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From: "tim at klingt dot org" <gcc-bugzilla@gcc.gnu.org>
To: gcc-bugs@gcc.gnu.org
Subject: [Bug c/38134] New: gcc-4.4 speed regression with sse code
Date: Sat, 15 Nov 2008 15:56:00 -0000 [thread overview]
Message-ID: <bug-38134-12873@http.gcc.gnu.org/bugzilla/> (raw)
the attached program, a simdfied version of the tanf function, shows a 20%
performance regression from gcc-4.3 to gcc-4.4:
the compared compilers are
g++-4.3
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu 4.3.2-1ubuntu11'
--with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
--enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr --enable-shared
--with-system-zlib --libexecdir=/usr/lib --without-included-gettext
--enable-threads=posix --enable-nls --with-gxx-include-dir=/usr/include/c++/4.3
--program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug
--enable-objc-gc --enable-mpfr --enable-checking=release
--build=x86_64-linux-gnu --host=x86_64-linux-gnu --target=x86_64-linux-gnu
Thread model: posix
gcc version 4.3.2 (Ubuntu 4.3.2-1ubuntu11)
and
Using built-in specs.
Target: x86_64-linux-gnu
Configured with: ../src/configure -v --with-pkgversion='Ubuntu
20081024-0ubuntu1' --with-bugurl=file:///usr/share/doc/gcc-snapshot/README.Bugs
--enable-languages=c,c++,java,fortran,objc,obj-c++,ada
--prefix=/usr/lib/gcc-snapshot --enable-shared --with-system-zlib --disable-nls
--enable-clocale=gnu --enable-libstdcxx-debug --enable-java-awt=gtk
--enable-gtk-cairo --disable-plugin --with-java-home=/usr/lib/gcc-snapshot
--enable-java-home --with-jvm-root-dir=/usr/lib/gcc-snapshot/jvm
--with-jvm-jar-dir=/usr/lib/gcc-snapshot/jvm-exports
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --enable-objc-gc --enable-mpfr
--disable-werror --build=x86_64-linux-gnu --host=x86_64-linux-gnu
--target=x86_64-linux-gnu
Thread model: posix
gcc version 4.4.0 20081024 (experimental) [trunk revision 141342] (Ubuntu
20081024-0ubuntu1)
the interesting part is the inner loop of the bench_1_simd function.
gcc-4.4 generates:
.L54:
movaps in(%rax), %xmm0
movdqa %xmm14, %xmm3
addl $4, %edx
pand %xmm0, %xmm3
#APP
# 325 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
xorps %xmm3, %xmm0
# 0 "" 2
#NO_APP
movaps %xmm0, %xmm4
movaps %xmm0, %xmm15
mulps %xmm13, %xmm4
#APP
# 328 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
cvttps2dq %xmm4, %xmm4
# 0 "" 2
#NO_APP
movdqa %xmm4, %xmm1
pand %xmm12, %xmm1
paddd %xmm1, %xmm4
#APP
# 331 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
cvtdq2ps %xmm4, %xmm1
# 0 "" 2
#NO_APP
pand .LC15(%rip), %xmm4
movaps %xmm1, %xmm2
psrld $1, %xmm4
mulps %xmm11, %xmm2
subps %xmm2, %xmm15
movaps %xmm15, %xmm2
movaps %xmm1, %xmm15
mulps %xmm9, %xmm1
mulps %xmm10, %xmm15
subps %xmm15, %xmm2
movaps %xmm8, %xmm15
subps %xmm1, %xmm2
cmpltps %xmm0, %xmm15
movaps %xmm2, %xmm1
mulps %xmm2, %xmm1
movaps %xmm1, %xmm0
mulps %xmm7, %xmm0
addps .LC10(%rip), %xmm0
mulps %xmm1, %xmm0
addps .LC11(%rip), %xmm0
mulps %xmm1, %xmm0
addps .LC12(%rip), %xmm0
mulps %xmm1, %xmm0
addps .LC13(%rip), %xmm0
mulps %xmm1, %xmm0
addps .LC14(%rip), %xmm0
mulps %xmm1, %xmm0
movdqa %xmm5, %xmm1
mulps %xmm2, %xmm0
psubd %xmm4, %xmm1
addps %xmm2, %xmm0
movdqa %xmm1, %xmm4
#APP
# 342 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
andps %xmm15, %xmm0
# 0 "" 2
#NO_APP
movaps .LC16(%rip), %xmm1
#APP
# 343 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
andnps %xmm2, %xmm15
# 0 "" 2
#NO_APP
movaps %xmm6, %xmm2
#APP
# 344 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
orps %xmm15, %xmm0
# 0 "" 2
#NO_APP
addps %xmm0, %xmm1
divps %xmm1, %xmm2
movaps %xmm2, %xmm1
#APP
# 145 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/simdconst.h" 1
andps %xmm4, %xmm1
# 0 "" 2
# 146 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/simdconst.h" 1
andnps %xmm0, %xmm4
# 0 "" 2
#NO_APP
movaps %xmm1, %xmm0
#APP
# 147 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/simdconst.h" 1
orps %xmm4, %xmm0
# 0 "" 2
# 349 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
xorps %xmm3, %xmm0
# 0 "" 2
#NO_APP
movaps %xmm0, out(%rax)
addq $16, %rax
cmpl %edi, %edx
jne .L54
while gcc-4.3 generates:
.L48:
movaps in(%rax), %xmm2
movdqa .LC2(%rip), %xmm5
movaps .LC3(%rip), %xmm0
pand %xmm2, %xmm5
movdqa .LC4(%rip), %xmm4
movaps .LC5(%rip), %xmm1
addl $4, %edx
#APP
# 325 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
xorps %xmm5, %xmm2
# 0 "" 2
#NO_APP
mulps %xmm2, %xmm0
movaps %xmm2, %xmm3
#APP
# 328 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
cvttps2dq %xmm0, %xmm0
# 0 "" 2
#NO_APP
pand %xmm0, %xmm4
paddd %xmm0, %xmm4
#APP
# 331 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
cvtdq2ps %xmm4, %xmm0
# 0 "" 2
#NO_APP
pand %xmm9, %xmm4
mulps %xmm0, %xmm1
psrld $1, %xmm4
subps %xmm1, %xmm3
movaps .LC6(%rip), %xmm1
mulps %xmm0, %xmm1
mulps .LC7(%rip), %xmm0
subps %xmm1, %xmm3
subps %xmm0, %xmm3
movaps .LC8(%rip), %xmm0
movaps %xmm3, %xmm1
cmpltps %xmm2, %xmm0
mulps %xmm3, %xmm1
movaps %xmm0, %xmm2
movaps %xmm1, %xmm0
mulps %xmm15, %xmm0
addps %xmm14, %xmm0
mulps %xmm1, %xmm0
addps %xmm13, %xmm0
mulps %xmm1, %xmm0
addps %xmm12, %xmm0
mulps %xmm1, %xmm0
addps %xmm11, %xmm0
mulps %xmm1, %xmm0
addps %xmm10, %xmm0
mulps %xmm1, %xmm0
mulps %xmm3, %xmm0
addps %xmm3, %xmm0
#APP
# 342 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
andps %xmm2, %xmm0
# 0 "" 2
# 343 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
andnps %xmm3, %xmm2
# 0 "" 2
#NO_APP
movaps %xmm7, %xmm3
#APP
# 344 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
orps %xmm2, %xmm0
# 0 "" 2
#NO_APP
movdqa %xmm6, %xmm2
movaps %xmm0, %xmm1
psubd %xmm4, %xmm2
addps %xmm8, %xmm1
divps %xmm1, %xmm3
movaps %xmm3, %xmm1
#APP
# 145 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/simdconst.h" 1
andps %xmm2, %xmm1
# 0 "" 2
# 146 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/simdconst.h" 1
andnps %xmm0, %xmm2
# 0 "" 2
# 147 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/simdconst.h" 1
orps %xmm2, %xmm1
# 0 "" 2
# 349 "benchmarks/../source/dsp/../../libs/libsimdmath/lib/sincosf4.h" 1
xorps %xmm5, %xmm1
# 0 "" 2
#NO_APP
movaps %xmm1, out(%rax)
addq $16, %rax
cmpl %edi, %edx
jne .L48
the code generated by gcc-4.4 requires more memory access. the code was
generated with the flags -O3 -march=core2. while the assembly code is generated
for the x86_64 architecture, similar results can be seen with x86 code (4.4 is
about 14% slower than 4.3)
--
Summary: gcc-4.4 speed regression with sse code
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: tim at klingt dot org
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=38134
next reply other threads:[~2008-11-15 15:56 UTC|newest]
Thread overview: 23+ messages / expand[flat|nested] mbox.gz Atom feed top
2008-11-15 15:56 tim at klingt dot org [this message]
2008-11-15 15:57 ` [Bug c/38134] " tim at klingt dot org
2008-11-15 16:47 ` ubizjak at gmail dot com
2008-11-15 17:05 ` tim at klingt dot org
2008-11-15 20:32 ` [Bug target/38134] [4.4 Regression] speed regression with inline-asm " rguenth at gcc dot gnu dot org
2008-11-16 0:07 ` hjl dot tools at gmail dot com
2008-11-16 0:09 ` hjl dot tools at gmail dot com
2008-11-17 9:36 ` jakub at gcc dot gnu dot org
2008-11-17 18:13 ` ubizjak at gmail dot com
2008-11-17 18:20 ` tim at klingt dot org
2008-11-17 18:31 ` tim at klingt dot org
2008-11-17 18:50 ` tim at klingt dot org
2009-02-03 9:47 ` bonzini at gnu dot org
2009-02-03 10:36 ` ubizjak at gmail dot com
2009-02-03 11:17 ` bonzini at gnu dot org
2009-02-03 11:34 ` ubizjak at gmail dot com
2009-02-13 9:57 ` [Bug target/38134] [4.4 Regression] speed regression with many loop invariants bonzini at gnu dot org
2009-02-13 10:03 ` steven at gcc dot gnu dot org
2009-04-21 16:02 ` [Bug target/38134] [4.4/4.5 " jakub at gcc dot gnu dot org
2009-07-22 10:35 ` jakub at gcc dot gnu dot org
2009-10-15 12:56 ` jakub at gcc dot gnu dot org
2010-01-21 13:16 ` jakub at gcc dot gnu dot org
2010-04-30 9:01 ` [Bug target/38134] [4.4/4.5/4.6 " jakub at gcc dot gnu dot org
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