[PatternMatch] Allow `m_ConstantInt` to match integer splats (#153692)

When matching integers, `m_ConstantInt` is a convenient alternative to
`m_APInt` for matching unsigned 64-bit integers, allowing one to
simplify

```cpp
const APInt *IntC;
if (match(V, m_APInt(IntC))) {
  if (IntC->ule(UINT64_MAX)) {
    uint64_t Int = IntC->getZExtValue();
    // ...
  }
}
```
to
```cpp
uint64_t Int;
if (match(V, m_ConstantInt(Int))) {
  // ...
}
```

However, this simplification is only true if `V` is a scalar type.
Specifically, `m_APInt` also matches integer splats, but `m_ConstantInt`
does not.

This patch ensures that the matching behaviour of `m_ConstantInt`
parallels that of `m_APInt`, and also incorporates it in some obvious
places.

1 files changed, 3 insertions, 3 deletions

diff --git a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
index 737321d..cc4eb2d 100644
--- a/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp
@@ -319,10 +319,10 @@ static void annotateNonNullAndDereferenceable(CallInst *CI, ArrayRef<unsigned> A
     annotateDereferenceableBytes(CI, ArgNos, LenC->getZExtValue());
   } else if (isKnownNonZero(Size, DL)) {
     annotateNonNullNoUndefBasedOnAccess(CI, ArgNos);
-    const APInt *X, *Y;
+    uint64_t X, Y;
     uint64_t DerefMin = 1;
-    if (match(Size, m_Select(m_Value(), m_APInt(X), m_APInt(Y)))) {
-      DerefMin = std::min(X->getZExtValue(), Y->getZExtValue());
+    if (match(Size, m_Select(m_Value(), m_ConstantInt(X), m_ConstantInt(Y)))) {
+      DerefMin = std::min(X, Y);
       annotateDereferenceableBytes(CI, ArgNos, DerefMin);
     }
   }