[InstCombine] Re-commit of r218721 (Optimize icmp-select-icmp sequence)
Fixes the self-host fail. Note that this commit activates dominator
analysis in the combiner by default (like the original commit did).
llvm-svn: 222590
diff --git a/llvm/lib/Transforms/InstCombine/InstCombine.h b/llvm/lib/Transforms/InstCombine/InstCombine.h
index d4b252b..3e53b73 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombine.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombine.h
@@ -14,6 +14,7 @@
#include "llvm/Analysis/AssumptionTracker.h"
#include "llvm/Analysis/TargetFolder.h"
#include "llvm/Analysis/ValueTracking.h"
+#include "llvm/IR/Dominators.h"
#include "llvm/IR/IRBuilder.h"
#include "llvm/IR/InstVisitor.h"
#include "llvm/IR/IntrinsicInst.h"
@@ -98,7 +99,7 @@
AssumptionTracker *AT;
const DataLayout *DL;
TargetLibraryInfo *TLI;
- DominatorTree *DT; // not required
+ DominatorTree *DT;
bool MadeIRChange;
LibCallSimplifier *Simplifier;
bool MinimizeSize;
@@ -113,7 +114,8 @@
BuilderTy *Builder;
static char ID; // Pass identification, replacement for typeid
- InstCombiner() : FunctionPass(ID), DL(nullptr), Builder(nullptr) {
+ InstCombiner()
+ : FunctionPass(ID), DL(nullptr), DT(nullptr), Builder(nullptr) {
MinimizeSize = false;
initializeInstCombinerPass(*PassRegistry::getPassRegistry());
}
@@ -245,6 +247,16 @@
// visitInstruction - Specify what to return for unhandled instructions...
Instruction *visitInstruction(Instruction &I) { return nullptr; }
+ // True when DB dominates all uses of DI execpt UI.
+ // UI must be in the same block as DI.
+ // The routine checks that the DI parent and DB are different.
+ bool dominatesAllUses(const Instruction *DI, const Instruction *UI,
+ const BasicBlock *DB) const;
+
+ // Replace select with select operand SIOpd in SI-ICmp sequence when possible
+ bool replacedSelectWithOperand(SelectInst *SI, const ICmpInst *Icmp,
+ const unsigned SIOpd);
+
private:
bool ShouldChangeType(Type *From, Type *To) const;
Value *dyn_castNegVal(Value *V) const;