[InstCombine] add a wrapper for a common pair of transforms; NFCI
Some of the callers are artificially limiting this transform to integer types;
this should make it easier to incrementally remove that restriction.
llvm-svn: 291620
diff --git a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
index 9a52874c..27fc34d 100644
--- a/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
+++ b/llvm/lib/Transforms/InstCombine/InstructionCombining.cpp
@@ -770,10 +770,6 @@
return RI;
}
-/// Given an instruction with a select as one operand and a constant as the
-/// other operand, try to fold the binary operator into the select arguments.
-/// This also works for Cast instructions, which obviously do not have a second
-/// operand.
Instruction *InstCombiner::FoldOpIntoSelect(Instruction &Op, SelectInst *SI) {
// Don't modify shared select instructions.
if (!SI->hasOneUse())
@@ -824,9 +820,6 @@
return SelectInst::Create(SI->getCondition(), NewTV, NewFV, "", nullptr, SI);
}
-/// Given a binary operator, cast instruction, or select which has a PHI node as
-/// operand #0, see if we can fold the instruction into the PHI (which is only
-/// possible if all operands to the PHI are constants).
Instruction *InstCombiner::FoldOpIntoPhi(Instruction &I) {
PHINode *PN = cast<PHINode>(I.getOperand(0));
unsigned NumPHIValues = PN->getNumIncomingValues();
@@ -964,6 +957,19 @@
return replaceInstUsesWith(I, NewPN);
}
+Instruction *InstCombiner::foldOpWithConstantIntoOperand(Instruction &I) {
+ assert(isa<Constant>(I.getOperand(1)) && "Unexpected operand type");
+
+ if (auto *Sel = dyn_cast<SelectInst>(I.getOperand(0))) {
+ if (Instruction *NewSel = FoldOpIntoSelect(I, Sel))
+ return NewSel;
+ } else if (isa<PHINode>(I.getOperand(0))) {
+ if (Instruction *NewPhi = FoldOpIntoPhi(I))
+ return NewPhi;
+ }
+ return nullptr;
+}
+
/// Given a pointer type and a constant offset, determine whether or not there
/// is a sequence of GEP indices into the pointed type that will land us at the
/// specified offset. If so, fill them into NewIndices and return the resultant