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* [Bug target/112936] New: LoongArch: Wrong instruction costs
@ 2023-12-09 9:12 xry111 at gcc dot gnu.org
2023-12-09 9:17 ` [Bug target/112936] " xry111 at gcc dot gnu.org
` (4 more replies)
0 siblings, 5 replies; 6+ messages in thread
From: xry111 at gcc dot gnu.org @ 2023-12-09 9:12 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112936
Bug ID: 112936
Summary: LoongArch: Wrong instruction costs
Product: gcc
Version: 14.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: target
Assignee: unassigned at gcc dot gnu.org
Reporter: xry111 at gcc dot gnu.org
Target Milestone: ---
Separated from PR112935 comment 3.
The current loongarch_rtx_cost_data constructor (for default cost model, used
by LA464 and LA664 for now) seems completely wrong. Per my micro-benchmark the
values in reality should be:
loongarch_rtx_cost_data::loongarch_rtx_cost_data ()
: fp_add (COSTS_N_INSNS (5)),
fp_mult_sf (COSTS_N_INSNS (5)),
fp_mult_df (COSTS_N_INSNS (5)),
fp_div_sf (COSTS_N_INSNS (8)),
fp_div_df (COSTS_N_INSNS (8)),
int_mult_si (COSTS_N_INSNS (4)),
int_mult_di (COSTS_N_INSNS (4)),
int_div_si (COSTS_N_INSNS (5)),
int_div_di (COSTS_N_INSNS (5)),
branch_cost (6),
memory_latency (4) {}
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/112936] LoongArch: Wrong instruction costs
2023-12-09 9:12 [Bug target/112936] New: LoongArch: Wrong instruction costs xry111 at gcc dot gnu.org
@ 2023-12-09 9:17 ` xry111 at gcc dot gnu.org
2023-12-10 5:26 ` xry111 at gcc dot gnu.org
` (3 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: xry111 at gcc dot gnu.org @ 2023-12-09 9:17 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112936
Xi Ruoyao <xry111 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Last reconfirmed| |2023-12-09
Status|UNCONFIRMED |NEW
Ever confirmed|0 |1
--- Comment #1 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
Self-confirming as the original performance issue is from Jia Jie and the cost
model issue was isolated by Andrew.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/112936] LoongArch: Wrong instruction costs
2023-12-09 9:12 [Bug target/112936] New: LoongArch: Wrong instruction costs xry111 at gcc dot gnu.org
2023-12-09 9:17 ` [Bug target/112936] " xry111 at gcc dot gnu.org
@ 2023-12-10 5:26 ` xry111 at gcc dot gnu.org
2023-12-10 5:27 ` xry111 at gcc dot gnu.org
` (2 subsequent siblings)
4 siblings, 0 replies; 6+ messages in thread
From: xry111 at gcc dot gnu.org @ 2023-12-10 5:26 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112936
Xi Ruoyao <xry111 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Keywords| |patch
URL| |https://gcc.gnu.org/piperma
| |il/gcc-patches/2023-Decembe
| |r/640012.html
Status|NEW |ASSIGNED
Assignee|unassigned at gcc dot gnu.org |xry111 at gcc dot gnu.org
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/112936] LoongArch: Wrong instruction costs
2023-12-09 9:12 [Bug target/112936] New: LoongArch: Wrong instruction costs xry111 at gcc dot gnu.org
2023-12-09 9:17 ` [Bug target/112936] " xry111 at gcc dot gnu.org
2023-12-10 5:26 ` xry111 at gcc dot gnu.org
@ 2023-12-10 5:27 ` xry111 at gcc dot gnu.org
2023-12-17 11:24 ` cvs-commit at gcc dot gnu.org
2023-12-17 11:25 ` xry111 at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: xry111 at gcc dot gnu.org @ 2023-12-10 5:27 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112936
--- Comment #2 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
Patch: https://gcc.gnu.org/pipermail/gcc-patches/2023-December/640012.html
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/112936] LoongArch: Wrong instruction costs
2023-12-09 9:12 [Bug target/112936] New: LoongArch: Wrong instruction costs xry111 at gcc dot gnu.org
` (2 preceding siblings ...)
2023-12-10 5:27 ` xry111 at gcc dot gnu.org
@ 2023-12-17 11:24 ` cvs-commit at gcc dot gnu.org
2023-12-17 11:25 ` xry111 at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: cvs-commit at gcc dot gnu.org @ 2023-12-17 11:24 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112936
--- Comment #3 from GCC Commits <cvs-commit at gcc dot gnu.org> ---
The master branch has been updated by Xi Ruoyao <xry111@gcc.gnu.org>:
https://gcc.gnu.org/g:50b3f596bd943ec6110c1987f14e5497ce39622f
commit r14-6642-g50b3f596bd943ec6110c1987f14e5497ce39622f
Author: Xi Ruoyao <xry111@xry111.site>
Date: Sat Dec 9 17:41:32 2023 +0800
LoongArch: Fix instruction costs [PR112936]
Replace the instruction costs in loongarch_rtx_cost_data constructor
based on micro-benchmark results on LA464 and LA664.
This allows optimizations like "x * 17" to alsl, and "x * 68" to alsl
and slli.
gcc/ChangeLog:
PR target/112936
* config/loongarch/loongarch-def.cc
(loongarch_rtx_cost_data::loongarch_rtx_cost_data): Update
instruction costs per micro-benchmark results.
(loongarch_rtx_cost_optimize_size): Set all instruction costs
to (COSTS_N_INSNS (1) + 1).
* config/loongarch/loongarch.cc (loongarch_rtx_costs): Remove
special case for multiplication when optimizing for size.
Adjust division cost when TARGET_64BIT && !TARGET_DIV32.
Account the extra cost when TARGET_CHECK_ZERO_DIV and
optimizing for speed.
gcc/testsuite/ChangeLog
PR target/112936
* gcc.target/loongarch/mul-const-reduction.c: New test.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [Bug target/112936] LoongArch: Wrong instruction costs
2023-12-09 9:12 [Bug target/112936] New: LoongArch: Wrong instruction costs xry111 at gcc dot gnu.org
` (3 preceding siblings ...)
2023-12-17 11:24 ` cvs-commit at gcc dot gnu.org
@ 2023-12-17 11:25 ` xry111 at gcc dot gnu.org
4 siblings, 0 replies; 6+ messages in thread
From: xry111 at gcc dot gnu.org @ 2023-12-17 11:25 UTC (permalink / raw)
To: gcc-bugs
https://gcc.gnu.org/bugzilla/show_bug.cgi?id=112936
Xi Ruoyao <xry111 at gcc dot gnu.org> changed:
What |Removed |Added
----------------------------------------------------------------------------
Target Milestone|--- |14.0
Status|ASSIGNED |RESOLVED
Resolution|--- |FIXED
--- Comment #4 from Xi Ruoyao <xry111 at gcc dot gnu.org> ---
Fixed for 14.
^ permalink raw reply [flat|nested] 6+ messages in thread
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