https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64164
Bug ID: 64164
Summary: [4.9/5 Regression] one more stack slot used due to one
less inlining level
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: ipa
Assignee: unassigned at gcc dot gnu.org
Reporter: patrick.marlier at gmail dot com
Host: x86_64-linux-gnu
Target: x86_64-linux-gnu
Build: x86_64-linux-gnu
Created attachment 34178
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=34178&action=edit
testcase
$ cc -O2 -S -o stm.s stm.c
$ cc -O2 -DOPT -S -o stm-opt.s stm.c
if you compare the 2 outputs, stm_load function is using one more slot on the
stack.
The difference is only this:
static inline size_t
AO_myload2(const volatile size_t *addr)
{
return *(size_t *)addr;
}
static inline size_t
AO_myload(const volatile size_t *addr)
{
#ifdef OPT
size_t result = AO_myload2(addr);
#else
size_t result = *(size_t *)addr;
#endif
return result;
}
Having one more inlined function should have the same optimization not a better
one.
4.8 does not have the problem and the code generated is the same.
