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* i386: Somewhat optimized fpc_mul_qword routine, got rid from variable 'r', registers esi and edi. Also ignore overflow checking when both operands have their high dwords equal to zero, because in such case multiplication cannot overflow.

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git-svn-id: trunk@26511 -
This commit is contained in:
sergei 2014-01-18 19:28:00 +00:00
parent e6a9f3b15b
commit 78e726b34f
1 changed files with 18 additions and 38 deletions
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56
rtl/i386/int64p.inc
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@ -170,7 +170,6 @@
} }
function fpc_mul_qword(f1,f2 : qword;checkoverflow : longbool) : qword;[public,alias: 'FPC_MUL_QWORD']; compilerproc; function fpc_mul_qword(f1,f2 : qword;checkoverflow : longbool) : qword;[public,alias: 'FPC_MUL_QWORD']; compilerproc;
var var
r : qword;
overflowed : boolean; overflowed : boolean;
begin begin
overflowed:=false; overflowed:=false;
@ -179,77 +178,58 @@
asm asm
movl f1+4,%edx movl f1+4,%edx
movl f2+4,%ecx movl f2+4,%ecx
cmpl $0,checkoverflow
jnz .Loverflowchecked
orl %ecx,%edx orl %ecx,%edx
movl f2,%edx movl f2,%edx
movl f1,%eax movl f1,%eax
jnz .Lqwordmultwomul jnz .Lqwordmultwomul
{ if both upper dwords are =0 then it cannot overflow }
mull %edx mull %edx
jmp .Lqwordmulready jmp .Lqwordmulready
.Lqwordmultwomul: .Lqwordmultwomul:
cmpl $0,checkoverflow
jnz .Loverflowchecked
imul f1+4,%edx imul f1+4,%edx
imul %eax,%ecx imul %eax,%ecx
addl %edx,%ecx addl %edx,%ecx
mull f2 mull f2
add %ecx,%edx add %ecx,%edx
.Lqwordmulready: .Lqwordmulready:
movl %eax,r movl %eax,__RESULT
movl %edx,r+4 movl %edx,__RESULT+4
jmp .Lend jmp .Lend
.Loverflowchecked: .Loverflowchecked:
{ if both upper dwords are <>0 then it overflows always } { if both upper dwords are <>0 then it overflows always }
or %ecx,%ecx or %ecx,%ecx
jz .Loverok1 jz .Loverok1
or %edx,%edx cmpl $0,f1+4
jnz .Loverflowed jnz .Loverflowed
.Loverok1: .Loverok1:
{ overflow checked code } { overflow checked code }
orl %ecx,%edx
movl f2,%edi
movl f1,%esi
jnz .Lqwordmultwomul2
movl %edi,%eax
mull %esi
movl %eax,%esi
movl %edx,%edi
jmp .Lqwordmulready2
.Lqwordmultwomul2:
movl f1+4,%eax movl f1+4,%eax
mull %edi mull f2
movl %eax,%edi
jc .Loverflowed
movl %esi,%eax
mull %ecx
movl %eax,%ecx movl %eax,%ecx
jc .Loverflowed jc .Loverflowed
addl %edi,%ecx movl f1,%eax
mull f2+4
jc .Loverflowed
addl %eax,%ecx
jc .Loverflowed jc .Loverflowed
movl f2,%eax movl f2,%eax
mull %esi mull f1
movl %eax,%esi addl %ecx,%edx
movl %edx,%edi movl %eax,__RESULT
movl %edx,__RESULT+4
addl %ecx,%edi jnc .Lend
jc .Loverflowed
.Lqwordmulready2:
movl %esi,r
movl %edi,r+4
jmp .Lend
.Loverflowed: .Loverflowed:
movb $1,overflowed movb $1,overflowed
.Lend: .Lend:
end [ 'eax','edx','ecx','edi','esi' ]; end [ 'eax','edx','ecx'];
fpc_mul_qword:=r;
if overflowed then if overflowed then
HandleErrorFrame(215,get_frame); HandleErrorFrame(215,get_frame);