[polly] cf9dae1 - [NFC] [DA] Refactoring getIndexExpressionsFromGEP
Bardia Mahjour via llvm-commits
llvm-commits at lists.llvm.org
Mon Feb 24 14:33:16 PST 2020
Author: Bardia Mahjour
Date: 2020-02-24T17:32:30-05:00
New Revision: cf9dae122e04f015424aff6e7706430161b5e396
URL: https://github.com/llvm/llvm-project/commit/cf9dae122e04f015424aff6e7706430161b5e396
DIFF: https://github.com/llvm/llvm-project/commit/cf9dae122e04f015424aff6e7706430161b5e396.diff
LOG: [NFC] [DA] Refactoring getIndexExpressionsFromGEP
Summary:
This patch moves the getIndexExpressionsFromGEP function from polly
into ScalarEvolution so that both polly and DependenceAnalysis can
use it for the purpose of subscript delinearization when the array
sizes are not parametric.
Authored By: bmahjour
Reviewer: Meinersbur, sebpop, fhahn, dmgreen, grosser, etiotto, bollu
Reviewed By: Meinersbur
Subscribers: hiraditya, arphaman, Whitney, ppc-slack, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73995
Added:
Modified:
llvm/include/llvm/Analysis/ScalarEvolution.h
llvm/lib/Analysis/ScalarEvolution.cpp
polly/include/polly/Support/ScopHelper.h
polly/lib/Analysis/ScopBuilder.cpp
polly/lib/Support/ScopHelper.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/Analysis/ScalarEvolution.h b/llvm/include/llvm/Analysis/ScalarEvolution.h
index 5286f6a220ec..faedc1b241cb 100644
--- a/llvm/include/llvm/Analysis/ScalarEvolution.h
+++ b/llvm/include/llvm/Analysis/ScalarEvolution.h
@@ -998,6 +998,19 @@ class ScalarEvolution {
SmallVectorImpl<const SCEV *> &Subscripts,
SmallVectorImpl<const SCEV *> &Sizes);
+ /// Gathers the individual index expressions from a GEP instruction.
+ ///
+ /// This function optimistically assumes the GEP references into a fixed size
+ /// array. If this is actually true, this function returns a list of array
+ /// subscript expressions in \p Subscripts and a list of integers describing
+ /// the size of the individual array dimensions in \p Sizes. Both lists have
+ /// either equal length or the size list is one element shorter in case there
+ /// is no known size available for the outermost array dimension. Returns true
+ /// if successful and false otherwise.
+ bool getIndexExpressionsFromGEP(const GetElementPtrInst *GEP,
+ SmallVectorImpl<const SCEV *> &Subscripts,
+ SmallVectorImpl<int> &Sizes);
+
/// Split this SCEVAddRecExpr into two vectors of SCEVs representing the
/// subscripts and sizes of an array access.
///
diff --git a/llvm/lib/Analysis/ScalarEvolution.cpp b/llvm/lib/Analysis/ScalarEvolution.cpp
index cd74815a895e..eeb5e507b0b6 100644
--- a/llvm/lib/Analysis/ScalarEvolution.cpp
+++ b/llvm/lib/Analysis/ScalarEvolution.cpp
@@ -11409,6 +11409,51 @@ void ScalarEvolution::delinearize(const SCEV *Expr,
});
}
+bool ScalarEvolution::getIndexExpressionsFromGEP(
+ const GetElementPtrInst *GEP, SmallVectorImpl<const SCEV *> &Subscripts,
+ SmallVectorImpl<int> &Sizes) {
+ assert(Subscripts.empty() && Sizes.empty() &&
+ "Expected output lists to be empty on entry to this function.");
+ assert(GEP && "getIndexExpressionsFromGEP called with a null GEP");
+ Type *Ty = GEP->getPointerOperandType();
+ bool DroppedFirstDim = false;
+ for (unsigned i = 1; i < GEP->getNumOperands(); i++) {
+ const SCEV *Expr = getSCEV(GEP->getOperand(i));
+ if (i == 1) {
+ if (auto *PtrTy = dyn_cast<PointerType>(Ty)) {
+ Ty = PtrTy->getElementType();
+ } else if (auto *ArrayTy = dyn_cast<ArrayType>(Ty)) {
+ Ty = ArrayTy->getElementType();
+ } else {
+ Subscripts.clear();
+ Sizes.clear();
+ return false;
+ }
+ if (auto *Const = dyn_cast<SCEVConstant>(Expr))
+ if (Const->getValue()->isZero()) {
+ DroppedFirstDim = true;
+ continue;
+ }
+ Subscripts.push_back(Expr);
+ continue;
+ }
+
+ auto *ArrayTy = dyn_cast<ArrayType>(Ty);
+ if (!ArrayTy) {
+ Subscripts.clear();
+ Sizes.clear();
+ return false;
+ }
+
+ Subscripts.push_back(Expr);
+ if (!(DroppedFirstDim && i == 2))
+ Sizes.push_back(ArrayTy->getNumElements());
+
+ Ty = ArrayTy->getElementType();
+ }
+ return !Subscripts.empty();
+}
+
//===----------------------------------------------------------------------===//
// SCEVCallbackVH Class Implementation
//===----------------------------------------------------------------------===//
diff --git a/polly/include/polly/Support/ScopHelper.h b/polly/include/polly/Support/ScopHelper.h
index 23937b12c47c..4adf9538e4de 100644
--- a/polly/include/polly/Support/ScopHelper.h
+++ b/polly/include/polly/Support/ScopHelper.h
@@ -502,22 +502,6 @@ bool canSynthesize(const llvm::Value *V, const Scop &S,
/// case this function returns nullptr.
llvm::BasicBlock *getUseBlock(const llvm::Use &U);
-/// Derive the individual index expressions from a GEP instruction.
-///
-/// This function optimistically assumes the GEP references into a fixed size
-/// array. If this is actually true, this function returns a list of array
-/// subscript expressions as SCEV as well as a list of integers describing
-/// the size of the individual array dimensions. Both lists have either equal
-/// length or the size list is one element shorter in case there is no known
-/// size available for the outermost array dimension.
-///
-/// @param GEP The GetElementPtr instruction to analyze.
-///
-/// @return A tuple with the subscript expressions and the dimension sizes.
-std::tuple<std::vector<const llvm::SCEV *>, std::vector<int>>
-getIndexExpressionsFromGEP(llvm::GetElementPtrInst *GEP,
- llvm::ScalarEvolution &SE);
-
// If the loop is nonaffine/boxed, return the first non-boxed surrounding loop
// for Polly. If the loop is affine, return the loop itself.
//
diff --git a/polly/lib/Analysis/ScopBuilder.cpp b/polly/lib/Analysis/ScopBuilder.cpp
index 85eef9ba1764..19e1f970438b 100644
--- a/polly/lib/Analysis/ScopBuilder.cpp
+++ b/polly/lib/Analysis/ScopBuilder.cpp
@@ -1629,9 +1629,9 @@ bool ScopBuilder::buildAccessMultiDimFixed(MemAccInst Inst, ScopStmt *Stmt) {
if (!GEP)
return false;
- std::vector<const SCEV *> Subscripts;
- std::vector<int> Sizes;
- std::tie(Subscripts, Sizes) = getIndexExpressionsFromGEP(GEP, SE);
+ SmallVector<const SCEV *, 4> Subscripts;
+ SmallVector<int, 4> Sizes;
+ SE.getIndexExpressionsFromGEP(GEP, Subscripts, Sizes);
auto *BasePtr = GEP->getOperand(0);
if (auto *BasePtrCast = dyn_cast<BitCastInst>(BasePtr))
diff --git a/polly/lib/Support/ScopHelper.cpp b/polly/lib/Support/ScopHelper.cpp
index 8582f00e8fe7..715d9a02b2b4 100644
--- a/polly/lib/Support/ScopHelper.cpp
+++ b/polly/lib/Support/ScopHelper.cpp
@@ -668,55 +668,6 @@ llvm::BasicBlock *polly::getUseBlock(const llvm::Use &U) {
return UI->getParent();
}
-std::tuple<std::vector<const SCEV *>, std::vector<int>>
-polly::getIndexExpressionsFromGEP(GetElementPtrInst *GEP, ScalarEvolution &SE) {
- std::vector<const SCEV *> Subscripts;
- std::vector<int> Sizes;
-
- Type *Ty = GEP->getPointerOperandType();
-
- bool DroppedFirstDim = false;
-
- for (unsigned i = 1; i < GEP->getNumOperands(); i++) {
-
- const SCEV *Expr = SE.getSCEV(GEP->getOperand(i));
-
- if (i == 1) {
- if (auto *PtrTy = dyn_cast<PointerType>(Ty)) {
- Ty = PtrTy->getElementType();
- } else if (auto *ArrayTy = dyn_cast<ArrayType>(Ty)) {
- Ty = ArrayTy->getElementType();
- } else {
- Subscripts.clear();
- Sizes.clear();
- break;
- }
- if (auto *Const = dyn_cast<SCEVConstant>(Expr))
- if (Const->getValue()->isZero()) {
- DroppedFirstDim = true;
- continue;
- }
- Subscripts.push_back(Expr);
- continue;
- }
-
- auto *ArrayTy = dyn_cast<ArrayType>(Ty);
- if (!ArrayTy) {
- Subscripts.clear();
- Sizes.clear();
- break;
- }
-
- Subscripts.push_back(Expr);
- if (!(DroppedFirstDim && i == 2))
- Sizes.push_back(ArrayTy->getNumElements());
-
- Ty = ArrayTy->getElementType();
- }
-
- return std::make_tuple(Subscripts, Sizes);
-}
-
llvm::Loop *polly::getFirstNonBoxedLoopFor(llvm::Loop *L, llvm::LoopInfo &LI,
const BoxedLoopsSetTy &BoxedLoops) {
while (BoxedLoops.count(L))
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