[llvm-commits] CVS: llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp
Chris Lattner
sabre at nondot.org
Mon Oct 23 17:36:35 PDT 2006
Changes in directory llvm/lib/Transforms/Scalar:
PredicateSimplifier.cpp updated: 1.25 -> 1.26
---
Log message:
Revert back to r1.21, which was the last revision of predsimplify that
passes llvm-gcc bootstrap.
---
Diffs of the changes: (+109 -134)
PredicateSimplifier.cpp | 243 +++++++++++++++++++++---------------------------
1 files changed, 109 insertions(+), 134 deletions(-)
Index: llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp
diff -u llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.25 llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.26
--- llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp:1.25 Sun Oct 22 20:56:02 2006
+++ llvm/lib/Transforms/Scalar/PredicateSimplifier.cpp Mon Oct 23 19:36:21 2006
@@ -41,7 +41,6 @@
#include "llvm/Support/Debug.h"
#include "llvm/Support/InstVisitor.h"
#include <iostream>
-#include <list>
using namespace llvm;
typedef DominatorTree::Node DTNodeType;
@@ -75,14 +74,14 @@
return leaders.empty();
}
- iterator findLeader(ElemTy &e) {
+ iterator findLeader(ElemTy e) {
typename std::map<ElemTy, unsigned>::iterator MI = mapping.find(e);
if (MI == mapping.end()) return 0;
return MI->second;
}
- const_iterator findLeader(ElemTy &e) const {
+ const_iterator findLeader(ElemTy e) const {
typename std::map<ElemTy, unsigned>::const_iterator MI =
mapping.find(e);
if (MI == mapping.end()) return 0;
@@ -117,11 +116,6 @@
// Mutators
- void remove(ElemTy &e) {
- ElemTy E = e; // The parameter to erase must not be a reference to
- mapping.erase(E); // an element contained in the map.
- }
-
/// Combine two sets referring to the same element, inserting the
/// elements as needed. Returns a valid iterator iff two already
/// existing disjoint synonym sets were combined. The iterator
@@ -130,7 +124,7 @@
/// Returns an iterator pointing to the synonym set containing
/// element e. If none exists, a new one is created and returned.
- iterator findOrInsert(ElemTy &e) {
+ iterator findOrInsert(ElemTy e) {
iterator I = findLeader(e);
if (I) return I;
@@ -209,19 +203,6 @@
return union_find.empty();
}
- void remove(Value *V) {
- SynonymIterator I = union_find.findLeader(V);
- if (!I) return;
-
- union_find.remove(V);
-
- for (PropertyIterator PI = Properties.begin(), PE = Properties.end();
- PI != PE;) {
- Property &P = *PI++;
- if (P.I1 == I || P.I2 == I) Properties.erase(PI);
- }
- }
-
void addEqual(Value *V1, Value *V2) {
// If %x = 0. and %y = -0., seteq %x, %y is true, but
// copysign(%x) is not the same as copysign(%y).
@@ -230,10 +211,6 @@
order(V1, V2);
if (isa<Constant>(V2)) return; // refuse to set false == true.
- if (union_find.findLeader(V1) &&
- union_find.findLeader(V1) == union_find.findLeader(V2))
- return; // no-op
-
SynonymIterator deleted = union_find.unionSets(V1, V2);
if (deleted) {
SynonymIterator replacement = union_find.findLeader(V1);
@@ -257,7 +234,7 @@
if (isa<Constant>(V1) && isa<Constant>(V2)) return;
if (findProperty(NE, V1, V2) != Properties.end())
- return; // no-op.
+ return; // found.
// Add the property.
SynonymIterator I1 = union_find.findOrInsert(V1),
@@ -331,73 +308,6 @@
}
}
- void addToResolve(Value *V, std::list<Value *> &WorkList) {
- if (!isa<Constant>(V) && !isa<BasicBlock>(V)) {
- for (Value::use_iterator UI = V->use_begin(), UE = V->use_end();
- UI != UE; ++UI) {
- if (!isa<Constant>(*UI) && !isa<BasicBlock>(*UI)) {
- WorkList.push_back(*UI);
- }
- }
- }
- }
-
- void resolve(std::list<Value *> &WorkList) {
- if (WorkList.empty()) return;
-
- Value *V = WorkList.front();
- WorkList.pop_front();
-
- if (empty()) return;
-
- Instruction *I = dyn_cast<Instruction>(V);
- if (!I) return;
-
- if (BinaryOperator *BO = dyn_cast<BinaryOperator>(I)) {
- Value *lhs = canonicalize(BO->getOperand(0)),
- *rhs = canonicalize(BO->getOperand(1));
-
- ConstantIntegral *CI1 = dyn_cast<ConstantIntegral>(lhs),
- *CI2 = dyn_cast<ConstantIntegral>(rhs);
-
- if (CI1 && CI2) {
- addToResolve(BO, WorkList);
- addEqual(BO, ConstantExpr::get(BO->getOpcode(), CI1, CI2));
- } else if (SetCondInst *SCI = dyn_cast<SetCondInst>(BO)) {
- PropertySet::ConstPropertyIterator NE =
- findProperty(PropertySet::NE, lhs, rhs);
-
- if (NE != Properties.end()) {
- switch (SCI->getOpcode()) {
- case Instruction::SetEQ:
- addToResolve(SCI, WorkList);
- addEqual(SCI, ConstantBool::getFalse());
- break;
- case Instruction::SetNE:
- addToResolve(SCI, WorkList);
- addEqual(SCI, ConstantBool::getTrue());
- break;
- case Instruction::SetLE:
- case Instruction::SetGE:
- case Instruction::SetLT:
- case Instruction::SetGT:
- break;
- default:
- assert(0 && "Unknown opcode in SetCondInst.");
- break;
- }
- }
- }
- } else if (SelectInst *SI = dyn_cast<SelectInst>(I)) {
- Value *Condition = canonicalize(SI->getCondition());
- if (ConstantBool *CB = dyn_cast<ConstantBool>(Condition)) {
- addToResolve(SI, WorkList);
- addEqual(SI, CB->getValue() ? SI->getTrueValue() : SI->getFalseValue());
- }
- }
- if (!WorkList.empty()) resolve(WorkList);
- }
-
// Finds the properties implied by an equivalence and adds them too.
// Example: ("seteq %a, %b", true, EQ) --> (%a, %b, EQ)
// ("seteq %a, %b", false, EQ) --> (%a, %b, NE)
@@ -424,45 +334,32 @@
if (V1 == ConstantBool::getFalse())
add(Opcode, BO->getOperand(0), BO->getOperand(1), true);
break;
- case Instruction::And: {
- ConstantIntegral *CI = dyn_cast<ConstantIntegral>(V1);
- if (CI && CI->isAllOnesValue()) {
+ case Instruction::And:
+ if (V1 == ConstantBool::getTrue()) {
add(Opcode, V1, BO->getOperand(0), false);
add(Opcode, V1, BO->getOperand(1), false);
}
- } break;
- case Instruction::Or: {
- ConstantIntegral *CI = dyn_cast<ConstantIntegral>(V1);
- if (CI && CI->isNullValue()) {
+ break;
+ case Instruction::Or:
+ if (V1 == ConstantBool::getFalse()) {
add(Opcode, V1, BO->getOperand(0), false);
add(Opcode, V1, BO->getOperand(1), false);
}
- } break;
- case Instruction::Xor: {
- if (ConstantIntegral *CI = dyn_cast<ConstantIntegral>(V1)) {
- const Type *Ty = BO->getType();
- if (CI->isAllOnesValue()) {
- if (BO->getOperand(0) == V1)
- add(Opcode, Constant::getNullValue(Ty),
- BO->getOperand(1), false);
- if (BO->getOperand(1) == V1)
- add(Opcode, Constant::getNullValue(Ty),
- BO->getOperand(0), false);
- }
- if (CI->isNullValue()) {
- ConstantIntegral *Op0 =
- dyn_cast<ConstantIntegral>(BO->getOperand(0));
- ConstantIntegral *Op1 =
- dyn_cast<ConstantIntegral>(BO->getOperand(1));
- if (Op0 && Op0->isAllOnesValue())
- add(Opcode, ConstantIntegral::getAllOnesValue(Ty),
- BO->getOperand(1), false);
- if (Op1 && Op1->isAllOnesValue())
- add(Opcode, ConstantIntegral::getAllOnesValue(Ty),
- BO->getOperand(0), false);
- }
+ break;
+ case Instruction::Xor:
+ if (V1 == ConstantBool::getTrue()) {
+ if (BO->getOperand(0) == V1)
+ add(Opcode, ConstantBool::getFalse(), BO->getOperand(1), false);
+ if (BO->getOperand(1) == V1)
+ add(Opcode, ConstantBool::getFalse(), BO->getOperand(0), false);
+ }
+ if (V1 == ConstantBool::getFalse()) {
+ if (BO->getOperand(0) == ConstantBool::getTrue())
+ add(Opcode, ConstantBool::getTrue(), BO->getOperand(1), false);
+ if (BO->getOperand(1) == ConstantBool::getTrue())
+ add(Opcode, ConstantBool::getTrue(), BO->getOperand(0), false);
}
- } break;
+ break;
default:
break;
}
@@ -479,11 +376,6 @@
else if (Opcode == EQ)
assert("Result of select not equal to either value.");
}
-
- std::list<Value *> WorkList;
- addToResolve(V1, WorkList);
- addToResolve(V2, WorkList);
- resolve(WorkList);
}
DominatorTree *DT;
@@ -514,6 +406,26 @@
virtual void getAnalysisUsage(AnalysisUsage &AU) const;
private:
+ /// Backwards - Try to replace the Use of the instruction with
+ /// something simpler. This resolves a value by walking backwards
+ /// through its definition and the operands of that definition to
+ /// see if any values can now be solved for with the properties
+ /// that are in effect now, but weren't at definition time.
+ class Backwards : public InstVisitor<Backwards, Value &> {
+ friend class InstVisitor<Backwards, Value &>;
+ const PropertySet &KP;
+
+ Value &visitSetCondInst(SetCondInst &SCI);
+ Value &visitBinaryOperator(BinaryOperator &BO);
+ Value &visitSelectInst(SelectInst &SI);
+ Value &visitInstruction(Instruction &I);
+
+ public:
+ explicit Backwards(const PropertySet &KP) : KP(KP) {}
+
+ Value *resolve(Value *V);
+ };
+
/// Forwards - Adds new properties into PropertySet and uses them to
/// simplify instructions. Because new properties sometimes apply to
/// a transition from one BasicBlock to another, this will use the
@@ -628,6 +540,69 @@
AU.addPreservedID(BreakCriticalEdgesID);
}
+Value &PredicateSimplifier::Backwards::visitSetCondInst(SetCondInst &SCI) {
+ Value &vBO = visitBinaryOperator(SCI);
+ if (&vBO != &SCI) return vBO;
+
+ Value *SCI0 = resolve(SCI.getOperand(0)),
+ *SCI1 = resolve(SCI.getOperand(1));
+
+ PropertySet::ConstPropertyIterator NE =
+ KP.findProperty(PropertySet::NE, SCI0, SCI1);
+
+ if (NE != KP.Properties.end()) {
+ switch (SCI.getOpcode()) {
+ case Instruction::SetEQ: return *ConstantBool::getFalse();
+ case Instruction::SetNE: return *ConstantBool::getTrue();
+ case Instruction::SetLE:
+ case Instruction::SetGE:
+ case Instruction::SetLT:
+ case Instruction::SetGT:
+ break;
+ default:
+ assert(0 && "Unknown opcode in SetCondInst.");
+ break;
+ }
+ }
+ return SCI;
+}
+
+Value &PredicateSimplifier::Backwards::visitBinaryOperator(BinaryOperator &BO) {
+ Value *V = KP.canonicalize(&BO);
+ if (V != &BO) return *V;
+
+ Value *lhs = resolve(BO.getOperand(0)),
+ *rhs = resolve(BO.getOperand(1));
+
+ ConstantIntegral *CI1 = dyn_cast<ConstantIntegral>(lhs),
+ *CI2 = dyn_cast<ConstantIntegral>(rhs);
+
+ if (CI1 && CI2) return *ConstantExpr::get(BO.getOpcode(), CI1, CI2);
+
+ return BO;
+}
+
+Value &PredicateSimplifier::Backwards::visitSelectInst(SelectInst &SI) {
+ Value *V = KP.canonicalize(&SI);
+ if (V != &SI) return *V;
+
+ Value *Condition = resolve(SI.getCondition());
+ if (ConstantBool *CB = dyn_cast<ConstantBool>(Condition))
+ return *resolve(CB->getValue() ? SI.getTrueValue() : SI.getFalseValue());
+ return SI;
+}
+
+Value &PredicateSimplifier::Backwards::visitInstruction(Instruction &I) {
+ return *KP.canonicalize(&I);
+}
+
+Value *PredicateSimplifier::Backwards::resolve(Value *V) {
+ if (isa<Constant>(V) || isa<BasicBlock>(V) || KP.empty()) return V;
+
+ if (Instruction *I = dyn_cast<Instruction>(V)) return &visit(*I);
+ return KP.canonicalize(V);
+}
+
void PredicateSimplifier::visitBasicBlock(BasicBlock *BB,
PropertySet &KnownProperties) {
for (BasicBlock::iterator I = BB->begin(), E = BB->end(); I != E;) {
@@ -638,12 +613,12 @@
void PredicateSimplifier::visitInstruction(Instruction *I,
PropertySet &KnownProperties) {
// Try to replace the whole instruction.
- Value *V = KnownProperties.canonicalize(I);
+ Backwards resolve(KnownProperties);
+ Value *V = resolve.resolve(I);
if (V != I) {
modified = true;
++NumInstruction;
DEBUG(std::cerr << "Removing " << *I);
- KnownProperties.remove(I);
I->replaceAllUsesWith(V);
I->eraseFromParent();
return;
@@ -652,7 +627,7 @@
// Try to substitute operands.
for (unsigned i = 0, e = I->getNumOperands(); i != e; ++i) {
Value *Oper = I->getOperand(i);
- Value *V = KnownProperties.canonicalize(Oper);
+ Value *V = resolve.resolve(Oper);
if (V != Oper) {
modified = true;
++NumVarsReplaced;
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