indvars: Prototyping Sign/ZeroExtend elimination without canonical IVs.
No functionality enabled by default. Use -disable-iv-rewrite.
Extended IVUsers to keep track of the phi that represents the users' IV.
Added the WidenIV transform to replace a narrow IV with a wide IV
by doing a one-for-one replacement of IV users instead of expanding the
SCEV expressions. [sz]exts are removed and truncs are inserted.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131744 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp
index a8fe545..2fde73d 100644
--- a/lib/Analysis/IVUsers.cpp
+++ b/lib/Analysis/IVUsers.cpp
@@ -89,7 +89,7 @@
/// AddUsersIfInteresting - Inspect the specified instruction. If it is a
/// reducible SCEV, recursively add its users to the IVUsesByStride set and
/// return true. Otherwise, return false.
-bool IVUsers::AddUsersIfInteresting(Instruction *I) {
+bool IVUsers::AddUsersIfInteresting(Instruction *I, PHINode *Phi) {
if (!SE->isSCEVable(I->getType()))
return false; // Void and FP expressions cannot be reduced.
@@ -136,13 +136,13 @@
bool AddUserToIVUsers = false;
if (LI->getLoopFor(User->getParent()) != L) {
if (isa<PHINode>(User) || Processed.count(User) ||
- !AddUsersIfInteresting(User)) {
+ !AddUsersIfInteresting(User, Phi)) {
DEBUG(dbgs() << "FOUND USER in other loop: " << *User << '\n'
<< " OF SCEV: " << *ISE << '\n');
AddUserToIVUsers = true;
}
} else if (Processed.count(User) ||
- !AddUsersIfInteresting(User)) {
+ !AddUsersIfInteresting(User, Phi)) {
DEBUG(dbgs() << "FOUND USER: " << *User << '\n'
<< " OF SCEV: " << *ISE << '\n');
AddUserToIVUsers = true;
@@ -150,7 +150,7 @@
if (AddUserToIVUsers) {
// Okay, we found a user that we cannot reduce.
- IVUses.push_back(new IVStrideUse(this, User, I));
+ IVUses.push_back(new IVStrideUse(this, User, I, Phi));
IVStrideUse &NewUse = IVUses.back();
// Transform the expression into a normalized form.
ISE = TransformForPostIncUse(NormalizeAutodetect,
@@ -163,8 +163,8 @@
return true;
}
-IVStrideUse &IVUsers::AddUser(Instruction *User, Value *Operand) {
- IVUses.push_back(new IVStrideUse(this, User, Operand));
+IVStrideUse &IVUsers::AddUser(Instruction *User, Value *Operand, PHINode *Phi) {
+ IVUses.push_back(new IVStrideUse(this, User, Operand, Phi));
return IVUses.back();
}
@@ -192,7 +192,7 @@
// them by stride. Start by finding all of the PHI nodes in the header for
// this loop. If they are induction variables, inspect their uses.
for (BasicBlock::iterator I = L->getHeader()->begin(); isa<PHINode>(I); ++I)
- (void)AddUsersIfInteresting(I);
+ (void)AddUsersIfInteresting(I, cast<PHINode>(I));
return false;
}