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* [Bug rtl-optimization/97607] New: Spurious sign extension
@ 2020-10-27 23:54 elronnd at elronnd dot net
2020-10-28 9:44 ` [Bug rtl-optimization/97607] " rguenth at gcc dot gnu.org
` (3 more replies)
0 siblings, 4 replies; 5+ messages in thread
From: elronnd at elronnd dot net @ 2020-10-27 23:54 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97607
Bug ID: 97607
Summary: Spurious sign extension
Product: gcc
Version: 11.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: elronnd at elronnd dot net
Target Milestone: ---
The following code
extern void fun(char);
void wrapper(char x) { fun(x); }
Should compile 'wrapper' to a single jump, but instead it does this (on amd64):
wrapper:
movsx edi, dil
jmp fun
Presumably 'x' is getting promoted to int in wrapper, and the promotion never
gets removed.
^ permalink raw reply [flat|nested] 5+ messages in thread* [Bug rtl-optimization/97607] Spurious sign extension 2020-10-27 23:54 [Bug rtl-optimization/97607] New: Spurious sign extension elronnd at elronnd dot net @ 2020-10-28 9:44 ` rguenth at gcc dot gnu.org 2021-03-04 21:03 ` [Bug target/97607] " pinskia at gcc dot gnu.org ` (2 subsequent siblings) 3 siblings, 0 replies; 5+ messages in thread From: rguenth at gcc dot gnu.org @ 2020-10-28 9:44 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97607 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Ever confirmed|0 |1 Target| |x86_64-linux Last reconfirmed| |2020-10-28 Status|UNCONFIRMED |NEW --- Comment #1 from Richard Biener <rguenth at gcc dot gnu.org> --- This is the TARGET_PROMOTE_PROTOTYPES target hook at play, directing the FEs to emit the sign-extension and RTL expansion failing to elide it. Note the x86 ABI does _not_ specify the incoming argument is sign-extended so it only works for functions where all calls are generated by GCC. IMHO TARGET_PROMOTE_PROTOTYPES should go away. ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/97607] Spurious sign extension 2020-10-27 23:54 [Bug rtl-optimization/97607] New: Spurious sign extension elronnd at elronnd dot net 2020-10-28 9:44 ` [Bug rtl-optimization/97607] " rguenth at gcc dot gnu.org @ 2021-03-04 21:03 ` pinskia at gcc dot gnu.org 2021-03-04 21:04 ` pinskia at gcc dot gnu.org 2021-03-04 23:57 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-03-04 21:03 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97607 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |gabravier at gmail dot com --- Comment #2 from Andrew Pinski <pinskia at gcc dot gnu.org> --- *** Bug 95453 has been marked as a duplicate of this bug. *** ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/97607] Spurious sign extension 2020-10-27 23:54 [Bug rtl-optimization/97607] New: Spurious sign extension elronnd at elronnd dot net 2020-10-28 9:44 ` [Bug rtl-optimization/97607] " rguenth at gcc dot gnu.org 2021-03-04 21:03 ` [Bug target/97607] " pinskia at gcc dot gnu.org @ 2021-03-04 21:04 ` pinskia at gcc dot gnu.org 2021-03-04 23:57 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-03-04 21:04 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97607 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |mike.k at digitalcarbide dot com --- Comment #3 from Andrew Pinski <pinskia at gcc dot gnu.org> --- *** Bug 93605 has been marked as a duplicate of this bug. *** ^ permalink raw reply [flat|nested] 5+ messages in thread
* [Bug target/97607] Spurious sign extension 2020-10-27 23:54 [Bug rtl-optimization/97607] New: Spurious sign extension elronnd at elronnd dot net ` (2 preceding siblings ...) 2021-03-04 21:04 ` pinskia at gcc dot gnu.org @ 2021-03-04 23:57 ` pinskia at gcc dot gnu.org 3 siblings, 0 replies; 5+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-03-04 23:57 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=97607 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |jonathan.poelen at gmail dot com --- Comment #4 from Andrew Pinski <pinskia at gcc dot gnu.org> --- *** Bug 99393 has been marked as a duplicate of this bug. *** ^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-03-04 23:57 UTC | newest] Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2020-10-27 23:54 [Bug rtl-optimization/97607] New: Spurious sign extension elronnd at elronnd dot net 2020-10-28 9:44 ` [Bug rtl-optimization/97607] " rguenth at gcc dot gnu.org 2021-03-04 21:03 ` [Bug target/97607] " pinskia at gcc dot gnu.org 2021-03-04 21:04 ` pinskia at gcc dot gnu.org 2021-03-04 23:57 ` pinskia at gcc dot gnu.org
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