Refactor instructions to support relative jumps

Introduce new macros that can be used for relative jumps and
use them consistently.

Test that everything works by using a non-zero constant JUMP_OFFSET.
The loader subtracts JUMP_OFFSET from loaded labels, and all
instructions that use 'f' operands add it back.

8 files changed, 64 insertions, 31 deletions

diff --git a/erts/emulator/beam/beam_load.c b/erts/emulator/beam/beam_load.c
index 7d3a19ff86..9b8f33f576 100644
--- a/erts/emulator/beam/beam_load.c
+++ b/erts/emulator/beam/beam_load.c
@@ -4840,7 +4840,11 @@ freeze_code(LoaderState* stp)
 	    ASSERT(this_patch < stp->ci);
 	    next_patch = codev[this_patch];
 	    ASSERT(next_patch < stp->ci);
-	    codev[this_patch] = (BeamInstr) (codev + value);
+            if (this_patch < stp->num_functions) {
+                codev[this_patch] = (BeamInstr) (codev + value);
+            } else {
+                codev[this_patch] = (BeamInstr) (codev + value - JUMP_OFFSET);
+            }
 	    this_patch = next_patch;
 	}
     }
@@ -4885,7 +4889,7 @@ final_touch(LoaderState* stp, struct erl_module_instance* inst_p)
     while (index != 0) {
 	BeamInstr next = codev[index];
 	codev[index] = BeamOpCode(op_catch_yf);
-	catches = beam_catches_cons((BeamInstr *)codev[index+2], catches);
+	catches = beam_catches_cons((BeamInstr *)codev[index+2]+JUMP_OFFSET, catches);
 	codev[index+2] = make_catch(catches);
 	index = next;
     }
diff --git a/erts/emulator/beam/beam_load.h b/erts/emulator/beam/beam_load.h
index c088bdb751..0b6543638f 100644
--- a/erts/emulator/beam/beam_load.h
+++ b/erts/emulator/beam/beam_load.h
@@ -21,6 +21,8 @@
 #ifndef _BEAM_LOAD_H
 #  define _BEAM_LOAD_H
 
+#define JUMP_OFFSET 0x5
+
 #include "beam_opcodes.h"
 #include "erl_process.h"
 
diff --git a/erts/emulator/beam/bif_instrs.tab b/erts/emulator/beam/bif_instrs.tab
index 3c95113907..0932b8b985 100644
--- a/erts/emulator/beam/bif_instrs.tab
+++ b/erts/emulator/beam/bif_instrs.tab
@@ -151,7 +151,7 @@ i_gc_bif1(Fail, Bif, Src, Live, Dst) {
         $NEXT0();
     }
     if (ERTS_LIKELY($Fail != 0)) { /* Handle error in guard. */
-        $NEXT($Fail);
+        $JUMP($Fail);
     }
 
     /* Handle error in body. */
@@ -202,7 +202,7 @@ i_gc_bif2(Fail, Bif, Live, Src1, Src2, Dst) {
     }
 
     if (ERTS_LIKELY($Fail != 0)) { /* Handle error in guard. */
-        $NEXT($Fail);
+        $JUMP($Fail);
     }
 
     /* Handle error in body. */
@@ -257,7 +257,7 @@ i_gc_bif3(Fail, Bif, Live, Src2, Src3, Dst) {
 
     /* Handle error in guard. */
     if (ERTS_LIKELY($Fail != 0)) {
-        $NEXT($Fail);
+        $JUMP($Fail);
     }
 
     /* Handle error in body. */
@@ -473,10 +473,10 @@ nif_bif.apply_bif() {
 
     /* In case we apply process_info/1,2 or load_nif/1 */
     c_p->current = codemfa;
-    c_p->i = I;		/* In case we apply check_process_code/2. */
-    c_p->arity = 0;		/* To allow garbage collection on ourselves
-                                 * (check_process_code/2).
-                                 */
+    $SET_CP_I_ABS(I);     /* In case we apply check_process_code/2. */
+    c_p->arity = 0;       /* To allow garbage collection on ourselves
+                           * (check_process_code/2).
+                           */
     DTRACE_BIF_ENTRY(c_p, codemfa);
 
     SWAPOUT;
diff --git a/erts/emulator/beam/instrs.tab b/erts/emulator/beam/instrs.tab
index 690bd3a848..7ea9dee299 100644
--- a/erts/emulator/beam/instrs.tab
+++ b/erts/emulator/beam/instrs.tab
@@ -78,7 +78,14 @@ move_deallocate_return(Src, Deallocate) {
 
 // Call instructions
 
-DISPATCH(CallDest) {
+DISPATCH_REL(CallDest) {
+    //| -no_next
+    $SET_I_REL($CallDest);
+    DTRACE_LOCAL_CALL(c_p, erts_code_to_codemfa(I));
+    Dispatch();
+}
+
+DISPATCH_ABS(CallDest) {
     //| -no_next
     SET_I((BeamInstr *) $CallDest);
     DTRACE_LOCAL_CALL(c_p, erts_code_to_codemfa(I));
@@ -87,18 +94,18 @@ DISPATCH(CallDest) {
 
 i_call(CallDest) {
     SET_CP(c_p, $NEXT_INSTRUCTION);
-    $DISPATCH($CallDest);
+    $DISPATCH_REL($CallDest);
 }
 
 move_call(Src, CallDest) {
     x(0) = $Src;
     SET_CP(c_p, $NEXT_INSTRUCTION);
-    $DISPATCH($CallDest);
+    $DISPATCH_REL($CallDest);
 }
 
 i_call_last(CallDest, Deallocate) {
     $deallocate($Deallocate);
-    $DISPATCH($CallDest);
+    $DISPATCH_REL($CallDest);
 }
 
 move_call_last(Src, CallDest, Deallocate) {
@@ -107,7 +114,7 @@ move_call_last(Src, CallDest, Deallocate) {
 }
 
 i_call_only(CallDest) {
-    $DISPATCH($CallDest);
+    $DISPATCH_REL($CallDest);
 }
 
 move_call_only(Src, CallDest) {
@@ -168,7 +175,8 @@ i_apply() {
     BeamInstr *next;
     $APPLY(NULL, 0, next);
     if (ERTS_LIKELY(next != NULL)) {
-        $i_call(next);
+        SET_CP(c_p, $NEXT_INSTRUCTION);
+        $DISPATCH_ABS(next);
     }
     $HANDLE_APPLY_ERROR();
 }
@@ -177,7 +185,8 @@ i_apply_last(Deallocate) {
     BeamInstr *next;
     $APPLY(I, $Deallocate, next);
     if (ERTS_LIKELY(next != NULL)) {
-        $i_call_last(next, $Deallocate);
+        $deallocate($Deallocate);
+        $DISPATCH_ABS(next);
     }
     $HANDLE_APPLY_ERROR();
 }
@@ -186,7 +195,7 @@ i_apply_only() {
     BeamInstr *next;
     $APPLY(I, 0, next);
     if (ERTS_LIKELY(next != NULL)) {
-        $i_call_only(next);
+        $DISPATCH_ABS(next);
     }
     $HANDLE_APPLY_ERROR();
 }
@@ -202,7 +211,8 @@ apply(Arity) {
     BeamInstr *next;
     $FIXED_APPLY($Arity, NULL, 0, next);
     if (ERTS_LIKELY(next != NULL)) {
-        $i_call(next);
+        SET_CP(c_p, $NEXT_INSTRUCTION);
+        $DISPATCH_ABS(next);
     }
     $HANDLE_APPLY_ERROR();
 }
@@ -211,7 +221,8 @@ apply_last(Arity, Deallocate) {
     BeamInstr *next;
     $FIXED_APPLY($Arity, I, $Deallocate, next);
     if (ERTS_LIKELY(next != NULL)) {
-        $i_call_last(next, $Deallocate);
+        $deallocate($Deallocate);
+        $DISPATCH_ABS(next);
     }
     $HANDLE_APPLY_ERROR();
 }
@@ -560,6 +571,7 @@ i_put_tuple.fill(Arity) {
         }
     } while (--arity != 0);
     HTOP = hp;
+    ASSERT(VALID_INSTR(* (Eterm *)I));
     Goto(*I);
 }
 
diff --git a/erts/emulator/beam/macros.tab b/erts/emulator/beam/macros.tab
index bac96be7d3..959f7b28df 100644
--- a/erts/emulator/beam/macros.tab
+++ b/erts/emulator/beam/macros.tab
@@ -28,15 +28,30 @@ REFRESH_GEN_DEST() {
     dst_ptr = REG_TARGET_PTR(dst);
 }
 
+SET_I_REL(Offset) {
+    ASSERT(VALID_INSTR(* (Eterm *)((BeamInstr *) ($Offset) + JUMP_OFFSET)));
+    I = (BeamInstr *) $Offset + JUMP_OFFSET;
+}
+
+SET_CP_I_ABS(Target) {
+    c_p->i = $Target;
+    ASSERT(VALID_INSTR(* (Eterm *)c_p->i));
+}
+
+SET_REL_I(Dst, Offset) {
+    $Dst = (BeamInstr *) ($Offset) + JUMP_OFFSET;
+    ASSERT(VALID_INSTR(*$Dst));
+}
+
 FAIL(Fail) {
     //| -no_prefetch
-    SET_I((BeamInstr *) $Fail);
+    $SET_I_REL($Fail);
     Goto(*I);
 }
 
 JUMP(Fail) {
     //| -no_next
-    SET_I((BeamInstr *) $Fail);
+    $SET_I_REL($Fail);
     Goto(*I);
 }
 
diff --git a/erts/emulator/beam/msg_instrs.tab b/erts/emulator/beam/msg_instrs.tab
index 093d48c64c..8055a8616f 100644
--- a/erts/emulator/beam/msg_instrs.tab
+++ b/erts/emulator/beam/msg_instrs.tab
@@ -49,7 +49,7 @@ recv_mark(Dest) {
      * the label for the loop_rec/2 instruction for the
      * the receive statement.
      */
-    c_p->msg.mark = (BeamInstr *) $Dest;
+    $SET_REL_I(c_p->msg.mark, $Dest);
     c_p->msg.saved_last = c_p->msg.last;
 }
 
@@ -116,7 +116,7 @@ i_loop_rec(Dest) {
             erts_proc_unlock(c_p, ERTS_PROC_LOCKS_MSG_RECEIVE);
         } else {
             c_p->flags &= ~F_DELAY_GC;
-            SET_I((BeamInstr *) $Dest);
+            $SET_I_REL($Dest);
             Goto(*I);		/* Jump to a wait or wait_timeout instruction */
         }
     }
@@ -253,7 +253,7 @@ loop_rec_end(Dest) {
 
     ASSERT(c_p->flags & F_DELAY_GC);
 
-    SET_I((BeamInstr *) $Dest);
+    $SET_I_REL($Dest);
     SAVE_MESSAGE(c_p);
     if (FCALLS > 0 || FCALLS > neg_o_reds) {
         FCALLS--;
@@ -261,7 +261,7 @@ loop_rec_end(Dest) {
     }
 
     c_p->flags &= ~F_DELAY_GC;
-    c_p->i = I;
+    $SET_CP_I_ABS(I);
     SWAPOUT;
     c_p->arity = 0;
     c_p->current = NULL;
@@ -374,7 +374,7 @@ wait.src(Src) {
 //
 
 wait.execute(JumpTarget) {
-    c_p->i = (BeamInstr *) $JumpTarget; /* L1 */
+    $SET_REL_I(c_p->i, $JumpTarget); /* L1 */
     SWAPOUT;
     c_p->arity = 0;
 
diff --git a/erts/emulator/beam/select_instrs.tab b/erts/emulator/beam/select_instrs.tab
index e85ed2c304..88049bbcf0 100644
--- a/erts/emulator/beam/select_instrs.tab
+++ b/erts/emulator/beam/select_instrs.tab
@@ -68,10 +68,10 @@ select_val_bins.select(Fail, NumElements) {
         } else if (select_val > mid->val) {
             low = mid + 1;
         } else {
-            $NEXT(mid->addr);
+            $JUMP(mid->addr);
         }
     }
-    $NEXT($Fail);
+    $JUMP($Fail);
 }
 
 i_select_tuple_arity2 := select_val2.src.ta_fail.execute;
@@ -150,8 +150,8 @@ select_val_lin.execute(N) {
     }
 
     if (vs[ix] == select_val) {
-        I = $NEXT_INSTRUCTION + $N + ix;
-        $JUMP(*I);
+        Eterm offset = *($NEXT_INSTRUCTION + $N + ix);
+        $JUMP(offset);
     } else {
         $JUMP(*select_fail);
     }
diff --git a/erts/emulator/beam/trace_instrs.tab b/erts/emulator/beam/trace_instrs.tab
index c28bc8ebcb..b10442c5e7 100644
--- a/erts/emulator/beam/trace_instrs.tab
+++ b/erts/emulator/beam/trace_instrs.tab
@@ -94,7 +94,7 @@ i_yield() {
     c_p->arg_reg[0] = am_true;
     c_p->arity = 1; /* One living register (the 'true' return value) */
     SWAPOUT;
-    c_p->i = $NEXT_INSTRUCTION;
+    $SET_CP_I_ABS($NEXT_INSTRUCTION);
     c_p->current = NULL;
     goto do_schedule;
     //| -no_next