https://gcc.gnu.org/bugzilla/show_bug.cgi?id=87522
Bug ID: 87522
Summary: LTO incorrectly merges target specific 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 lto-test-functions]$ cat a.c
char a[32] = {};
void no_avx (void)
{
__builtin_memset(a, 0, sizeof(a));
}
[hjl@gnu-cfl-1 lto-test-functions]$ cat b.c
char b[32] = {};
void avx (void)
{
__builtin_memset(b, 0, sizeof(b));
}
[hjl@gnu-cfl-1 lto-test-functions]$ cat c.c
char c[32] = {};
void sse_only (void)
{
__builtin_memset(c, 0, sizeof(c));
}
[hjl@gnu-cfl-1 lto-test-functions]$ make
cc -O2 -fPIC -flto -g -mno-avx -c -o a.o a.c
cc -O2 -fPIC -flto -g -mavx -c -o b.o b.c
cc -shared -O2 -fPIC -flto -g -o lib1.so a.o b.o
cc -O2 -fPIC -flto -g -c -o c.o c.c
cc -shared -O2 -fPIC -flto -g -o lib2.so c.o b.o
[hjl@gnu-cfl-1 lto-test-functions]$
0000000000001100 <avx>:
1100: 48 8b 05 d1 2e 00 00 mov 0x2ed1(%rip),%rax # 3fd8
<b@@Base-0x88>
1107: c5 f9 ef c0 vpxor %xmm0,%xmm0,%xmm0
110b: c5 f8 29 00 vmovaps %xmm0,(%rax)
110f: c5 f8 29 40 10 vmovaps %xmm0,0x10(%rax)
1114: c3 retq
1115: 66 66 2e 0f 1f 84 00 00 00 00 00 data16 nopw
%cs:0x0(%rax,%rax,1)
0000000000001120 <no_avx>:
1120: 48 8b 05 c1 2e 00 00 mov 0x2ec1(%rip),%rax # 3fe8
<a@@Base-0x58>
1127: 66 0f ef c0 pxor %xmm0,%xmm0
112b: 0f 29 00 movaps %xmm0,(%rax)
112e: 0f 29 40 10 movaps %xmm0,0x10(%rax)
1132: c3 retq
no_avx has no AVX instructions.
0000000000001100 <avx>:
1100: 48 8b 05 d1 2e 00 00 mov 0x2ed1(%rip),%rax # 3fd8
<b@@Base-0x88>
1107: c5 f9 ef c0 vpxor %xmm0,%xmm0,%xmm0
110b: c5 f8 29 00 vmovaps %xmm0,(%rax)
110f: c5 f8 29 40 10 vmovaps %xmm0,0x10(%rax)
1114: c3 retq
1115: 66 66 2e 0f 1f 84 00 00 00 00 00 data16 nopw
%cs:0x0(%rax,%rax,1)
0000000000001120 <sse_only>:
1120: 48 8b 05 c1 2e 00 00 mov 0x2ec1(%rip),%rax # 3fe8
<c@@Base-0x58>
1127: c5 f9 ef c0 vpxor %xmm0,%xmm0,%xmm0
112b: c5 f8 29 00 vmovaps %xmm0,(%rax)
112f: c5 f8 29 40 10 vmovaps %xmm0,0x10(%rax)
1134: c3 retq
sse_only has AVX instructions.
