1 files changed, 231 insertions, 0 deletions
diff --git a/lib/VMCore/InlineAsm.cpp b/lib/VMCore/InlineAsm.cpp
new file mode 100644
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--- /dev/null
+++ b/lib/VMCore/InlineAsm.cpp
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+//===-- InlineAsm.cpp - Implement the InlineAsm class ---------------------===//
+//
+//                     The LLVM Compiler Infrastructure
+//
+// This file 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 <algorithm>
+#include <cctype>
+using namespace llvm;
+
+// Implement the first virtual method in this class in this file so the
+// InlineAsm vtable is emitted here.
+InlineAsm::~InlineAsm() {
+}
+
+
+// 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::getUnqual(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());
+}
+
+/// 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(const std::string &Str,
+                     std::vector<InlineAsm::ConstraintInfo> &ConstraintsSoFar) {
+  std::string::const_iterator I = Str.begin(), E = Str.end();
+  
+  // Initialize
+  Type = isInput;
+  isEarlyClobber = false;
+  MatchingInput = -1;
+  isCommutative = false;
+  isIndirect = false;
+  
+  // Parse prefixes.
+  if (*I == '~') {
+    Type = isClobber;
+    ++I;
+  } 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.
+      std::string::const_iterator ConstraintEnd = std::find(I+1, E, '}');
+      if (ConstraintEnd == E) return true;  // "{foo"
+      Codes.push_back(std::string(I, ConstraintEnd+1));
+      I = ConstraintEnd+1;
+    } else if (isdigit(*I)) {     // Matching Constraint
+      // Maximal munch numbers.
+      std::string::const_iterator NumStart = I;
+      while (I != E && isdigit(*I))
+        ++I;
+      Codes.push_back(std::string(NumStart, I));
+      unsigned N = atoi(Codes.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 (ConstraintsSoFar[N].hasMatchingInput())
+        return true;
+      
+      // Note that operand #n has a matching input.
+      ConstraintsSoFar[N].MatchingInput = ConstraintsSoFar.size();
+    } else {
+      // Single letter constraint.
+      Codes.push_back(std::string(I, I+1));
+      ++I;
+    }
+  }
+
+  return false;
+}
+
+std::vector<InlineAsm::ConstraintInfo>
+InlineAsm::ParseConstraints(const std::string &Constraints) {
+  std::vector<ConstraintInfo> Result;
+  
+  // Scan the constraints string.
+  for (std::string::const_iterator I = Constraints.begin(), 
+       E = Constraints.end(); I != E; ) {
+    ConstraintInfo Info;
+
+    // Find the end of this constraint.
+    std::string::const_iterator ConstraintEnd = std::find(I, E, ',');
+
+    if (ConstraintEnd == I ||  // Empty constraint like ",,"
+        Info.Parse(std::string(I, ConstraintEnd), 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(const FunctionType *Ty, const std::string &ConstStr) {
+  if (Ty->isVarArg()) return false;
+  
+  std::vector<ConstraintInfo> 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;
+      // FALLTHROUGH 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() != Type::VoidTy) return false;
+    break;
+  case 1:
+    if (isa<StructType>(Ty->getReturnType())) return false;
+    break;
+  default:
+    const StructType *STy = dyn_cast<StructType>(Ty->getReturnType());
+    if (STy == 0 || STy->getNumElements() != NumOutputs)
+      return false;
+    break;
+  }      
+  
+  if (Ty->getNumParams() != NumInputs) return false;
+  return true;
+}
+