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//===-- InlineAsm.cpp - Implement the InlineAsm class ---------------------===//
//
// The LLVM Compiler Infrastructure
//
// This file was developed by Chris Lattner and is distributed under the
// University of Illinois Open Source License. See LICENSE.TXT for details.
//
//===----------------------------------------------------------------------===//
//
// This file implements the InlineAsm class.
//
//===----------------------------------------------------------------------===//
#include "llvm/InlineAsm.h"
#include "llvm/DerivedTypes.h"
#include <cctype>
using namespace llvm;
// NOTE: when memoizing the function type, we have to be careful to handle the
// case when the type gets refined.
InlineAsm *InlineAsm::get(const FunctionType *Ty, const std::string &AsmString,
const std::string &Constraints, bool hasSideEffects) {
// FIXME: memoize!
return new InlineAsm(Ty, AsmString, Constraints, hasSideEffects);
}
InlineAsm::InlineAsm(const FunctionType *Ty, const std::string &asmString,
const std::string &constraints, bool hasSideEffects)
: Value(PointerType::get(Ty), Value::InlineAsmVal), AsmString(asmString),
Constraints(constraints), HasSideEffects(hasSideEffects) {
// Do various checks on the constraint string and type.
assert(Verify(Ty, constraints) && "Function type not legal for constraints!");
}
const FunctionType *InlineAsm::getFunctionType() const {
return cast<FunctionType>(getType()->getElementType());
}
/// Verify - Verify that the specified constraint string is reasonable for the
/// specified function type, and otherwise validate the constraint string.
bool InlineAsm::Verify(const FunctionType *Ty, const std::string &Constraints) {
if (Ty->isVarArg()) return false;
unsigned NumOutputs = 0, NumInputs = 0, NumClobbers = 0;
// Scan the constraints string.
for (std::string::const_iterator I = Constraints.begin(),
E = Constraints.end(); I != E; ) {
if (*I == ',') return false; // Empty constraint like ",,"
// Parse the prefix.
enum {
isInput, // 'x'
isOutput, // '=x'
isIndirectOutput, // '==x'
isClobber, // '~x'
} ConstraintType = isInput;
if (*I == '~') {
ConstraintType = isClobber;
++I;
} else if (*I == '=') {
++I;
if (I != E && *I == '=') {
ConstraintType = isIndirectOutput;
++I;
} else {
ConstraintType = isOutput;
}
}
if (I == E) return false; // Just a prefix, like "==" or "~".
switch (ConstraintType) {
case isOutput:
if (NumInputs || NumClobbers) return false; // outputs come first.
++NumOutputs;
break;
case isInput:
case isIndirectOutput:
if (NumClobbers) return false; // inputs before clobbers.
++NumInputs;
break;
case isClobber:
++NumClobbers;
break;
}
// Parse the id. We accept [a-zA-Z0-9] currently.
while (I != E && isalnum(*I)) ++I;
// If we reached the end of the ID, we must have the end of the string or a
// comma, which we skip now.
if (I != E) {
if (*I != ',') return false;
++I;
if (I == E) return false; // don't allow "xyz,"
}
}
if (NumOutputs > 1) return false; // Only one result allowed.
if ((Ty->getReturnType() != Type::VoidTy) != NumOutputs)
return false; // NumOutputs = 1 iff has a result type.
if (Ty->getNumParams() != NumInputs) return false;
return true;
}
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