add a new SimplifyInstruction API, which is like ConstantFoldInstruction,
except that the result may not be a constant. Switch jump threading to
use it so that it gets things like (X & 0) -> 0, which occur when phi preds
are deleted and the remaining phi pred was a zero.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86637 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Transforms/Scalar/JumpThreading.cpp b/lib/Transforms/Scalar/JumpThreading.cpp
index 7eaae9b..46d40ef 100644
--- a/lib/Transforms/Scalar/JumpThreading.cpp
+++ b/lib/Transforms/Scalar/JumpThreading.cpp
@@ -16,7 +16,6 @@
#include "llvm/IntrinsicInst.h"
#include "llvm/LLVMContext.h"
#include "llvm/Pass.h"
-#include "llvm/Analysis/ConstantFolding.h"
#include "llvm/Analysis/InstructionSimplify.h"
#include "llvm/Transforms/Utils/BasicBlockUtils.h"
#include "llvm/Transforms/Utils/Local.h"
@@ -223,9 +222,9 @@
Instruction *User = cast<Instruction>(U.getUser());
U = PNV;
- // See if we can simplify it (constant folding).
- if (Constant *C = ConstantFoldInstruction(User, TD)) {
- User->replaceAllUsesWith(C);
+ // See if we can simplify it.
+ if (Value *V = SimplifyInstruction(User, TD)) {
+ User->replaceAllUsesWith(V);
User->eraseFromParent();
}
}
@@ -1203,8 +1202,8 @@
BI = NewBB->begin();
for (BasicBlock::iterator E = NewBB->end(); BI != E; ) {
Instruction *Inst = BI++;
- if (Constant *C = ConstantFoldInstruction(Inst, TD)) {
- Inst->replaceAllUsesWith(C);
+ if (Value *V = SimplifyInstruction(Inst, TD)) {
+ Inst->replaceAllUsesWith(V);
Inst->eraseFromParent();
continue;
}