[Bug c/29818] New: code with SSE segfaults with gcc-3.4.6, runs fine with gcc-4.1.1

["sergstesh at yahoo dot com" <gcc-bugzilla at gcc dot gnu dot org>]

A (now pretty simple) piece of code segfaults when compiled with gcc-3.4.6,
but runs fine with gcc-4.1.1.

The offending line is:

   vtmp1.v = *(vFloat *)&inp_array_1[bn];

-please wait until upload the source file.

Both gcc-3.4.6 and gcc-4.1.1 were built by myself; the same code segfaults
when compiled using stock Mandrivaa gcc-3.3.6 and runs fine when compiled
using stock Mandriva gcc-4.0.1, so, I guess, it doesn't really matter
how I built gcc-3.4.6 and gcc-4.1.1.

Anyway, gcc-3.4.6 and gcc-4.1.1 were built using my

http://appsfromscratch.berlios.de/

tool, I can send the log files showing pretty standard, except for
local installation dir, configuration options.

When the code fails (i.e. compiled by gcc-3.4.6), the screen output is:

"
checkpoint 1
&inp_array_1[0]=80498e0
checkpoint 2
bn=1
&inp_array_1[1]=80498e4
checkpoint 3
Segmentation fault
";

when the code runs fine (i.e. compiled by gcc-4.1.1), the screen output is:

"
checkpoint 1
&inp_array_1[0]=80498e0
checkpoint 2
bn=1
&inp_array_1[1]=80498e4
checkpoint 3
checkpoint 4
bn=5
&inp_array_1[5]=80498f4
checkpoint 3
checkpoint 4
bn=9
&inp_array_1[9]=8049904
checkpoint 3
checkpoint 4
inp_array_1[0]=1
inp_array_1[1]=2
inp_array_1[2]=3
inp_array_1[3]=4
inp_array_1[4]=5
inp_array_1[5]=6
inp_array_1[6]=7
inp_array_1[7]=8
inp_array_1[8]=9
inp_array_1[9]=10
inp_array_1[10]=11
inp_array_1[11]=12
inp_array_1[12]=13
inp_array_1[13]=14
inp_array_1[14]=15
inp_array_1[15]=16
inp_array_1[16]=17
inp_array_1[17]=18
inp_array_1[18]=19
inp_array_1[19]=20
inp_array_1[20]=21
inp_array_1[21]=22
inp_array_1[22]=23
inp_array_1[23]=24
inp_array_1[24]=25
inp_array_1[25]=26
inp_array_1[26]=27
inp_array_1[27]=28
inp_array_1[28]=29
inp_array_1[29]=30
inp_array_1[30]=31
inp_array_1[31]=32
".


The command line used for compilation:

/AppsFromScratchWD/install/gcc-3.4.6/bin/gcc -save-temps -O2 -Wall -msse
-mfpmath=sse -o sse_bug sse_bug.c 
.

The command line used to run:

./sse_bug
.


-- 
           Summary: code with SSE segfaults with gcc-3.4.6, runs fine with
                    gcc-4.1.1
           Product: gcc
           Version: 3.4.6
            Status: UNCONFIRMED
          Severity: blocker
          Priority: P3
         Component: c
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: sergstesh at yahoo dot com
 GCC build triplet: Linux comp.home.net 2.6.12-27mdk-i686-up-4GB #1 Tue Sep
                    26 12:41
  GCC host triplet: Linux comp.home.net 2.6.12-27mdk-i686-up-4GB #1 Tue Sep
                    26 12:41
GCC target triplet: Linux comp.home.net 2.6.12-27mdk-i686-up-4GB #1 Tue Sep
                    26 12:41


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=29818