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* improved fillchar for small amounts of data

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git-svn-id: trunk@17644 -
This commit is contained in:
florian 2011-06-02 20:54:29 +00:00
parent 7173b9dfed
commit ceb739fbf5
1 changed files with 16 additions and 25 deletions
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39
rtl/i386/i386.inc
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@ -204,32 +204,27 @@ end;
{$ifndef FPC_SYSTEM_HAS_FILLCHAR} {$ifndef FPC_SYSTEM_HAS_FILLCHAR}
{$define FPC_SYSTEM_HAS_FILLCHAR} {$define FPC_SYSTEM_HAS_FILLCHAR}
Procedure FillChar(var x;count:SizeInt;value:byte);assembler; Procedure FillChar(var x;count:SizeInt;value:byte);assembler; nostackframe;
{$ifndef regcall}
var
saveedi: longint;
{$endif}
asm asm
{A push is prefered over a local variable because a local cmpl $22,%edx { empirically determined value on a Core 2 Duo Conroe }
variable causes the compiler to generate a stackframe.} jg .LFillFull
orl %edx,%edx
jle .LFillZero
.LFillLoop:
movb %cl,(%eax)
incl %eax
decl %edx
jne .LFillLoop
.LFillZero:
ret
.LFillFull:
cld cld
{$ifdef REGCALL}
push %edi push %edi
movl %eax,%edi movl %eax,%edi
movzbl %cl,%eax movzbl %cl,%eax
movl %edx,%ecx movl %edx,%ecx
{$else}
movl %edi, saveedi
movl x,%edi
movl count,%ecx
movzbl value,%eax
movl %ecx,%edx
{$endif}
{ check for zero or negative count }
or %ecx,%ecx
jle .LFillEnd
cmpl $7,%ecx
jl .LFill1
imul $0x01010101,%eax { Expand al into a 4 subbytes of eax} imul $0x01010101,%eax { Expand al into a 4 subbytes of eax}
shrl $2,%ecx shrl $2,%ecx
andl $3,%edx andl $3,%edx
@ -240,11 +235,7 @@ asm
rep rep
stosb stosb
.LFillEnd: .LFillEnd:
{$ifdef REGCALL}
pop %edi pop %edi
{$else}
movl saveedi,%edi
{$endif}
end; end;
{$endif FPC_SYSTEM_HAS_FILLCHAR} {$endif FPC_SYSTEM_HAS_FILLCHAR}