tcg/optimize: Fix a_mask computation for orc

In computing a_mask, for or, we remove the bits from t1->o_mask
which are known to be zero.  For orc, the bits known to be zero
are the inverse of those known to be one.

Cc: qemu-stable@nongnu.org
Fixes: cc4033ee47c ("tcg/optimize: Build and use zero, one and affected bits in fold_orc")
Reviewed-by: Pierrick Bouvier <pierrick.bouvier@linaro.org>
Signed-off-by: Richard Henderson <richard.henderson@linaro.org>

diff --git a/tcg/optimize.c b/tcg/optimize.c
index 1f95da487b99d06262313459a6f42be72b8f376d..db1d89396b079ad006140ec2bf5deee7db4c93cf 100644 (file)
--- a/tcg/optimize.c
+++ b/tcg/optimize.c
@@ -2360,7 +2360,7 @@ static bool fold_orc(OptContext *ctx, TCGOp *op)
     s_mask = t1->s_mask & t2->s_mask;
 
     /* Affected bits are those not known one, masked by those known one. */
-    a_mask = ~t1->o_mask & t2->o_mask;
+    a_mask = ~t1->o_mask & ~t2->o_mask;
 
     return fold_masks_zosa(ctx, op, z_mask, o_mask, s_mask, a_mask);
 }