[llvm] ca10e73 - [NFC] Rename isPointerOffset to getPointerOffsetFrom and move to Value.h

via llvm-commits llvm-commits at lists.llvm.org
Wed Apr 19 04:23:52 PDT 2023


Author: OCHyams
Date: 2023-04-19T12:22:58+01:00
New Revision: ca10e73b530376e191fbaa4920b5dde02d8b5930

URL: https://github.com/llvm/llvm-project/commit/ca10e73b530376e191fbaa4920b5dde02d8b5930
DIFF: https://github.com/llvm/llvm-project/commit/ca10e73b530376e191fbaa4920b5dde02d8b5930.diff

LOG: [NFC] Rename isPointerOffset to getPointerOffsetFrom and move to Value.h

Linking LLVMCore failed when building D148536 with shared libs enabled:
https://lab.llvm.org/buildbot/#/builders/121/builds/29766

Make isPointerOffset a Value method and rename it to getPointerOffsetFrom.

Reviewed By: jmorse

Differential Revision: https://reviews.llvm.org/D148698

Added: 
    

Modified: 
    llvm/include/llvm/Analysis/ValueTracking.h
    llvm/include/llvm/IR/Value.h
    llvm/lib/Analysis/ValueTracking.cpp
    llvm/lib/IR/Value.cpp
    llvm/lib/Target/AArch64/AArch64StackTagging.cpp
    llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/include/llvm/Analysis/ValueTracking.h b/llvm/include/llvm/Analysis/ValueTracking.h
index 1891dcb301155..1daef70b483dd 100644
--- a/llvm/include/llvm/Analysis/ValueTracking.h
+++ b/llvm/include/llvm/Analysis/ValueTracking.h
@@ -1017,12 +1017,6 @@ std::optional<bool> isImpliedByDomCondition(CmpInst::Predicate Pred,
                                             const Value *LHS, const Value *RHS,
                                             const Instruction *ContextI,
                                             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.
-std::optional<int64_t> isPointerOffset(const Value *Ptr1, const Value *Ptr2,
-                                       const DataLayout &DL);
 } // end namespace llvm
 
 #endif // LLVM_ANALYSIS_VALUETRACKING_H

diff  --git a/llvm/include/llvm/IR/Value.h b/llvm/include/llvm/IR/Value.h
index d0cd83bec89d3..16ae451114b52 100644
--- a/llvm/include/llvm/IR/Value.h
+++ b/llvm/include/llvm/IR/Value.h
@@ -744,6 +744,11 @@ class Value {
         static_cast<const Value *>(this)->stripInBoundsOffsets(Func));
   }
 
+  /// If this ptr is provably equal to \p Other plus a constant offset, return
+  /// that offset in bytes. Essentially `ptr this` subtract `ptr Other`.
+  std::optional<int64_t> getPointerOffsetFrom(const Value *Other,
+                                              const DataLayout &DL) const;
+
   /// Return true if the memory object referred to by V can by freed in the
   /// scope for which the SSA value defining the allocation is statically
   /// defined.  E.g.  deallocation after the static scope of a value does not

diff  --git a/llvm/lib/Analysis/ValueTracking.cpp b/llvm/lib/Analysis/ValueTracking.cpp
index 3f2ee99c595c8..c25f02becc8dd 100644
--- a/llvm/lib/Analysis/ValueTracking.cpp
+++ b/llvm/lib/Analysis/ValueTracking.cpp
@@ -8224,74 +8224,3 @@ ConstantRange llvm::computeConstantRange(const Value *V, bool ForSigned,
 
   return CR;
 }
-
-static std::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)
-    /*skip along*/;
-
-  // Compute the offset implied by the rest of the indices.
-  int64_t Offset = 0;
-  for (unsigned i = Idx, e = GEP->getNumOperands(); i != e; ++i, ++GTI) {
-    ConstantInt *OpC = dyn_cast<ConstantInt>(GEP->getOperand(i));
-    if (!OpC)
-      return std::nullopt;
-    if (OpC->isZero())
-      continue; // No offset.
-
-    // Handle struct indices, which add their field offset to the pointer.
-    if (StructType *STy = GTI.getStructTypeOrNull()) {
-      Offset += DL.getStructLayout(STy)->getElementOffset(OpC->getZExtValue());
-      continue;
-    }
-
-    // Otherwise, we have a sequential type like an array or fixed-length
-    // vector. Multiply the index by the ElementSize.
-    TypeSize Size = DL.getTypeAllocSize(GTI.getIndexedType());
-    if (Size.isScalable())
-      return std::nullopt;
-    Offset += Size.getFixedValue() * OpC->getSExtValue();
-  }
-
-  return Offset;
-}
-
-std::optional<int64_t> llvm::isPointerOffset(const Value *Ptr1,
-                                             const Value *Ptr2,
-                                             const DataLayout &DL) {
-  APInt Offset1(DL.getIndexTypeSizeInBits(Ptr1->getType()), 0);
-  APInt Offset2(DL.getIndexTypeSizeInBits(Ptr2->getType()), 0);
-  Ptr1 = Ptr1->stripAndAccumulateConstantOffsets(DL, Offset1, true);
-  Ptr2 = Ptr2->stripAndAccumulateConstantOffsets(DL, Offset2, true);
-
-  // Handle the trivial case first.
-  if (Ptr1 == Ptr2)
-    return Offset2.getSExtValue() - Offset1.getSExtValue();
-
-  const GEPOperator *GEP1 = dyn_cast<GEPOperator>(Ptr1);
-  const GEPOperator *GEP2 = dyn_cast<GEPOperator>(Ptr2);
-
-  // Right now we handle the case when Ptr1/Ptr2 are both GEPs with an identical
-  // base.  After that base, they may have some number of common (and
-  // potentially variable) indices.  After that they handle some constant
-  // 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) ||
-      GEP1->getSourceElementType() != GEP2->getSourceElementType())
-    return std::nullopt;
-
-  // Skip any common indices and track the GEP types.
-  unsigned Idx = 1;
-  for (; Idx != GEP1->getNumOperands() && Idx != GEP2->getNumOperands(); ++Idx)
-    if (GEP1->getOperand(Idx) != GEP2->getOperand(Idx))
-      break;
-
-  auto IOffset1 = getOffsetFromIndex(GEP1, Idx, DL);
-  auto IOffset2 = getOffsetFromIndex(GEP2, Idx, DL);
-  if (!IOffset1 || !IOffset2)
-    return std::nullopt;
-  return *IOffset2 - *IOffset1 + Offset2.getSExtValue() -
-         Offset1.getSExtValue();
-}

diff  --git a/llvm/lib/IR/Value.cpp b/llvm/lib/IR/Value.cpp
index 11dc5060edfd0..41260a98e3ce7 100644
--- a/llvm/lib/IR/Value.cpp
+++ b/llvm/lib/IR/Value.cpp
@@ -20,6 +20,7 @@
 #include "llvm/IR/DebugInfo.h"
 #include "llvm/IR/DerivedTypes.h"
 #include "llvm/IR/DerivedUser.h"
+#include "llvm/IR/GetElementPtrTypeIterator.h"
 #include "llvm/IR/InstrTypes.h"
 #include "llvm/IR/Instructions.h"
 #include "llvm/IR/IntrinsicInst.h"
@@ -985,6 +986,78 @@ Align Value::getPointerAlignment(const DataLayout &DL) const {
   return Align(1);
 }
 
+static std::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)
+    /*skip along*/;
+
+  // Compute the offset implied by the rest of the indices.
+  int64_t Offset = 0;
+  for (unsigned i = Idx, e = GEP->getNumOperands(); i != e; ++i, ++GTI) {
+    ConstantInt *OpC = dyn_cast<ConstantInt>(GEP->getOperand(i));
+    if (!OpC)
+      return std::nullopt;
+    if (OpC->isZero())
+      continue; // No offset.
+
+    // Handle struct indices, which add their field offset to the pointer.
+    if (StructType *STy = GTI.getStructTypeOrNull()) {
+      Offset += DL.getStructLayout(STy)->getElementOffset(OpC->getZExtValue());
+      continue;
+    }
+
+    // Otherwise, we have a sequential type like an array or fixed-length
+    // vector. Multiply the index by the ElementSize.
+    TypeSize Size = DL.getTypeAllocSize(GTI.getIndexedType());
+    if (Size.isScalable())
+      return std::nullopt;
+    Offset += Size.getFixedValue() * OpC->getSExtValue();
+  }
+
+  return Offset;
+}
+
+std::optional<int64_t> Value::getPointerOffsetFrom(const Value *Other,
+                                                   const DataLayout &DL) const {
+  const Value *Ptr1 = Other;
+  const Value *Ptr2 = this;
+  APInt Offset1(DL.getIndexTypeSizeInBits(Ptr1->getType()), 0);
+  APInt Offset2(DL.getIndexTypeSizeInBits(Ptr2->getType()), 0);
+  Ptr1 = Ptr1->stripAndAccumulateConstantOffsets(DL, Offset1, true);
+  Ptr2 = Ptr2->stripAndAccumulateConstantOffsets(DL, Offset2, true);
+
+  // Handle the trivial case first.
+  if (Ptr1 == Ptr2)
+    return Offset2.getSExtValue() - Offset1.getSExtValue();
+
+  const GEPOperator *GEP1 = dyn_cast<GEPOperator>(Ptr1);
+  const GEPOperator *GEP2 = dyn_cast<GEPOperator>(Ptr2);
+
+  // Right now we handle the case when Ptr1/Ptr2 are both GEPs with an identical
+  // base.  After that base, they may have some number of common (and
+  // potentially variable) indices.  After that they handle some constant
+  // 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) ||
+      GEP1->getSourceElementType() != GEP2->getSourceElementType())
+    return std::nullopt;
+
+  // Skip any common indices and track the GEP types.
+  unsigned Idx = 1;
+  for (; Idx != GEP1->getNumOperands() && Idx != GEP2->getNumOperands(); ++Idx)
+    if (GEP1->getOperand(Idx) != GEP2->getOperand(Idx))
+      break;
+
+  auto IOffset1 = getOffsetFromIndex(GEP1, Idx, DL);
+  auto IOffset2 = getOffsetFromIndex(GEP2, Idx, DL);
+  if (!IOffset1 || !IOffset2)
+    return std::nullopt;
+  return *IOffset2 - *IOffset1 + Offset2.getSExtValue() -
+         Offset1.getSExtValue();
+}
+
 const Value *Value::DoPHITranslation(const BasicBlock *CurBB,
                                      const BasicBlock *PredBB) const {
   auto *PN = dyn_cast<PHINode>(this);

diff  --git a/llvm/lib/Target/AArch64/AArch64StackTagging.cpp b/llvm/lib/Target/AArch64/AArch64StackTagging.cpp
index 97afb66ed9ab5..3ac86b3cde2ed 100644
--- a/llvm/lib/Target/AArch64/AArch64StackTagging.cpp
+++ b/llvm/lib/Target/AArch64/AArch64StackTagging.cpp
@@ -380,7 +380,7 @@ Instruction *AArch64StackTagging::collectInitializers(Instruction *StartInst,
 
       // Check to see if this store is to a constant offset from the start ptr.
       std::optional<int64_t> Offset =
-          isPointerOffset(StartPtr, NextStore->getPointerOperand(), *DL);
+          NextStore->getPointerOperand()->getPointerOffsetFrom(StartPtr, *DL);
       if (!Offset)
         break;
 
@@ -398,7 +398,7 @@ Instruction *AArch64StackTagging::collectInitializers(Instruction *StartInst,
 
       // Check to see if this store is to a constant offset from the start ptr.
       std::optional<int64_t> Offset =
-          isPointerOffset(StartPtr, MSI->getDest(), *DL);
+          MSI->getDest()->getPointerOffsetFrom(StartPtr, *DL);
       if (!Offset)
         break;
 

diff  --git a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
index 95f7370c8103e..bf54c42a4eb58 100644
--- a/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
+++ b/llvm/lib/Transforms/Scalar/MemCpyOptimizer.cpp
@@ -412,7 +412,7 @@ Instruction *MemCpyOptPass::tryMergingIntoMemset(Instruction *StartInst,
 
       // Check to see if this store is to a constant offset from the start ptr.
       std::optional<int64_t> Offset =
-          isPointerOffset(StartPtr, NextStore->getPointerOperand(), DL);
+          NextStore->getPointerOperand()->getPointerOffsetFrom(StartPtr, DL);
       if (!Offset)
         break;
 
@@ -426,7 +426,7 @@ Instruction *MemCpyOptPass::tryMergingIntoMemset(Instruction *StartInst,
 
       // Check to see if this store is to a constant offset from the start ptr.
       std::optional<int64_t> Offset =
-          isPointerOffset(StartPtr, MSI->getDest(), DL);
+          MSI->getDest()->getPointerOffsetFrom(StartPtr, DL);
       if (!Offset)
         break;
 


        


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