[Bug c/48036] New: unexpected byte swap in sse _mm_cvtpu16_ps in 64-bit 4.5.1

[cck0011 at yahoo dot com]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=48036

           Summary: unexpected byte swap in sse _mm_cvtpu16_ps in 64-bit
                    4.5.1
           Product: gcc
           Version: 4.5.1
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: c
        AssignedTo: unassigned@gcc.gnu.org
        ReportedBy: cck0011@yahoo.com


Created attachment 23586
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=23586
.i file

Hi folks,

  I'm getting an unexpected byte swap in _mm_cvtpu16_ps. Version 32-bit 4.3.2
has the behavior I was expecting. I'm posting a program that takes a vector of
chars, widens them to vectors of shorts, and then converts the shorts to
vectors of floats. I was expecting the order of the floats in the vectors to
match the order of the chars in the starting vector. My understanding is wrong
or a bug crept in after 4.3.2. What am I missing?

Thanks!

Using built-in specs.
COLLECT_GCC=/usr/bin/cc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.5.1/lto-wrapper
Target: x86_64-redhat-linux
Configured with: ../configure --prefix=/usr --mandir=/usr/share/man
--infodir=/usr/share/info --with-bugurl=http://bugzilla.redhat.com/bugzilla
--enable-bootstrap --enable-shared --enable-threads=posix
--enable-checking=release --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada,lto --enable-plugin
--enable-java-awt=gtk --disable-dssi
--with-java-home=/usr/lib/jvm/java-1.5.0-gcj-1.5.0.0/jre
--enable-libgcj-multifile --enable-java-maintainer-mode
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--with-ppl --with-cloog --with-tune=generic --with-arch_32=i686
--build=x86_64-redhat-linux
Thread model: posix
gcc version 4.5.1 20100924 (Red Hat 4.5.1-4) (GCC) 
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-g' '-o' 'char_to_float' '-I.' '-msse'
'-mmmx' '-mtune=generic' '-march=x86-64'
 /usr/libexec/gcc/x86_64-redhat-linux/4.5.1/cc1 -E -quiet -v -I.
char_to_float.c -msse -mmmx -mtune=generic -march=x86-64 -g -fworking-directory
-fpch-preprocess -o char_to_float.i
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-redhat-linux/4.5.1/include-fixed"
ignoring nonexistent directory
"/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../x86_64-redhat-linux/include"
#include "..." search starts here:
#include <...> search starts here:
 .
 /usr/local/include
 /usr/lib/gcc/x86_64-redhat-linux/4.5.1/include
 /usr/include
End of search list.
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-g' '-o' 'char_to_float' '-I.' '-msse'
'-mmmx' '-mtune=generic' '-march=x86-64'
 /usr/libexec/gcc/x86_64-redhat-linux/4.5.1/cc1 -fpreprocessed char_to_float.i
-quiet -dumpbase char_to_float.c -msse -mmmx -mtune=generic -march=x86-64
-auxbase char_to_float -g -version -o char_to_float.s
GNU C (GCC) version 4.5.1 20100924 (Red Hat 4.5.1-4) (x86_64-redhat-linux)
    compiled by GNU C version 4.5.1 20100924 (Red Hat 4.5.1-4), GMP version
4.3.1, MPFR version 2.4.2, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
GNU C (GCC) version 4.5.1 20100924 (Red Hat 4.5.1-4) (x86_64-redhat-linux)
    compiled by GNU C version 4.5.1 20100924 (Red Hat 4.5.1-4), GMP version
4.3.1, MPFR version 2.4.2, MPC version 0.8.1
GGC heuristics: --param ggc-min-expand=100 --param ggc-min-heapsize=131072
Compiler executable checksum: ea394b69293dd698607206e8e43d607e
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-g' '-o' 'char_to_float' '-I.' '-msse'
'-mmmx' '-mtune=generic' '-march=x86-64'
 as -V -Qy --64 -o char_to_float.o char_to_float.s
GNU assembler version 2.20.51.0.7 (x86_64-redhat-linux) using BFD version
version 2.20.51.0.7-5.fc14 20100318
COMPILER_PATH=/usr/libexec/gcc/x86_64-redhat-linux/4.5.1/:/usr/libexec/gcc/x86_64-redhat-linux/4.5.1/:/usr/libexec/gcc/x86_64-redhat-linux/:/usr/lib/gcc/x86_64-redhat-linux/4.5.1/:/usr/lib/gcc/x86_64-redhat-linux/
LIBRARY_PATH=/usr/lib/gcc/x86_64-redhat-linux/4.5.1/:/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64/:/lib/../lib64/:/usr/lib/../lib64/:/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../:/lib/:/usr/lib/
COLLECT_GCC_OPTIONS='-v' '-save-temps' '-g' '-o' 'char_to_float' '-I.' '-msse'
'-mmmx' '-mtune=generic' '-march=x86-64'
 /usr/libexec/gcc/x86_64-redhat-linux/4.5.1/collect2 --build-id --no-add-needed
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/lib64/ld-linux-x86-64.so.2 -o char_to_float
/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64/crt1.o
/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64/crti.o
/usr/lib/gcc/x86_64-redhat-linux/4.5.1/crtbegin.o
-L/usr/lib/gcc/x86_64-redhat-linux/4.5.1
-L/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64 -L/lib/../lib64
-L/usr/lib/../lib64 -L/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../..
char_to_float.o -lgcc --as-needed -lgcc_s --no-as-needed -lc -lgcc --as-needed
-lgcc_s --no-as-needed /usr/lib/gcc/x86_64-redhat-linux/4.5.1/crtend.o
/usr/lib/gcc/x86_64-redhat-linux/4.5.1/../../../../lib64/crtn.o