From: Florian Hahn <flo@fhahn.com>
Date: Thu, 25 Apr 2019 10:12:43 +0000 (+0000)
Subject: [ConstantRange] [a, b) udiv a full range is [0, umax(b)).
X-Git-Url: https://granicus.if.org/sourcecode?a=commitdiff_plain;h=32986d30ff257822b8c7a3899637b18356cbe026;p=llvm

[ConstantRange] [a, b) udiv a full range is [0, umax(b)).

Reviewers: nikic, spatel, efriedma

Reviewed By: nikic

Differential Revision: https://reviews.llvm.org/D60536

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@359180 91177308-0d34-0410-b5e6-96231b3b80d8
---

diff --git a/lib/IR/ConstantRange.cpp b/lib/IR/ConstantRange.cpp
index 7e2c6727703..af71fd3ac65 100644
--- a/lib/IR/ConstantRange.cpp
+++ b/lib/IR/ConstantRange.cpp
@@ -974,8 +974,6 @@ ConstantRange
 ConstantRange::udiv(const ConstantRange &RHS) const {
   if (isEmptySet() || RHS.isEmptySet() || RHS.getUnsignedMax().isNullValue())
     return getEmpty();
-  if (RHS.isFullSet())
-    return getFull();
 
   APInt Lower = getUnsignedMin().udiv(RHS.getUnsignedMax());
 
diff --git a/unittests/IR/ConstantRangeTest.cpp b/unittests/IR/ConstantRangeTest.cpp
index 692d151778e..b9d8fe071e3 100644
--- a/unittests/IR/ConstantRangeTest.cpp
+++ b/unittests/IR/ConstantRangeTest.cpp
@@ -821,6 +821,16 @@ TEST_F(ConstantRangeTest, UDiv) {
   EXPECT_EQ(Some.udiv(Some), ConstantRange(APInt(16, 0), APInt(16, 0x111)));
   EXPECT_EQ(Some.udiv(Wrap), ConstantRange(APInt(16, 0), APInt(16, 0xaaa)));
   EXPECT_EQ(Wrap.udiv(Wrap), Full);
+
+
+  ConstantRange Zero(APInt(16, 0));
+  EXPECT_EQ(Zero.udiv(One), Zero);
+  EXPECT_EQ(Zero.udiv(Full), Zero);
+
+  EXPECT_EQ(ConstantRange(APInt(16, 0), APInt(16, 99)).udiv(Full),
+            ConstantRange(APInt(16, 0), APInt(16, 99)));
+  EXPECT_EQ(ConstantRange(APInt(16, 10), APInt(16, 99)).udiv(Full),
+            ConstantRange(APInt(16, 0), APInt(16, 99)));
 }
 
 TEST_F(ConstantRangeTest, URem) {