[llvm] [Xtensa] Add basic support for inline asm constraints. (PR #108986)

[Andrei Safronov via llvm-commits]

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@@ -142,6 +142,74 @@ bool XtensaTargetLowering::isOffsetFoldingLegal(
   return false;
 }
 
+//===----------------------------------------------------------------------===//
+// Inline asm support
+//===----------------------------------------------------------------------===//
+TargetLowering::ConstraintType
+XtensaTargetLowering::getConstraintType(StringRef Constraint) const {
+  if (Constraint.size() == 1) {
+    switch (Constraint[0]) {
+    case 'r':
+      return C_RegisterClass;
+    default:
+      break;
+    }
+  }
+  return TargetLowering::getConstraintType(Constraint);
+}
+
+TargetLowering::ConstraintWeight
+XtensaTargetLowering::getSingleConstraintMatchWeight(
+    AsmOperandInfo &Info, const char *Constraint) const {
+  ConstraintWeight Weight = CW_Invalid;
+  Value *CallOperandVal = Info.CallOperandVal;
+  // If we don't have a value, we can't do a match,
+  // but allow it at the lowest weight.
+  if (CallOperandVal == NULL)
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andreisfr wrote:

Fxied

https://github.com/llvm/llvm-project/pull/108986