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diff --git a/llvm/lib/IR/InlineAsm.cpp b/llvm/lib/IR/InlineAsm.cpp
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+//===- InlineAsm.cpp - Implement the InlineAsm class ----------------------===//
+//
+// Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
+// See https://llvm.org/LICENSE.txt for license information.
+// SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+//
+//===----------------------------------------------------------------------===//
+//
+// This file implements the InlineAsm class.
+//
+//===----------------------------------------------------------------------===//
+
+#include "llvm/IR/InlineAsm.h"
+#include "ConstantsContext.h"
+#include "LLVMContextImpl.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/IR/DerivedTypes.h"
+#include "llvm/IR/LLVMContext.h"
+#include "llvm/IR/Value.h"
+#include "llvm/Support/Casting.h"
+#include "llvm/Support/Compiler.h"
+#include <algorithm>
+#include <cassert>
+#include <cctype>
+#include <cstddef>
+#include <cstdlib>
+
+using namespace llvm;
+
+InlineAsm::InlineAsm(FunctionType *FTy, const std::string &asmString,
+ const std::string &constraints, bool hasSideEffects,
+ bool isAlignStack, AsmDialect asmDialect)
+ : Value(PointerType::getUnqual(FTy), Value::InlineAsmVal),
+ AsmString(asmString), Constraints(constraints), FTy(FTy),
+ HasSideEffects(hasSideEffects), IsAlignStack(isAlignStack),
+ Dialect(asmDialect) {
+ // Do various checks on the constraint string and type.
+ assert(Verify(getFunctionType(), constraints) &&
+ "Function type not legal for constraints!");
+}
+
+InlineAsm *InlineAsm::get(FunctionType *FTy, StringRef AsmString,
+ StringRef Constraints, bool hasSideEffects,
+ bool isAlignStack, AsmDialect asmDialect) {
+ InlineAsmKeyType Key(AsmString, Constraints, FTy, hasSideEffects,
+ isAlignStack, asmDialect);
+ LLVMContextImpl *pImpl = FTy->getContext().pImpl;
+ return pImpl->InlineAsms.getOrCreate(PointerType::getUnqual(FTy), Key);
+}
+
+void InlineAsm::destroyConstant() {
+ getType()->getContext().pImpl->InlineAsms.remove(this);
+ delete this;
+}
+
+FunctionType *InlineAsm::getFunctionType() const {
+ return FTy;
+}
+
+/// Parse - Analyze the specified string (e.g. "==&{eax}") and fill in the
+/// fields in this structure. If the constraint string is not understood,
+/// return true, otherwise return false.
+bool InlineAsm::ConstraintInfo::Parse(StringRef Str,
+ InlineAsm::ConstraintInfoVector &ConstraintsSoFar) {
+ StringRef::iterator I = Str.begin(), E = Str.end();
+ unsigned multipleAlternativeCount = Str.count('|') + 1;
+ unsigned multipleAlternativeIndex = 0;
+ ConstraintCodeVector *pCodes = &Codes;
+
+ // Initialize
+ isMultipleAlternative = multipleAlternativeCount > 1;
+ if (isMultipleAlternative) {
+ multipleAlternatives.resize(multipleAlternativeCount);
+ pCodes = &multipleAlternatives[0].Codes;
+ }
+ Type = isInput;
+ isEarlyClobber = false;
+ MatchingInput = -1;
+ isCommutative = false;
+ isIndirect = false;
+ currentAlternativeIndex = 0;
+
+ // Parse prefixes.
+ if (*I == '~') {
+ Type = isClobber;
+ ++I;
+
+ // '{' must immediately follow '~'.
+ if (I != E && *I != '{')
+ return true;
+ } else if (*I == '=') {
+ ++I;
+ Type = isOutput;
+ }
+
+ if (*I == '*') {
+ isIndirect = true;
+ ++I;
+ }
+
+ if (I == E) return true; // Just a prefix, like "==" or "~".
+
+ // Parse the modifiers.
+ bool DoneWithModifiers = false;
+ while (!DoneWithModifiers) {
+ switch (*I) {
+ default:
+ DoneWithModifiers = true;
+ break;
+ case '&': // Early clobber.
+ if (Type != isOutput || // Cannot early clobber anything but output.
+ isEarlyClobber) // Reject &&&&&&
+ return true;
+ isEarlyClobber = true;
+ break;
+ case '%': // Commutative.
+ if (Type == isClobber || // Cannot commute clobbers.
+ isCommutative) // Reject %%%%%
+ return true;
+ isCommutative = true;
+ break;
+ case '#': // Comment.
+ case '*': // Register preferencing.
+ return true; // Not supported.
+ }
+
+ if (!DoneWithModifiers) {
+ ++I;
+ if (I == E) return true; // Just prefixes and modifiers!
+ }
+ }
+
+ // Parse the various constraints.
+ while (I != E) {
+ if (*I == '{') { // Physical register reference.
+ // Find the end of the register name.
+ StringRef::iterator ConstraintEnd = std::find(I+1, E, '}');
+ if (ConstraintEnd == E) return true; // "{foo"
+ pCodes->push_back(StringRef(I, ConstraintEnd+1 - I));
+ I = ConstraintEnd+1;
+ } else if (isdigit(static_cast<unsigned char>(*I))) { // Matching Constraint
+ // Maximal munch numbers.
+ StringRef::iterator NumStart = I;
+ while (I != E && isdigit(static_cast<unsigned char>(*I)))
+ ++I;
+ pCodes->push_back(StringRef(NumStart, I - NumStart));
+ unsigned N = atoi(pCodes->back().c_str());
+ // Check that this is a valid matching constraint!
+ if (N >= ConstraintsSoFar.size() || ConstraintsSoFar[N].Type != isOutput||
+ Type != isInput)
+ return true; // Invalid constraint number.
+
+ // If Operand N already has a matching input, reject this. An output
+ // can't be constrained to the same value as multiple inputs.
+ if (isMultipleAlternative) {
+ if (multipleAlternativeIndex >=
+ ConstraintsSoFar[N].multipleAlternatives.size())
+ return true;
+ InlineAsm::SubConstraintInfo &scInfo =
+ ConstraintsSoFar[N].multipleAlternatives[multipleAlternativeIndex];
+ if (scInfo.MatchingInput != -1)
+ return true;
+ // Note that operand #n has a matching input.
+ scInfo.MatchingInput = ConstraintsSoFar.size();
+ assert(scInfo.MatchingInput >= 0);
+ } else {
+ if (ConstraintsSoFar[N].hasMatchingInput() &&
+ (size_t)ConstraintsSoFar[N].MatchingInput !=
+ ConstraintsSoFar.size())
+ return true;
+ // Note that operand #n has a matching input.
+ ConstraintsSoFar[N].MatchingInput = ConstraintsSoFar.size();
+ assert(ConstraintsSoFar[N].MatchingInput >= 0);
+ }
+ } else if (*I == '|') {
+ multipleAlternativeIndex++;
+ pCodes = &multipleAlternatives[multipleAlternativeIndex].Codes;
+ ++I;
+ } else if (*I == '^') {
+ // Multi-letter constraint
+ // FIXME: For now assuming these are 2-character constraints.
+ pCodes->push_back(StringRef(I+1, 2));
+ I += 3;
+ } else if (*I == '@') {
+ // Multi-letter constraint
+ ++I;
+ unsigned char C = static_cast<unsigned char>(*I);
+ assert(isdigit(C) && "Expected a digit!");
+ int N = C - '0';
+ assert(N > 0 && "Found a zero letter constraint!");
+ ++I;
+ pCodes->push_back(StringRef(I, N));
+ I += N;
+ } else {
+ // Single letter constraint.
+ pCodes->push_back(StringRef(I, 1));
+ ++I;
+ }
+ }
+
+ return false;
+}
+
+/// selectAlternative - Point this constraint to the alternative constraint
+/// indicated by the index.
+void InlineAsm::ConstraintInfo::selectAlternative(unsigned index) {
+ if (index < multipleAlternatives.size()) {
+ currentAlternativeIndex = index;
+ InlineAsm::SubConstraintInfo &scInfo =
+ multipleAlternatives[currentAlternativeIndex];
+ MatchingInput = scInfo.MatchingInput;
+ Codes = scInfo.Codes;
+ }
+}
+
+InlineAsm::ConstraintInfoVector
+InlineAsm::ParseConstraints(StringRef Constraints) {
+ ConstraintInfoVector Result;
+
+ // Scan the constraints string.
+ for (StringRef::iterator I = Constraints.begin(),
+ E = Constraints.end(); I != E; ) {
+ ConstraintInfo Info;
+
+ // Find the end of this constraint.
+ StringRef::iterator ConstraintEnd = std::find(I, E, ',');
+
+ if (ConstraintEnd == I || // Empty constraint like ",,"
+ Info.Parse(StringRef(I, ConstraintEnd-I), Result)) {
+ Result.clear(); // Erroneous constraint?
+ break;
+ }
+
+ Result.push_back(Info);
+
+ // ConstraintEnd may be either the next comma or the end of the string. In
+ // the former case, we skip the comma.
+ I = ConstraintEnd;
+ if (I != E) {
+ ++I;
+ if (I == E) {
+ Result.clear();
+ break;
+ } // don't allow "xyz,"
+ }
+ }
+
+ return Result;
+}
+
+/// Verify - Verify that the specified constraint string is reasonable for the
+/// specified function type, and otherwise validate the constraint string.
+bool InlineAsm::Verify(FunctionType *Ty, StringRef ConstStr) {
+ if (Ty->isVarArg()) return false;
+
+ ConstraintInfoVector Constraints = ParseConstraints(ConstStr);
+
+ // Error parsing constraints.
+ if (Constraints.empty() && !ConstStr.empty()) return false;
+
+ unsigned NumOutputs = 0, NumInputs = 0, NumClobbers = 0;
+ unsigned NumIndirect = 0;
+
+ for (unsigned i = 0, e = Constraints.size(); i != e; ++i) {
+ switch (Constraints[i].Type) {
+ case InlineAsm::isOutput:
+ if ((NumInputs-NumIndirect) != 0 || NumClobbers != 0)
+ return false; // outputs before inputs and clobbers.
+ if (!Constraints[i].isIndirect) {
+ ++NumOutputs;
+ break;
+ }
+ ++NumIndirect;
+ LLVM_FALLTHROUGH; // We fall through for Indirect Outputs.
+ case InlineAsm::isInput:
+ if (NumClobbers) return false; // inputs before clobbers.
+ ++NumInputs;
+ break;
+ case InlineAsm::isClobber:
+ ++NumClobbers;
+ break;
+ }
+ }
+
+ switch (NumOutputs) {
+ case 0:
+ if (!Ty->getReturnType()->isVoidTy()) return false;
+ break;
+ case 1:
+ if (Ty->getReturnType()->isStructTy()) return false;
+ break;
+ default:
+ StructType *STy = dyn_cast<StructType>(Ty->getReturnType());
+ if (!STy || STy->getNumElements() != NumOutputs)
+ return false;
+ break;
+ }
+
+ if (Ty->getNumParams() != NumInputs) return false;
+ return true;
+}
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