[EMAIL PROTECTED] tmp]# cat a.cpp #include <xmmintrin.h> #include <stdio.h>
__m128 mm; void test ( const __m128& vm, float r ) { mm = _mm_add_ps( mm, _mm_set_ps( 0.0f, r, r, r) ); float vm0, vm1, vm2; _mm_store_ss( &vm0, vm ); _mm_store_ss( &vm1, _mm_shuffle_ps( vm, vm, 1 ) ); _mm_store_ss( &vm2, _mm_shuffle_ps( vm, vm, 2 ) ); _mm_store_ss( &vm2, _mm_shuffle_ps( vm, vm, 2 ) ); printf("In TEST: %f %f %f\n", vm0, vm1, vm2 ); } int main() { __m128 vm = _mm_set_ps( 4.0f, 3.0f, 2.0f, 1.0f ); float vm0, vm1, vm2; _mm_store_ss( &vm0, vm ); _mm_store_ss( &vm1, _mm_shuffle_ps( vm, vm, 1 ) ); _mm_store_ss( &vm2, _mm_shuffle_ps( vm, vm, 2 ) ); printf("Before TEST: %f %f %f\n", vm0, vm1, vm2 ); test(vm, 0.5f); _mm_store_ss( &vm0, vm ); _mm_store_ss( &vm1, _mm_shuffle_ps( vm, vm, 1 ) ); _mm_store_ss( &vm2, _mm_shuffle_ps( vm, vm, 2 ) ); printf("After TEST: %f %f %f\n", vm0, vm1, vm2 ); return 0; } [EMAIL PROTECTED] tmp]# g++ -Wall -O3 -msse a.cpp; ./a.out Before TEST: 1.000000 2.000000 3.000000 In TEST: nan nan nan After TEST: 1.000000 2.000000 3.000000 [EMAIL PROTECTED] tmp]# g++ -Wall -O2 -msse a.cpp; ./a.out Before TEST: 1.000000 2.000000 3.000000 In TEST: nan nan nan After TEST: 1.000000 2.000000 3.000000 [EMAIL PROTECTED] tmp]# g++ -Wall -O1 -msse a.cpp; ./a.out Before TEST: 1.000000 2.000000 3.000000 In TEST: nan nan nan After TEST: 1.000000 2.000000 3.000000 [EMAIL PROTECTED] tmp]# g++ -Wall -O0 -msse a.cpp; ./a.out Before TEST: 1.000000 2.000000 3.000000 In TEST: 1.000000 2.000000 3.000000 After TEST: 1.000000 2.000000 3.000000 [EMAIL PROTECTED] tmp]# [EMAIL PROTECTED] tmp]# uname -a Linux localhost.localdomain 2.6.17-1.2139_FC5smp #1 SMP Fri Jun 23 13:12:06 EDT 2006 i686 i686 i386 GNU/Linux [EMAIL PROTECTED] tmp]# gcc -v Using built-in specs. Target: i386-redhat-linux Configured with: ../configure --prefix=/usr --mandir=/usr/share/man --infodir=/usr/share/info --enable-shared --enable-threads=posix --enable-checking =release --with-system-zlib --enable-__cxa_atexit --disable-libunwind-exceptions --enable-libgcj-multifile --enable-languages=c,c++,objc,obj-c++,java, fortran,ada --enable-java-awt=gtk --disable-dssi --with-java-home=/usr/lib/jvm/java-1.4.2-gcj-1.4.2.0/jre --with-cpu=generic --host=i386-redhat-linux Thread model: posix gcc version 4.1.1 20060525 (Red Hat 4.1.1-1) [EMAIL PROTECTED] tmp]# gcc3 is OK -- Summary: optimized bug with ia32 sse Product: gcc Version: 4.1.1 Status: UNCONFIRMED Severity: critical Priority: P3 Component: c++ AssignedTo: unassigned at gcc dot gnu dot org ReportedBy: zengpan at goldhuman dot com http://gcc.gnu.org/bugzilla/show_bug.cgi?id=28960