https://gcc.gnu.org/bugzilla/show_bug.cgi?id=90289
Bug ID: 90289
Summary: an unnecessary relocation record
Product: gcc
Version: 4.6.3
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: chen...@agile-china.com
Target Milestone: ---
In the below code. Is it an unnecessary relocation record for function 'f()'?
Is it better to fill "F3 FF FF FF" in CALL instruction directly?
* uname -a
Linux ubuntu 3.13.0-32-generic #57~precise1-Ubuntu SMP Tue Jul 15 03:50:54
UTC 2014 i686 i686 i386 GNU/Linux
* gcc --version
gcc (Ubuntu/Linaro 4.6.3-1ubuntu5) 4.6.3
* cat test.c
void f() {}
void fun()
{
f();
}
* gcc -c f.c -g -Wall
* objdump -S f.o
00000000 <f>:
void f() {}
0: 55 push %ebp
1: 89 e5 mov %esp,%ebp
3: 5d pop %ebp
4: c3 ret
00000005 <fun>:
void fun()
{
5: 55 push %ebp
6: 89 e5 mov %esp,%ebp
f();
8: e8 fc ff ff ff call 9 <fun+0x4>
}
* objdump -r f.o
00000009 R_386_PC32 f
* gcc -shared f.o -o libf.so
* objdump -S libf.so
0000042c <f>:
void f() {}
42c: 55 push %ebp
42d: 89 e5 mov %esp,%ebp
42f: 5d pop %ebp
430: c3 ret
00000431 <fun>:
void fun()
{
431: 55 push %ebp
432: 89 e5 mov %esp,%ebp
f();
434: e8 fc ff ff ff call 435 <fun+0x4>
}
* objdump -R libf.so
00000435 R_386_PC32 f
