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llvm-project/clang/lib/CodeGen/CGStmt.cpp

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//===--- CGStmt.cpp - Emit LLVM Code from Statements ----------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file is distributed under the University of Illinois Open Source
// License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This contains code to emit Stmt nodes as LLVM code.
//
//===----------------------------------------------------------------------===//
#include "CGDebugInfo.h"
#include "CodeGenModule.h"
#include "CodeGenFunction.h"
#include "clang/AST/ASTContext.h"
#include "clang/AST/StmtVisitor.h"
#include "clang/Basic/TargetInfo.h"
#include "llvm/Constants.h"
#include "llvm/DerivedTypes.h"
#include "llvm/Function.h"
#include "llvm/InlineAsm.h"
#include "llvm/ADT/StringExtras.h"
using namespace clang;
using namespace CodeGen;
//===----------------------------------------------------------------------===//
// Statement Emission
//===----------------------------------------------------------------------===//
void CodeGenFunction::EmitStmt(const Stmt *S) {
assert(S && "Null statement?");
// Generate stoppoints if we are emitting debug info.
// Beginning of a Compound Statement (e.g. an opening '{') does not produce
// executable code. So do not generate a stoppoint for that.
CGDebugInfo *DI = CGM.getDebugInfo();
if (DI && S->getStmtClass() != Stmt::CompoundStmtClass) {
if (S->getLocStart().isValid()) {
DI->setLocation(S->getLocStart());
}
DI->EmitStopPoint(CurFn, Builder);
}
switch (S->getStmtClass()) {
default:
// Must be an expression in a stmt context. Emit the value (to get
// side-effects) and ignore the result.
if (const Expr *E = dyn_cast<Expr>(S)) {
if (!hasAggregateLLVMType(E->getType()))
EmitScalarExpr(E);
else if (E->getType()->isAnyComplexType())
EmitComplexExpr(E);
else
EmitAggExpr(E, 0, false);
} else {
WarnUnsupported(S, "statement");
}
break;
case Stmt::NullStmtClass: break;
case Stmt::CompoundStmtClass: EmitCompoundStmt(cast<CompoundStmt>(*S)); break;
case Stmt::LabelStmtClass: EmitLabelStmt(cast<LabelStmt>(*S)); break;
case Stmt::GotoStmtClass: EmitGotoStmt(cast<GotoStmt>(*S)); break;
case Stmt::IndirectGotoStmtClass:
EmitIndirectGotoStmt(cast<IndirectGotoStmt>(*S)); break;
case Stmt::IfStmtClass: EmitIfStmt(cast<IfStmt>(*S)); break;
case Stmt::WhileStmtClass: EmitWhileStmt(cast<WhileStmt>(*S)); break;
case Stmt::DoStmtClass: EmitDoStmt(cast<DoStmt>(*S)); break;
case Stmt::ForStmtClass: EmitForStmt(cast<ForStmt>(*S)); break;
case Stmt::ReturnStmtClass: EmitReturnStmt(cast<ReturnStmt>(*S)); break;
case Stmt::DeclStmtClass: EmitDeclStmt(cast<DeclStmt>(*S)); break;
case Stmt::BreakStmtClass: EmitBreakStmt(); break;
case Stmt::ContinueStmtClass: EmitContinueStmt(); break;
case Stmt::SwitchStmtClass: EmitSwitchStmt(cast<SwitchStmt>(*S)); break;
case Stmt::DefaultStmtClass: EmitDefaultStmt(cast<DefaultStmt>(*S)); break;
case Stmt::CaseStmtClass: EmitCaseStmt(cast<CaseStmt>(*S)); break;
case Stmt::AsmStmtClass: EmitAsmStmt(cast<AsmStmt>(*S)); break;
}
}
/// EmitCompoundStmt - Emit a compound statement {..} node. If GetLast is true,
/// this captures the expression result of the last sub-statement and returns it
/// (for use by the statement expression extension).
RValue CodeGenFunction::EmitCompoundStmt(const CompoundStmt &S, bool GetLast,
llvm::Value *AggLoc, bool isAggVol) {
// FIXME: handle vla's etc.
CGDebugInfo *DI = CGM.getDebugInfo();
if (DI) {
if (S.getLBracLoc().isValid())
DI->setLocation(S.getLBracLoc());
DI->EmitRegionStart(CurFn, Builder);
}
for (CompoundStmt::const_body_iterator I = S.body_begin(),
E = S.body_end()-GetLast; I != E; ++I)
EmitStmt(*I);
if (DI) {
if (S.getRBracLoc().isValid())
DI->setLocation(S.getRBracLoc());
DI->EmitRegionEnd(CurFn, Builder);
}
if (!GetLast)
return RValue::get(0);
// We have to special case labels here. They are statements, but when put at
// the end of a statement expression, they yield the value of their
// subexpression. Handle this by walking through all labels we encounter,
// emitting them before we evaluate the subexpr.
const Stmt *LastStmt = S.body_back();
while (const LabelStmt *LS = dyn_cast<LabelStmt>(LastStmt)) {
EmitLabel(*LS);
LastStmt = LS->getSubStmt();
}
return EmitAnyExpr(cast<Expr>(LastStmt), AggLoc);
}
void CodeGenFunction::EmitBlock(llvm::BasicBlock *BB) {
// Emit a branch from this block to the next one if this was a real block. If
// this was just a fall-through block after a terminator, don't emit it.
llvm::BasicBlock *LastBB = Builder.GetInsertBlock();
if (LastBB->getTerminator()) {
// If the previous block is already terminated, don't touch it.
} else if (LastBB->empty() && isDummyBlock(LastBB)) {
// If the last block was an empty placeholder, remove it now.
// TODO: cache and reuse these.
LastBB->eraseFromParent();
} else {
// Otherwise, create a fall-through branch.
Builder.CreateBr(BB);
}
CurFn->getBasicBlockList().push_back(BB);
Builder.SetInsertPoint(BB);
}
void CodeGenFunction::EmitLabel(const LabelStmt &S) {
llvm::BasicBlock *NextBB = getBasicBlockForLabel(&S);
EmitBlock(NextBB);
}
void CodeGenFunction::EmitLabelStmt(const LabelStmt &S) {
EmitLabel(S);
EmitStmt(S.getSubStmt());
}
void CodeGenFunction::EmitGotoStmt(const GotoStmt &S) {
Builder.CreateBr(getBasicBlockForLabel(S.getLabel()));
// Emit a block after the branch so that dead code after a goto has some place
// to go.
Builder.SetInsertPoint(llvm::BasicBlock::Create("", CurFn));
}
void CodeGenFunction::EmitIndirectGotoStmt(const IndirectGotoStmt &S) {
// Emit initial switch which will be patched up later by
// EmitIndirectSwitches(). We need a default dest, so we use the
// current BB, but this is overwritten.
llvm::Value *V = Builder.CreatePtrToInt(EmitScalarExpr(S.getTarget()),
llvm::Type::Int32Ty,
"addr");
llvm::SwitchInst *I = Builder.CreateSwitch(V, Builder.GetInsertBlock());
IndirectSwitches.push_back(I);
// Emit a block after the branch so that dead code after a goto has some place
// to go.
Builder.SetInsertPoint(llvm::BasicBlock::Create("", CurFn));
}
void CodeGenFunction::EmitIfStmt(const IfStmt &S) {
// FIXME: It would probably be nice for us to skip emission of if
// (0) code here.
// C99 6.8.4.1: The first substatement is executed if the expression compares
// unequal to 0. The condition must be a scalar type.
llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
llvm::BasicBlock *ContBlock = llvm::BasicBlock::Create("ifend");
llvm::BasicBlock *ThenBlock = llvm::BasicBlock::Create("ifthen");
llvm::BasicBlock *ElseBlock = ContBlock;
if (S.getElse())
ElseBlock = llvm::BasicBlock::Create("ifelse");
// Insert the conditional branch.
Builder.CreateCondBr(BoolCondVal, ThenBlock, ElseBlock);
// Emit the 'then' code.
EmitBlock(ThenBlock);
EmitStmt(S.getThen());
llvm::BasicBlock *BB = Builder.GetInsertBlock();
if (isDummyBlock(BB)) {
BB->eraseFromParent();
Builder.SetInsertPoint(ThenBlock);
} else {
Builder.CreateBr(ContBlock);
}
// Emit the 'else' code if present.
if (const Stmt *Else = S.getElse()) {
EmitBlock(ElseBlock);
EmitStmt(Else);
llvm::BasicBlock *BB = Builder.GetInsertBlock();
if (isDummyBlock(BB)) {
BB->eraseFromParent();
Builder.SetInsertPoint(ElseBlock);
} else {
Builder.CreateBr(ContBlock);
}
}
// Emit the continuation block for code after the if.
EmitBlock(ContBlock);
}
void CodeGenFunction::EmitWhileStmt(const WhileStmt &S) {
// Emit the header for the loop, insert it, which will create an uncond br to
// it.
llvm::BasicBlock *LoopHeader = llvm::BasicBlock::Create("whilecond");
EmitBlock(LoopHeader);
// Evaluate the conditional in the while header. C99 6.8.5.1: The evaluation
// of the controlling expression takes place before each execution of the loop
// body.
llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
// while(1) is common, avoid extra exit blocks. Be sure
// to correctly handle break/continue though.
bool EmitBoolCondBranch = true;
if (llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal))
if (C->isOne())
EmitBoolCondBranch = false;
// Create an exit block for when the condition fails, create a block for the
// body of the loop.
llvm::BasicBlock *ExitBlock = llvm::BasicBlock::Create("whileexit");
llvm::BasicBlock *LoopBody = llvm::BasicBlock::Create("whilebody");
// As long as the condition is true, go to the loop body.
if (EmitBoolCondBranch)
Builder.CreateCondBr(BoolCondVal, LoopBody, ExitBlock);
// Store the blocks to use for break and continue.
BreakContinueStack.push_back(BreakContinue(ExitBlock, LoopHeader));
// Emit the loop body.
EmitBlock(LoopBody);
EmitStmt(S.getBody());
BreakContinueStack.pop_back();
// Cycle to the condition.
Builder.CreateBr(LoopHeader);
// Emit the exit block.
EmitBlock(ExitBlock);
// If LoopHeader is a simple forwarding block then eliminate it.
if (!EmitBoolCondBranch
&& &LoopHeader->front() == LoopHeader->getTerminator()) {
LoopHeader->replaceAllUsesWith(LoopBody);
LoopHeader->getTerminator()->eraseFromParent();
LoopHeader->eraseFromParent();
}
}
void CodeGenFunction::EmitDoStmt(const DoStmt &S) {
// Emit the body for the loop, insert it, which will create an uncond br to
// it.
llvm::BasicBlock *LoopBody = llvm::BasicBlock::Create("dobody");
llvm::BasicBlock *AfterDo = llvm::BasicBlock::Create("afterdo");
EmitBlock(LoopBody);
llvm::BasicBlock *DoCond = llvm::BasicBlock::Create("docond");
// Store the blocks to use for break and continue.
BreakContinueStack.push_back(BreakContinue(AfterDo, DoCond));
// Emit the body of the loop into the block.
EmitStmt(S.getBody());
BreakContinueStack.pop_back();
EmitBlock(DoCond);
// C99 6.8.5.2: "The evaluation of the controlling expression takes place
// after each execution of the loop body."
// Evaluate the conditional in the while header.
// C99 6.8.5p2/p4: The first substatement is executed if the expression
// compares unequal to 0. The condition must be a scalar type.
llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
// "do {} while (0)" is common in macros, avoid extra blocks. Be sure
// to correctly handle break/continue though.
bool EmitBoolCondBranch = true;
if (llvm::ConstantInt *C = dyn_cast<llvm::ConstantInt>(BoolCondVal))
if (C->isZero())
EmitBoolCondBranch = false;
// As long as the condition is true, iterate the loop.
if (EmitBoolCondBranch)
Builder.CreateCondBr(BoolCondVal, LoopBody, AfterDo);
// Emit the exit block.
EmitBlock(AfterDo);
// If DoCond is a simple forwarding block then eliminate it.
if (!EmitBoolCondBranch && &DoCond->front() == DoCond->getTerminator()) {
DoCond->replaceAllUsesWith(AfterDo);
DoCond->getTerminator()->eraseFromParent();
DoCond->eraseFromParent();
}
}
void CodeGenFunction::EmitForStmt(const ForStmt &S) {
// FIXME: What do we do if the increment (f.e.) contains a stmt expression,
// which contains a continue/break?
// TODO: We could keep track of whether the loop body contains any
// break/continue statements and not create unnecessary blocks (like
// "afterfor" for a condless loop) if it doesn't.
// Evaluate the first part before the loop.
if (S.getInit())
EmitStmt(S.getInit());
// Start the loop with a block that tests the condition.
llvm::BasicBlock *CondBlock = llvm::BasicBlock::Create("forcond");
llvm::BasicBlock *AfterFor = llvm::BasicBlock::Create("afterfor");
EmitBlock(CondBlock);
// Evaluate the condition if present. If not, treat it as a non-zero-constant
// according to 6.8.5.3p2, aka, true.
if (S.getCond()) {
// C99 6.8.5p2/p4: The first substatement is executed if the expression
// compares unequal to 0. The condition must be a scalar type.
llvm::Value *BoolCondVal = EvaluateExprAsBool(S.getCond());
// As long as the condition is true, iterate the loop.
llvm::BasicBlock *ForBody = llvm::BasicBlock::Create("forbody");
Builder.CreateCondBr(BoolCondVal, ForBody, AfterFor);
EmitBlock(ForBody);
} else {
// Treat it as a non-zero constant. Don't even create a new block for the
// body, just fall into it.
}
// If the for loop doesn't have an increment we can just use the
// condition as the continue block.
llvm::BasicBlock *ContinueBlock;
if (S.getInc())
ContinueBlock = llvm::BasicBlock::Create("forinc");
else
ContinueBlock = CondBlock;
// Store the blocks to use for break and continue.
BreakContinueStack.push_back(BreakContinue(AfterFor, ContinueBlock));
// If the condition is true, execute the body of the for stmt.
EmitStmt(S.getBody());
BreakContinueStack.pop_back();
if (S.getInc())
EmitBlock(ContinueBlock);
// If there is an increment, emit it next.
if (S.getInc())
EmitStmt(S.getInc());
// Finally, branch back up to the condition for the next iteration.
Builder.CreateBr(CondBlock);
// Emit the fall-through block.
EmitBlock(AfterFor);
}
/// EmitReturnStmt - Note that due to GCC extensions, this can have an operand
/// if the function returns void, or may be missing one if the function returns
/// non-void. Fun stuff :).
void CodeGenFunction::EmitReturnStmt(const ReturnStmt &S) {
// Emit the result value, even if unused, to evalute the side effects.
const Expr *RV = S.getRetValue();
llvm::Value* RetValue = 0;
if (FnRetTy->isVoidType()) {
// Make sure not to return anything
if (RV) {
// Evaluate the expression for side effects
EmitAnyExpr(RV);
}
} else if (RV == 0) {
const llvm::Type *RetTy = CurFn->getFunctionType()->getReturnType();
if (RetTy != llvm::Type::VoidTy) {
// Handle "return;" in a function that returns a value.
RetValue = llvm::UndefValue::get(RetTy);
}
} else if (!hasAggregateLLVMType(RV->getType())) {
RetValue = EmitScalarExpr(RV);
} else if (RV->getType()->isAnyComplexType()) {
EmitComplexExprIntoAddr(RV, CurFn->arg_begin(), false);
} else {
EmitAggExpr(RV, CurFn->arg_begin(), false);
}
if (RetValue) {
Builder.CreateRet(RetValue);
} else {
Builder.CreateRetVoid();
}
// Emit a block after the branch so that dead code after a return has some
// place to go.
EmitBlock(llvm::BasicBlock::Create());
}
void CodeGenFunction::EmitDeclStmt(const DeclStmt &S) {
for (const ScopedDecl *Decl = S.getDecl(); Decl;
Decl = Decl->getNextDeclarator())
EmitDecl(*Decl);
}
void CodeGenFunction::EmitBreakStmt() {
assert(!BreakContinueStack.empty() && "break stmt not in a loop or switch!");
llvm::BasicBlock *Block = BreakContinueStack.back().BreakBlock;
Builder.CreateBr(Block);
EmitBlock(llvm::BasicBlock::Create());
}
void CodeGenFunction::EmitContinueStmt() {
assert(!BreakContinueStack.empty() && "continue stmt not in a loop!");
llvm::BasicBlock *Block = BreakContinueStack.back().ContinueBlock;
Builder.CreateBr(Block);
EmitBlock(llvm::BasicBlock::Create());
}
/// EmitCaseStmtRange - If case statement range is not too big then
/// add multiple cases to switch instruction, one for each value within
/// the range. If range is too big then emit "if" condition check.
void CodeGenFunction::EmitCaseStmtRange(const CaseStmt &S) {
// XXX kill me with param - ddunbar
assert(S.getRHS() && "Expected RHS value in CaseStmt");
llvm::APSInt LHS = S.getLHS()->getIntegerConstantExprValue(getContext());
llvm::APSInt RHS = S.getRHS()->getIntegerConstantExprValue(getContext());
// Emit the code for this case. We do this first to make sure it is
// properly chained from our predecessor before generating the
// switch machinery to enter this block.
StartBlock("sw.bb");
llvm::BasicBlock *CaseDest = Builder.GetInsertBlock();
EmitStmt(S.getSubStmt());
// If range is empty, do nothing.
if (LHS.isSigned() ? RHS.slt(LHS) : RHS.ult(LHS))
return;
llvm::APInt Range = RHS - LHS;
// FIXME: parameters such as this should not be hardcoded.
if (Range.ult(llvm::APInt(Range.getBitWidth(), 64))) {
// Range is small enough to add multiple switch instruction cases.
for (unsigned i = 0, e = Range.getZExtValue() + 1; i != e; ++i) {
SwitchInsn->addCase(llvm::ConstantInt::get(LHS), CaseDest);
LHS++;
}
return;
}
// The range is too big. Emit "if" condition into a new block,
// making sure to save and restore the current insertion point.
llvm::BasicBlock *RestoreBB = Builder.GetInsertBlock();
// Push this test onto the chain of range checks (which terminates
// in the default basic block). The switch's default will be changed
// to the top of this chain after switch emission is complete.
llvm::BasicBlock *FalseDest = CaseRangeBlock;
CaseRangeBlock = llvm::BasicBlock::Create("sw.caserange");
CurFn->getBasicBlockList().push_back(CaseRangeBlock);
Builder.SetInsertPoint(CaseRangeBlock);
// Emit range check.
llvm::Value *Diff =
Builder.CreateSub(SwitchInsn->getCondition(), llvm::ConstantInt::get(LHS),
"tmp");
llvm::Value *Cond =
Builder.CreateICmpULE(Diff, llvm::ConstantInt::get(Range), "tmp");
Builder.CreateCondBr(Cond, CaseDest, FalseDest);
// Restore the appropriate insertion point.
Builder.SetInsertPoint(RestoreBB);
}
void CodeGenFunction::EmitCaseStmt(const CaseStmt &S) {
if (S.getRHS()) {
EmitCaseStmtRange(S);
return;
}
StartBlock("sw.bb");
llvm::BasicBlock *CaseDest = Builder.GetInsertBlock();
llvm::APSInt CaseVal = S.getLHS()->getIntegerConstantExprValue(getContext());
SwitchInsn->addCase(llvm::ConstantInt::get(CaseVal),
CaseDest);
EmitStmt(S.getSubStmt());
}
void CodeGenFunction::EmitDefaultStmt(const DefaultStmt &S) {
llvm::BasicBlock *DefaultBlock = SwitchInsn->getDefaultDest();
assert(DefaultBlock->empty() && "EmitDefaultStmt: Default block already defined?");
EmitBlock(DefaultBlock);
EmitStmt(S.getSubStmt());
}
void CodeGenFunction::EmitSwitchStmt(const SwitchStmt &S) {
llvm::Value *CondV = EmitScalarExpr(S.getCond());
// Handle nested switch statements.
llvm::SwitchInst *SavedSwitchInsn = SwitchInsn;
llvm::BasicBlock *SavedCRBlock = CaseRangeBlock;
// Create basic block to hold stuff that comes after switch
// statement. We also need to create a default block now so that
// explicit case ranges tests can have a place to jump to on
// failure.
llvm::BasicBlock *NextBlock = llvm::BasicBlock::Create("sw.epilog");
llvm::BasicBlock *DefaultBlock = llvm::BasicBlock::Create("sw.default");
SwitchInsn = Builder.CreateSwitch(CondV, DefaultBlock);
CaseRangeBlock = DefaultBlock;
// Create basic block for body of switch
StartBlock("sw.body");
// All break statements jump to NextBlock. If BreakContinueStack is non empty
// then reuse last ContinueBlock.
llvm::BasicBlock *ContinueBlock = NULL;
if (!BreakContinueStack.empty())
ContinueBlock = BreakContinueStack.back().ContinueBlock;
BreakContinueStack.push_back(BreakContinue(NextBlock, ContinueBlock));
// Emit switch body.
EmitStmt(S.getBody());
BreakContinueStack.pop_back();
// Update the default block in case explicit case range tests have
// been chained on top.
SwitchInsn->setSuccessor(0, CaseRangeBlock);
// If a default was never emitted then reroute any jumps to it and
// discard.
if (!DefaultBlock->getParent()) {
DefaultBlock->replaceAllUsesWith(NextBlock);
delete DefaultBlock;
}
// Emit continuation.
EmitBlock(NextBlock);
SwitchInsn = SavedSwitchInsn;
CaseRangeBlock = SavedCRBlock;
}
static std::string ConvertAsmString(const char *Start, unsigned NumOperands,
bool IsSimple) {
static unsigned AsmCounter = 0;
AsmCounter++;
std::string Result;
if (IsSimple) {
while (*Start) {
switch (*Start) {
default:
Result += *Start;
break;
case '$':
Result += "$$";
break;
}
Start++;
}
return Result;
}
while (*Start) {
switch (*Start) {
default:
Result += *Start;
break;
case '$':
Result += "$$";
break;
case '%':
// Escaped character
Start++;
if (!*Start) {
// FIXME: This should be caught during Sema.
assert(0 && "Trailing '%' in asm string.");
}
char EscapedChar = *Start;
if (EscapedChar == '%') {
// Escaped percentage sign.
Result += '%';
} else if (EscapedChar == '=') {
// Generate an unique ID.
Result += llvm::utostr(AsmCounter);
} else if (isdigit(EscapedChar)) {
// %n - Assembler operand n
char *End;
unsigned long n = strtoul(Start, &End, 10);
if (Start == End) {
// FIXME: This should be caught during Sema.
assert(0 && "Missing operand!");
} else if (n >= NumOperands) {
// FIXME: This should be caught during Sema.
assert(0 && "Operand number out of range!");
}
Result += '$' + llvm::utostr(n);
Start = End - 1;
} else if (isalpha(EscapedChar)) {
char *End;
unsigned long n = strtoul(Start + 1, &End, 10);
if (Start == End) {
// FIXME: This should be caught during Sema.
assert(0 && "Missing operand!");
} else if (n >= NumOperands) {
// FIXME: This should be caught during Sema.
assert(0 && "Operand number out of range!");
}
Result += "${" + llvm::utostr(n) + ':' + EscapedChar + '}';
Start = End - 1;
} else {
assert(0 && "Unhandled asm escaped character!");
}
}
Start++;
}
return Result;
}
static std::string SimplifyConstraint(const char* Constraint,
TargetInfo &Target) {
std::string Result;
while (*Constraint) {
switch (*Constraint) {
default:
Result += Target.convertConstraint(*Constraint);
break;
// Ignore these
case '*':
case '?':
case '!':
break;
case 'g':
Result += "imr";
break;
}
Constraint++;
}
return Result;
}
void CodeGenFunction::EmitAsmStmt(const AsmStmt &S) {
std::string AsmString =
ConvertAsmString(std::string(S.getAsmString()->getStrData(),
S.getAsmString()->getByteLength()).c_str(),
S.getNumOutputs() + S.getNumInputs(), S.isSimple());
std::string Constraints;
llvm::Value *ResultAddr = 0;
const llvm::Type *ResultType = llvm::Type::VoidTy;
std::vector<const llvm::Type*> ArgTypes;
std::vector<llvm::Value*> Args;
// Keep track of inout constraints.
std::string InOutConstraints;
std::vector<llvm::Value*> InOutArgs;
std::vector<const llvm::Type*> InOutArgTypes;
for (unsigned i = 0, e = S.getNumOutputs(); i != e; i++) {
std::string OutputConstraint(S.getOutputConstraint(i)->getStrData(),
S.getOutputConstraint(i)->getByteLength());
TargetInfo::ConstraintInfo Info;
bool result = Target.validateOutputConstraint(OutputConstraint.c_str(),
Info);
assert(result && "Failed to parse output constraint");
// Simplify the output constraint.
OutputConstraint = SimplifyConstraint(OutputConstraint.c_str() + 1, Target);
LValue Dest = EmitLValue(S.getOutputExpr(i));
const llvm::Type *DestValueType =
cast<llvm::PointerType>(Dest.getAddress()->getType())->getElementType();
// If the first output operand is not a memory dest, we'll
// make it the return value.
if (i == 0 && !(Info & TargetInfo::CI_AllowsMemory) &&
DestValueType->isSingleValueType()) {
ResultAddr = Dest.getAddress();
ResultType = DestValueType;
Constraints += "=" + OutputConstraint;
} else {
ArgTypes.push_back(Dest.getAddress()->getType());
Args.push_back(Dest.getAddress());
if (i != 0)
Constraints += ',';
Constraints += "=*";
Constraints += OutputConstraint;
}
if (Info & TargetInfo::CI_ReadWrite) {
// FIXME: This code should be shared with the code that handles inputs.
InOutConstraints += ',';
const Expr *InputExpr = S.getOutputExpr(i);
llvm::Value *Arg;
if ((Info & TargetInfo::CI_AllowsRegister) ||
!(Info & TargetInfo::CI_AllowsMemory)) {
if (ConvertType(InputExpr->getType())->isSingleValueType()) {
Arg = EmitScalarExpr(InputExpr);
} else {
assert(0 && "FIXME: Implement passing multiple-value types as inputs");
}
} else {
LValue Dest = EmitLValue(InputExpr);
Arg = Dest.getAddress();
InOutConstraints += '*';
}
InOutArgTypes.push_back(Arg->getType());
InOutArgs.push_back(Arg);
InOutConstraints += OutputConstraint;
}
}
unsigned NumConstraints = S.getNumOutputs() + S.getNumInputs();
for (unsigned i = 0, e = S.getNumInputs(); i != e; i++) {
const Expr *InputExpr = S.getInputExpr(i);
std::string InputConstraint(S.getInputConstraint(i)->getStrData(),
S.getInputConstraint(i)->getByteLength());
TargetInfo::ConstraintInfo Info;
bool result = Target.validateInputConstraint(InputConstraint.c_str(),
NumConstraints,
Info);
assert(result && "Failed to parse input constraint");
if (i != 0 || S.getNumOutputs() > 0)
Constraints += ',';
// Simplify the input constraint.
InputConstraint = SimplifyConstraint(InputConstraint.c_str(), Target);
llvm::Value *Arg;
if ((Info & TargetInfo::CI_AllowsRegister) ||
!(Info & TargetInfo::CI_AllowsMemory)) {
if (ConvertType(InputExpr->getType())->isSingleValueType()) {
Arg = EmitScalarExpr(InputExpr);
} else {
assert(0 && "FIXME: Implement passing multiple-value types as inputs");
}
} else {
LValue Dest = EmitLValue(InputExpr);
Arg = Dest.getAddress();
Constraints += '*';
}
ArgTypes.push_back(Arg->getType());
Args.push_back(Arg);
Constraints += InputConstraint;
}
// Append the "input" part of inout constraints last.
for (unsigned i = 0, e = InOutArgs.size(); i != e; i++) {
ArgTypes.push_back(InOutArgTypes[i]);
Args.push_back(InOutArgs[i]);
}
Constraints += InOutConstraints;
// Clobbers
for (unsigned i = 0, e = S.getNumClobbers(); i != e; i++) {
std::string Clobber(S.getClobber(i)->getStrData(),
S.getClobber(i)->getByteLength());
Clobber = Target.getNormalizedGCCRegisterName(Clobber.c_str());
if (i != 0 || NumConstraints != 0)
Constraints += ',';
Constraints += "~{";
Constraints += Clobber;
Constraints += '}';
}
// Add machine specific clobbers
if (const char *C = Target.getClobbers()) {
if (!Constraints.empty())
Constraints += ',';
Constraints += C;
}
const llvm::FunctionType *FTy =
llvm::FunctionType::get(ResultType, ArgTypes, false);
llvm::InlineAsm *IA =
llvm::InlineAsm::get(FTy, AsmString, Constraints,
S.isVolatile() || S.getNumOutputs() == 0);
llvm::Value *Result = Builder.CreateCall(IA, Args.begin(), Args.end(), "");
if (ResultAddr) // FIXME: volatility
Builder.CreateStore(Result, ResultAddr);
}
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