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* [Bug target/63354] New: -pg -mprofile-kernel creates unused stack frames on leaf functions on ppc64le
@ 2014-09-24 6:52 anton at samba dot org
2014-09-24 14:31 ` [Bug target/63354] gcc " segher at gcc dot gnu.org
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: anton at samba dot org @ 2014-09-24 6:52 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63354
Bug ID: 63354
Summary: -pg -mprofile-kernel creates unused stack frames on
leaf functions on ppc64le
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: anton at samba dot org
The following testcase:
int foo(void)
{
return 1;
}
compiled with:
gcc -O2 -pg -mprofile-kernel -S foo.c
produces an unused stack frame:
foo:
mflr 0
std 0,16(1)
bl _mcount
mflr 0
li 3,1
std 0,16(1)
stdu 1,-32(1)
addi 1,1,32
ori 2,2,0
ld 0,16(1)
mtlr 0
blr
Note that older gcc versions allowed -mprofile-kernel to used on its own. While
there are issues with that (eg ignoring attribute no_instrument_function), it
does show the expected behaviour:
gcc -O2 -mprofile-kernel -S foo.c
foo:
mflr 0
std 0,16(1)
bl _mcount
li 3,1
blr
So it seems to be something to do with -pg.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/63354] gcc -pg -mprofile-kernel creates unused stack frames on leaf functions on ppc64le
2014-09-24 6:52 [Bug target/63354] New: -pg -mprofile-kernel creates unused stack frames on leaf functions on ppc64le anton at samba dot org
@ 2014-09-24 14:31 ` segher at gcc dot gnu.org
2014-09-25 1:45 ` anton at samba dot org
2015-03-10 2:36 ` msebor at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: segher at gcc dot gnu.org @ 2014-09-24 14:31 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63354
Segher Boessenkool <segher at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target|powerpc64le-linux |powerpc*-*-*
Status|UNCONFIRMED |NEW
Last reconfirmed| |2014-09-24
CC| |segher at gcc dot gnu.org
Ever confirmed|0 |1
--- Comment #1 from Segher Boessenkool <segher at gcc dot gnu.org> ---
Confirmed. We need
#define TARGET_KEEP_LEAF_WHEN_PROFILED hook_bool_void_true
to have it behave as you want.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/63354] gcc -pg -mprofile-kernel creates unused stack frames on leaf functions on ppc64le
2014-09-24 6:52 [Bug target/63354] New: -pg -mprofile-kernel creates unused stack frames on leaf functions on ppc64le anton at samba dot org
2014-09-24 14:31 ` [Bug target/63354] gcc " segher at gcc dot gnu.org
@ 2014-09-25 1:45 ` anton at samba dot org
2015-03-10 2:36 ` msebor at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: anton at samba dot org @ 2014-09-25 1:45 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63354
--- Comment #2 from Anton Blanchard <anton at samba dot org> ---
Created attachment 33555
--> https://gcc.gnu.org/bugzilla/attachment.cgi?id=33555&action=edit
Avoid an unused stack frame for -mprofile-kernel profiling on leaf functions.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug target/63354] gcc -pg -mprofile-kernel creates unused stack frames on leaf functions on ppc64le
2014-09-24 6:52 [Bug target/63354] New: -pg -mprofile-kernel creates unused stack frames on leaf functions on ppc64le anton at samba dot org
2014-09-24 14:31 ` [Bug target/63354] gcc " segher at gcc dot gnu.org
2014-09-25 1:45 ` anton at samba dot org
@ 2015-03-10 2:36 ` msebor at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: msebor at gcc dot gnu.org @ 2015-03-10 2:36 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63354
Martin Sebor <msebor at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
CC| |msebor at gcc dot gnu.org
--- Comment #3 from Martin Sebor <msebor at gcc dot gnu.org> ---
The attached patch still fixes the problem. Anton, would you like to submit
the patch to gcc-patches?
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2015-03-10 2:36 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2014-09-24 6:52 [Bug target/63354] New: -pg -mprofile-kernel creates unused stack frames on leaf functions on ppc64le anton at samba dot org
2014-09-24 14:31 ` [Bug target/63354] gcc " segher at gcc dot gnu.org
2014-09-25 1:45 ` anton at samba dot org
2015-03-10 2:36 ` msebor at gcc dot gnu.org
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