[llvm] [ConstantRange][LVI] Add initial support for `multiplyWithNoWrap` (PR #92356)

[Nikita Popov via llvm-commits]

================
@@ -1019,6 +1019,99 @@ TEST_F(ConstantRangeTest, Multiply) {
       });
 }
 
+TEST_F(ConstantRangeTest, MultiplyWithNoWrap) {
+  using OBO = OverflowingBinaryOperator;
+
+  EXPECT_EQ(Empty.multiplyWithNoWrap(Some, OBO::NoUnsignedWrap), Empty);
+  EXPECT_EQ(Some.multiplyWithNoWrap(Empty, OBO::NoUnsignedWrap), Empty);
+  EXPECT_EQ(Full.multiplyWithNoWrap(Full, OBO::NoUnsignedWrap), Full);
+  EXPECT_EQ(Full.multiplyWithNoWrap(Some, OBO::NoUnsignedWrap), Full);
+  EXPECT_EQ(Some.multiplyWithNoWrap(Full, OBO::NoUnsignedWrap), Full);
+  EXPECT_EQ(ConstantRange(APInt(4, 0), APInt(4, 2))
+                .multiplyWithNoWrap(ConstantRange(APInt(4, 2), APInt(4, 0)),
+                                    OBO::NoUnsignedWrap),
+            ConstantRange(4, true));
+  EXPECT_EQ(ConstantRange(APInt(4, 1), APInt(4, 5))
+                .multiplyWithNoWrap(ConstantRange(APInt(4, 1), APInt(4, 5)),
+                                    OBO::NoUnsignedWrap),
+            ConstantRange(APInt(4, 1), APInt(4, 0)));
+  EXPECT_EQ(ConstantRange(APInt(8, 254), APInt(8, 0))
+                .multiplyWithNoWrap(ConstantRange(APInt(8, 252), APInt(8, 4)),
+                                    OBO::NoUnsignedWrap),
+            ConstantRange(APInt(8, 250), APInt(8, 9)));
+  EXPECT_EQ(ConstantRange(APInt(8, 254), APInt(8, 255))
+                .multiplyWithNoWrap(ConstantRange(APInt(8, 2), APInt(8, 4)),
+                                    OBO::NoUnsignedWrap),
+            ConstantRange(8, false));
+
+  EXPECT_EQ(Empty.multiplyWithNoWrap(Some, OBO::NoSignedWrap), Empty);
+  EXPECT_EQ(Some.multiplyWithNoWrap(Empty, OBO::NoSignedWrap), Empty);
+  EXPECT_EQ(Full.multiplyWithNoWrap(Full, OBO::NoSignedWrap), Full);
+  EXPECT_EQ(Full.multiplyWithNoWrap(Some, OBO::NoSignedWrap), Full);
+  EXPECT_EQ(Some.multiplyWithNoWrap(Full, OBO::NoSignedWrap), Full);
+  EXPECT_EQ(ConstantRange(APInt(4, 0), APInt(4, 4))
+                .multiplyWithNoWrap(ConstantRange(APInt(4, -5), APInt(4, 4)),
----------------
nikic wrote:

```suggestion
                .multiplyWithNoWrap(ConstantRange(APInt(4, -5, true), APInt(4, 4)),
```
But this is... (also below).

https://github.com/llvm/llvm-project/pull/92356