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* [Bug tree-optimization/96336] New: Multiple multiplications fails to optimize
@ 2020-07-27 15:14 fazedo at gmail dot com
2020-07-27 15:20 ` [Bug tree-optimization/96336] " fazedo at gmail dot com
` (2 more replies)
0 siblings, 3 replies; 4+ messages in thread
From: fazedo at gmail dot com @ 2020-07-27 15:14 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96336
Bug ID: 96336
Summary: Multiple multiplications fails to optimize
Product: gcc
Version: 9.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: tree-optimization
Assignee: unassigned at gcc dot gnu.org
Reporter: fazedo at gmail dot com
Target Milestone: ---
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/96336] Multiple multiplications fails to optimize
2020-07-27 15:14 [Bug tree-optimization/96336] New: Multiple multiplications fails to optimize fazedo at gmail dot com
@ 2020-07-27 15:20 ` fazedo at gmail dot com
2020-07-28 5:59 ` [Bug tree-optimization/96336] Multiple multiplications fail " rguenth at gcc dot gnu.org
2021-08-03 23:30 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: fazedo at gmail dot com @ 2020-07-27 15:20 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96336
--- Comment #1 from Fabio Azevedo <fazedo at gmail dot com> ---
int f(int x) {
return x*x*x*x*x*x*x*x*x*x*x*x*x*x*x*x; //x**16
}
int g(int x) {
return x*x*x*x*x*x*x*x*x*x*x*x*x*x*x*x + x*x; //x**16 + x**2
}
Using gcc -O3, the first function simplifies to 4 integer multiplications while
the second function requires 13.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/96336] Multiple multiplications fail to optimize
2020-07-27 15:14 [Bug tree-optimization/96336] New: Multiple multiplications fails to optimize fazedo at gmail dot com
2020-07-27 15:20 ` [Bug tree-optimization/96336] " fazedo at gmail dot com
@ 2020-07-28 5:59 ` rguenth at gcc dot gnu.org
2021-08-03 23:30 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: rguenth at gcc dot gnu.org @ 2020-07-28 5:59 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96336
Richard Biener <rguenth at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Ever confirmed|0 |1
Known to fail| |11.0
Keywords| |missed-optimization
Last reconfirmed| |2020-07-28
Status|UNCONFIRMED |NEW
--- Comment #2 from Richard Biener <rguenth at gcc dot gnu.org> ---
This only gets optimized on RTL, confirmed. It doesn't get optimized on GIMPLE
because reassoc doesn't like signed integers.
^ permalink raw reply [flat|nested] 4+ messages in thread
* [Bug tree-optimization/96336] Multiple multiplications fail to optimize
2020-07-27 15:14 [Bug tree-optimization/96336] New: Multiple multiplications fails to optimize fazedo at gmail dot com
2020-07-27 15:20 ` [Bug tree-optimization/96336] " fazedo at gmail dot com
2020-07-28 5:59 ` [Bug tree-optimization/96336] Multiple multiplications fail " rguenth at gcc dot gnu.org
@ 2021-08-03 23:30 ` pinskia at gcc dot gnu.org
2 siblings, 0 replies; 4+ messages in thread
From: pinskia at gcc dot gnu.org @ 2021-08-03 23:30 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=96336
Andrew Pinski <pinskia at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Severity|normal |enhancement
^ permalink raw reply [flat|nested] 4+ messages in thread
end of thread, other threads:[~2021-08-03 23:30 UTC | newest]
Thread overview: 4+ messages (download: mbox.gz / follow: Atom feed)
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2020-07-27 15:14 [Bug tree-optimization/96336] New: Multiple multiplications fails to optimize fazedo at gmail dot com
2020-07-27 15:20 ` [Bug tree-optimization/96336] " fazedo at gmail dot com
2020-07-28 5:59 ` [Bug tree-optimization/96336] Multiple multiplications fail " rguenth at gcc dot gnu.org
2021-08-03 23:30 ` pinskia at gcc dot gnu.org
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