tree-optimization/97085 - fold some trivial bool vector ?:

The following aovids the ICE in the testcase by doing some additional
simplification of VEC_COND_EXPRs for VECTOR_BOOLEAN_TYPE_P which
we don't really expect, esp. when they are not classical vectors,
thus AVX512 or SVE masks.

2020-09-24  Richard Biener  <rguenther@suse.de>

	PR tree-optimization/97085
	* match.pd (mask ? { false,..} : { true, ..} -> ~mask): New.

	* gcc.dg/vect/pr97085.c: New testcase.

diff --git a/gcc/match.pd b/gcc/match.pd
index 7d63bb973cbd70251a510d1d7be30c011e1071bf..e6dcdd0b855881c49f4eb7e4640a5421ea0480aa 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -3521,6 +3521,17 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
  (if (optimize_vectors_before_lowering_p () && types_match (@0, @1))
   (vec_cond (bit_and (bit_not @0) @1) @2 @3)))
 
+/* Canonicalize mask ? { 0, ... } : { -1, ...} to ~mask if the mask
+   types are compatible.  */
+(simplify
+ (vec_cond @0 VECTOR_CST@1 VECTOR_CST@2)
+ (if (VECTOR_BOOLEAN_TYPE_P (type)
+      && types_match (type, TREE_TYPE (@0)))
+  (if (integer_zerop (@1) && integer_all_onesp (@2))
+   (bit_not @0)
+   (if (integer_all_onesp (@1) && integer_zerop (@2))
+    @0))))
+
 /* Simplification moved from fold_cond_expr_with_comparison.  It may also
    be extended.  */
 /* This pattern implements two kinds simplification:

diff --git a/gcc/testsuite/gcc.dg/vect/pr97085.c b/gcc/testsuite/gcc.dg/vect/pr97085.c
new file mode 100644 (file)
index 0000000..ffde9f1
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/vect/pr97085.c
@@ -0,0 +1,13 @@
+/* { dg-do compile } */
+/* { dg-additional-options "-march=armv8.2-a+sve" { target aarch64-*-* } } */
+
+int a, b, c, d;
+short e, g;
+unsigned short f;
+void h() {
+  for (; d; d++) {
+    g = d;
+    e = b == 0 ? 1 : a % b;
+    c ^= (f = e) > (g == 5);
+  }
+}