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| author | Tim Shen <timshen91@gmail.com> | 2018-02-16 01:44:36 +0000 |
|---|---|---|
| committer | Tim Shen <timshen91@gmail.com> | 2018-02-16 01:44:36 +0000 |
| commit | 89337750a0286ac970738ac22a8462d82008b09f (patch) | |
| tree | 53c022d3515c555a21e64beea4c972802096470c | |
| parent | 3dc6de619a7a5778c1338187d3181ac5613b3959 (diff) | |
| download | bcm5719-llvm-89337750a0286ac970738ac22a8462d82008b09f.tar.gz bcm5719-llvm-89337750a0286ac970738ac22a8462d82008b09f.zip | |
[APInt] Fix extractBits to correctly handle Result.isSingleWord() case.
Summary: extractBits assumes that `!this->isSingleWord() implies !Result.isSingleWord()`, which may not necessarily be true. Handle both cases.
Reviewers: RKSimon
Subscribers: sanjoy, llvm-commits, hiraditya
Differential Revision: https://reviews.llvm.org/D43363
llvm-svn: 325311
| -rw-r--r-- | llvm/lib/Support/APInt.cpp | 3 | ||||
| -rw-r--r-- | llvm/unittests/ADT/APIntTest.cpp | 7 |
2 files changed, 9 insertions, 1 deletions
diff --git a/llvm/lib/Support/APInt.cpp b/llvm/lib/Support/APInt.cpp index 1ea6319acfa..48b9613b3ec 100644 --- a/llvm/lib/Support/APInt.cpp +++ b/llvm/lib/Support/APInt.cpp @@ -428,11 +428,12 @@ APInt APInt::extractBits(unsigned numBits, unsigned bitPosition) const { unsigned NumSrcWords = getNumWords(); unsigned NumDstWords = Result.getNumWords(); + uint64_t *DestPtr = Result.isSingleWord() ? &Result.U.VAL : Result.U.pVal; for (unsigned word = 0; word < NumDstWords; ++word) { uint64_t w0 = U.pVal[loWord + word]; uint64_t w1 = (loWord + word + 1) < NumSrcWords ? U.pVal[loWord + word + 1] : 0; - Result.U.pVal[word] = (w0 >> loBit) | (w1 << (APINT_BITS_PER_WORD - loBit)); + DestPtr[word] = (w0 >> loBit) | (w1 << (APINT_BITS_PER_WORD - loBit)); } return Result.clearUnusedBits(); diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp index 05fad386064..331b3997071 100644 --- a/llvm/unittests/ADT/APIntTest.cpp +++ b/llvm/unittests/ADT/APIntTest.cpp @@ -1768,6 +1768,13 @@ TEST(APIntTest, extractBits) { i257.extractBits(128, 1).getSExtValue()); EXPECT_EQ(static_cast<int64_t>(0xFFFFFFFFFF80007Full), i257.extractBits(129, 1).getSExtValue()); + + EXPECT_EQ(APInt(48, 0), + APInt(144, "281474976710655", 10).extractBits(48, 48)); + EXPECT_EQ(APInt(48, 0x0000ffffffffffffull), + APInt(144, "281474976710655", 10).extractBits(48, 0)); + EXPECT_EQ(APInt(48, 0x00007fffffffffffull), + APInt(144, "281474976710655", 10).extractBits(48, 1)); } TEST(APIntTest, getLowBitsSet) { |
