On Wed, 2023-12-13 at 14:32 +0800, Jiahao Xu wrote:
>
> 在 2023/12/13 下午2:21, Xi Ruoyao 写道:
> > On Wed, 2023-12-13 at 14:17 +0800, Jiahao Xu wrote:
> > > This test was extracted from the hot functions of 526.blender_r. Setting
> > > LOGICAL_OP_NON_SHORT_CIRCUIT to 0 resulted in a 26% decrease in dynamic
> > > instruction count and a 13.4% performance improvement. After applying
> > > the patch mentioned above, the assembly code looks much better with
> > > LOGICAL_OP_NON_SHORT_CIRCUIT=1, bringing an 11% improvement to 526.
> > > Based on this, setting LOGICAL_OP_NON_SHORT_CIRCUIT to 0 further
> > > improved the performance of 526 by 3%. The definition of
> > > LOGICAL_OP_NON_SHORT_CIRCUIT determines how gimple is generated, while
> > > the optimizations you made determine how rtl is generated. They are not
> > > conflicting and combining them would yield better results. Currently, I
> > > have only tested it on 526, and I will continue testing its impact on
> > > the entire SPEC 2017 suite.
> > The problem with LOGICAL_OP_NON_SHORT_CIRCUIT = 0 is it may regress
> > fixed-point only code. In practice the usage of -ffast-math is very
> > rare ("real" Linux packages invoking floating-point operations often
> > just malfunction with it) and it seems not good to regress common cases
> > with uncommon cases.
> >
> Setting LOGICAL_OP_NON_SHORT_CIRCUIT to 0 in SPEC2017 intrate benchmark
> results in a 1.6% decrease in dynamic instruction count and an overall
> performance improvement of 0.5%. Most of the SPEC2017 int programs
> experience a decrease in instruction count, and there are no instances
> of performance regression observed.
Ok then. But add these info into commit message.
--
Xi Ruoyao <xry...@xry111.site>
School of Aerospace Science and Technology, Xidian University
