[llvm] r369300 - Refactor isPointerOffset (NFC).
Evgeniy Stepanov via llvm-commits
llvm-commits at lists.llvm.org
Mon Aug 19 14:08:04 PDT 2019
Author: eugenis
Date: Mon Aug 19 14:08:04 2019
New Revision: 369300
URL: http://llvm.org/viewvc/llvm-project?rev=369300&view=rev
Log:
Refactor isPointerOffset (NFC).
Summary:
Simplify the API using Optional<> and address comments in
https://reviews.llvm.org/D66165
Reviewers: vitalybuka
Subscribers: hiraditya, llvm-commits, ostannard, pcc
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66317
Modified:
llvm/trunk/include/llvm/Analysis/ValueTracking.h
llvm/trunk/lib/Analysis/ValueTracking.cpp
llvm/trunk/lib/Target/AArch64/AArch64StackTagging.cpp
llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
Modified: llvm/trunk/include/llvm/Analysis/ValueTracking.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ValueTracking.h?rev=369300&r1=369299&r2=369300&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/ValueTracking.h (original)
+++ llvm/trunk/include/llvm/Analysis/ValueTracking.h Mon Aug 19 14:08:04 2019
@@ -661,11 +661,11 @@ class Value;
const Instruction *ContextI,
const DataLayout &DL);
- /// Return true if Ptr1 is provably equal to Ptr2 plus a constant offset, and
- /// return that constant offset. For example, Ptr1 might be &A[42], and Ptr2
- /// might be &A[40]. In this case offset would be -8.
- bool isPointerOffset(Value *Ptr1, Value *Ptr2, int64_t &Offset,
- const DataLayout &DL);
+ /// If Ptr1 is provably equal to Ptr2 plus a constant offset, return that
+ /// offset. For example, Ptr1 might be &A[42], and Ptr2 might be &A[40]. In
+ /// this case offset would be -8.
+ Optional<int64_t> isPointerOffset(const Value *Ptr1, const Value *Ptr2,
+ const DataLayout &DL);
} // end namespace llvm
#endif // LLVM_ANALYSIS_VALUETRACKING_H
Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=369300&r1=369299&r2=369300&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Mon Aug 19 14:08:04 2019
@@ -5702,9 +5702,8 @@ ConstantRange llvm::computeConstantRange
return CR;
}
-static int64_t getOffsetFromIndex(const GEPOperator *GEP, unsigned Idx,
- bool &VariableIdxFound,
- const DataLayout &DL) {
+static Optional<int64_t>
+getOffsetFromIndex(const GEPOperator *GEP, unsigned Idx, const DataLayout &DL) {
// Skip over the first indices.
gep_type_iterator GTI = gep_type_begin(GEP);
for (unsigned i = 1; i != Idx; ++i, ++GTI)
@@ -5715,7 +5714,7 @@ static int64_t getOffsetFromIndex(const
for (unsigned i = Idx, e = GEP->getNumOperands(); i != e; ++i, ++GTI) {
ConstantInt *OpC = dyn_cast<ConstantInt>(GEP->getOperand(i));
if (!OpC)
- return VariableIdxFound = true;
+ return None;
if (OpC->isZero())
continue; // No offset.
@@ -5734,32 +5733,30 @@ static int64_t getOffsetFromIndex(const
return Offset;
}
-bool llvm::isPointerOffset(Value *Ptr1, Value *Ptr2, int64_t &Offset,
- const DataLayout &DL) {
+Optional<int64_t> llvm::isPointerOffset(const Value *Ptr1, const Value *Ptr2,
+ const DataLayout &DL) {
Ptr1 = Ptr1->stripPointerCasts();
Ptr2 = Ptr2->stripPointerCasts();
// Handle the trivial case first.
if (Ptr1 == Ptr2) {
- Offset = 0;
- return true;
+ return 0;
}
- GEPOperator *GEP1 = dyn_cast<GEPOperator>(Ptr1);
- GEPOperator *GEP2 = dyn_cast<GEPOperator>(Ptr2);
-
- bool VariableIdxFound = false;
+ const GEPOperator *GEP1 = dyn_cast<GEPOperator>(Ptr1);
+ const GEPOperator *GEP2 = dyn_cast<GEPOperator>(Ptr2);
// If one pointer is a GEP and the other isn't, then see if the GEP is a
// constant offset from the base, as in "P" and "gep P, 1".
if (GEP1 && !GEP2 && GEP1->getOperand(0)->stripPointerCasts() == Ptr2) {
- Offset = -getOffsetFromIndex(GEP1, 1, VariableIdxFound, DL);
- return !VariableIdxFound;
+ auto Offset = getOffsetFromIndex(GEP1, 1, DL);
+ if (!Offset)
+ return None;
+ return -*Offset;
}
if (GEP2 && !GEP1 && GEP2->getOperand(0)->stripPointerCasts() == Ptr1) {
- Offset = getOffsetFromIndex(GEP2, 1, VariableIdxFound, DL);
- return !VariableIdxFound;
+ return getOffsetFromIndex(GEP2, 1, DL);
}
// Right now we handle the case when Ptr1/Ptr2 are both GEPs with an identical
@@ -5768,7 +5765,7 @@ bool llvm::isPointerOffset(Value *Ptr1,
// offset, which determines their offset from each other. At this point, we
// handle no other case.
if (!GEP1 || !GEP2 || GEP1->getOperand(0) != GEP2->getOperand(0))
- return false;
+ return None;
// Skip any common indices and track the GEP types.
unsigned Idx = 1;
@@ -5776,11 +5773,9 @@ bool llvm::isPointerOffset(Value *Ptr1,
if (GEP1->getOperand(Idx) != GEP2->getOperand(Idx))
break;
- int64_t Offset1 = getOffsetFromIndex(GEP1, Idx, VariableIdxFound, DL);
- int64_t Offset2 = getOffsetFromIndex(GEP2, Idx, VariableIdxFound, DL);
- if (VariableIdxFound)
- return false;
-
- Offset = Offset2 - Offset1;
- return true;
+ auto Offset1 = getOffsetFromIndex(GEP1, Idx, DL);
+ auto Offset2 = getOffsetFromIndex(GEP2, Idx, DL);
+ if (!Offset1 || !Offset2)
+ return None;
+ return *Offset2 - *Offset1;
}
Modified: llvm/trunk/lib/Target/AArch64/AArch64StackTagging.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Target/AArch64/AArch64StackTagging.cpp?rev=369300&r1=369299&r2=369300&view=diff
==============================================================================
--- llvm/trunk/lib/Target/AArch64/AArch64StackTagging.cpp (original)
+++ llvm/trunk/lib/Target/AArch64/AArch64StackTagging.cpp Mon Aug 19 14:08:04 2019
@@ -358,12 +358,12 @@ Instruction *AArch64StackTagging::collec
break;
// Check to see if this store is to a constant offset from the start ptr.
- int64_t Offset;
- if (!isPointerOffset(StartPtr, NextStore->getPointerOperand(), Offset,
- *DL))
+ Optional<int64_t> Offset =
+ isPointerOffset(StartPtr, NextStore->getPointerOperand(), *DL);
+ if (!Offset)
break;
- if (!IB.addStore(Offset, NextStore, DL))
+ if (!IB.addStore(*Offset, NextStore, DL))
break;
LastInst = NextStore;
} else {
@@ -376,11 +376,11 @@ Instruction *AArch64StackTagging::collec
break;
// Check to see if this store is to a constant offset from the start ptr.
- int64_t Offset;
- if (!isPointerOffset(StartPtr, MSI->getDest(), Offset, *DL))
+ Optional<int64_t> Offset = isPointerOffset(StartPtr, MSI->getDest(), *DL);
+ if (!Offset)
break;
- if (!IB.addMemSet(Offset, MSI))
+ if (!IB.addMemSet(*Offset, MSI))
break;
LastInst = MSI;
}
Modified: llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp?rev=369300&r1=369299&r2=369300&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/MemCpyOptimizer.cpp Mon Aug 19 14:08:04 2019
@@ -335,12 +335,12 @@ Instruction *MemCpyOptPass::tryMergingIn
break;
// Check to see if this store is to a constant offset from the start ptr.
- int64_t Offset;
- if (!isPointerOffset(StartPtr, NextStore->getPointerOperand(), Offset,
- DL))
+ Optional<int64_t> Offset =
+ isPointerOffset(StartPtr, NextStore->getPointerOperand(), DL);
+ if (!Offset)
break;
- Ranges.addStore(Offset, NextStore);
+ Ranges.addStore(*Offset, NextStore);
} else {
MemSetInst *MSI = cast<MemSetInst>(BI);
@@ -349,11 +349,11 @@ Instruction *MemCpyOptPass::tryMergingIn
break;
// Check to see if this store is to a constant offset from the start ptr.
- int64_t Offset;
- if (!isPointerOffset(StartPtr, MSI->getDest(), Offset, DL))
+ Optional<int64_t> Offset = isPointerOffset(StartPtr, MSI->getDest(), DL);
+ if (!Offset)
break;
- Ranges.addMemSet(Offset, MSI);
+ Ranges.addMemSet(*Offset, MSI);
}
}
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