Hi,
Now that I have Power8 hardware to test on, I've discovered that I
introduced a problem with
http://gcc.gnu.org/ml/gcc-patches/2014-01/msg01547.html that causes a
bootstrap failure when specifying -mcpu=power8. I moved some logic from
rs6000_expand_vec_perm_const_1 into vsx_xxpermdi2_<mode>_1. I failed to
notice there is another path into vsx_xxpermdi2_<mode>_1 that is
exercised during the bootstrap.
To avoid the problem, this patch adjusts the code generated along this
other path so that the later transformation will be correct.
Bootstrapped and tested on powerpc64{,le}-unknown-linux-gnu configured
both with -mcpu=power7 and with -mcpu=power8 with no regressions. The
Power8 LE bootstrap now completes cleanly. Is this ok for trunk?
Thanks,
Bill
2014-02-16 Bill Schmidt <wschm...@linux.vnet.ibm.com>
* config/rs6000/vsx.md (vsx_xxpermdi_<mode>): Handle little
endian targets.
Index: gcc/config/rs6000/vsx.md
===================================================================
--- gcc/config/rs6000/vsx.md (revision 207809)
+++ gcc/config/rs6000/vsx.md (working copy)
@@ -1621,7 +1621,18 @@
op1 = gen_lowpart (V2DImode, op1);
}
}
- emit_insn (gen (target, op0, op1, perm0, perm1));
+ /* In little endian mode, vsx_xxpermdi2_<mode>_1 will perform a
+ transformation we don't want; it is necessary for
+ rs6000_expand_vec_perm_const_1 but not for this use. So we
+ prepare for that by reversing the transformation here. */
+ if (BYTES_BIG_ENDIAN)
+ emit_insn (gen (target, op0, op1, perm0, perm1));
+ else
+ {
+ rtx p0 = GEN_INT (3 - INTVAL (perm1));
+ rtx p1 = GEN_INT (3 - INTVAL (perm0));
+ emit_insn (gen (target, op1, op0, p0, p1));
+ }
DONE;
})
