1 //===-- InlineAsm.cpp - Implement the InlineAsm class ---------------------===//
3 // The LLVM Compiler Infrastructure
5 // This file was developed by Chris Lattner and is distributed under the
6 // University of Illinois Open Source License. See LICENSE.TXT for details.
8 //===----------------------------------------------------------------------===//
10 // This file implements the InlineAsm class.
12 //===----------------------------------------------------------------------===//
14 #include "llvm/InlineAsm.h"
15 #include "llvm/DerivedTypes.h"
20 // Implement the first virtual method in this class in this file so the
21 // InlineAsm vtable is emitted here.
22 InlineAsm::~InlineAsm() {
26 // NOTE: when memoizing the function type, we have to be careful to handle the
27 // case when the type gets refined.
29 InlineAsm *InlineAsm::get(const FunctionType *Ty, const std::string &AsmString,
30 const std::string &Constraints, bool hasSideEffects) {
32 return new InlineAsm(Ty, AsmString, Constraints, hasSideEffects);
35 InlineAsm::InlineAsm(const FunctionType *Ty, const std::string &asmString,
36 const std::string &constraints, bool hasSideEffects)
37 : Value(PointerType::get(Ty), Value::InlineAsmVal), AsmString(asmString),
38 Constraints(constraints), HasSideEffects(hasSideEffects) {
40 // Do various checks on the constraint string and type.
41 assert(Verify(Ty, constraints) && "Function type not legal for constraints!");
44 const FunctionType *InlineAsm::getFunctionType() const {
45 return cast<FunctionType>(getType()->getElementType());
48 /// Parse - Analyze the specified string (e.g. "==&{eax}") and fill in the
49 /// fields in this structure. If the constraint string is not understood,
50 /// return true, otherwise return false.
51 bool InlineAsm::ConstraintInfo::Parse(const std::string &Str,
52 std::vector<InlineAsm::ConstraintInfo> &ConstraintsSoFar) {
53 std::string::const_iterator I = Str.begin(), E = Str.end();
57 isEarlyClobber = false;
58 isIndirectOutput = false;
59 hasMatchingInput = false;
60 isCommutative = false;
66 } else if (*I == '=') {
69 if (I != E && *I == '=') {
70 isIndirectOutput = true;
75 if (I == E) return true; // Just a prefix, like "==" or "~".
77 // Parse the modifiers.
78 bool DoneWithModifiers = false;
79 while (!DoneWithModifiers) {
82 DoneWithModifiers = true;
84 case '&': // Early clobber.
85 if (Type != isOutput || // Cannot early clobber anything but output.
86 isEarlyClobber) // Reject &&&&&&
88 isEarlyClobber = true;
90 case '%': // Commutative.
91 if (Type == isClobber || // Cannot commute clobbers.
92 isCommutative) // Reject %%%%%
97 case '*': // Register preferencing.
98 return true; // Not supported.
101 if (!DoneWithModifiers) {
103 if (I == E) return true; // Just prefixes and modifiers!
107 // Parse the various constraints.
109 if (*I == '{') { // Physical register reference.
110 // Find the end of the register name.
111 std::string::const_iterator ConstraintEnd = std::find(I+1, E, '}');
112 if (ConstraintEnd == E) return true; // "{foo"
113 Codes.push_back(std::string(I, ConstraintEnd+1));
115 } else if (isdigit(*I)) { // Matching Constraint
116 // Maximal munch numbers.
117 std::string::const_iterator NumStart = I;
118 while (I != E && isdigit(*I))
120 Codes.push_back(std::string(NumStart, I));
121 unsigned N = atoi(Codes.back().c_str());
122 // Check that this is a valid matching constraint!
123 if (N >= ConstraintsSoFar.size() || ConstraintsSoFar[N].Type != isOutput||
125 return true; // Invalid constraint number.
127 // Note that operand #n has a matching input.
128 ConstraintsSoFar[N].hasMatchingInput = true;
130 // Single letter constraint.
131 Codes.push_back(std::string(I, I+1));
139 std::vector<InlineAsm::ConstraintInfo>
140 InlineAsm::ParseConstraints(const std::string &Constraints) {
141 std::vector<ConstraintInfo> Result;
143 // Scan the constraints string.
144 for (std::string::const_iterator I = Constraints.begin(),
145 E = Constraints.end(); I != E; ) {
148 // Find the end of this constraint.
149 std::string::const_iterator ConstraintEnd = std::find(I, E, ',');
151 if (ConstraintEnd == I || // Empty constraint like ",,"
152 Info.Parse(std::string(I, ConstraintEnd), Result)) {
153 Result.clear(); // Erroneous constraint?
157 Result.push_back(Info);
159 // ConstraintEnd may be either the next comma or the end of the string. In
160 // the former case, we skip the comma.
164 if (I == E) { Result.clear(); break; } // don't allow "xyz,"
172 /// Verify - Verify that the specified constraint string is reasonable for the
173 /// specified function type, and otherwise validate the constraint string.
174 bool InlineAsm::Verify(const FunctionType *Ty, const std::string &ConstStr) {
175 if (Ty->isVarArg()) return false;
177 std::vector<ConstraintInfo> Constraints = ParseConstraints(ConstStr);
179 // Error parsing constraints.
180 if (Constraints.empty() && !ConstStr.empty()) return false;
182 unsigned NumOutputs = 0, NumInputs = 0, NumClobbers = 0;
184 for (unsigned i = 0, e = Constraints.size(); i != e; ++i) {
185 switch (Constraints[i].Type) {
186 case InlineAsm::isOutput:
187 if (!Constraints[i].isIndirectOutput) {
188 if (NumInputs || NumClobbers) return false; // outputs come first.
192 // FALLTHROUGH for IndirectOutputs.
193 case InlineAsm::isInput:
194 if (NumClobbers) return false; // inputs before clobbers.
197 case InlineAsm::isClobber:
203 if (NumOutputs > 1) return false; // Only one result allowed so far.
205 if ((Ty->getReturnType() != Type::VoidTy) != NumOutputs)
206 return false; // NumOutputs = 1 iff has a result type.
208 if (Ty->getNumParams() != NumInputs) return false;
212 DEFINING_FILE_FOR(InlineAsm)