1 //===-- InlineAsm.cpp - Implement the InlineAsm class ---------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file is distributed under the University of Illinois Open Source
6 // License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the InlineAsm class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/InlineAsm.h"
15 #include "ConstantsContext.h"
16 #include "LLVMContextImpl.h"
17 #include "llvm/DerivedTypes.h"
22 // Implement the first virtual method in this class in this file so the
23 // InlineAsm vtable is emitted here.
24 InlineAsm::~InlineAsm() {
28 InlineAsm *InlineAsm::get(const FunctionType *Ty, StringRef AsmString,
29 StringRef Constraints, bool hasSideEffects,
31 InlineAsmKeyType Key(AsmString, Constraints, hasSideEffects, isAlignStack);
32 LLVMContextImpl *pImpl = Ty->getContext().pImpl;
33 return pImpl->InlineAsms.getOrCreate(PointerType::getUnqual(Ty), Key);
36 InlineAsm::InlineAsm(const PointerType *Ty, const std::string &asmString,
37 const std::string &constraints, bool hasSideEffects,
39 : Value(Ty, Value::InlineAsmVal),
41 Constraints(constraints), HasSideEffects(hasSideEffects),
42 IsAlignStack(isAlignStack) {
44 // Do various checks on the constraint string and type.
45 assert(Verify(getFunctionType(), constraints) &&
46 "Function type not legal for constraints!");
49 void InlineAsm::destroyConstant() {
53 const FunctionType *InlineAsm::getFunctionType() const {
54 return cast<FunctionType>(getType()->getElementType());
57 /// Parse - Analyze the specified string (e.g. "==&{eax}") and fill in the
58 /// fields in this structure. If the constraint string is not understood,
59 /// return true, otherwise return false.
60 bool InlineAsm::ConstraintInfo::Parse(StringRef Str,
61 std::vector<InlineAsm::ConstraintInfo> &ConstraintsSoFar) {
62 StringRef::iterator I = Str.begin(), E = Str.end();
66 isEarlyClobber = false;
68 isCommutative = false;
75 } else if (*I == '=') {
85 if (I == E) return true; // Just a prefix, like "==" or "~".
87 // Parse the modifiers.
88 bool DoneWithModifiers = false;
89 while (!DoneWithModifiers) {
92 DoneWithModifiers = true;
94 case '&': // Early clobber.
95 if (Type != isOutput || // Cannot early clobber anything but output.
96 isEarlyClobber) // Reject &&&&&&
98 isEarlyClobber = true;
100 case '%': // Commutative.
101 if (Type == isClobber || // Cannot commute clobbers.
102 isCommutative) // Reject %%%%%
104 isCommutative = true;
106 case '#': // Comment.
107 case '*': // Register preferencing.
108 return true; // Not supported.
111 if (!DoneWithModifiers) {
113 if (I == E) return true; // Just prefixes and modifiers!
117 // Parse the various constraints.
119 if (*I == '{') { // Physical register reference.
120 // Find the end of the register name.
121 StringRef::iterator ConstraintEnd = std::find(I+1, E, '}');
122 if (ConstraintEnd == E) return true; // "{foo"
123 Codes.push_back(std::string(I, ConstraintEnd+1));
125 } else if (isdigit(*I)) { // Matching Constraint
126 // Maximal munch numbers.
127 StringRef::iterator NumStart = I;
128 while (I != E && isdigit(*I))
130 Codes.push_back(std::string(NumStart, I));
131 unsigned N = atoi(Codes.back().c_str());
132 // Check that this is a valid matching constraint!
133 if (N >= ConstraintsSoFar.size() || ConstraintsSoFar[N].Type != isOutput||
135 return true; // Invalid constraint number.
137 // If Operand N already has a matching input, reject this. An output
138 // can't be constrained to the same value as multiple inputs.
139 if (ConstraintsSoFar[N].hasMatchingInput())
142 // Note that operand #n has a matching input.
143 ConstraintsSoFar[N].MatchingInput = ConstraintsSoFar.size();
145 // Single letter constraint.
146 Codes.push_back(std::string(I, I+1));
154 std::vector<InlineAsm::ConstraintInfo>
155 InlineAsm::ParseConstraints(StringRef Constraints) {
156 std::vector<ConstraintInfo> Result;
158 // Scan the constraints string.
159 for (StringRef::iterator I = Constraints.begin(),
160 E = Constraints.end(); I != E; ) {
163 // Find the end of this constraint.
164 StringRef::iterator ConstraintEnd = std::find(I, E, ',');
166 if (ConstraintEnd == I || // Empty constraint like ",,"
167 Info.Parse(std::string(I, ConstraintEnd), Result)) {
168 Result.clear(); // Erroneous constraint?
172 Result.push_back(Info);
174 // ConstraintEnd may be either the next comma or the end of the string. In
175 // the former case, we skip the comma.
179 if (I == E) { Result.clear(); break; } // don't allow "xyz,"
187 /// Verify - Verify that the specified constraint string is reasonable for the
188 /// specified function type, and otherwise validate the constraint string.
189 bool InlineAsm::Verify(const FunctionType *Ty, StringRef ConstStr) {
190 if (Ty->isVarArg()) return false;
192 std::vector<ConstraintInfo> Constraints = ParseConstraints(ConstStr);
194 // Error parsing constraints.
195 if (Constraints.empty() && !ConstStr.empty()) return false;
197 unsigned NumOutputs = 0, NumInputs = 0, NumClobbers = 0;
198 unsigned NumIndirect = 0;
200 for (unsigned i = 0, e = Constraints.size(); i != e; ++i) {
201 switch (Constraints[i].Type) {
202 case InlineAsm::isOutput:
203 if ((NumInputs-NumIndirect) != 0 || NumClobbers != 0)
204 return false; // outputs before inputs and clobbers.
205 if (!Constraints[i].isIndirect) {
210 // FALLTHROUGH for Indirect Outputs.
211 case InlineAsm::isInput:
212 if (NumClobbers) return false; // inputs before clobbers.
215 case InlineAsm::isClobber:
221 switch (NumOutputs) {
223 if (!Ty->getReturnType()->isVoidTy()) return false;
226 if (Ty->getReturnType()->isStructTy()) return false;
229 const StructType *STy = dyn_cast<StructType>(Ty->getReturnType());
230 if (STy == 0 || STy->getNumElements() != NumOutputs)
235 if (Ty->getNumParams() != NumInputs) return false;