From: Andrew MacLeod <amacleod@redhat.com>
Date: Mon, 26 Oct 2020 18:55:00 +0000 (-0400)
Subject: Combine logical OR ranges properly.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=48722d158cbf692c24025e345ecbbbb570f66aa5;p=gcc.git

Combine logical OR ranges properly.

When combining logical OR operands with a FALSE result, union the false
ranges for operand1 and operand2... not intersection.

	gcc/
	PR tree-optimization/97567
	* gimple-range-gori.cc (gori_compute::logical_combine): Union the
	ranges of operand1 and operand2, not intersect.
	gcc/testsuite/
	* gcc.dg/pr97567.c: New.
---

diff --git a/gcc/gimple-range-gori.cc b/gcc/gimple-range-gori.cc
index 5d50b111d2a..de0f653860d 100644
--- a/gcc/gimple-range-gori.cc
+++ b/gcc/gimple-range-gori.cc
@@ -730,10 +730,10 @@ gori_compute::logical_combine (irange &r, enum tree_code code,
         if (lhs.zero_p ())
 	  {
 	    // An OR operation will only take the FALSE path if both
-	    // operands are false, so [20, 255] intersect [0, 5] is the
+	    // operands are false, so either [20, 255] or [0, 5] is the
 	    // union: [0,5][20,255].
 	    r = op1.false_range;
-	    r.intersect (op2.false_range);
+	    r.union_ (op2.false_range);
 	  }
 	else
 	  {
diff --git a/gcc/testsuite/gcc.dg/pr97567.c b/gcc/testsuite/gcc.dg/pr97567.c
new file mode 100644
index 00000000000..b2b72a4d2a7
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr97567.c
@@ -0,0 +1,34 @@
+/* { dg-do run } */
+/* { dg-options "-O2" } */
+
+int a, b, c, d;
+void k() {
+  unsigned f = 1;
+  long g = 4073709551615;
+  for (; a; a++)
+    for (;;) {
+      d = 0;
+    L1:
+      break;
+    }
+  if (f)
+    for (; a; a++)
+      ;
+  g || f;
+  int i = 0 - f || g;
+  long j = g - f;
+  if (j || f) {
+    if (g < 4073709551615)
+      for (;;)
+        ;
+    int e = ~f, h = b / ~e;
+    if (c)
+      goto L2;
+    g = f = h;
+  }
+  g || d;
+L2:
+  if (c)
+    goto L1;
+}
+int main() { k(); return 0; }