[APInt] Added APInt::clearBits() method (#137098)

Added APInt::clearBits(unsigned loBit, unsigned hiBit) that clears bits within a certain range.

Fixes #136550

---------

Co-authored-by: Simon Pilgrim <llvm-dev@redking.me.uk>

1 files changed, 64 insertions, 0 deletions

diff --git a/llvm/unittests/ADT/APIntTest.cpp b/llvm/unittests/ADT/APIntTest.cpp
index b14366e..a58fbd6 100644
--- a/llvm/unittests/ADT/APIntTest.cpp
+++ b/llvm/unittests/ADT/APIntTest.cpp
@@ -2520,6 +2520,70 @@ TEST(APIntTest, setAllBits) {
   EXPECT_EQ(128u, i128.popcount());
 }
 
+TEST(APIntTest, clearBits) {
+  APInt i32 = APInt::getAllOnes(32);
+  i32.clearBits(1, 3);
+  EXPECT_EQ(1u, i32.countr_one());
+  EXPECT_EQ(0u, i32.countr_zero());
+  EXPECT_EQ(32u, i32.getActiveBits());
+  EXPECT_EQ(0u, i32.countl_zero());
+  EXPECT_EQ(29u, i32.countl_one());
+  EXPECT_EQ(30u, i32.popcount());
+
+  i32.clearBits(15, 15);
+  EXPECT_EQ(1u, i32.countr_one());
+  EXPECT_EQ(0u, i32.countr_zero());
+  EXPECT_EQ(32u, i32.getActiveBits());
+  EXPECT_EQ(0u, i32.countl_zero());
+  EXPECT_EQ(29u, i32.countl_one());
+  EXPECT_EQ(30u, i32.popcount());
+
+  i32.clearBits(28, 31);
+  EXPECT_EQ(1u, i32.countr_one());
+  EXPECT_EQ(0u, i32.countr_zero());
+  EXPECT_EQ(32u, i32.getActiveBits());
+  EXPECT_EQ(0u, i32.countl_zero());
+  EXPECT_EQ(1u, i32.countl_one());
+  EXPECT_EQ(27u, i32.popcount());
+  EXPECT_EQ(APInt(32, "8FFFFFF9", 16), i32);
+
+  APInt i256 = APInt::getAllOnes(256);
+  i256.clearBits(10, 250);
+  EXPECT_EQ(10u, i256.countr_one());
+  EXPECT_EQ(0u, i256.countr_zero());
+  EXPECT_EQ(256u, i256.getActiveBits());
+  EXPECT_EQ(0u, i256.countl_zero());
+  EXPECT_EQ(6u, i256.countl_one());
+  EXPECT_EQ(16u, i256.popcount());
+
+  APInt i311 = APInt::getAllOnes(311);
+  i311.clearBits(33, 99);
+  EXPECT_EQ(33u, i311.countr_one());
+  EXPECT_EQ(0u, i311.countr_zero());
+  EXPECT_EQ(311u, i311.getActiveBits());
+  EXPECT_EQ(0u, i311.countl_zero());
+  EXPECT_EQ(212u, i311.countl_one());
+  EXPECT_EQ(245u, i311.popcount());
+
+  APInt i64hi32 = APInt::getAllOnes(64);
+  i64hi32.clearBits(0, 32);
+  EXPECT_EQ(32u, i64hi32.countl_one());
+  EXPECT_EQ(0u, i64hi32.countl_zero());
+  EXPECT_EQ(64u, i64hi32.getActiveBits());
+  EXPECT_EQ(32u, i64hi32.countr_zero());
+  EXPECT_EQ(0u, i64hi32.countr_one());
+  EXPECT_EQ(32u, i64hi32.popcount());
+
+  i64hi32 = APInt::getAllOnes(64);
+  i64hi32.clearBits(32, 64);
+  EXPECT_EQ(32u, i64hi32.countr_one());
+  EXPECT_EQ(0u, i64hi32.countr_zero());
+  EXPECT_EQ(32u, i64hi32.getActiveBits());
+  EXPECT_EQ(32u, i64hi32.countl_zero());
+  EXPECT_EQ(0u, i64hi32.countl_one());
+  EXPECT_EQ(32u, i64hi32.popcount());
+}
+
 TEST(APIntTest, getLoBits) {
   APInt i32(32, 0xfa);
   i32.setHighBits(1);