On Sat, Dec 05, 2020 at 11:22:24AM +0100, Richard Biener wrote:
> >two_value_replacement and didn't restrict it to !early_p. Shall we
> >instead
> >do two_value_replacement only in late phiopt?
>
> Yeah, I guess that would make sense. I don't remember exactly but I saw
> regressions with early doing if conversion besides min/max/abs detection.
So that would be then following patch instead.
Ok if it passes bootstrap/regtest?
2020-12-05 Jakub Jelinek <ja...@redhat.com>
PR tree-optimization/96232
* tree-ssa-phiopt.c (two_value_replacement): Optimize even boolean lhs
cases as long as arg0 has wider precision and conditional_replacement
doesn't handle that case.
(tree_ssa_phiopt_worker): Don't call two_value_replacement during
early phiopt.
* gcc.dg/tree-ssa/pr96232-2.c: New test.
--- gcc/tree-ssa-phiopt.c.jj 2020-12-05 11:37:39.216203475 +0100
+++ gcc/tree-ssa-phiopt.c 2020-12-05 11:51:57.497472991 +0100
@@ -337,7 +337,7 @@ tree_ssa_phiopt_worker (bool do_store_el
}
/* Do the replacement of conditional if it can be done. */
- if (two_value_replacement (bb, bb1, e2, phi, arg0, arg1))
+ if (!early_p && two_value_replacement (bb, bb1, e2, phi, arg0, arg1))
cfgchanged = true;
else if (!early_p
&& conditional_replacement (bb, bb1, e1, e2, phi,
@@ -635,7 +635,6 @@ two_value_replacement (basic_block cond_
if (TREE_CODE (lhs) != SSA_NAME
|| !INTEGRAL_TYPE_P (TREE_TYPE (lhs))
- || TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE
|| TREE_CODE (rhs) != INTEGER_CST)
return false;
@@ -648,9 +647,25 @@ two_value_replacement (basic_block cond_
return false;
}
+ /* Defer boolean x ? 0 : {1,-1} or x ? {1,-1} : 0 to
+ conditional_replacement. */
+ if (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE
+ && (integer_zerop (arg0)
+ || integer_zerop (arg1)
+ || TREE_CODE (TREE_TYPE (arg0)) == BOOLEAN_TYPE
+ || (TYPE_PRECISION (TREE_TYPE (arg0))
+ <= TYPE_PRECISION (TREE_TYPE (lhs)))))
+ return false;
+
wide_int min, max;
- if (get_range_info (lhs, &min, &max) != VR_RANGE
- || min + 1 != max
+ if (TREE_CODE (TREE_TYPE (lhs)) == BOOLEAN_TYPE)
+ {
+ min = wi::to_wide (boolean_false_node);
+ max = wi::to_wide (boolean_true_node);
+ }
+ else if (get_range_info (lhs, &min, &max) != VR_RANGE)
+ return false;
+ if (min + 1 != max
|| (wi::to_wide (rhs) != min
&& wi::to_wide (rhs) != max))
return false;
--- gcc/testsuite/gcc.dg/tree-ssa/pr96232-2.c.jj 2020-12-05
11:51:01.891103252 +0100
+++ gcc/testsuite/gcc.dg/tree-ssa/pr96232-2.c 2020-12-05 11:51:01.891103252
+0100
@@ -0,0 +1,18 @@
+/* PR tree-optimization/96232 */
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+/* { dg-final { scan-tree-dump " 38 - " "optimized" } } */
+/* { dg-final { scan-tree-dump " \\+ 97;" "optimized" } } */
+/* { dg-final { scan-tree-dump-not "PHI <" "optimized" } } */
+
+int
+foo (_Bool x)
+{
+ return x ? 37 : 38;
+}
+
+int
+bar (_Bool x)
+{
+ return x ? 98 : 97;
+}
Jakub
