[APInt] Add setLowBits/setHighBits methods to APInt.
Summary:
There are quite a few places in the code base that do something like the following to set the high or low bits in an APInt.
KnownZero |= APInt::getHighBitsSet(BitWidth, BitWidth - 1);
For BitWidths larger than 64 this creates a short lived APInt with malloced storage. I think it might even call malloc twice. Its better to just provide methods that can set the necessary bits without the temporary APInt.
I'll update usages that benefit in a separate patch.
Reviewers: majnemer, MatzeB, davide, RKSimon, hans
Reviewed By: hans
Subscribers: llvm-commits
Differential Revision: https://reviews.llvm.org/D30525
llvm-svn: 297111
diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index aa1288e..8a9c4eb 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -1565,3 +1565,124 @@
EXPECT_EQ(0u, i64hi32.countTrailingOnes());
EXPECT_EQ(32u, i64hi32.countPopulation());
}
+
+TEST(APIntTest, setLowBits) {
+ APInt i64lo32(64, 0);
+ i64lo32.setLowBits(32);
+ EXPECT_EQ(0u, i64lo32.countLeadingOnes());
+ EXPECT_EQ(32u, i64lo32.countLeadingZeros());
+ EXPECT_EQ(32u, i64lo32.getActiveBits());
+ EXPECT_EQ(0u, i64lo32.countTrailingZeros());
+ EXPECT_EQ(32u, i64lo32.countTrailingOnes());
+ EXPECT_EQ(32u, i64lo32.countPopulation());
+
+ APInt i128lo64(128, 0);
+ i128lo64.setLowBits(64);
+ EXPECT_EQ(0u, i128lo64.countLeadingOnes());
+ EXPECT_EQ(64u, i128lo64.countLeadingZeros());
+ EXPECT_EQ(64u, i128lo64.getActiveBits());
+ EXPECT_EQ(0u, i128lo64.countTrailingZeros());
+ EXPECT_EQ(64u, i128lo64.countTrailingOnes());
+ EXPECT_EQ(64u, i128lo64.countPopulation());
+
+ APInt i128lo24(128, 0);
+ i128lo24.setLowBits(24);
+ EXPECT_EQ(0u, i128lo24.countLeadingOnes());
+ EXPECT_EQ(104u, i128lo24.countLeadingZeros());
+ EXPECT_EQ(24u, i128lo24.getActiveBits());
+ EXPECT_EQ(0u, i128lo24.countTrailingZeros());
+ EXPECT_EQ(24u, i128lo24.countTrailingOnes());
+ EXPECT_EQ(24u, i128lo24.countPopulation());
+
+ APInt i128lo104(128, 0);
+ i128lo104.setLowBits(104);
+ EXPECT_EQ(0u, i128lo104.countLeadingOnes());
+ EXPECT_EQ(24u, i128lo104.countLeadingZeros());
+ EXPECT_EQ(104u, i128lo104.getActiveBits());
+ EXPECT_EQ(0u, i128lo104.countTrailingZeros());
+ EXPECT_EQ(104u, i128lo104.countTrailingOnes());
+ EXPECT_EQ(104u, i128lo104.countPopulation());
+
+ APInt i128lo0(128, 0);
+ i128lo0.setLowBits(0);
+ EXPECT_EQ(0u, i128lo0.countLeadingOnes());
+ EXPECT_EQ(128u, i128lo0.countLeadingZeros());
+ EXPECT_EQ(0u, i128lo0.getActiveBits());
+ EXPECT_EQ(128u, i128lo0.countTrailingZeros());
+ EXPECT_EQ(0u, i128lo0.countTrailingOnes());
+ EXPECT_EQ(0u, i128lo0.countPopulation());
+
+ APInt i80lo79(80, 0);
+ i80lo79.setLowBits(79);
+ EXPECT_EQ(0u, i80lo79.countLeadingOnes());
+ EXPECT_EQ(1u, i80lo79.countLeadingZeros());
+ EXPECT_EQ(79u, i80lo79.getActiveBits());
+ EXPECT_EQ(0u, i80lo79.countTrailingZeros());
+ EXPECT_EQ(79u, i80lo79.countTrailingOnes());
+ EXPECT_EQ(79u, i80lo79.countPopulation());
+}
+
+TEST(APIntTest, setHighBits) {
+ APInt i64hi32(64, 0);
+ i64hi32.setHighBits(32);
+ EXPECT_EQ(32u, i64hi32.countLeadingOnes());
+ EXPECT_EQ(0u, i64hi32.countLeadingZeros());
+ EXPECT_EQ(64u, i64hi32.getActiveBits());
+ EXPECT_EQ(32u, i64hi32.countTrailingZeros());
+ EXPECT_EQ(0u, i64hi32.countTrailingOnes());
+ EXPECT_EQ(32u, i64hi32.countPopulation());
+
+ APInt i128hi64(128, 0);
+ i128hi64.setHighBits(64);
+ EXPECT_EQ(64u, i128hi64.countLeadingOnes());
+ EXPECT_EQ(0u, i128hi64.countLeadingZeros());
+ EXPECT_EQ(128u, i128hi64.getActiveBits());
+ EXPECT_EQ(64u, i128hi64.countTrailingZeros());
+ EXPECT_EQ(0u, i128hi64.countTrailingOnes());
+ EXPECT_EQ(64u, i128hi64.countPopulation());
+
+ APInt i128hi24(128, 0);
+ i128hi24.setHighBits(24);
+ EXPECT_EQ(24u, i128hi24.countLeadingOnes());
+ EXPECT_EQ(0u, i128hi24.countLeadingZeros());
+ EXPECT_EQ(128u, i128hi24.getActiveBits());
+ EXPECT_EQ(104u, i128hi24.countTrailingZeros());
+ EXPECT_EQ(0u, i128hi24.countTrailingOnes());
+ EXPECT_EQ(24u, i128hi24.countPopulation());
+
+ APInt i128hi104(128, 0);
+ i128hi104.setHighBits(104);
+ EXPECT_EQ(104u, i128hi104.countLeadingOnes());
+ EXPECT_EQ(0u, i128hi104.countLeadingZeros());
+ EXPECT_EQ(128u, i128hi104.getActiveBits());
+ EXPECT_EQ(24u, i128hi104.countTrailingZeros());
+ EXPECT_EQ(0u, i128hi104.countTrailingOnes());
+ EXPECT_EQ(104u, i128hi104.countPopulation());
+
+ APInt i128hi0(128, 0);
+ i128hi0.setHighBits(0);
+ EXPECT_EQ(0u, i128hi0.countLeadingOnes());
+ EXPECT_EQ(128u, i128hi0.countLeadingZeros());
+ EXPECT_EQ(0u, i128hi0.getActiveBits());
+ EXPECT_EQ(128u, i128hi0.countTrailingZeros());
+ EXPECT_EQ(0u, i128hi0.countTrailingOnes());
+ EXPECT_EQ(0u, i128hi0.countPopulation());
+
+ APInt i80hi1(80, 0);
+ i80hi1.setHighBits(1);
+ EXPECT_EQ(1u, i80hi1.countLeadingOnes());
+ EXPECT_EQ(0u, i80hi1.countLeadingZeros());
+ EXPECT_EQ(80u, i80hi1.getActiveBits());
+ EXPECT_EQ(79u, i80hi1.countTrailingZeros());
+ EXPECT_EQ(0u, i80hi1.countTrailingOnes());
+ EXPECT_EQ(1u, i80hi1.countPopulation());
+
+ APInt i32hi16(32, 0);
+ i32hi16.setHighBits(16);
+ EXPECT_EQ(16u, i32hi16.countLeadingOnes());
+ EXPECT_EQ(0u, i32hi16.countLeadingZeros());
+ EXPECT_EQ(32u, i32hi16.getActiveBits());
+ EXPECT_EQ(16u, i32hi16.countTrailingZeros());
+ EXPECT_EQ(0u, i32hi16.countTrailingOnes());
+ EXPECT_EQ(16u, i32hi16.countPopulation());
+}