Alpha doesnt unroll loops

[Oskar Enoksson]

I can't make loop unrolling work with gcc for alpha. I've tried egcs
1.1 and snapshot 980914. I think this must be a bug because:

1) The same loops are unrolled with the same version of gcc on Pentium.
2) g77 unrolls fortran loops ok on both Pentium and Alpha.

For example:

main() {
  double a[50];
  int i;

  for(i=0; i<50; i++)
    a[i]=0;
}

> gcc -O3 -fstrict-aliasing -funroll-loops -S

        .verstamp 3 11
        .set noreorder
        .set volatile
        .set noat
        .arch ev56
        .file   1 "foo.c"
.text
        .align 5
        .globl main
        .ent main
main:
        .frame $30,400,$26,0
$main..ng:
        lda $30,-400($30)
        .prologue 0
        bis $31,$31,$3
        bis $30,$30,$2
        .align 4
$L5:
        stq $31,0($2)
        addl $3,1,$3
        addq $2,8,$2
        cmple $3,49,$1
        bne $1,$L5
        lda $30,400($30)
        ret $31,($26),1
        .end main


As can be seen above, no loop unrolling is done on Alpha. On Pentium loop
is unrolled however.

Mail me if you need more info!

Regards.
/Oskar

*/              Oskar Enoksson, Linkoping, Sweden                  /*