http://gcc.gnu.org/bugzilla/show_bug.cgi?id=42494
Arnaud Lacombe <lacombar at gmail dot com> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |lacombar at gmail dot com
--- Comment #13 from Arnaud Lacombe <lacombar at gmail dot com> 2011-05-13
19:26:40 UTC ---
It would seem that GCC 4.5.1 is still generating a call to func(), at -Os.
Considering the following reduced test-case:
extern int outcnt;
void test ()
{
outcnt = 0;
if (outcnt == 1) func ();
if (outcnt == 1) func ();
if (outcnt == 1) func ();
if (outcnt == 1) func ();
if (outcnt == 1) func ();
if (outcnt == 1) func ();
if (outcnt == 1) func ();
if (outcnt == 1) func ();
}
At -O2:
/usr/libexec/gcc/x86_64-redhat-linux/4.5.1/cc1 -O2 -o - test.c
.file "test.c"
test
Analyzing compilation unit
Performing interprocedural optimizations
<*free_lang_data> <visibility> <early_local_cleanups> <whole-program> <cp>
<inline> <static-var> <pure-const>Assembling functions:
test .text
.p2align 4,,15
.globl test
.type test, @function
test:
.LFB0:
.cfi_startproc
movl $0, outcnt(%rip)
ret
.cfi_endproc
.LFE0:
.size test, .-test
.ident "GCC: (GNU) 4.5.1 20100924 (Red Hat 4.5.1-4)"
.section .note.GNU-stack,"",@progbits
Now, at -Os:
/usr/libexec/gcc/x86_64-redhat-linux/4.5.1/cc1 -Os -o - test.c
.file "test.c"
test
Analyzing compilation unit
Performing interprocedural optimizations
<*free_lang_data> <visibility> <early_local_cleanups> <whole-program> <cp>
<inline> <static-var> <pure-const>Assembling functions:
test .text
.globl test
.type test, @function
test:
.LFB0:
.cfi_startproc
movl $0, outcnt(%rip)
cmpl $1, outcnt(%rip)
jne .L1
xorl %eax, %eax
jmp func
.L1:
ret
.cfi_endproc
.LFE0:
.size test, .-test
.ident "GCC: (GNU) 4.5.1 20100924 (Red Hat 4.5.1-4)"
.section .note.GNU-stack,"",@progbits
