Hello!
Attached patch implements reg->reg move cost function for x86, as
required by new lower-subreg.c patch. The patch fixes:
FAIL: gcc.dg/lower-subreg-1.c scan-rtl-dump subreg1 "Splitting reg"
failure on 32bit x86 targets, and for following testcase:
long long test (long long a, long long b)
{
return a * b;
}
reverts generated asm code from:
test:
subl $12, %esp
movl %edi, 8(%esp)
movl 28(%esp), %edi
movl %ebx, (%esp)
movl 16(%esp), %ecx
movl %esi, 4(%esp)
movl 20(%esp), %ebx
movl 24(%esp), %esi
movl %edi, %eax
imull %ecx, %eax
imull %esi, %ebx
addl %eax, %ebx
movl %ecx, %eax
mull %esi
movl 4(%esp), %esi
movl %edx, %edi
addl %ebx, %edi
movl (%esp), %ebx
movl %edi, %edx
movl 8(%esp), %edi
addl $12, %esp
ret
back to:
test:
pushl %ebx
movl 8(%esp), %edx
movl 16(%esp), %eax
movl 12(%esp), %ebx
movl 20(%esp), %ecx
imull %eax, %ebx
imull %edx, %ecx
mull %edx
addl %ebx, %ecx
addl %ecx, %edx
popl %ebx
ret
Patch was tested on x86_64-pc-linux-gnu {,-m32}.
I have also #define LOG_COST 1 temporarily and looked at generated
cost calculations for various -msse* settings.
I will wait for a day for possible comments on the implementation
before the patch will be committed to mainline SVN.
Uros.
