https://gcc.gnu.org/bugzilla/show_bug.cgi?id=69519
Bug ID: 69519
Summary: STV doesn't use xmm register for DImove move
Product: gcc
Version: 6.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
CC: ienkovich at gcc dot gnu.org
Target Milestone: ---
Target: i686
[hjl@gnu-6 gcc]$ cat x.i
long long a, b;
extern void fn2 (void);
void
fn1 (void)
{
long long c = a;
a = b ^ a;
fn2 ();
a = c;
}
[hjl@gnu-6 gcc]$ ./xgcc -B./ -S -O2 x.i -m32 -msse2
[hjl@gnu-6 gcc]$ cat x.s
.file "x.i"
.text
.p2align 4,,15
.globl fn1
.type fn1, @function
fn1:
.LFB0:
.cfi_startproc
subl $28, %esp
.cfi_def_cfa_offset 32
movl a, %eax
movl a+4, %edx
movq b, %xmm0
movl %eax, (%esp)
movl %edx, 4(%esp)
movdqa (%esp), %xmm2
I am expecting xmm register is used to move `a' onto stack.
pxor %xmm2, %xmm0
movq %xmm0, a
call fn2
movq (%esp), %xmm1
movq %xmm1, a
addl $28, %esp
.cfi_def_cfa_offset 4
ret
.cfi_endproc
.LFE0:
.size fn1, .-fn1
.comm b,8,8
.comm a,8,8
.ident "GCC: (GNU) 6.0.0 20160126 (experimental)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-6 gcc]$
