnot Fail x Live Dst
+i_int_bnot Fail Src=c Dst => move Src x | i_int_bnot Fail x Dst
 
-i_int_bnot j? S t d
+i_int_bnot j? S d
 
 #
 # Old guard BIFs that creates heap fragments are no longer allowed.
@@ -1587,27 +1590,14 @@ bif1 Fail u$bif:erlang:trunc/1 s d => too_old_compiler
 #
 # Guard BIFs.
 #
-gc_bif1 Fail I Bif Src Dst => \
-	gen_guard_bif1(Fail, I, Bif, Src, Dst)
+gc_bif1 p Live Bif Src Dst           => i_bif1_body Bif Src Dst
+gc_bif1 Fail=f Live Bif Src Dst      => i_bif1 Fail Bif Src Dst
 
-gc_bif2 Fail I Bif S1 S2 Dst => \
-	gen_guard_bif2(Fail, I, Bif, S1, S2, Dst)
+gc_bif2 p Live Bif S1 S2 Dst         => i_bif2_body Bif S1 S2 Dst
+gc_bif2 Fail=f Live Bif S1 S2 Dst    => i_bif2 Fail Bif S1 S2 Dst
 
-gc_bif3 Fail I Bif S1 S2 S3 Dst => \
-	gen_guard_bif3(Fail, I, Bif, S1, S2, S3, Dst)
-
-i_gc_bif1 j? W s t? d
-
-i_gc_bif2 j? W t? s s d
-
-ii_gc_bif3/7
-
-# A specific instruction can only have 6 operands, so we must
-# pass one of the arguments in an x register.
-ii_gc_bif3 Fail Bif Live S1 S2 S3 Dst => \
-  move S1 x | i_gc_bif3 Fail Bif Live S2 S3 Dst
-
-i_gc_bif3 j? W t? s s d
+gc_bif3 p Live Bif S1 S2 S3 Dst      => i_bif3_body Bif S1 S2 S3 Dst
+gc_bif3 Fail=f Live Bif S1 S2 S3 Dst => i_bif3 Fail Bif S1 S2 S3 Dst
 
 #
 # The following instruction is specially handled in beam_load.c