Changes in directory llvm/lib/VMCore:
InlineAsm.cpp updated: 1.5 -> 1.6
---
Log message:
Beef up the interface to inline asm constraint parsing, making it more general,
useful, and easier to use.
---
Diffs of the changes: (+96 -44)
InlineAsm.cpp | 140 +++++++++++++++++++++++++++++++++++++++-------------------
1 files changed, 96 insertions(+), 44 deletions(-)
Index: llvm/lib/VMCore/InlineAsm.cpp
diff -u llvm/lib/VMCore/InlineAsm.cpp:1.5 llvm/lib/VMCore/InlineAsm.cpp:1.6
--- llvm/lib/VMCore/InlineAsm.cpp:1.5 Wed Jan 25 20:21:59 2006
+++ llvm/lib/VMCore/InlineAsm.cpp Tue Jan 31 19:29:47 2006
@@ -38,50 +38,101 @@
return cast<FunctionType>(getType()->getElementType());
}
-std::vector<std::pair<InlineAsm::ConstraintPrefix, std::string> >
-InlineAsm::ParseConstraints(const std::string &Constraints) {
- std::vector<std::pair<InlineAsm::ConstraintPrefix, std::string> > Result;
+/// 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::string::const_iterator I = Str.begin(), E = Str.end();
+
+ // Initialize
+ Type = isInput;
+ isEarlyClobber = false;
+ isIndirectOutput =false;
+
+ // Parse the prefix.
+ if (*I == '~') {
+ Type = isClobber;
+ ++I;
+ } else if (*I == '=') {
+ ++I;
+ Type = isOutput;
+ if (I != E && *I == '=') {
+ isIndirectOutput = true;
+ ++I;
+ }
+ }
- // Scan the constraints string.
- for (std::string::const_iterator I = Constraints.begin(),
- E = Constraints.end(); I != E; ) {
- if (*I == ',') { Result.clear(); break; } // Empty constraint like ",,"
-
- // Parse the prefix.
- ConstraintPrefix ConstraintType = isInput;
+ 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 '&':
+ if (Type != isOutput || // Cannot early clobber anything but output.
+ isEarlyClobber) // Reject &&&&&&
+ return true;
+ isEarlyClobber = true;
+ break;
+ }
- if (*I == '~') {
- ConstraintType = isClobber;
+ if (!DoneWithModifiers) {
++I;
- } else if (*I == '=') {
- ++I;
- if (I != E && *I == '=') {
- ConstraintType = isIndirectOutput;
+ 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)) {
+ // Maximal munch numbers.
+ std::string::const_iterator NumStart = I;
+ while (I != E && isdigit(*I))
++I;
- } else {
- ConstraintType = isOutput;
- }
+ Codes.push_back(std::string(NumStart, I));
+ } else {
+ // Single letter constraint.
+ Codes.push_back(std::string(I, I+1));
+ ++I;
}
-
- if (I == E) { Result.clear(); break; } // Just a prefix, like "==" or "~".
-
- std::string::const_iterator IdStart = I;
-
- // Parse the id. We accept [a-zA-Z0-9] currently.
- while (I != E && isalnum(*I)) ++I;
-
- if (IdStart == I) { // Requires more than just a prefix
+ }
+
+ 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))) { // Erroneous constraint?
Result.clear();
break;
}
+
+ Result.push_back(Info);
- // Remember this constraint.
- Result.push_back(std::make_pair(ConstraintType, std::string(IdStart, I)));
-
- // If we reached the end of the ID, we must have the end of the string or a
- // comma, which we skip now.
+ // 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) {
- if (*I != ',') { Result.clear(); break; }
++I;
if (I == E) { Result.clear(); break; } // don't allow "xyz,"
}
@@ -96,8 +147,7 @@
bool InlineAsm::Verify(const FunctionType *Ty, const std::string &ConstStr) {
if (Ty->isVarArg()) return false;
- std::vector<std::pair<ConstraintPrefix, std::string> >
- Constraints = ParseConstraints(ConstStr);
+ std::vector<ConstraintInfo> Constraints = ParseConstraints(ConstStr);
// Error parsing constraints.
if (Constraints.empty() && !ConstStr.empty()) return false;
@@ -105,17 +155,19 @@
unsigned NumOutputs = 0, NumInputs = 0, NumClobbers = 0;
for (unsigned i = 0, e = Constraints.size(); i != e; ++i) {
- switch (Constraints[i].first) {
- case isOutput:
- if (NumInputs || NumClobbers) return false; // outputs come first.
- ++NumOutputs;
- break;
- case isInput:
- case isIndirectOutput:
+ switch (Constraints[i].Type) {
+ case InlineAsm::isOutput:
+ if (!Constraints[i].isIndirectOutput) {
+ if (NumInputs || NumClobbers) return false; // outputs come first.
+ ++NumOutputs;
+ break;
+ }
+ // FALLTHROUGH for IndirectOutputs.
+ case InlineAsm::isInput:
if (NumClobbers) return false; // inputs before clobbers.
++NumInputs;
break;
- case isClobber:
+ case InlineAsm::isClobber:
++NumClobbers;
break;
}
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