https://gcc.gnu.org/bugzilla/show_bug.cgi?id=67841
--- Comment #5 from H.J. Lu <hjl.tools at gmail dot com> ---
I updated hjl/interrupt/calls branch to update stack boundary for
use of SSE registers. Now I got
[hjl@gnu-tools-1 interrupt-1]$ cat x.i
void
__attribute__((no_caller_saved_registers))
fn (void)
{
asm ("#"
:
:
: "xmm3");
}
[hjl@gnu-tools-1 interrupt-1]$ make x.s
/export/build/gnu/gcc/build-x86_64-linux/gcc/xgcc
-B/export/build/gnu/gcc/build-x86_64-linux/gcc/ -O2 -m32
-mincoming-stack-boundary=2 -maccumulate-outgoing-args -S x.i
[hjl@gnu-tools-1 interrupt-1]$ cat x.s
.file "x.i"
.text
.p2align 4,,15
.globl fn
.type fn, @function
fn:
.LFB0:
.cfi_startproc
pushl %ebp
.cfi_def_cfa_offset 8
.cfi_offset 5, -8
movl %esp, %ebp
.cfi_def_cfa_register 5
subl $136, %esp
andl $-16, %esp
movups %xmm3, -136(%ebp)
.cfi_offset 24, -144
#APP
# 5 "x.i" 1
#
# 0 "" 2
#NO_APP
movups -136(%ebp), %xmm3
leave
.cfi_restore 5
.cfi_restore 24
.cfi_def_cfa 4, 4
ret
.cfi_endproc
.LFE0:
.size fn, .-fn
.ident "GCC: (GNU) 6.0.0 20151002 (experimental)"
.section .note.GNU-stack,"",@progbits
[hjl@gnu-tools-1 interrupt-1]$
But is incompatible how registers are saved in prologue
which uses the original stack before realignment to save
registers. To use aligned load/store to save vector
registers in prologue requires significant changes.
