On Thu, May 21, 2015 at 12:06 PM, Richard Henderson <r...@redhat.com> wrote:
> On 05/21/2015 12:01 PM, H.J. Lu wrote:
>> +++ b/gcc/testsuite/gcc.target/i386/pr66232-1.c
>> @@ -0,0 +1,13 @@
>> +/* { dg-do compile { target *-*-linux* } } */
>> +/* { dg-options "-O2 -fpic -fno-plt" } */
>> +
>> +extern void bar (void);
>> +
>> +void
>> +foo (void)
>> +{
>> + bar ();
>> +}
>> +
>> +/* { dg-final { scan-assembler "jmp\[ \t\]*.bar@GOTPCREL" { target { ! ia32
>> } } } } */
>> +/* { dg-final { scan-assembler "call\[ \t\]*.bar@GOT\\(" { target ia32 } }
>> } */
>
> Do you really want to check for no tail call for ia32 here?
> That's really just a missed optimization, surely.
>
>
I'd like to keep it. When it is fixed, we can update it. I tried:
https://gcc.gnu.org/ml/gcc-patches/2015-05/msg00230.html
and got
call __x86.get_pc_thunk.ax
addl $_GLOBAL_OFFSET_TABLE_, %eax
subl $28, %esp
.cfi_def_cfa_offset 32
movl bar@GOT(%eax), %eax
movl %eax, 12(%esp)
addl $28, %esp
.cfi_def_cfa_offset 4
jmp *%eax
This is very odd code, comparing against
call __x86.get_pc_thunk.ax
addl $_GLOBAL_OFFSET_TABLE_, %eax
subl $12, %esp
.cfi_def_cfa_offset 16
call *bar@GOT(%eax)
addl $12, %esp
.cfi_def_cfa_offset 4
ret
--
H.J.
