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* [Bug rtl-optimization/103829] New: [9/10/11/12 Regression] missing shrink wrapping for simple/obvious code
@ 2021-12-25 22:16 pinskia at gcc dot gnu.org
2021-12-25 22:17 ` [Bug rtl-optimization/103829] " pinskia at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-12-25 22:16 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103829
Bug ID: 103829
Summary: [9/10/11/12 Regression] missing shrink wrapping for
simple/obvious code
Product: gcc
Version: 12.0
Status: UNCONFIRMED
Keywords: missed-optimization
Severity: normal
Priority: P3
Component: rtl-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: pinskia at gcc dot gnu.org
Target Milestone: ---
Target: x86_64-linux-gnu aarch64-linux-gnu
Take:
extern int _IO_getc (void *) ;
extern int *__errno_location (void) __attribute__ ((__const__));
void readError ( void );
typedef
struct {
void* handle;
int buffer;
int buffLive;
char mode;
}
BitStream;
int bsGetBit ( BitStream* bs )
{
if (bs->buffLive > 0) {
bs->buffLive --;
return ( ((bs->buffer) >> (bs->buffLive)) & 0x1 );
} else {
int retVal = _IO_getc (bs->handle);
if ( retVal == (-1) ) {
if ((*__errno_location ()) != 0) readError();
return 2;
}
bs->buffLive = 7;
bs->buffer = retVal;
return ( ((bs->buffer) >> 7) & 0x1 );
}
}
----- CUT ----
GCC 4.9.0-8.5.0 was able to shrink wrap the above function.
But starting in GCC 9, GCC does not; there is an extra mov using a callee saved
register.
This happens on both aarch64 and x86_64 So I suspect it was a generic change
which caused it.
^ permalink raw reply [flat|nested] 6+ messages in thread* [Bug rtl-optimization/103829] [9/10/11/12 Regression] missing shrink wrapping for simple/obvious code 2021-12-25 22:16 [Bug rtl-optimization/103829] New: [9/10/11/12 Regression] missing shrink wrapping for simple/obvious code pinskia at gcc dot gnu.org @ 2021-12-25 22:17 ` pinskia at gcc dot gnu.org 2022-05-27 9:47 ` [Bug rtl-optimization/103829] [10/11/12/13 " rguenth at gcc dot gnu.org ` (3 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: pinskia at gcc dot gnu.org @ 2021-12-25 22:17 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103829 Andrew Pinski <pinskia at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Known to fail| |9.1.0 Known to work| |8.5.0 See Also| |https://gcc.gnu.org/bugzill | |a/show_bug.cgi?id=87902 Target Milestone|--- |9.5 --- Comment #1 from Andrew Pinski <pinskia at gcc dot gnu.org> --- Might be similar to PR 87902 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug rtl-optimization/103829] [10/11/12/13 Regression] missing shrink wrapping for simple/obvious code 2021-12-25 22:16 [Bug rtl-optimization/103829] New: [9/10/11/12 Regression] missing shrink wrapping for simple/obvious code pinskia at gcc dot gnu.org 2021-12-25 22:17 ` [Bug rtl-optimization/103829] " pinskia at gcc dot gnu.org @ 2022-05-27 9:47 ` rguenth at gcc dot gnu.org 2022-06-28 10:47 ` jakub at gcc dot gnu.org ` (2 subsequent siblings) 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu.org @ 2022-05-27 9:47 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103829 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|9.5 |10.4 --- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> --- GCC 9 branch is being closed ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug rtl-optimization/103829] [10/11/12/13 Regression] missing shrink wrapping for simple/obvious code 2021-12-25 22:16 [Bug rtl-optimization/103829] New: [9/10/11/12 Regression] missing shrink wrapping for simple/obvious code pinskia at gcc dot gnu.org 2021-12-25 22:17 ` [Bug rtl-optimization/103829] " pinskia at gcc dot gnu.org 2022-05-27 9:47 ` [Bug rtl-optimization/103829] [10/11/12/13 " rguenth at gcc dot gnu.org @ 2022-06-28 10:47 ` jakub at gcc dot gnu.org 2023-04-14 4:53 ` law at gcc dot gnu.org 2023-07-07 10:41 ` [Bug rtl-optimization/103829] [11/12/13/14 " rguenth at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: jakub at gcc dot gnu.org @ 2022-06-28 10:47 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103829 Jakub Jelinek <jakub at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|10.4 |10.5 --- Comment #3 from Jakub Jelinek <jakub at gcc dot gnu.org> --- GCC 10.4 is being released, retargeting bugs to GCC 10.5. ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug rtl-optimization/103829] [10/11/12/13 Regression] missing shrink wrapping for simple/obvious code 2021-12-25 22:16 [Bug rtl-optimization/103829] New: [9/10/11/12 Regression] missing shrink wrapping for simple/obvious code pinskia at gcc dot gnu.org ` (2 preceding siblings ...) 2022-06-28 10:47 ` jakub at gcc dot gnu.org @ 2023-04-14 4:53 ` law at gcc dot gnu.org 2023-07-07 10:41 ` [Bug rtl-optimization/103829] [11/12/13/14 " rguenth at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: law at gcc dot gnu.org @ 2023-04-14 4:53 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103829 Jeffrey A. Law <law at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- CC| |law at gcc dot gnu.org Priority|P3 |P2 ^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug rtl-optimization/103829] [11/12/13/14 Regression] missing shrink wrapping for simple/obvious code 2021-12-25 22:16 [Bug rtl-optimization/103829] New: [9/10/11/12 Regression] missing shrink wrapping for simple/obvious code pinskia at gcc dot gnu.org ` (3 preceding siblings ...) 2023-04-14 4:53 ` law at gcc dot gnu.org @ 2023-07-07 10:41 ` rguenth at gcc dot gnu.org 4 siblings, 0 replies; 6+ messages in thread From: rguenth at gcc dot gnu.org @ 2023-07-07 10:41 UTC (permalink / raw) To: gcc-bugs https://gcc.gnu.org/bugzilla/show_bug.cgi?id=103829 Richard Biener <rguenth at gcc dot gnu.org> changed: What |Removed |Added ---------------------------------------------------------------------------- Target Milestone|10.5 |11.5 --- Comment #4 from Richard Biener <rguenth at gcc dot gnu.org> --- GCC 10 branch is being closed. ^ permalink raw reply [flat|nested] 6+ messages in thread
end of thread, other threads:[~2023-07-07 10:41 UTC | newest] Thread overview: 6+ messages (download: mbox.gz / follow: Atom feed) -- links below jump to the message on this page -- 2021-12-25 22:16 [Bug rtl-optimization/103829] New: [9/10/11/12 Regression] missing shrink wrapping for simple/obvious code pinskia at gcc dot gnu.org 2021-12-25 22:17 ` [Bug rtl-optimization/103829] " pinskia at gcc dot gnu.org 2022-05-27 9:47 ` [Bug rtl-optimization/103829] [10/11/12/13 " rguenth at gcc dot gnu.org 2022-06-28 10:47 ` jakub at gcc dot gnu.org 2023-04-14 4:53 ` law at gcc dot gnu.org 2023-07-07 10:41 ` [Bug rtl-optimization/103829] [11/12/13/14 " rguenth at gcc dot gnu.org
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