c++/7542: compiling for powerpc Altivec

[eyal@mobileye.com]

>Number:         7542
>Category:       c++
>Synopsis:       compiling for powerpc Altivec
>Confidential:   no
>Severity:       critical
>Priority:       medium
>Responsible:    unassigned
>State:          open
>Class:          wrong-code
>Submitter-Id:   net
>Arrival-Date:   Thu Aug 08 05:06:00 PDT 2002
>Closed-Date:
>Last-Modified:
>Originator:     eyal@mobileye.com
>Release:        gcc-3.1
>Organization:
>Environment:
linux , powerpc 
>Description:
I tried to compile Altivec code - and used vec_msum(__vector signed char c1, __vector unsigned char c2, __vector signed int i1) ... 

the compiler change this to the assembler code vmsumubm - which uses 2 UNsigned char vectors instead of vmsummbm which uses one SIGNES and one UNSIGND !!

this bug causes the signed operand to be treated as unsigned !!
>How-To-Repeat:
the following compilation:
g++ -S -Wall -pedantic -ansi -Wno-long-long -DNDEBUG -O6 -DALTIVEC -maltivec testZevel.cpp

the g++ version is :
Reading specs from /opt/gcc-3.1/lib/gcc-lib/i686-pc-linux-gnu/3.1/specs
Configured with: ../gcc-3.1/configure --prefix=/opt/gcc-3.1 --enable-shared --enable-threads --enable-languages=c,c++
Thread model: posix
gcc version 3.1
>Fix:
need to be find fast so if you have something please let me know !!!
>Release-Note:
>Audit-Trail:
>Unformatted:
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