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* [Bug middle-end/64621] New: MIssed tail call oppurtunity
@ 2015-01-16 1:26 hubicka at gcc dot gnu.org
2015-01-16 9:12 ` [Bug middle-end/64621] " rguenth at gcc dot gnu.org
2015-01-16 18:10 ` pinskia at gcc dot gnu.org
0 siblings, 2 replies; 3+ messages in thread
From: hubicka at gcc dot gnu.org @ 2015-01-16 1:26 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64621
Bug ID: 64621
Summary: MIssed tail call oppurtunity
Product: gcc
Version: 5.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: middle-end
Assignee: unassigned at gcc dot gnu.org
Reporter: hubicka at gcc dot gnu.org
Compiling the following at x86_64:
extern long int strtol (__const char *__restrict __nptr,
char **__restrict __endptr, int __base)
__attribute__ ((__nothrow__)) __attribute__ ((__nonnull__ (1))) ;
extern __inline int
__attribute__ ((__nothrow__)) atoi (__const char *__nptr)
{
return (int) strtol (__nptr, (char **) ((void *)0), 10);
}
will not produce tailcall even though it is perfectly possible because of the
extra (int) conversion that is noop and could be ignored.
^ permalink raw reply [flat|nested] 3+ messages in thread* [Bug middle-end/64621] MIssed tail call oppurtunity 2015-01-16 1:26 [Bug middle-end/64621] New: MIssed tail call oppurtunity hubicka at gcc dot gnu.org @ 2015-01-16 9:12 ` rguenth at gcc dot gnu.org 2015-01-16 18:10 ` pinskia at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: rguenth at gcc dot gnu.org @ 2015-01-16 9:12 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64621 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Status|UNCONFIRMED |RESOLVED Resolution|--- |INVALID --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- Well, this really really asks for the function signatures to be updated to the call ABI at the GIMPLE level... OTOH, (int) strtol (...) possibly truncates the value so it's not a noop (it's a noop on i?86 only). ^ permalink raw reply [flat|nested] 3+ messages in thread
* [Bug middle-end/64621] MIssed tail call oppurtunity 2015-01-16 1:26 [Bug middle-end/64621] New: MIssed tail call oppurtunity hubicka at gcc dot gnu.org 2015-01-16 9:12 ` [Bug middle-end/64621] " rguenth at gcc dot gnu.org @ 2015-01-16 18:10 ` pinskia at gcc dot gnu.org 1 sibling, 0 replies; 3+ messages in thread From: pinskia at gcc dot gnu.org @ 2015-01-16 18:10 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=64621 --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- (In reply to Richard Biener from comment #1) > Well, this really really asks for the function signatures to be updated to > the > call ABI at the GIMPLE level... > > OTOH, (int) strtol (...) possibly truncates the value so it's not a noop > (it's a noop on i?86 only). Actually it is a NOP on targets which define the upper bits of the register being undefined when returning. That includes x86_64 and aarch64. Thanks, Andrew Pinski ^ permalink raw reply [flat|nested] 3+ messages in thread
end of thread, other threads:[~2015-01-16 18:10 UTC | newest] Thread overview: 3+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2015-01-16 1:26 [Bug middle-end/64621] New: MIssed tail call oppurtunity hubicka at gcc dot gnu.org 2015-01-16 9:12 ` [Bug middle-end/64621] " rguenth at gcc dot gnu.org 2015-01-16 18:10 ` pinskia at gcc dot gnu.org
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