It's not necessary to do rounding for alloca operations when the requested
alignment is equal to the stack alignment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40004 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/ValueNumbering.cpp b/lib/Analysis/ValueNumbering.cpp
new file mode 100644
index 0000000..bdb9422
--- /dev/null
+++ b/lib/Analysis/ValueNumbering.cpp
@@ -0,0 +1,280 @@
+//===- ValueNumbering.cpp - Value #'ing Implementation ----------*- C++ -*-===//
+//
+// The LLVM Compiler Infrastructure
+//
+// This file was developed by the LLVM research group and is distributed under
+// the University of Illinois Open Source License. See LICENSE.TXT for details.
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the non-abstract Value Numbering methods as well as a
+// default implementation for the analysis group.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/Analysis/Passes.h"
+#include "llvm/Analysis/ValueNumbering.h"
+#include "llvm/Support/InstVisitor.h"
+#include "llvm/BasicBlock.h"
+#include "llvm/Instructions.h"
+#include "llvm/Pass.h"
+#include "llvm/Type.h"
+#include "llvm/Support/Compiler.h"
+using namespace llvm;
+
+char ValueNumbering::ID = 0;
+// Register the ValueNumbering interface, providing a nice name to refer to.
+static RegisterAnalysisGroup<ValueNumbering> X("Value Numbering");
+
+/// ValueNumbering destructor: DO NOT move this to the header file for
+/// ValueNumbering or else clients of the ValueNumbering class may not depend on
+/// the ValueNumbering.o file in the current .a file, causing alias analysis
+/// support to not be included in the tool correctly!
+///
+ValueNumbering::~ValueNumbering() {}
+
+//===----------------------------------------------------------------------===//
+// Basic ValueNumbering Pass Implementation
+//===----------------------------------------------------------------------===//
+//
+// Because of the way .a files work, the implementation of the BasicVN class
+// MUST be in the ValueNumbering file itself, or else we run the risk of
+// ValueNumbering being used, but the default implementation not being linked
+// into the tool that uses it. As such, we register and implement the class
+// here.
+//
+
+namespace {
+ /// BasicVN - This class is the default implementation of the ValueNumbering
+ /// interface. It walks the SSA def-use chains to trivially identify
+ /// lexically identical expressions. This does not require any ahead of time
+ /// analysis, so it is a very fast default implementation.
+ ///
+ struct VISIBILITY_HIDDEN BasicVN
+ : public ImmutablePass, public ValueNumbering {
+ static char ID; // Class identification, replacement for typeinfo
+ BasicVN() : ImmutablePass((intptr_t)&ID) {}
+
+ /// getEqualNumberNodes - Return nodes with the same value number as the
+ /// specified Value. This fills in the argument vector with any equal
+ /// values.
+ ///
+ /// This is where our implementation is.
+ ///
+ virtual void getEqualNumberNodes(Value *V1,
+ std::vector<Value*> &RetVals) const;
+ };
+
+ char BasicVN::ID = 0;
+ // Register this pass...
+ RegisterPass<BasicVN>
+ X("basicvn", "Basic Value Numbering (default GVN impl)");
+
+ // Declare that we implement the ValueNumbering interface
+ RegisterAnalysisGroup<ValueNumbering, true> Y(X);
+
+ /// BVNImpl - Implement BasicVN in terms of a visitor class that
+ /// handles the different types of instructions as appropriate.
+ ///
+ struct VISIBILITY_HIDDEN BVNImpl : public InstVisitor<BVNImpl> {
+ std::vector<Value*> &RetVals;
+ BVNImpl(std::vector<Value*> &RV) : RetVals(RV) {}
+
+ void visitCastInst(CastInst &I);
+ void visitGetElementPtrInst(GetElementPtrInst &I);
+ void visitCmpInst(CmpInst &I);
+
+ void handleBinaryInst(Instruction &I);
+ void visitBinaryOperator(Instruction &I) { handleBinaryInst(I); }
+ void visitShiftInst(Instruction &I) { handleBinaryInst(I); }
+ void visitExtractElementInst(Instruction &I) { handleBinaryInst(I); }
+
+ void handleTernaryInst(Instruction &I);
+ void visitSelectInst(Instruction &I) { handleTernaryInst(I); }
+ void visitInsertElementInst(Instruction &I) { handleTernaryInst(I); }
+ void visitShuffleVectorInst(Instruction &I) { handleTernaryInst(I); }
+ void visitInstruction(Instruction &) {
+ // Cannot value number calls or terminator instructions.
+ }
+ };
+}
+
+ImmutablePass *llvm::createBasicVNPass() { return new BasicVN(); }
+
+// getEqualNumberNodes - Return nodes with the same value number as the
+// specified Value. This fills in the argument vector with any equal values.
+//
+void BasicVN::getEqualNumberNodes(Value *V, std::vector<Value*> &RetVals) const{
+ assert(V->getType() != Type::VoidTy &&
+ "Can only value number non-void values!");
+ // We can only handle the case where I is an instruction!
+ if (Instruction *I = dyn_cast<Instruction>(V))
+ BVNImpl(RetVals).visit(I);
+}
+
+void BVNImpl::visitCastInst(CastInst &CI) {
+ Instruction &I = (Instruction&)CI;
+ Value *Op = I.getOperand(0);
+ Function *F = I.getParent()->getParent();
+
+ for (Value::use_iterator UI = Op->use_begin(), UE = Op->use_end();
+ UI != UE; ++UI)
+ if (CastInst *Other = dyn_cast<CastInst>(*UI))
+ // Check that the opcode is the same
+ if (Other->getOpcode() == Instruction::CastOps(I.getOpcode()) &&
+ // Check that the destination types are the same
+ Other->getType() == I.getType() &&
+ // Is it embedded in the same function? (This could be false if LHS
+ // is a constant or global!)
+ Other->getParent()->getParent() == F &&
+ // Check to see if this new cast is not I.
+ Other != &I) {
+ // These instructions are identical. Add to list...
+ RetVals.push_back(Other);
+ }
+}
+
+void BVNImpl::visitCmpInst(CmpInst &CI1) {
+ Value *LHS = CI1.getOperand(0);
+ for (Value::use_iterator UI = LHS->use_begin(), UE = LHS->use_end();
+ UI != UE; ++UI)
+ if (CmpInst *CI2 = dyn_cast<CmpInst>(*UI))
+ // Check to see if this compare instruction is not CI, but same opcode,
+ // same predicate, and in the same function.
+ if (CI2 != &CI1 && CI2->getOpcode() == CI1.getOpcode() &&
+ CI2->getPredicate() == CI1.getPredicate() &&
+ CI2->getParent()->getParent() == CI1.getParent()->getParent())
+ // If the operands are the same
+ if ((CI2->getOperand(0) == CI1.getOperand(0) &&
+ CI2->getOperand(1) == CI1.getOperand(1)) ||
+ // Or the compare is commutative and the operands are reversed
+ (CI1.isCommutative() &&
+ CI2->getOperand(0) == CI1.getOperand(1) &&
+ CI2->getOperand(1) == CI1.getOperand(0)))
+ // Then the instructiosn are identical, add to list.
+ RetVals.push_back(CI2);
+}
+
+
+
+// isIdenticalBinaryInst - Return true if the two binary instructions are
+// identical.
+//
+static inline bool isIdenticalBinaryInst(const Instruction &I1,
+ const Instruction *I2) {
+ // Is it embedded in the same function? (This could be false if LHS
+ // is a constant or global!)
+ if (I1.getOpcode() != I2->getOpcode() ||
+ I1.getParent()->getParent() != I2->getParent()->getParent())
+ return false;
+
+ // If they are CmpInst instructions, check their predicates
+ if (CmpInst *CI1 = dyn_cast<CmpInst>(&const_cast<Instruction&>(I1)))
+ if (CI1->getPredicate() != cast<CmpInst>(I2)->getPredicate())
+ return false;
+
+ // They are identical if both operands are the same!
+ if (I1.getOperand(0) == I2->getOperand(0) &&
+ I1.getOperand(1) == I2->getOperand(1))
+ return true;
+
+ // If the instruction is commutative, the instruction can match if the
+ // operands are swapped!
+ //
+ if ((I1.getOperand(0) == I2->getOperand(1) &&
+ I1.getOperand(1) == I2->getOperand(0)) &&
+ I1.isCommutative())
+ return true;
+
+ return false;
+}
+
+// isIdenticalTernaryInst - Return true if the two ternary instructions are
+// identical.
+//
+static inline bool isIdenticalTernaryInst(const Instruction &I1,
+ const Instruction *I2) {
+ // Is it embedded in the same function? (This could be false if LHS
+ // is a constant or global!)
+ if (I1.getParent()->getParent() != I2->getParent()->getParent())
+ return false;
+
+ // They are identical if all operands are the same!
+ return I1.getOperand(0) == I2->getOperand(0) &&
+ I1.getOperand(1) == I2->getOperand(1) &&
+ I1.getOperand(2) == I2->getOperand(2);
+}
+
+
+
+void BVNImpl::handleBinaryInst(Instruction &I) {
+ Value *LHS = I.getOperand(0);
+
+ for (Value::use_iterator UI = LHS->use_begin(), UE = LHS->use_end();
+ UI != UE; ++UI)
+ if (Instruction *Other = dyn_cast<Instruction>(*UI))
+ // Check to see if this new binary operator is not I, but same operand...
+ if (Other != &I && isIdenticalBinaryInst(I, Other)) {
+ // These instructions are identical. Handle the situation.
+ RetVals.push_back(Other);
+ }
+}
+
+// IdenticalComplexInst - Return true if the two instructions are the same, by
+// using a brute force comparison. This is useful for instructions with an
+// arbitrary number of arguments.
+//
+static inline bool IdenticalComplexInst(const Instruction *I1,
+ const Instruction *I2) {
+ assert(I1->getOpcode() == I2->getOpcode());
+ // Equal if they are in the same function...
+ return I1->getParent()->getParent() == I2->getParent()->getParent() &&
+ // And return the same type...
+ I1->getType() == I2->getType() &&
+ // And have the same number of operands...
+ I1->getNumOperands() == I2->getNumOperands() &&
+ // And all of the operands are equal.
+ std::equal(I1->op_begin(), I1->op_end(), I2->op_begin());
+}
+
+void BVNImpl::visitGetElementPtrInst(GetElementPtrInst &I) {
+ Value *Op = I.getOperand(0);
+
+ // Try to pick a local operand if possible instead of a constant or a global
+ // that might have a lot of uses.
+ for (unsigned i = 1, e = I.getNumOperands(); i != e; ++i)
+ if (isa<Instruction>(I.getOperand(i)) || isa<Argument>(I.getOperand(i))) {
+ Op = I.getOperand(i);
+ break;
+ }
+
+ for (Value::use_iterator UI = Op->use_begin(), UE = Op->use_end();
+ UI != UE; ++UI)
+ if (GetElementPtrInst *Other = dyn_cast<GetElementPtrInst>(*UI))
+ // Check to see if this new getelementptr is not I, but same operand...
+ if (Other != &I && IdenticalComplexInst(&I, Other)) {
+ // These instructions are identical. Handle the situation.
+ RetVals.push_back(Other);
+ }
+}
+
+void BVNImpl::handleTernaryInst(Instruction &I) {
+ Value *Op0 = I.getOperand(0);
+ Instruction *OtherInst;
+
+ for (Value::use_iterator UI = Op0->use_begin(), UE = Op0->use_end();
+ UI != UE; ++UI)
+ if ((OtherInst = dyn_cast<Instruction>(*UI)) &&
+ OtherInst->getOpcode() == I.getOpcode()) {
+ // Check to see if this new select is not I, but has the same operands.
+ if (OtherInst != &I && isIdenticalTernaryInst(I, OtherInst)) {
+ // These instructions are identical. Handle the situation.
+ RetVals.push_back(OtherInst);
+ }
+
+ }
+}
+
+
+// Ensure that users of ValueNumbering.h will link with this file
+DEFINING_FILE_FOR(BasicValueNumbering)