From b97a02c7d3db767018e5e92c6516fd321a8eb4b5 Mon Sep 17 00:00:00 2001 From: Craig Topper Date: Wed, 10 May 2017 20:01:48 +0000 Subject: [PATCH] [ConstantRange] Fix the early out in ConstantRange::multiply for positive numbers to really do what the comment says r271020 added an early out to skip the signed multiply portion of ConstantRange::multiply. The comment says we don't need to do signed multiply if the range is only positive numbers, but the implemented check only ensures that the start of the range is positive. It doesn't look at the end of the range. This patch checks the end of the range instead. Because Upper is one more than the end we have to see if its positive or if its one past the last positive number. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@302717 91177308-0d34-0410-b5e6-96231b3b80d8 --- lib/IR/ConstantRange.cpp | 3 ++- unittests/IR/ConstantRangeTest.cpp | 2 +- 2 files changed, 3 insertions(+), 2 deletions(-) diff --git a/lib/IR/ConstantRange.cpp b/lib/IR/ConstantRange.cpp index a33d062dbea..509caba3acd 100644 --- a/lib/IR/ConstantRange.cpp +++ b/lib/IR/ConstantRange.cpp @@ -757,7 +757,8 @@ ConstantRange::multiply(const ConstantRange &Other) const { // from one positive number to another which is as good as we can generate. // In this case, skip the extra work of generating signed ranges which aren't // going to be better than this range. - if (!UR.isWrappedSet() && UR.getLower().isNonNegative()) + if (!UR.isWrappedSet() && + (UR.getUpper().isNonNegative() || UR.getUpper().isMinSignedValue())) return UR; // Now the signed range. Because we could be dealing with negative numbers diff --git a/unittests/IR/ConstantRangeTest.cpp b/unittests/IR/ConstantRangeTest.cpp index 6c5c8f50340..593580e2f61 100644 --- a/unittests/IR/ConstantRangeTest.cpp +++ b/unittests/IR/ConstantRangeTest.cpp @@ -447,7 +447,7 @@ TEST_F(ConstantRangeTest, Multiply) { // TODO: This should be return [-2, 0] EXPECT_EQ(ConstantRange(APInt(8, -2)).multiply( ConstantRange(APInt(8, 0), APInt(8, 2))), - ConstantRange(APInt(8, 0), APInt(8, 255))); + ConstantRange(APInt(8, -2), APInt(8, 1))); } TEST_F(ConstantRangeTest, UMax) { -- 2.50.1