[Bug tree-optimization/39068] New: signed short plus and signed char plus not vectorized

[dann at godzilla dot ics dot uci dot edu]

gcc -march=core2 -O3 -ftree-vectorizer-verbose=6 
for this code: 

#define SIZE 10000
signed short a[SIZE];
signed short b[SIZE];
signed short c[SIZE];

void add()
{
  int i;
  for (i = 0; i < SIZE; ++i)
    a[i] = b[i] + c[i];
}

cannot vectorize the loop:

add_sshort.c:9: note: vect_model_load_cost: aligned.
add_sshort.c:9: note: vect_model_load_cost: inside_cost = 1, outside_cost = 0 .
add_sshort.c:9: note: not vectorized: relevant stmt not supported: D.1580_6 =
(short unsigned int) D.1579_5
add_sshort.c:7: note: vectorized 0 loops in function.

The same happens if the type for a,b and c is "signed char".

But if the type is "unsigned short" or "unsigned char" the loop is vectorized.


-- 
           Summary: signed short plus and signed char plus not vectorized
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Severity: normal
          Priority: P3
         Component: tree-optimization
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: dann at godzilla dot ics dot uci dot edu
  GCC host triplet: i686-pc-linux-gnu
GCC target triplet: i686-pc-linux-gnu


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=39068