From c6b05b86edbdc0d00e54145a115135c84cbf8402 Mon Sep 17 00:00:00 2001
From: Aldy Hernandez <aldyh@redhat.com>
Date: Tue, 31 Mar 2020 16:19:37 +0200
Subject: Intersect known global ranges of LHS in gimple_ranger::range_of_call.

---
 gcc/ssa-range.cc | 14 +++++++++++---
 1 file changed, 11 insertions(+), 3 deletions(-)

(limited to 'gcc')

diff --git a/gcc/ssa-range.cc b/gcc/ssa-range.cc
index e8fe078..64cce18 100644
--- a/gcc/ssa-range.cc
+++ b/gcc/ssa-range.cc
@@ -212,15 +212,23 @@ bool
 gimple_ranger::range_of_call (irange &r, gcall *call)
 {
   tree type = gimple_call_return_type (call);
+  tree lhs = gimple_call_lhs (call);
+
   if (!irange::supports_type_p (type))
     return false;
 
   if (gimple_call_nonnull_result_p (call))
+    r = range_nonzero (type);
+  else
+    r.set_varying (type);
+
+  // If there is a lHS, intersect that with what is known.
+  if (lhs)
     {
-      r = range_nonzero (type);
-      return true;
+      value_range def;
+      def = gimple_range_global (lhs);
+      r.intersect (def);
     }
-  r.set_varying (type);
   return true;
 }
 
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