hipe: Fix constructing huge binaries

Bugs were fixed in
hipe_rtl_binary_match:{first_part/3,make_size/3,set_high/1} in commit
5aea81c49, but it turns out these had been copy-pasted verbatim into
hipe_rtl_binary_construct, where they were causing further bugs. They
have now moved to hipe_rtl_binary, from where they are included by the
other two modules.

Furthermore, first_part/3 (reamed get_word_integer/3, since it loads
integers that fits into an unsigned word), and make_size/3 now accepts a
fourth argument to distinguish too large arguments (which should cause a
system_limit exception) from negative or non-integral arguments.

The use of first_part/3 (get_word_integer/3) from 5aea81c49 in
hipe_rtl_binary_construct now allows several binary construction
instructions to accept bignum sizes, as they were supposed to.

Additionally, calls to
hipe_rtl_binary_construct:check_and_untag_fixnum/3 were replaced with
get_word_integer/4 since all of them were also supposed to accept
sufficiently small bignums, but didn't, and check_and_untag_fixnum/3 was
essentially identical to first_part/3 anyway.

HiPE is now capable of passing bs_construct_SUITE completely unmodified.

4 files changed, 176 insertions, 220 deletions

diff --git a/lib/hipe/rtl/hipe_rtl_binary.erl b/lib/hipe/rtl/hipe_rtl_binary.erl
index 4525994f7d..9cbab08ee2 100644
--- a/lib/hipe/rtl/hipe_rtl_binary.erl
+++ b/lib/hipe/rtl/hipe_rtl_binary.erl
@@ -1,3 +1,4 @@
+%% -*- erlang-indent-level: 2 -*-
 %%%
 %%% %CopyrightBegin%
 %%% 
@@ -28,11 +29,20 @@
 
 -export([gen_rtl/7]).
 
+-export([floorlog2/1, get_word_integer/4, make_size/3, make_size/4]).
+
+%%--------------------------------------------------------------------
+
+-define(BYTE_SHIFT, 3). %% Turn bits into bytes or vice versa
+-define(BYTE_SIZE, 8).
+
+%%--------------------------------------------------------------------
+
 gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SysLimName, ConstTab) ->
   case type_of_operation(BsOP) of
     match ->
       {hipe_rtl_binary_match:gen_rtl(
-	BsOP, Dst, Args, TrueLblName, FalseLblName),ConstTab};
+	 BsOP, Dst, Args, TrueLblName, FalseLblName),ConstTab};
     construct ->
       hipe_rtl_binary_construct:gen_rtl(
 	BsOP, Dst, Args, TrueLblName, FalseLblName, SysLimName, ConstTab)
@@ -79,3 +89,133 @@ type_of_operation(bs_final) -> construct;
 type_of_operation({bs_append,_,_,_,_}) -> construct;
 type_of_operation({bs_private_append,_,_}) -> construct;
 type_of_operation(bs_init_writable) -> construct.
+
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+%%
+%% Small utility functions:
+%%
+%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
+
+create_lbls(X) when X > 0 ->
+  [hipe_rtl:mk_new_label()|create_lbls(X-1)];
+create_lbls(0) ->
+  [].
+
+%%------------------------------------------------------------------------------
+%% Utilities used by both hipe_rtl_binary_construct and hipe_rtl_binary_match
+%%------------------------------------------------------------------------------
+
+get_word_integer(Var, Register, SystemLimitLblName, FalseLblName) ->
+  [EndLbl] = create_lbls(1),
+  EndName = hipe_rtl:label_name(EndLbl),
+  get_word_integer(Var, Register,SystemLimitLblName,  FalseLblName, EndName, EndName,
+		   [EndLbl]).
+
+get_word_integer(Var, Register, SystemLimitLblName, FalseLblName, TrueLblName,
+		 BigLblName, Tail) ->
+  [FixnumLbl, NotFixnumLbl, BignumLbl, SuccessLbl] = create_lbls(4),
+  [hipe_tagscheme:test_fixnum(Var, hipe_rtl:label_name(FixnumLbl),
+			      hipe_rtl:label_name(NotFixnumLbl), 0.99),
+   FixnumLbl,
+   hipe_tagscheme:fixnum_ge(Var, hipe_rtl:mk_imm(hipe_tagscheme:mk_fixnum(0)),
+			    hipe_rtl:label_name(SuccessLbl), FalseLblName,
+			    0.99),
+   SuccessLbl,
+   hipe_tagscheme:untag_fixnum(Register, Var),
+   hipe_rtl:mk_goto(TrueLblName),
+   NotFixnumLbl,
+   hipe_tagscheme:test_pos_bignum_arity(Var, 1, hipe_rtl:label_name(BignumLbl),
+					FalseLblName, SystemLimitLblName, 0.99),
+   BignumLbl,
+   hipe_tagscheme:unsafe_get_one_word_pos_bignum(Register, Var),
+   hipe_rtl:mk_goto(BigLblName) | Tail].
+
+make_size(UnitImm, BitsVar, FailLblName) ->
+  make_size(UnitImm, BitsVar, FailLblName, FailLblName).
+
+make_size(1, BitsVar, OverflowLblName, FalseLblName) ->
+  DstReg = hipe_rtl:mk_new_reg_gcsafe(),
+  {get_word_integer(BitsVar, DstReg, OverflowLblName, FalseLblName), DstReg};
+make_size(?BYTE_SIZE, BitsVar, OverflowLblName, FalseLblName) ->
+  DstReg = hipe_rtl:mk_new_reg_gcsafe(),
+  [FixnumLbl, BignumLbl] = create_lbls(2),
+  WordBits = hipe_rtl_arch:word_size() * ?BYTE_SIZE,
+  FixnumLblName = hipe_rtl:label_name(FixnumLbl),
+  Tail = [BignumLbl,
+	  hipe_rtl:mk_branch(DstReg, 'ltu',
+			     hipe_rtl:mk_imm(1 bsl (WordBits - ?BYTE_SHIFT)),
+			     FixnumLblName, OverflowLblName, 0.99),
+	  FixnumLbl,
+	  hipe_rtl:mk_alu(DstReg, DstReg, sll, hipe_rtl:mk_imm(?BYTE_SHIFT))],
+  Code = get_word_integer(BitsVar, DstReg, OverflowLblName, FalseLblName,
+			  FixnumLblName, hipe_rtl:label_name(BignumLbl), Tail),
+  {Code, DstReg};
+make_size(UnitImm, BitsVar, OverflowLblName, FalseLblName) ->
+  DstReg = hipe_rtl:mk_new_reg_gcsafe(),
+  UnitList = number2list(UnitImm),
+  Code = multiply_code(UnitList, BitsVar, DstReg, OverflowLblName, FalseLblName),
+  {Code, DstReg}.
+
+multiply_code(List=[Head|_Tail], Variable, Result, OverflowLblName,
+	      FalseLblName) ->
+  Test = set_high(Head),
+  Tmp1 = hipe_rtl:mk_new_reg(),
+  SuccessLbl = hipe_rtl:mk_new_label(),
+  Register = hipe_rtl:mk_new_reg(),
+  Code = [hipe_rtl:mk_move(Result, hipe_rtl:mk_imm(0))|
+	  get_word_integer(Variable, Register, OverflowLblName, FalseLblName)]
+    ++
+    [hipe_rtl:mk_alub(Tmp1, Register, 'and', hipe_rtl:mk_imm(Test),
+		      eq, hipe_rtl:label_name(SuccessLbl),
+		      OverflowLblName, 0.99),
+     SuccessLbl],
+  multiply_code(List, Register, Result, OverflowLblName, Tmp1, Code).
+
+multiply_code([ShiftSize|Rest], Register, Result, OverflowLblName, Tmp1,
+	      OldCode) ->
+  SuccessLbl = hipe_rtl:mk_new_label(),
+  Code =
+    OldCode ++
+    [hipe_rtl:mk_alu(Tmp1, Register, sll, hipe_rtl:mk_imm(ShiftSize)),
+     hipe_rtl:mk_alub(Result, Tmp1, 'add', Result, not_overflow,
+		      hipe_rtl:label_name(SuccessLbl), OverflowLblName, 0.99),
+     SuccessLbl],
+  multiply_code(Rest, Register, Result, OverflowLblName, Tmp1, Code);
+multiply_code([], _Register, _Result, _OverflowLblName, _Tmp1, Code) ->
+  Code.
+
+set_high(X) ->
+  WordBits = hipe_rtl_arch:word_size() * ?BYTE_SIZE,
+  set_high(min(X, WordBits), WordBits, 0).
+
+set_high(0, _, Y) ->
+  Y;
+set_high(X, WordBits, Y) ->
+  set_high(X-1, WordBits, Y+(1 bsl (WordBits-X))).
+
+
+number2list(X) when is_integer(X), X >= 0 ->
+  number2list(X, []).
+
+number2list(1, Acc) ->
+  lists:reverse([0|Acc]);
+number2list(0, Acc) ->
+  lists:reverse(Acc);
+number2list(X, Acc) ->
+  F = floorlog2(X),
+  number2list(X-(1 bsl F), [F|Acc]).
+
+floorlog2(X) ->
+  %% Double-precision floats do not have enough precision to make floorlog2
+  %% exact for integers larger than 2^47.
+  Approx = round(math:log(X)/math:log(2)-0.5),
+  floorlog2_refine(X, Approx).
+
+floorlog2_refine(X, Approx) ->
+  if (1 bsl Approx) > X ->
+      floorlog2_refine(X, Approx - 1);
+     (1 bsl (Approx+1)) > X ->
+      Approx;
+     true ->
+      floorlog2_refine(X, Approx + 1)
+  end.
diff --git a/lib/hipe/rtl/hipe_rtl_binary_construct.erl b/lib/hipe/rtl/hipe_rtl_binary_construct.erl
index 1a78320592..80436a6931 100644
--- a/lib/hipe/rtl/hipe_rtl_binary_construct.erl
+++ b/lib/hipe/rtl/hipe_rtl_binary_construct.erl
@@ -34,6 +34,10 @@
 			 get_field_from_term/3,
 			 set_field_from_pointer/3,
 			 get_field_from_pointer/3]).
+
+-import(hipe_rtl_binary, [floorlog2/1,
+			  get_word_integer/4,
+			  make_size/4]).
 %%-------------------------------------------------------------------------
 
 -include("../main/hipe.hrl").
@@ -111,7 +115,9 @@ gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SystemLimitLblName, ConstTab
 		    put_static_binary(NewOffset, Src, Size, Base, Offset, 
 				      TrueLblName, FalseLblName);
 		  [Src, Bits, Base, Offset]  ->
-		    {SizeCode, SizeReg} = make_size(Size, Bits, FalseLblName),
+		    {SizeCode, SizeReg} = make_size(Size, Bits,
+						    SystemLimitLblName,
+						    FalseLblName),
 		    InCode = put_dynamic_binary(NewOffset, Src, SizeReg, Base, 
 						Offset, TrueLblName, FalseLblName),
 		    SizeCode ++ InCode
@@ -133,7 +139,9 @@ gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SystemLimitLblName, ConstTab
 		   put_float(NewOffset, Src, Base, Offset, Size, CCode, Aligned, 
 			     LittleEndian, ConstInfo, TrueLblName);
 		 [Src, Bits, Base, Offset] ->
-		   {SizeCode, SizeReg} = make_size(Size, Bits, FalseLblName),
+		   {SizeCode, SizeReg} = make_size(Size, Bits,
+						   SystemLimitLblName,
+						   FalseLblName),
 		   InCode = float_c_code(NewOffset, Src, Base, Offset, SizeReg, 
 					 Flags, TrueLblName, FalseLblName),
 		   SizeCode ++ InCode
@@ -162,6 +170,7 @@ gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SystemLimitLblName, ConstTab
 				       CCode, Aligned, LittleEndian, TrueLblName); 
 		      [Src, Bits, Base, Offset] -> 
 		    {SizeCode, SizeReg} = make_size(Size, Bits,
+						    SystemLimitLblName,
 						    FalseLblName), 
 			CCode = int_c_code(NewOffset, Src, Base,
 					   Offset, SizeReg, Flags, 
@@ -210,6 +219,7 @@ gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SystemLimitLblName, ConstTab
 					       TrueLblName); 
 		       [Src, Bits, Base, Offset] -> 
 			 {SizeCode, SizeReg} = make_size(Size, Bits,
+							 SystemLimitLblName,
 							 FalseLblName), 
 			 CCode = int_c_code(NewOffset, Src, Base,
 					    Offset, SizeReg, Flags, 
@@ -294,7 +304,7 @@ gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SystemLimitLblName, ConstTab
 	    [SizeReg] = create_regs(1),
 	    [Base] = create_unsafe_regs(1),
 	    [hipe_rtl:mk_gctest(?PROC_BIN_WORDSIZE + ?SUB_BIN_WORDSIZE),
-	     check_and_untag_fixnum(Size, SizeReg, FalseLblName),
+	     get_word_integer(Size, SizeReg, SystemLimitLblName, FalseLblName),
 	     allocate_writable(DstVar, Base, SizeReg, Zero, Zero),
 	     hipe_rtl:mk_goto(TrueLblName)]; 
 	  
@@ -306,7 +316,7 @@ gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SystemLimitLblName, ConstTab
 	    SubBinSize = {sub_binary, binsize},
 	    [get_field_from_term({sub_binary, orig}, Bin, ProcBin),
 	     get_field_from_term(SubBinSize, Bin, SubSize),
-	     check_and_untag_fixnum(Size, SizeReg, FalseLblName),
+	     get_word_integer(Size, SizeReg, SystemLimitLblName, FalseLblName),
 	     realloc_binary(SizeReg, ProcBin, Base),
 	     calculate_sizes(Bin, SizeReg, Offset, EndSubSize, EndSubBitSize),
 	     set_field_from_term(SubBinSize, Bin, EndSubSize),
@@ -328,7 +338,7 @@ gen_rtl(BsOP, Dst, Args, TrueLblName, FalseLblName, SystemLimitLblName, ConstTab
 	    Zero = hipe_rtl:mk_imm(0),
 	    SubIsWritable = {sub_binary, is_writable},
 	    [hipe_rtl:mk_gctest(?SUB_BIN_WORDSIZE + ?PROC_BIN_WORDSIZE),
-	     check_and_untag_fixnum(Size, SizeReg, FalseLblName),
+	     get_word_integer(Size, SizeReg, SystemLimitLblName, FalseLblName),
 	     hipe_tagscheme:test_bitstr(Bin, ContLblName, FalseLblName, 0.99), 
 	     ContLbl, 
 	     hipe_tagscheme:test_subbinary(Bin,ContLbl2Name, NotWritable), 
@@ -401,16 +411,6 @@ allocate_writable(Dst, Base, UsedBytes, TotBytes, TotSize) ->
    hipe_tagscheme:mk_sub_binary(Dst, EndSubSize, Zero, EndSubBitSize,
 				Zero, hipe_rtl:mk_imm(1), ProcBin)].
 
-check_and_untag_fixnum(Size, SizeReg, FalseLblName) ->
-  [ContLbl,NextLbl] = Lbls = create_lbls(2),
-  [ContLblName,NextLblName] = get_label_names(Lbls),
-  [hipe_tagscheme:test_fixnum(Size, ContLblName, FalseLblName, 0.99),
-   ContLbl,
-   hipe_tagscheme:untag_fixnum(SizeReg,Size),
-   hipe_rtl:mk_branch(SizeReg, ge, hipe_rtl:mk_imm(0), NextLblName, 
-		      FalseLblName),
-   NextLbl].
-
 realloc_binary(SizeReg, ProcBin, Base) -> 
   [NoReallocLbl, ReallocLbl, NextLbl, ContLbl] = Lbls = create_lbls(4),
   [NoReallocLblName, ReallocLblName, NextLblName, ContLblName] =
@@ -673,7 +673,7 @@ var_init2(Size, Dst, Base, Offset, TrueLblName, SystemLimitLblName, FalseLblName
   WordSize = hipe_rtl_arch:word_size(),
   [ContLbl,HeapLbl,REFCLbl,NextLbl] = create_lbls(4),
   [USize,Tmp] = create_unsafe_regs(2),
-  [get_32_bit_value(Size, USize, SystemLimitLblName, FalseLblName),
+  [get_word_integer(Size, USize, SystemLimitLblName, FalseLblName),
    hipe_rtl:mk_branch(USize, le, hipe_rtl:mk_imm(?MAX_BINSIZE), 
 		      hipe_rtl:label_name(ContLbl), 
 		      SystemLimitLblName),
@@ -709,7 +709,7 @@ var_init_bits(Size, Dst, Base, Offset, TrueLblName, SystemLimitLblName, FalseLbl
 	       ?PROC_BIN_WORDSIZE) + ?SUB_BIN_WORDSIZE,
   Zero = hipe_rtl:mk_imm(0),
   [hipe_rtl:mk_gctest(MaximumWords),
-   get_32_bit_value(Size, USize, SystemLimitLblName, FalseLblName),
+   get_word_integer(Size, USize, SystemLimitLblName, FalseLblName),
    hipe_rtl:mk_alu(ByteSize, USize, srl, ?BYTE_SHIFT),
    hipe_rtl:mk_alub(OffsetBits, USize, 'and', ?LOW_BITS, eq, 
 		    hipe_rtl:label_name(NoSubLbl),
@@ -1286,103 +1286,6 @@ copy_float_big(Base, Offset, NewOffset, Src, FalseLblName, TrueLblName, var) ->
   hipe_tagscheme:test_flonum(Src, hipe_rtl:label_name(SuccessLbl), FalseLblName, 0.99) ++
     [SuccessLbl|copy_float_big(Base, Offset, NewOffset, Src, FalseLblName, TrueLblName, pass)].
 
-make_size(1, BitsVar, FalseLblName) ->
-  [DstReg] = create_regs(1),
-  {first_part(BitsVar, DstReg, FalseLblName), DstReg};
-make_size(?BYTE_SIZE, BitsVar, FalseLblName) ->
-  [DstReg] = create_regs(1),
-  Code = 
-    first_part(BitsVar, DstReg, FalseLblName) ++
-    [hipe_rtl:mk_alu(DstReg, DstReg, 'sll', ?BYTE_SHIFT)],
-  {Code, DstReg};
-make_size(UnitImm, BitsVar, FalseLblName) ->
-  [DstReg] = create_regs(1),
-  UnitList = number2list(UnitImm),
-  Code = multiply_code(UnitList, BitsVar, DstReg, FalseLblName),
-  {Code, DstReg}.
-
-multiply_code(List=[Head|_Tail], Variable, Result, FalseLblName) ->
-  Test = set_high(Head),
-  Tmp1 = hipe_rtl:mk_new_reg(),
-  SuccessLbl = hipe_rtl:mk_new_label(),
-  Register = hipe_rtl:mk_new_reg(),
-  Code = [hipe_rtl:mk_move(Result, hipe_rtl:mk_imm(0))|
-	  first_part(Variable, Register, FalseLblName)]
-    ++
-    [hipe_rtl:mk_alub(Tmp1, Register, 'and', hipe_rtl:mk_imm(Test), 
-		      'eq', hipe_rtl:label_name(SuccessLbl), 
-		      FalseLblName, 0.99),
-     SuccessLbl],
-  multiply_code(List, Register, Result, FalseLblName, Tmp1, Code).
-
-multiply_code([ShiftSize|Rest], Register, Result, FalseLblName, Tmp1, OldCode) ->
-  SuccessLbl = hipe_rtl:mk_new_label(),
-  Code = OldCode ++ [hipe_rtl:mk_alu(Tmp1, Register, 'sll',
-				     hipe_rtl:mk_imm(ShiftSize)),
-		     hipe_rtl:mk_alub(Result, Tmp1, 'add', Result, not_overflow, hipe_rtl:label_name(SuccessLbl), FalseLblName, 0.99),
-		     SuccessLbl],
-  multiply_code(Rest, Register, Result, FalseLblName, Tmp1, Code);
-multiply_code([], _Register, _Result, _FalseLblName, _Tmp1, Code) ->
-  Code.
-
-number2list(X) when is_integer(X), X >= 0 ->
-  number2list(X, []).
-
-number2list(1, Acc) ->
-  lists:reverse([0|Acc]);
-number2list(0, Acc) ->
-  lists:reverse(Acc);
-number2list(X, Acc) ->
-  F = floorlog2(X),
-  number2list(X-(1 bsl F), [F|Acc]).
-
-floorlog2(X) ->
-  %% Double-precision floats do not have enough precision to make floorlog2
-  %% exact for integers larger than 2^47.
-  Approx = round(math:log(X)/math:log(2)-0.5),
-  floorlog2_refine(X, Approx).
-
-floorlog2_refine(X, Approx) ->
-  if (1 bsl Approx) > X ->
-      floorlog2_refine(X, Approx - 1);
-     (1 bsl (Approx+1)) > X ->
-      Approx;
-     true ->
-      floorlog2_refine(X, Approx + 1)
-  end.
-
-set_high(X) ->
-  set_high(X, 0).
-
-set_high(0, Y) ->
-  Y;
-set_high(X, Y) ->
-  set_high(X-1, Y+(1 bsl (27-X))).
-
-get_32_bit_value(Size, USize, SystemLimitLblName, NegLblName) ->
-  Lbls = [FixLbl, BigLbl, OkLbl, PosBigLbl] = create_lbls(4),
-  [FixLblName, BigLblName, OkLblName, PosBigLblName] = [hipe_rtl:label_name(Lbl) || Lbl <- Lbls],
-  [hipe_tagscheme:test_fixnum(Size, FixLblName, BigLblName, 0.99),
-   FixLbl,
-   hipe_tagscheme:untag_fixnum(USize, Size),
-   hipe_rtl:mk_branch(USize, ge, hipe_rtl:mk_imm(0), OkLblName, NegLblName), 
-   BigLbl,
-   hipe_tagscheme:test_pos_bignum(Size, PosBigLblName, NegLblName, 0.99),
-   PosBigLbl,
-   hipe_tagscheme:get_one_word_pos_bignum(USize, Size, SystemLimitLblName),
-   OkLbl].  
-   
-
-first_part(Var, Register, FalseLblName) ->
-  [SuccessLbl1, SuccessLbl2] = create_lbls(2),
-  [hipe_tagscheme:test_fixnum(Var, hipe_rtl:label_name(SuccessLbl1),
-			      FalseLblName, 0.99),
-  SuccessLbl1,
-  hipe_tagscheme:fixnum_ge(Var, hipe_rtl:mk_imm(hipe_tagscheme:mk_fixnum(0)), 
-			   hipe_rtl:label_name(SuccessLbl2), FalseLblName, 0.99),
-  SuccessLbl2,
-  hipe_tagscheme:untag_fixnum(Register, Var)].
-
 is_divisible(_Dividend, 1, SuccLbl, _FailLbl) ->
   [hipe_rtl:mk_goto(SuccLbl)];
 is_divisible(Dividend, Divisor, SuccLbl, FailLbl) ->
diff --git a/lib/hipe/rtl/hipe_rtl_binary_match.erl b/lib/hipe/rtl/hipe_rtl_binary_match.erl
index 51213b71d1..b385ea6afc 100644
--- a/lib/hipe/rtl/hipe_rtl_binary_match.erl
+++ b/lib/hipe/rtl/hipe_rtl_binary_match.erl
@@ -31,6 +31,8 @@
 
 -import(hipe_tagscheme, [set_field_from_term/3, get_field_from_term/3]).
 
+-import(hipe_rtl_binary, [make_size/3]).
+
 -include("hipe_literals.hrl").
 
 %%--------------------------------------------------------------------
@@ -1100,103 +1102,5 @@ create_gcsafe_regs(X) when X > 0 ->
 create_gcsafe_regs(0) ->
   [].
 
-first_part(Var, Register, FalseLblName) ->
-  [EndLbl] = create_lbls(1),
-  EndName = hipe_rtl:label_name(EndLbl),
-  first_part(Var, Register, FalseLblName, EndName, EndName, [EndLbl]).
-
-first_part(Var, Register, FalseLblName, TrueLblName, BigLblName, Tail) ->
-  [FixnumLbl, NotFixnumLbl, BignumLbl, SuccessLbl] = create_lbls(4),
-  [hipe_tagscheme:test_fixnum(Var, hipe_rtl:label_name(FixnumLbl),
-			      hipe_rtl:label_name(NotFixnumLbl), 0.99),
-   FixnumLbl,
-   hipe_tagscheme:fixnum_ge(Var, hipe_rtl:mk_imm(hipe_tagscheme:mk_fixnum(0)),
-			    hipe_rtl:label_name(SuccessLbl), FalseLblName,
-			    0.99),
-   SuccessLbl,
-   hipe_tagscheme:untag_fixnum(Register, Var),
-   hipe_rtl:mk_goto(TrueLblName),
-   NotFixnumLbl,
-   %% Since binaries are not allowed to be larger than 2^wordsize bits
-   %% and since bignum digits are words, we know that a bignum with an
-   %% arity larger than one can't match.
-   hipe_tagscheme:test_pos_bignum_arity(Var, 1, hipe_rtl:label_name(BignumLbl),
-					FalseLblName, 0.99),
-   BignumLbl,
-   hipe_tagscheme:unsafe_get_one_word_pos_bignum(Register, Var),
-   hipe_rtl:mk_goto(BigLblName) | Tail].
-
-make_size(1, BitsVar, FalseLblName) ->
-  [DstReg] = create_regs(1),
-  {first_part(BitsVar, DstReg, FalseLblName), DstReg};
-make_size(?BYTE_SIZE, BitsVar, FalseLblName) ->
-  [DstReg] = create_regs(1),
-  [FixnumLbl, BignumLbl] = create_lbls(2),
-  WordBits = hipe_rtl_arch:word_size() * ?BYTE_SIZE,
-  FixnumLblName = hipe_rtl:label_name(FixnumLbl),
-  Tail = [BignumLbl,
-	  hipe_rtl:mk_branch(DstReg, 'ltu',
-			     hipe_rtl:mk_imm(1 bsl (WordBits - ?BYTE_SHIFT)),
-			     FixnumLblName, FalseLblName, 0.99),
-	  FixnumLbl,
-	  hipe_rtl:mk_alu(DstReg, DstReg, sll, hipe_rtl:mk_imm(?BYTE_SHIFT))],
-  Code = first_part(BitsVar, DstReg, FalseLblName, FixnumLblName,
-		    hipe_rtl:label_name(BignumLbl), Tail),
-  {Code, DstReg};
-make_size(UnitImm, BitsVar, FalseLblName) ->
-  [DstReg] = create_regs(1),
-  UnitList = number2list(UnitImm),
-  Code = multiply_code(UnitList, BitsVar, DstReg, FalseLblName),
-  {Code, DstReg}.
-
-multiply_code(List=[Head|_Tail], Variable, Result, FalseLblName) ->
-  Test = set_high(Head),
-  Tmp1 = hipe_rtl:mk_new_reg(),
-  SuccessLbl = hipe_rtl:mk_new_label(),
-  Register = hipe_rtl:mk_new_reg(),
-  Code = [hipe_rtl:mk_move(Result, hipe_rtl:mk_imm(0))|
-	  first_part(Variable, Register, FalseLblName)]
-	++
-	 [hipe_rtl:mk_alub(Tmp1, Register, 'and', hipe_rtl:mk_imm(Test), 
-			   eq, hipe_rtl:label_name(SuccessLbl), 
-			   FalseLblName, 0.99),
-	  SuccessLbl],
-  multiply_code(List, Register, Result, FalseLblName, Tmp1, Code).
-
-multiply_code([ShiftSize|Rest], Register, Result, FalseLblName, Tmp1, OldCode) ->
-  SuccessLbl = hipe_rtl:mk_new_label(),
-  Code =
-    OldCode ++
-    [hipe_rtl:mk_alu(Tmp1, Register, sll, hipe_rtl:mk_imm(ShiftSize)),
-     hipe_rtl:mk_alub(Result, Tmp1, 'add', Result, not_overflow,
-		      hipe_rtl:label_name(SuccessLbl), FalseLblName, 0.99),
-     SuccessLbl],
-  multiply_code(Rest, Register, Result, FalseLblName, Tmp1, Code);
-multiply_code([], _Register, _Result, _FalseLblName, _Tmp1, Code) ->
-  Code.
-
-number2list(X) when is_integer(X), X >= 0 ->
-  number2list(X, []).
-
-number2list(1, Acc) ->
-  lists:reverse([0|Acc]);
-number2list(0, Acc) ->
-  lists:reverse(Acc);
-number2list(X, Acc) ->
-  F = floorlog2(X),
-  number2list(X-(1 bsl F), [F|Acc]).
-
-floorlog2(X) ->
-  round(math:log(X)/math:log(2)-0.5). 
-
-set_high(X) ->
-  WordBits = hipe_rtl_arch:word_size() * ?BYTE_SIZE,
-  set_high(min(X, WordBits), WordBits, 0).
-
-set_high(0, _, Y) ->
-  Y;
-set_high(X, WordBits, Y) ->
-  set_high(X-1, WordBits, Y+(1 bsl (WordBits-X))).
-
 is_illegal_const(Const) ->
   Const >=  1 bsl (hipe_rtl_arch:word_size() * ?BYTE_SIZE) orelse Const < 0.
diff --git a/lib/hipe/rtl/hipe_tagscheme.erl b/lib/hipe/rtl/hipe_tagscheme.erl
index d77078acb6..8825a3ade3 100644
--- a/lib/hipe/rtl/hipe_tagscheme.erl
+++ b/lib/hipe/rtl/hipe_tagscheme.erl
@@ -42,7 +42,7 @@
 	 test_ref/4, test_fun/4, test_fun2/5, test_matchstate/4,
 	 test_binary/4, test_bitstr/4, test_list/4, test_map/4,
 	 test_integer/4, test_number/4, test_tuple_N/5,
-	 test_pos_bignum_arity/5]).
+	 test_pos_bignum_arity/6]).
 -export([realtag_fixnum/2, tag_fixnum/2, realuntag_fixnum/2, untag_fixnum/2]).
 -export([test_two_fixnums/3, test_fixnums/4, unsafe_fixnum_add/3,
 	 unsafe_fixnum_sub/3,
@@ -351,14 +351,23 @@ test_pos_bignum(X, TrueLab, FalseLab, Pred) ->
    mask_and_compare(Tmp, BigMask, ?TAG_HEADER_POS_BIG,
 		    TrueLab, FalseLab, Pred)].
 
-test_pos_bignum_arity(X, Arity, TrueLab, FalseLab, Pred) ->
+test_pos_bignum_arity(X, Arity, TrueLab, NotPosBignumLab, FalseLab, Pred) ->
   Tmp = hipe_rtl:mk_new_reg_gcsafe(),
-  HalfTrueLab = hipe_rtl:mk_new_label(),
+  BoxedLab = hipe_rtl:mk_new_label(),
   HeaderImm = hipe_rtl:mk_imm(mk_header(Arity, ?TAG_HEADER_POS_BIG)),
-  [test_is_boxed(X, hipe_rtl:label_name(HalfTrueLab), FalseLab, Pred),
-   HalfTrueLab,
-   get_header(Tmp, X),
-   hipe_rtl:mk_branch(Tmp, 'eq', HeaderImm, TrueLab, FalseLab, Pred)].
+  [test_is_boxed(X, hipe_rtl:label_name(BoxedLab), NotPosBignumLab, Pred),
+   BoxedLab,
+   get_header(Tmp, X)] ++
+    case NotPosBignumLab =:= FalseLab of
+      true -> [];
+      false ->
+	BignumLab = hipe_rtl:mk_new_label(),
+	BigMask = ?TAG_HEADER_MASK,
+	[mask_and_compare(Tmp, BigMask, ?TAG_HEADER_POS_BIG,
+			  hipe_rtl:label_name(BignumLab), NotPosBignumLab, Pred),
+	 BignumLab]
+    end ++
+    [hipe_rtl:mk_branch(Tmp, 'eq', HeaderImm, TrueLab, FalseLab, Pred)].
 
 test_matchstate(X, TrueLab, FalseLab, Pred) ->
   Tmp = hipe_rtl:mk_new_reg_gcsafe(),