https://gcc.gnu.org/bugzilla/show_bug.cgi?id=88250
Bug ID: 88250
Summary: -flto doesn't preserve -Wa options
Product: gcc
Version: 9.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: lto
Assignee: unassigned at gcc dot gnu.org
Reporter: hjl.tools at gmail dot com
CC: marxin at gcc dot gnu.org
Target Milestone: ---
[hjl@gnu-cfl-1 pr23929]$ cat y.c
float
foo (float x, float y)
{
return y;
}
[hjl@gnu-cfl-1 pr23929]$ gcc -c y.c -Wa,-msse2avx
[hjl@gnu-cfl-1 pr23929]$ gcc -shared y.o
[hjl@gnu-cfl-1 pr23929]$ objdump --disassemble=foo a.out
a.out: file format elf64-x86-64
Disassembly of section .init:
Disassembly of section .plt:
Disassembly of section .plt.got:
Disassembly of section .text:
00000000000010f9 <foo>:
10f9: 55 push %rbp
10fa: 48 89 e5 mov %rsp,%rbp
10fd: c5 fa 11 45 fc vmovss %xmm0,-0x4(%rbp)
1102: c5 fa 11 4d f8 vmovss %xmm1,-0x8(%rbp)
1107: c5 fa 10 45 f8 vmovss -0x8(%rbp),%xmm0
110c: 5d pop %rbp
110d: c3 retq
Disassembly of section .fini:
[hjl@gnu-cfl-1 pr23929]$ gcc -c y.c -Wa,-msse2avx -flto
[hjl@gnu-cfl-1 pr23929]$ gcc -shared y.o -Wa,-msse2avx
[hjl@gnu-cfl-1 pr23929]$ objdump --disassemble=foo a.out
a.out: file format elf64-x86-64
Disassembly of section .init:
Disassembly of section .plt:
Disassembly of section .plt.got:
Disassembly of section .text:
00000000000010f9 <foo>:
10f9: 55 push %rbp
10fa: 48 89 e5 mov %rsp,%rbp
10fd: f3 0f 11 45 fc movss %xmm0,-0x4(%rbp)
1102: f3 0f 11 4d f8 movss %xmm1,-0x8(%rbp)
1107: f3 0f 10 45 f8 movss -0x8(%rbp),%xmm0
110c: 5d pop %rbp
110d: c3 retq
Disassembly of section .fini:
[hjl@gnu-cfl-1 pr23929]$
-msse2avx is never passed to assembler with -flto.
