tree-optimization/110269 - restore missed condition folding

The following makes sure we optimize x != 0 using range info
via tree_expr_nonzero_p via match.pd.

	PR tree-optimization/110269
	* fold-const.cc (fold_binary_loc): Merge x != 0 folding
	with tree_expr_nonzero_p ...
	* match.pd (cmp (convert? addr@0) integer_zerop): With this
	pattern.

	* gcc.dg/tree-ssa/pr110269.c: New testcase.

diff --git a/gcc/fold-const.cc b/gcc/fold-const.cc
index 9ea055d452397ba95666e1edebf9767068f69440..3aa6851acd5eed486bad2da13560314ab95bb7aa 100644 (file)
--- a/gcc/fold-const.cc
+++ b/gcc/fold-const.cc
@@ -12298,13 +12298,6 @@ fold_binary_loc (location_t loc, enum tree_code code, tree type,
                              tem, build_int_cst (TREE_TYPE (tem), 0));
        }
 
-      if (integer_zerop (arg1)
-         && tree_expr_nonzero_p (arg0))
-        {
-         tree res = constant_boolean_node (code==NE_EXPR, type);
-         return omit_one_operand_loc (loc, type, res, arg0);
-       }
-
       if (TREE_CODE (arg0) == BIT_XOR_EXPR
          && TREE_CODE (arg1) == BIT_XOR_EXPR)
        {

diff --git a/gcc/match.pd b/gcc/match.pd
index a17d6838c1467fe4999e74a1c16e5b344dcc9b81..b7baad6bf1bd028c63d6c21b5544dfc39382c31f 100644 (file)
--- a/gcc/match.pd
+++ b/gcc/match.pd
@@ -6120,8 +6120,8 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT)
    (cmp @0 (bit_xor @1 (convert @2)))))
 
  (simplify
-  (cmp (convert? addr@0) integer_zerop)
-  (if (tree_single_nonzero_warnv_p (@0, NULL))
+  (cmp (nop_convert? @0) integer_zerop)
+  (if (tree_expr_nonzero_p (@0))
    { constant_boolean_node (cmp == NE_EXPR, type); }))
 
  /* (X & C) op (Y & C) into (X ^ Y) & C op 0.  */

diff --git a/gcc/testsuite/gcc.dg/tree-ssa/pr110269.c b/gcc/testsuite/gcc.dg/tree-ssa/pr110269.c
new file mode 100644 (file)
index 0000000..c68a6f9
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/tree-ssa/pr110269.c
@@ -0,0 +1,34 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -fdump-tree-ccp2 -fdump-tree-optimized" } */
+
+void foo(void);
+static int a = 1, c;
+static int *b = &a;
+static int **d = &b;
+static int ***e = &d;
+void __assert_fail() __attribute__((__noreturn__));
+static int f() {
+    if (a) return a;
+    for (; c;) *e = 0;
+    if (b) __assert_fail();
+    return 6;
+}
+int main() {
+    if (f()) {
+        *d = 0;
+        if (b == 0)
+            ;
+        else {
+            __builtin_unreachable();
+            __assert_fail();
+        }
+    }
+    if (b == 0)
+        ;
+    else
+        foo();
+    ;
+}
+
+/* { dg-final { scan-tree-dump-times "Folding predicate" 2 "ccp2" } } */
+/* { dg-final { scan-tree-dump-not "foo" "optimized" } } */