Remove the code from IVUsers that attempted to handle
casted induction variables in cases where the cast
isn't foldable. It ended up being a pessimization in
many cases. This could be fixed, but it would require
a bunch of complicated code in IVUsers' clients. The
advantages of this approach aren't visible enough to
justify it at this time.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@73706 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/IVUsers.cpp b/lib/Analysis/IVUsers.cpp
index 4f77641..0bacc39 100644
--- a/lib/Analysis/IVUsers.cpp
+++ b/lib/Analysis/IVUsers.cpp
@@ -82,11 +82,8 @@
/// outer loop of the current loop.
static bool getSCEVStartAndStride(const SCEVHandle &SH, Loop *L, Loop *UseLoop,
SCEVHandle &Start, SCEVHandle &Stride,
- bool &isSigned,
ScalarEvolution *SE, DominatorTree *DT) {
SCEVHandle TheAddRec = Start; // Initialize to zero.
- bool isSExt = false;
- bool isZExt = false;
// If the outer level is an AddExpr, the operands are all start values except
// for a nested AddRecExpr.
@@ -101,13 +98,6 @@
} else {
Start = SE->getAddExpr(Start, AE->getOperand(i));
}
-
- } else if (const SCEVZeroExtendExpr *Z = dyn_cast<SCEVZeroExtendExpr>(SH)) {
- TheAddRec = Z->getOperand();
- isZExt = true;
- } else if (const SCEVSignExtendExpr *S = dyn_cast<SCEVSignExtendExpr>(SH)) {
- TheAddRec = S->getOperand();
- isSExt = true;
} else if (isa<SCEVAddRecExpr>(SH)) {
TheAddRec = SH;
} else {
@@ -131,9 +121,6 @@
if (containsAddRecFromDifferentLoop(AddRecStart, L))
return false;
- if (isSExt || isZExt)
- Start = SE->getTruncateExpr(Start, AddRec->getType());
-
Start = SE->getAddExpr(Start, AddRecStart);
// If stride is an instruction, make sure it dominates the loop preheader.
@@ -148,7 +135,6 @@
}
Stride = AddRecStride;
- isSigned = isSExt;
return true;
}
@@ -218,9 +204,8 @@
Loop *UseLoop = LI->getLoopFor(I->getParent());
SCEVHandle Start = SE->getIntegerSCEV(0, ISE->getType());
SCEVHandle Stride = Start;
- bool isSigned = false; // Arbitrary initial value - pacifies compiler.
- if (!getSCEVStartAndStride(ISE, L, UseLoop, Start, Stride, isSigned, SE, DT))
+ if (!getSCEVStartAndStride(ISE, L, UseLoop, Start, Stride, SE, DT))
return false; // Non-reducible symbolic expression, bail out.
SmallPtrSet<Instruction *, 4> UniqueUsers;
@@ -271,11 +256,11 @@
// The value used will be incremented by the stride more than we are
// expecting, so subtract this off.
SCEVHandle NewStart = SE->getMinusSCEV(Start, Stride);
- StrideUses->addUser(NewStart, User, I, isSigned);
+ StrideUses->addUser(NewStart, User, I);
StrideUses->Users.back().setIsUseOfPostIncrementedValue(true);
DOUT << " USING POSTINC SCEV, START=" << *NewStart<< "\n";
} else {
- StrideUses->addUser(Start, User, I, isSigned);
+ StrideUses->addUser(Start, User, I);
}
}
}
@@ -312,7 +297,6 @@
/// getReplacementExpr - Return a SCEV expression which computes the
/// value of the OperandValToReplace of the given IVStrideUse.
SCEVHandle IVUsers::getReplacementExpr(const IVStrideUse &U) const {
- const Type *UseTy = U.getOperandValToReplace()->getType();
// Start with zero.
SCEVHandle RetVal = SE->getIntegerSCEV(0, U.getParent()->Stride->getType());
// Create the basic add recurrence.
@@ -329,14 +313,6 @@
if (ExitVal->isLoopInvariant(L))
RetVal = ExitVal;
}
- // Promote the result to the type of the use.
- if (SE->getTypeSizeInBits(RetVal->getType()) !=
- SE->getTypeSizeInBits(UseTy)) {
- if (U.isSigned())
- RetVal = SE->getSignExtendExpr(RetVal, UseTy);
- else
- RetVal = SE->getZeroExtendExpr(RetVal, UseTy);
- }
return RetVal;
}