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* regvars are now zeroed at the start of their life if they contain an 8

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or 16bit var/parameter, because the full 32bits are used if they are
    necessary for a btrl instruction
This commit is contained in:
Jonas Maebe 2000-09-30 13:08:16 +00:00
parent bec76ee738
commit b8388b3143
1 changed files with 50 additions and 5 deletions
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55
compiler/regvars.pas
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@ -307,6 +307,11 @@ implementation
i: longint;
hr : preference;
regvarinfo: pregvarinfo;
{$ifdef i386}
opsize: topsize;
opcode: tasmop;
signed: boolean;
{$endif i386}
begin
if (cs_regalloc in aktglobalswitches) and
((procinfo^.flags and (pi_uses_asm or pi_uses_exceptions))=0) then
@ -332,14 +337,41 @@ implementation
hr^.offset:=pvarsym(regvarinfo^.regvars[i])^.address+procinfo^.para_offset;
hr^.base:=procinfo^.framepointer;
{$ifdef i386}
asml^.concat(new(paicpu,op_ref_reg(A_MOV,regsize(regvarinfo^.regvars[i]^.reg),
hr,regvarinfo^.regvars[i]^.reg)));
{ zero the regvars because the upper 48bits must be clear }
{ for 8bits vars when using them with btrl (JM) }
signed :=
(pvarsym(regvarinfo^.regvars[i])^.vartype.def^.deftype =
orddef) and
is_signed(pvarsym(regvarinfo^.regvars[i])^.vartype.def);
case regsize(regvarinfo^.regvars[i]^.reg) of
S_L:
begin
opsize := S_L;
opcode := A_MOV;
end;
S_W:
begin
opsize := S_WL;
if signed then
opcode := A_MOVSX
else opcode := A_MOVZX;
end;
S_B:
begin
opsize := S_BL;
if signed then
opcode := A_MOVSX
else opcode := A_MOVZX;
end;
end;
asml^.concat(new(paicpu,op_ref_reg(opcode,opsize,
hr,reg32(regvarinfo^.regvars[i]^.reg))));
{$endif i386}
{$ifdef m68k}
asml^.concat(new(paicpu,op_ref_reg(A_MOVE,regsize(regvarinfo^.regvars[i]^.reg),
hr,regvarinfo^.regvars[i]^.reg)));
{$endif m68k}
end;
end
end;
for i:=1 to maxvarregs do
begin
@ -347,7 +379,15 @@ implementation
begin
{$ifdef i386}
if not(regvarinfo^.regvars_para[i]) then
asml^.concat(new(pairegalloc,alloc(reg32(regvarinfo^.regvars[i]^.reg))));
begin
asml^.concat(new(pairegalloc,alloc(reg32(regvarinfo^.regvars[i]^.reg))));
{ zero the regvars because the upper 48bits must be clear }
{ for 8bits vars when using them with btrl (JM) }
if (regsize(regvarinfo^.regvars[i]^.reg) in [S_B,S_W]) then
asml^.concat(new(paicpu,op_reg_reg(A_XOR,S_L,
reg32(regvarinfo^.regvars[i]^.reg),
reg32(regvarinfo^.regvars[i]^.reg))));
end;
{$endif i386}
if cs_asm_source in aktglobalswitches then
asml^.insert(new(pai_asm_comment,init(strpnew(regvarinfo^.regvars[i]^.name+
@ -441,7 +481,12 @@ end.
{
$Log$
Revision 1.6 2000-09-24 15:06:27 peter
Revision 1.7 2000-09-30 13:08:16 jonas
* regvars are now zeroed at the start of their life if they contain an 8
or 16bit var/parameter, because the full 32bits are used if they are
necessary for a btrl instruction
Revision 1.6 2000/09/24 15:06:27 peter
* use defines.inc
Revision 1.5 2000/08/27 16:11:52 peter