From a5f9c27bfc4417224e332392bb81a2d733b2b5bf Mon Sep 17 00:00:00 2001
From: Andrew MacLeod <amacleod@redhat.com>
Date: Tue, 17 Nov 2020 10:04:38 -0500
Subject: IOR with nonzero, range cannot contain 0.

Remove zero from IOR ranges with non-zero masks.

	gcc/
	PR tree-optimization/83072
	* range-op.cc (wi_optimize_and_or): Remove zero from IOR range when
	mask is non-zero.
	gcc/testsuite/
	* gcc.dg/pr83072.c: New.
---
 gcc/range-op.cc | 8 ++++++++
 1 file changed, 8 insertions(+)

(limited to 'gcc/range-op.cc')

diff --git a/gcc/range-op.cc b/gcc/range-op.cc
index b746aad..d0adc95 100644
--- a/gcc/range-op.cc
+++ b/gcc/range-op.cc
@@ -2163,6 +2163,14 @@ wi_optimize_and_or (irange &r,
   else
     gcc_unreachable ();
   value_range_with_overflow (r, type, res_lb, res_ub);
+
+  // Furthermore, if the mask is non-zero, an IOR cannot contain zero.
+  if (code == BIT_IOR_EXPR && wi::ne_p (mask, 0))
+    {
+      int_range<2> tmp;
+      tmp.set_nonzero (type);
+      r.intersect (tmp);
+    }
   return true;
 }
 
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