[ValueTracking] Range of cmp intrinsics are -1, 0, and 1

[AZero13]

No description provided.

[llvmbot]

@llvm/pr-subscribers-llvm-analysis

Author: AZero13 (AZero13)

Changes

---

Full diff: https://github.com/llvm/llvm-project/pull/144365.diff

1 Files Affected:

• (modified) llvm/lib/Analysis/ValueTracking.cpp (+4)

diff --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 9df667926faf0..2379aba69aad0 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -9785,6 +9785,10 @@ static ConstantRange getRangeForIntrinsic(const IntrinsicInst &II,
   unsigned Width = II.getType()->getScalarSizeInBits();
   const APInt *C;
   switch (II.getIntrinsicID()) {
+  case Intrinsic::scmp:
+  case Intrinsic::ucmp:
+    return ConstantRange::getNonEmpty(APInt::getAllOnes(Width),
+                                      APInt::getOneBitSet(Width, 0));
   case Intrinsic::ctlz:
   case Intrinsic::cttz: {
     APInt Upper(Width, Width);

[nikic]

This is redundant with attributes on the intrinsic.

Please do not submit patches without test coverage.