[InstCombine] use m_APInt to allow demanded bits analysis on splat constants
llvm-svn: 294628
diff --git a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
index fb7177f..42ce76b 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstCombineSimplifyDemanded.cpp
@@ -30,18 +30,20 @@
assert(I && "No instruction?");
assert(OpNo < I->getNumOperands() && "Operand index too large");
- // If the operand is not a constant integer, nothing to do.
- ConstantInt *OpC = dyn_cast<ConstantInt>(I->getOperand(OpNo));
- if (!OpC) return false;
+ // The operand must be a constant integer or splat integer.
+ Value *Op = I->getOperand(OpNo);
+ const APInt *C;
+ if (!match(Op, m_APInt(C)))
+ return false;
// If there are no bits set that aren't demanded, nothing to do.
- Demanded = Demanded.zextOrTrunc(OpC->getValue().getBitWidth());
- if ((~Demanded & OpC->getValue()) == 0)
+ Demanded = Demanded.zextOrTrunc(C->getBitWidth());
+ if ((~Demanded & *C) == 0)
return false;
// This instruction is producing bits that are not demanded. Shrink the RHS.
- Demanded &= OpC->getValue();
- I->setOperand(OpNo, ConstantInt::get(OpC->getType(), Demanded));
+ Demanded &= *C;
+ I->setOperand(OpNo, ConstantInt::get(Op->getType(), Demanded));
return true;
}
@@ -114,9 +116,10 @@
KnownOne.getBitWidth() == BitWidth &&
"Value *V, DemandedMask, KnownZero and KnownOne "
"must have same BitWidth");
- if (ConstantInt *CI = dyn_cast<ConstantInt>(V)) {
- // We know all of the bits for a constant!
- KnownOne = CI->getValue() & DemandedMask;
+ const APInt *C;
+ if (match(V, m_APInt(C))) {
+ // We know all of the bits for a scalar constant or a splat vector constant!
+ KnownOne = *C & DemandedMask;
KnownZero = ~KnownOne & DemandedMask;
return nullptr;
}