https://gcc.gnu.org/bugzilla/show_bug.cgi?id=70064
Uroš Bizjak <ubizjak at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |hjl.tools at gmail dot com
--- Comment #2 from Uroš Bizjak <ubizjak at gmail dot com> ---
Hohum, the problem here is where following asm part is positioned:
call __x86.get_pc_thunk.bx # 263 set_got [length = 12]
addl $_GLOBAL_OFFSET_TABLE_, %ebx
If these two insns are positioned as in the attached assembly, we get:
$ gcc -m32 pr70064.s
$ ./a.out
0000318f9e133088
Aborted (core dumped)
But moving insns to the beginning of the assembly, like:
--- pr70064.s 2016-03-03 22:57:32.576740271 +0100
+++ pr70064_.s 2016-03-03 23:20:27.579594191 +0100
@@ -18,6 +18,8 @@
pushl %ebx # 623 *pushsi2 [length = 1]
.cfi_def_cfa_offset 20
.cfi_offset 3, -20
+ call __x86.get_pc_thunk.bx # 263 set_got [length = 12]
+ addl $_GLOBAL_OFFSET_TABLE_, %ebx
subl $340, %esp # 624 pro_epilogue_adjust_stack_si_add/1
.cfi_def_cfa_offset 360
movl 364(%esp), %eax # 4 *movsi_internal/1 [length = 7]
@@ -48,8 +50,6 @@
movl 384(%esp), %ecx # 639 *movsi_internal/1 [length = 7]
movl %edi, -56(%esp) # 282 *movsi_internal/2 [length = 4]
movl 388(%esp), %edi # 460 *movsi_internal/1 [length = 7]
- call __x86.get_pc_thunk.bx # 263 set_got [length = 12]
- addl $_GLOBAL_OFFSET_TABLE_, %ebx
negl %esi # 461 *negsi2_cmpz [length = 2]
adcl $0, %edi # 462 addsi3_carry/1 [length = 3]
negl %edi # 463 *negsi2_1 [length = 2]
the test passes:
$ gcc -m32 pr70064_.s
$ ./a.out
0000318f9e1392ce
I have checked that neither ebx is clobbered, nor flags chain is broken by the
above two insns, so I really fail to see where and if compiler is at fault.
Binutils bug maybe?
