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//===-- InlineAsm.cpp - Implement the InlineAsm class ---------------------===//
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// The LLVM Compiler Infrastructure
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// This file is distributed under the University of Illinois Open Source
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// License. See LICENSE.TXT for details.
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//===----------------------------------------------------------------------===//
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// This file implements the InlineAsm class.
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//===----------------------------------------------------------------------===//
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#include "llvm/InlineAsm.h"
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#include "llvm/DerivedTypes.h"
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// Implement the first virtual method in this class in this file so the
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// InlineAsm vtable is emitted here.
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InlineAsm::~InlineAsm() {
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// NOTE: when memoizing the function type, we have to be careful to handle the
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// case when the type gets refined.
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InlineAsm *InlineAsm::get(const FunctionType *Ty, StringRef AsmString,
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StringRef Constraints, bool hasSideEffects,
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return new InlineAsm(Ty, AsmString, Constraints, hasSideEffects,
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InlineAsm::InlineAsm(const FunctionType *Ty, StringRef asmString,
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StringRef constraints, bool hasSideEffects,
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: Value(PointerType::getUnqual(Ty),
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Constraints(constraints), HasSideEffects(hasSideEffects),
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IsAlignStack(isAlignStack) {
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// Do various checks on the constraint string and type.
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assert(Verify(Ty, constraints) && "Function type not legal for constraints!");
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const FunctionType *InlineAsm::getFunctionType() const {
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return cast<FunctionType>(getType()->getElementType());
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/// Parse - Analyze the specified string (e.g. "==&{eax}") and fill in the
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/// fields in this structure. If the constraint string is not understood,
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/// return true, otherwise return false.
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bool InlineAsm::ConstraintInfo::Parse(StringRef Str,
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std::vector<InlineAsm::ConstraintInfo> &ConstraintsSoFar) {
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StringRef::iterator I = Str.begin(), E = Str.end();
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isEarlyClobber = false;
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isCommutative = false;
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} else if (*I == '=') {
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if (I == E) return true; // Just a prefix, like "==" or "~".
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// Parse the modifiers.
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bool DoneWithModifiers = false;
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while (!DoneWithModifiers) {
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DoneWithModifiers = true;
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case '&': // Early clobber.
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if (Type != isOutput || // Cannot early clobber anything but output.
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isEarlyClobber) // Reject &&&&&&
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isEarlyClobber = true;
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case '%': // Commutative.
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if (Type == isClobber || // Cannot commute clobbers.
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isCommutative) // Reject %%%%%
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isCommutative = true;
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case '#': // Comment.
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case '*': // Register preferencing.
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return true; // Not supported.
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if (!DoneWithModifiers) {
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if (I == E) return true; // Just prefixes and modifiers!
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// Parse the various constraints.
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if (*I == '{') { // Physical register reference.
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// Find the end of the register name.
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StringRef::iterator ConstraintEnd = std::find(I+1, E, '}');
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if (ConstraintEnd == E) return true; // "{foo"
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Codes.push_back(std::string(I, ConstraintEnd+1));
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} else if (isdigit(*I)) { // Matching Constraint
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// Maximal munch numbers.
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StringRef::iterator NumStart = I;
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while (I != E && isdigit(*I))
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Codes.push_back(std::string(NumStart, I));
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unsigned N = atoi(Codes.back().c_str());
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// Check that this is a valid matching constraint!
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if (N >= ConstraintsSoFar.size() || ConstraintsSoFar[N].Type != isOutput||
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return true; // Invalid constraint number.
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// If Operand N already has a matching input, reject this. An output
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// can't be constrained to the same value as multiple inputs.
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if (ConstraintsSoFar[N].hasMatchingInput())
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// Note that operand #n has a matching input.
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ConstraintsSoFar[N].MatchingInput = ConstraintsSoFar.size();
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// Single letter constraint.
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Codes.push_back(std::string(I, I+1));
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std::vector<InlineAsm::ConstraintInfo>
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InlineAsm::ParseConstraints(StringRef Constraints) {
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std::vector<ConstraintInfo> Result;
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// Scan the constraints string.
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for (StringRef::iterator I = Constraints.begin(),
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E = Constraints.end(); I != E; ) {
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// Find the end of this constraint.
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StringRef::iterator ConstraintEnd = std::find(I, E, ',');
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if (ConstraintEnd == I || // Empty constraint like ",,"
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Info.Parse(std::string(I, ConstraintEnd), Result)) {
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Result.clear(); // Erroneous constraint?
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Result.push_back(Info);
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// ConstraintEnd may be either the next comma or the end of the string. In
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// the former case, we skip the comma.
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if (I == E) { Result.clear(); break; } // don't allow "xyz,"
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/// Verify - Verify that the specified constraint string is reasonable for the
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/// specified function type, and otherwise validate the constraint string.
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bool InlineAsm::Verify(const FunctionType *Ty, StringRef ConstStr) {
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if (Ty->isVarArg()) return false;
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std::vector<ConstraintInfo> Constraints = ParseConstraints(ConstStr);
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// Error parsing constraints.
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if (Constraints.empty() && !ConstStr.empty()) return false;
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unsigned NumOutputs = 0, NumInputs = 0, NumClobbers = 0;
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unsigned NumIndirect = 0;
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for (unsigned i = 0, e = Constraints.size(); i != e; ++i) {
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switch (Constraints[i].Type) {
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case InlineAsm::isOutput:
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if ((NumInputs-NumIndirect) != 0 || NumClobbers != 0)
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return false; // outputs before inputs and clobbers.
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if (!Constraints[i].isIndirect) {
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// FALLTHROUGH for Indirect Outputs.
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case InlineAsm::isInput:
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if (NumClobbers) return false; // inputs before clobbers.
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case InlineAsm::isClobber:
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switch (NumOutputs) {
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if (!Ty->getReturnType()->isVoidTy()) return false;
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if (Ty->getReturnType()->isStructTy()) return false;
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const StructType *STy = dyn_cast<StructType>(Ty->getReturnType());
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if (STy == 0 || STy->getNumElements() != NumOutputs)
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if (Ty->getNumParams() != NumInputs) return false;