[ConstantRange] Add support for `shlWithNoWrap` (#100594)

This patch adds initial support for `ConstantRange:: shlWithNoWrap` to
fold https://github.com/dtcxzyw/llvm-tools/issues/22. However, this
patch cannot fix the original issue. Improvements will be submitted in subsequent patches.

1 files changed, 42 insertions, 0 deletions

diff --git a/llvm/unittests/IR/ConstantRangeTest.cpp b/llvm/unittests/IR/ConstantRangeTest.cpp
index 7977a78..1705f3e 100644
--- a/llvm/unittests/IR/ConstantRangeTest.cpp
+++ b/llvm/unittests/IR/ConstantRangeTest.cpp
@@ -1502,6 +1502,48 @@ TEST_F(ConstantRangeTest, Shl) {
       });
 }
 
+TEST_F(ConstantRangeTest, ShlWithNoWrap) {
+  using OBO = OverflowingBinaryOperator;
+  TestBinaryOpExhaustive(
+      [](const ConstantRange &CR1, const ConstantRange &CR2) {
+        return CR1.shlWithNoWrap(CR2, OBO::NoUnsignedWrap);
+      },
+      [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
+        bool IsOverflow;
+        APInt Res = N1.ushl_ov(N2, IsOverflow);
+        if (IsOverflow)
+          return std::nullopt;
+        return Res;
+      },
+      PreferSmallest, CheckCorrectnessOnly);
+  TestBinaryOpExhaustive(
+      [](const ConstantRange &CR1, const ConstantRange &CR2) {
+        return CR1.shlWithNoWrap(CR2, OBO::NoSignedWrap);
+      },
+      [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
+        bool IsOverflow;
+        APInt Res = N1.sshl_ov(N2, IsOverflow);
+        if (IsOverflow)
+          return std::nullopt;
+        return Res;
+      },
+      PreferSmallest, CheckCorrectnessOnly);
+  TestBinaryOpExhaustive(
+      [](const ConstantRange &CR1, const ConstantRange &CR2) {
+        return CR1.shlWithNoWrap(CR2, OBO::NoUnsignedWrap | OBO::NoSignedWrap);
+      },
+      [](const APInt &N1, const APInt &N2) -> std::optional<APInt> {
+        bool IsOverflow1, IsOverflow2;
+        APInt Res1 = N1.ushl_ov(N2, IsOverflow1);
+        APInt Res2 = N1.sshl_ov(N2, IsOverflow2);
+        if (IsOverflow1 || IsOverflow2)
+          return std::nullopt;
+        assert(Res1 == Res2 && "Left shift results differ?");
+        return Res1;
+      },
+      PreferSmallest, CheckCorrectnessOnly);
+}
+
 TEST_F(ConstantRangeTest, Lshr) {
   EXPECT_EQ(Full.lshr(Full), Full);
   EXPECT_EQ(Full.lshr(Empty), Empty);