[llvm] r359180 - [ConstantRange] [a, b) udiv a full range is [0, umax(b)).

[Florian Hahn via llvm-commits]

Author: fhahn
Date: Thu Apr 25 03:12:43 2019
New Revision: 359180

URL: http://llvm.org/viewvc/llvm-project?rev=359180&view=rev
Log:
[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

Modified:
    llvm/trunk/lib/IR/ConstantRange.cpp
    llvm/trunk/unittests/IR/ConstantRangeTest.cpp

Modified: llvm/trunk/lib/IR/ConstantRange.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/ConstantRange.cpp?rev=359180&r1=359179&r2=359180&view=diff
==============================================================================
--- llvm/trunk/lib/IR/ConstantRange.cpp (original)
+++ llvm/trunk/lib/IR/ConstantRange.cpp Thu Apr 25 03:12:43 2019
@@ -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());
 

Modified: llvm/trunk/unittests/IR/ConstantRangeTest.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/unittests/IR/ConstantRangeTest.cpp?rev=359180&r1=359179&r2=359180&view=diff
==============================================================================
--- llvm/trunk/unittests/IR/ConstantRangeTest.cpp (original)
+++ llvm/trunk/unittests/IR/ConstantRangeTest.cpp Thu Apr 25 03:12:43 2019
@@ -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) {