Test program attached.
Command line:
[EMAIL PROTECTED]:~/exp-sum-delta$ /home/mec/gcc-4.3-20070707/install/bin/g++
-v -S
-O2 -msse2 sum-delta.cc
Using built-in specs.
Target: i686-pc-linux-gnu
Configured with: /home/mec/gcc-4.3-20070707/src/configure
--build=i686-pc-linux-
gnu --host=i686-pc-linux-gnu --target=i686-pc-linux-gnu
--prefix=/home/mec/gcc-4
.3-20070707/install --enable-languages=c,c++,objc,obj-c++,treelang
--with-gmp=/h
ome/mec/gmp-4.2.1/install --with-mpfr=/home/mec/mpfr-2.2.1/install
Thread model: posix
gcc version 4.3.0 20070707 (experimental)
/home/mec/gcc-4.3-20070707/install/libexec/gcc/i686-pc-linux-gnu/4.3.0/cc1plus
-quiet -v -D_GNU_SOURCE sum-delta.cc -quiet -dumpbase sum-delta.cc -msse2
-mtune
=generic -auxbase sum-delta -O2 -version -o sum-delta.s
ignoring nonexistent directory
"/home/mec/gcc-4.3-20070707/install/lib/gcc/i686-
pc-linux-gnu/4.3.0/../../../../i686-pc-linux-gnu/include"
#include "..." search starts here:
#include <...> search starts here:
/home/mec/gcc-4.3-20070707/install/lib/gcc/i686-pc-linux-gnu/4.3.0/../../../../
include/c++/4.3.0
/home/mec/gcc-4.3-20070707/install/lib/gcc/i686-pc-linux-gnu/4.3.0/../../../../
include/c++/4.3.0/i686-pc-linux-gnu
/home/mec/gcc-4.3-20070707/install/lib/gcc/i686-pc-linux-gnu/4.3.0/../../../../
include/c++/4.3.0/backward
/usr/local/include
/home/mec/gcc-4.3-20070707/install/include
/home/mec/gcc-4.3-20070707/install/lib/gcc/i686-pc-linux-gnu/4.3.0/include
/home/mec/gcc-4.3-20070707/install/lib/gcc/i686-pc-linux-gnu/4.3.0/include-fixe
d
/usr/include
End of search list.
GNU C++ version 4.3.0 20070707 (experimental) (i686-pc-linux-gnu)
compiled by GNU C version 4.3.0 20070707 (experimental), GMP version
4.2
.1, MPFR version 2.2.1.
warning: GMP header version 4.2.1 differs from library version 4.1.4.
GGC heuristics: --param ggc-min-expand=30 --param ggc-min-heapsize=4096
Compiler executable checksum: 1338ea4083517ffee92283f96caf8872
===
The loop for CallSumDeltas2 compiles to:
.L7:
movdqa %xmm1, %xmm0
pslldq $4, %xmm0
addl $1, %eax
paddd %xmm1, %xmm0
cmpl $100000000, %eax
movdqa %xmm0, %xmm1
pslldq $8, %xmm1
paddd %xmm1, %xmm0
movdqa %xmm0, %xmm1
movdqa %xmm0, foo1
jne .L7
===
This is two more movdqa then the hand-written code in CallSumDeltas3.
--
Summary: i686 sse2 generates more movdqa than necessary
Product: gcc
Version: 4.3.0
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c++
AssignedTo: unassigned at gcc dot gnu dot org
ReportedBy: mec at google dot com
GCC build triplet: i686-pc-linux-gnu
GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu
http://gcc.gnu.org/bugzilla/show_bug.cgi?id=32735
