Hello,
SRA uses char when scalarizing bool, and we end up with
_6 = u_1(D) == 0.0;
_7 = (unsigned char) _6;
_3 = VIEW_CONVERT_EXPR<_Bool>(_7);
which we currently do not simplify. I am not completely sure what happens
with types whose precision does not cover their size, I hope this is safe.
Bootstrap+testsuite on powerpc64le-unknown-linux-gnu.
2017-05-22 Marc Glisse <marc.gli...@inria.fr>
gcc/
* match.pd (view_convert (convert@0 @1)): Handle zero-extension.
gcc/testsuite/
* gcc.dg/tree-ssa/vce-1.c: New file.
--
Marc GlisseIndex: match.pd
===================================================================
--- match.pd (revision 248312)
+++ match.pd (working copy)
@@ -1798,27 +1798,30 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
/* For integral conversions with the same precision or pointer
conversions use a NOP_EXPR instead. */
(simplify
(view_convert @0)
(if ((INTEGRAL_TYPE_P (type) || POINTER_TYPE_P (type))
&& (INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
&& TYPE_PRECISION (type) == TYPE_PRECISION (TREE_TYPE (@0)))
(convert @0)))
-/* Strip inner integral conversions that do not change precision or size. */
+/* Strip inner integral conversions that do not change precision or size, or
+ zero-extend while keeping the same size (for bool-to-char). */
(simplify
(view_convert (convert@0 @1))
(if ((INTEGRAL_TYPE_P (TREE_TYPE (@0)) || POINTER_TYPE_P (TREE_TYPE (@0)))
&& (INTEGRAL_TYPE_P (TREE_TYPE (@1)) || POINTER_TYPE_P (TREE_TYPE (@1)))
- && (TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (TREE_TYPE (@1)))
- && (TYPE_SIZE (TREE_TYPE (@0)) == TYPE_SIZE (TREE_TYPE (@1))))
+ && TYPE_SIZE (TREE_TYPE (@0)) == TYPE_SIZE (TREE_TYPE (@1))
+ && (TYPE_PRECISION (TREE_TYPE (@0)) == TYPE_PRECISION (TREE_TYPE (@1))
+ || (TYPE_PRECISION (TREE_TYPE (@0)) > TYPE_PRECISION (TREE_TYPE (@1))
+ && TYPE_UNSIGNED (TREE_TYPE (@1)))))
(view_convert @1)))
/* Re-association barriers around constants and other re-association
barriers can be removed. */
(simplify
(paren CONSTANT_CLASS_P@0)
@0)
(simplify
(paren (paren@1 @0))
@1)
Index: testsuite/gcc.dg/tree-ssa/vce-1.c
===================================================================
--- testsuite/gcc.dg/tree-ssa/vce-1.c (nonexistent)
+++ testsuite/gcc.dg/tree-ssa/vce-1.c (working copy)
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-optimized" } */
+
+typedef struct { _Bool b; } A;
+_Bool f(double u){
+ A a;
+ if(u==0)
+ a.b=1;
+ else
+ a.b=0;
+ return a.b;
+}
+
+/* { dg-final { scan-tree-dump-not "VIEW_CONVERT_EXPR" "optimized" } } */
