From 1f02c8910a4d9388e69d909b203e537509bed7d2 Mon Sep 17 00:00:00 2001
From: Chris Lattner <sabre@nondot.org>
Date: Thu, 9 May 2002 20:14:10 +0000
Subject: * Clean up how PHI nodes are handled * Correct global variable
references * Fix loads & stores with zero indices * Do not emit an else part
of a branch if there is no code (no phi node and a fallthrough branch),
makes code more readable to get: if (l2_cond240) { goto l13_bb10; }
with no else{} branch
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@2583 91177308-0d34-0410-b5e6-96231b3b80d8
---
lib/Target/CBackend/CBackend.cpp | 127 ++++++++++++++++++++++-----------------
lib/Target/CBackend/Writer.cpp | 127 ++++++++++++++++++++++-----------------
2 files changed, 146 insertions(+), 108 deletions(-)
(limited to 'lib')
diff --git a/lib/Target/CBackend/CBackend.cpp b/lib/Target/CBackend/CBackend.cpp
index 5da8367..77aef46 100644
--- a/lib/Target/CBackend/CBackend.cpp
+++ b/lib/Target/CBackend/CBackend.cpp
@@ -176,6 +176,8 @@ static string calcTypeNameVar(const Type *Ty,
case Type::IntTyID: return "int " + NameSoFar;
case Type::ULongTyID: return "unsigned long long " + NameSoFar;
case Type::LongTyID: return "signed long long " + NameSoFar;
+ case Type::FloatTyID: return "float " + NameSoFar;
+ case Type::DoubleTyID: return "double " + NameSoFar;
default :
cerr << "Unknown primitive type: " << Ty << "\n";
abort();
@@ -330,7 +332,8 @@ namespace {
ostream &Out;
void outputLValue(Instruction *);
- void printPhiFromNextBlock(TerminatorInst *tI, int indx);
+ void printBranchToBlock(BasicBlock *CurBlock, BasicBlock *SuccBlock,
+ unsigned Indent);
void printIndexingExpr(MemAccessInst *MAI);
public:
@@ -361,26 +364,6 @@ void CInstPrintVisitor::outputLValue(Instruction *I) {
Out << " " << CW.getValueName(I) << " = ";
}
-void CInstPrintVisitor::printPhiFromNextBlock(TerminatorInst *tI, int indx) {
- BasicBlock *bb = tI->getSuccessor(indx);
- BasicBlock::const_iterator insIt = bb->begin();
- while (insIt != bb->end()) {
- if (PHINode *pI = dyn_cast<PHINode>(*insIt)) {
- //Its a phinode!
- //Calculate the incoming index for this
- int incindex = pI->getBasicBlockIndex(tI->getParent());
- if (incindex != -1) {
- //now we have to do the printing
- outputLValue(pI);
- CW.writeOperand(pI->getIncomingValue(incindex));
- Out << ";\n";
- }
- }
- else break;
- insIt++;
- }
-}
-
// Implement all "other" instructions, except for PHINode
void CInstPrintVisitor::visitCastInst(CastInst *I) {
outputLValue(I);
@@ -418,6 +401,11 @@ void CInstPrintVisitor::visitCallInst(CallInst *I) {
// neccesary because we use the instruction classes as opaque types...
//
void CInstPrintVisitor::visitReturnInst(ReturnInst *I) {
+ // Don't output a void return if this is the last basic block in the function
+ if (I->getNumOperands() == 0 &&
+ *(I->getParent()->getParent()->end()-1) == I->getParent())
+ return;
+
Out << " return";
if (I->getNumOperands()) {
Out << " ";
@@ -434,39 +422,62 @@ static bool BBFollowsBB(BasicBlock *BB1, BasicBlock *BB2) {
return *(I+1) == BB2;
}
+static bool isGotoCodeNeccessary(BasicBlock *From, BasicBlock *To) {
+ // If PHI nodes need copies, we need the copy code...
+ if (isa<PHINode>(To->front()) ||
+ !BBFollowsBB(From, To)) // Not directly successor, need goto
+ return true;
+
+ // Otherwise we don't need the code.
+ return false;
+}
+
+void CInstPrintVisitor::printBranchToBlock(BasicBlock *CurBB, BasicBlock *Succ,
+ unsigned Indent) {
+ for (BasicBlock::iterator I = Succ->begin();
+ PHINode *PN = dyn_cast<PHINode>(*I); ++I) {
+ // now we have to do the printing
+ Out << string(Indent, ' ');
+ outputLValue(PN);
+ CW.writeOperand(PN->getIncomingValue(PN->getBasicBlockIndex(CurBB)));
+ Out << "; /* for PHI node */\n";
+ }
+
+ if (!BBFollowsBB(CurBB, Succ)) {
+ Out << string(Indent, ' ') << " goto ";
+ CW.writeOperand(Succ);
+ Out << ";\n";
+ }
+}
+
// Brach instruction printing - Avoid printing out a brach to a basic block that
// immediately succeeds the current one.
//
void CInstPrintVisitor::visitBranchInst(BranchInst *I) {
- TerminatorInst *tI = cast<TerminatorInst>(I);
if (I->isConditional()) {
- Out << " if (";
- CW.writeOperand(I->getCondition());
- Out << ") {\n";
- printPhiFromNextBlock(tI,0);
-
- if (!BBFollowsBB(I->getParent(), cast<BasicBlock>(I->getOperand(0)))) {
- Out << " goto ";
- CW.writeOperand(I->getOperand(0));
- Out << ";\n";
- }
- Out << " } else {\n";
- printPhiFromNextBlock(tI,1);
+ if (isGotoCodeNeccessary(I->getParent(), I->getSuccessor(0))) {
+ Out << " if (";
+ CW.writeOperand(I->getCondition());
+ Out << ") {\n";
+
+ printBranchToBlock(I->getParent(), I->getSuccessor(0), 2);
+
+ if (isGotoCodeNeccessary(I->getParent(), I->getSuccessor(1))) {
+ Out << " } else {\n";
+ printBranchToBlock(I->getParent(), I->getSuccessor(1), 2);
+ }
+ } else {
+ // First goto not neccesary, assume second one is...
+ Out << " if (!";
+ CW.writeOperand(I->getCondition());
+ Out << ") {\n";
- if (!BBFollowsBB(I->getParent(), cast<BasicBlock>(I->getOperand(1)))) {
- Out << " goto ";
- CW.writeOperand(I->getOperand(1));
- Out << ";\n";
+ printBranchToBlock(I->getParent(), I->getSuccessor(1), 2);
}
+
Out << " }\n";
} else {
- printPhiFromNextBlock(tI,0);
-
- if (!BBFollowsBB(I->getParent(), cast<BasicBlock>(I->getOperand(0)))) {
- Out << " goto ";
- CW.writeOperand(I->getOperand(0));
- Out << ";\n";
- }
+ printBranchToBlock(I->getParent(), I->getSuccessor(0), 0);
}
Out << "\n";
}
@@ -508,16 +519,19 @@ void CInstPrintVisitor::visitAllocaInst(AllocaInst *I) {
Out << ");\n";
}
-void CInstPrintVisitor::visitFreeInst(FreeInst *I) {
- Out << "free(";
+void CInstPrintVisitor::visitFreeInst(FreeInst *I) {
+ Out << " free(";
CW.writeOperand(I->getOperand(0));
Out << ");\n";
}
void CInstPrintVisitor::printIndexingExpr(MemAccessInst *MAI) {
+ MemAccessInst::op_iterator I = MAI->idx_begin(), E = MAI->idx_end();
+ if (I == E)
+ Out << "*"; // Implicit zero first argument: '*x' is equivalent to 'x[0]'
+
CW.writeOperand(MAI->getPointerOperand());
- MemAccessInst::op_iterator I = MAI->idx_begin(), E = MAI->idx_end();
if (I == E) return;
// Print out the -> operator if possible...
@@ -705,9 +719,12 @@ void CWriter::printSymbolTable(const SymbolTable &ST) {
for (; I != End; ++I) {
const Value *V = I->second;
if (const Type *Ty = dyn_cast<const Type>(V)) {
- Out << "typedef ";
string Name = "l_" + I->first;
- if (isa<StructType>(Ty)) Name = "struct " + Name;
+ if (isa<StructType>(Ty))
+ Name = "struct " + Name;
+ else
+ Out << "typedef ";
+
Out << calcTypeNameVar(Ty, TypeNames, Name, true) << ";\n";
}
}
@@ -730,7 +747,7 @@ void CWriter::printFunctionSignature(const Function *F) {
// Print out the return type and name...
printType(F->getReturnType());
- Out << " " << getValueName(F) << "(";
+ Out << getValueName(F) << "(";
if (!F->isExternal()) {
if (!F->getArgumentList().empty()) {
@@ -830,9 +847,11 @@ void CWriter::writeOperand(const Value *Operand) {
if (Operand->hasName()) {
Out << getValueName(Operand);
} else if (const Constant *CPV = dyn_cast<const Constant>(Operand)) {
- if (isa<ConstantPointerNull>(CPV))
- Out << "NULL";
- else
+ if (isa<ConstantPointerNull>(CPV)) {
+ Out << "((";
+ printTypeVar(CPV->getType(), "");
+ Out << ")NULL)";
+ } else
Out << getConstStrValue(CPV);
} else {
int Slot = Table.getValSlot(Operand);
diff --git a/lib/Target/CBackend/Writer.cpp b/lib/Target/CBackend/Writer.cpp
index 5da8367..77aef46 100644
--- a/lib/Target/CBackend/Writer.cpp
+++ b/lib/Target/CBackend/Writer.cpp
@@ -176,6 +176,8 @@ static string calcTypeNameVar(const Type *Ty,
case Type::IntTyID: return "int " + NameSoFar;
case Type::ULongTyID: return "unsigned long long " + NameSoFar;
case Type::LongTyID: return "signed long long " + NameSoFar;
+ case Type::FloatTyID: return "float " + NameSoFar;
+ case Type::DoubleTyID: return "double " + NameSoFar;
default :
cerr << "Unknown primitive type: " << Ty << "\n";
abort();
@@ -330,7 +332,8 @@ namespace {
ostream &Out;
void outputLValue(Instruction *);
- void printPhiFromNextBlock(TerminatorInst *tI, int indx);
+ void printBranchToBlock(BasicBlock *CurBlock, BasicBlock *SuccBlock,
+ unsigned Indent);
void printIndexingExpr(MemAccessInst *MAI);
public:
@@ -361,26 +364,6 @@ void CInstPrintVisitor::outputLValue(Instruction *I) {
Out << " " << CW.getValueName(I) << " = ";
}
-void CInstPrintVisitor::printPhiFromNextBlock(TerminatorInst *tI, int indx) {
- BasicBlock *bb = tI->getSuccessor(indx);
- BasicBlock::const_iterator insIt = bb->begin();
- while (insIt != bb->end()) {
- if (PHINode *pI = dyn_cast<PHINode>(*insIt)) {
- //Its a phinode!
- //Calculate the incoming index for this
- int incindex = pI->getBasicBlockIndex(tI->getParent());
- if (incindex != -1) {
- //now we have to do the printing
- outputLValue(pI);
- CW.writeOperand(pI->getIncomingValue(incindex));
- Out << ";\n";
- }
- }
- else break;
- insIt++;
- }
-}
-
// Implement all "other" instructions, except for PHINode
void CInstPrintVisitor::visitCastInst(CastInst *I) {
outputLValue(I);
@@ -418,6 +401,11 @@ void CInstPrintVisitor::visitCallInst(CallInst *I) {
// neccesary because we use the instruction classes as opaque types...
//
void CInstPrintVisitor::visitReturnInst(ReturnInst *I) {
+ // Don't output a void return if this is the last basic block in the function
+ if (I->getNumOperands() == 0 &&
+ *(I->getParent()->getParent()->end()-1) == I->getParent())
+ return;
+
Out << " return";
if (I->getNumOperands()) {
Out << " ";
@@ -434,39 +422,62 @@ static bool BBFollowsBB(BasicBlock *BB1, BasicBlock *BB2) {
return *(I+1) == BB2;
}
+static bool isGotoCodeNeccessary(BasicBlock *From, BasicBlock *To) {
+ // If PHI nodes need copies, we need the copy code...
+ if (isa<PHINode>(To->front()) ||
+ !BBFollowsBB(From, To)) // Not directly successor, need goto
+ return true;
+
+ // Otherwise we don't need the code.
+ return false;
+}
+
+void CInstPrintVisitor::printBranchToBlock(BasicBlock *CurBB, BasicBlock *Succ,
+ unsigned Indent) {
+ for (BasicBlock::iterator I = Succ->begin();
+ PHINode *PN = dyn_cast<PHINode>(*I); ++I) {
+ // now we have to do the printing
+ Out << string(Indent, ' ');
+ outputLValue(PN);
+ CW.writeOperand(PN->getIncomingValue(PN->getBasicBlockIndex(CurBB)));
+ Out << "; /* for PHI node */\n";
+ }
+
+ if (!BBFollowsBB(CurBB, Succ)) {
+ Out << string(Indent, ' ') << " goto ";
+ CW.writeOperand(Succ);
+ Out << ";\n";
+ }
+}
+
// Brach instruction printing - Avoid printing out a brach to a basic block that
// immediately succeeds the current one.
//
void CInstPrintVisitor::visitBranchInst(BranchInst *I) {
- TerminatorInst *tI = cast<TerminatorInst>(I);
if (I->isConditional()) {
- Out << " if (";
- CW.writeOperand(I->getCondition());
- Out << ") {\n";
- printPhiFromNextBlock(tI,0);
-
- if (!BBFollowsBB(I->getParent(), cast<BasicBlock>(I->getOperand(0)))) {
- Out << " goto ";
- CW.writeOperand(I->getOperand(0));
- Out << ";\n";
- }
- Out << " } else {\n";
- printPhiFromNextBlock(tI,1);
+ if (isGotoCodeNeccessary(I->getParent(), I->getSuccessor(0))) {
+ Out << " if (";
+ CW.writeOperand(I->getCondition());
+ Out << ") {\n";
+
+ printBranchToBlock(I->getParent(), I->getSuccessor(0), 2);
+
+ if (isGotoCodeNeccessary(I->getParent(), I->getSuccessor(1))) {
+ Out << " } else {\n";
+ printBranchToBlock(I->getParent(), I->getSuccessor(1), 2);
+ }
+ } else {
+ // First goto not neccesary, assume second one is...
+ Out << " if (!";
+ CW.writeOperand(I->getCondition());
+ Out << ") {\n";
- if (!BBFollowsBB(I->getParent(), cast<BasicBlock>(I->getOperand(1)))) {
- Out << " goto ";
- CW.writeOperand(I->getOperand(1));
- Out << ";\n";
+ printBranchToBlock(I->getParent(), I->getSuccessor(1), 2);
}
+
Out << " }\n";
} else {
- printPhiFromNextBlock(tI,0);
-
- if (!BBFollowsBB(I->getParent(), cast<BasicBlock>(I->getOperand(0)))) {
- Out << " goto ";
- CW.writeOperand(I->getOperand(0));
- Out << ";\n";
- }
+ printBranchToBlock(I->getParent(), I->getSuccessor(0), 0);
}
Out << "\n";
}
@@ -508,16 +519,19 @@ void CInstPrintVisitor::visitAllocaInst(AllocaInst *I) {
Out << ");\n";
}
-void CInstPrintVisitor::visitFreeInst(FreeInst *I) {
- Out << "free(";
+void CInstPrintVisitor::visitFreeInst(FreeInst *I) {
+ Out << " free(";
CW.writeOperand(I->getOperand(0));
Out << ");\n";
}
void CInstPrintVisitor::printIndexingExpr(MemAccessInst *MAI) {
+ MemAccessInst::op_iterator I = MAI->idx_begin(), E = MAI->idx_end();
+ if (I == E)
+ Out << "*"; // Implicit zero first argument: '*x' is equivalent to 'x[0]'
+
CW.writeOperand(MAI->getPointerOperand());
- MemAccessInst::op_iterator I = MAI->idx_begin(), E = MAI->idx_end();
if (I == E) return;
// Print out the -> operator if possible...
@@ -705,9 +719,12 @@ void CWriter::printSymbolTable(const SymbolTable &ST) {
for (; I != End; ++I) {
const Value *V = I->second;
if (const Type *Ty = dyn_cast<const Type>(V)) {
- Out << "typedef ";
string Name = "l_" + I->first;
- if (isa<StructType>(Ty)) Name = "struct " + Name;
+ if (isa<StructType>(Ty))
+ Name = "struct " + Name;
+ else
+ Out << "typedef ";
+
Out << calcTypeNameVar(Ty, TypeNames, Name, true) << ";\n";
}
}
@@ -730,7 +747,7 @@ void CWriter::printFunctionSignature(const Function *F) {
// Print out the return type and name...
printType(F->getReturnType());
- Out << " " << getValueName(F) << "(";
+ Out << getValueName(F) << "(";
if (!F->isExternal()) {
if (!F->getArgumentList().empty()) {
@@ -830,9 +847,11 @@ void CWriter::writeOperand(const Value *Operand) {
if (Operand->hasName()) {
Out << getValueName(Operand);
} else if (const Constant *CPV = dyn_cast<const Constant>(Operand)) {
- if (isa<ConstantPointerNull>(CPV))
- Out << "NULL";
- else
+ if (isa<ConstantPointerNull>(CPV)) {
+ Out << "((";
+ printTypeVar(CPV->getType(), "");
+ Out << ")NULL)";
+ } else
Out << getConstStrValue(CPV);
} else {
int Slot = Table.getValSlot(Operand);
--
cgit v1.1