https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61938
Bug ID: 61938
Summary: Vectorization not happening .
Product: gcc
Version: unknown
Status: UNCONFIRMED
Severity: normal
Priority: P3
Component: c
Assignee: unassigned at gcc dot gnu.org
Reporter: harmeeksingh at gmail dot com
$ gcc -v
Using built-in specs.
COLLECT_GCC=gcc
COLLECT_LTO_WRAPPER=/usr/libexec/gcc/x86_64-redhat-linux/4.7.2/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 --disable-build-with-cxx
--disable-build-poststage1-with-cxx --with-system-zlib --enable-__cxa_atexit
--disable-libunwind-exceptions --enable-gnu-unique-object
--enable-linker-build-id --with-linker-hash-style=gnu
--enable-languages=c,c++,objc,obj-c++,java,fortran,ada,go,lto --enable-plugin
--enable-initfini-array --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
--with-ecj-jar=/usr/share/java/eclipse-ecj.jar --disable-libjava-multilib
--with-ppl --with-cloog --with-tune=generic --with-arch_32=i686
--build=x86_64-redhat-linux
Thread model: posix
gcc version 4.7.2 20120921 (Red Hat 4.7.2-2) (GCC)
Testcase
#include <stdio.h>
#define VEC 1024
typedef long int int64;
typedef int int32;
void foo (int arraysize,
int *result,
int *selectvector,
int selectelements,
int32 *array,
int32 compval)
{
int k, i;
for (k =0,i=0; i < selectelements; ++i) {
result[k] = selectvector[i]; k += (((array[selectvector[i]])) ==
compval);
}
}
main()
{
int result[VEC];
int selectvector[VEC];
int selectelements;
int32 array[VEC];
int k, i;
foo(VEC, &result[0], &selectvector[0], VEC, &array[0], 1);
}
Compilation log
gcc -fPIC -ggdb -O3 -march=native -ftree-vectorize -ftree-vectorizer-verbose=7
/tmp/x.c -o /tmp/x
Analyzing loop at /tmp/x.c:17
17: not vectorized: data ref analysis failed *D.2502_9 = D.2506_14;
17: not vectorized: data ref analysis failed *D.2502_9 = D.2506_14;
/tmp/x.c:9: note: vectorized 0 loops in function.
