[clang] [CIR]Upstream generic intrinsic emission path (PR #179098)

[Andy Kaylor via cfe-commits]

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@@ -726,15 +727,108 @@ static RValue tryEmitFPMathIntrinsic(CIRGenFunction &cgf, const CallExpr *e,
   return RValue::getIgnored();
 }
 
+// FIXME: Remove cgf parameter when all descriptor kinds are implemented
+static mlir::Type
+decodeFixedType(CIRGenFunction &cgf,
+                ArrayRef<llvm::Intrinsic::IITDescriptor> &infos,
+                mlir::MLIRContext *context) {
+  using namespace llvm::Intrinsic;
+
+  IITDescriptor descriptor = infos.front();
+  infos = infos.slice(1);
+
+  switch (descriptor.Kind) {
+  case IITDescriptor::Void:
+    return cir::VoidType::get(context);
+  // If the intrinsic expects unsigned integers, the signedness is corrected in
+  // correctIntegerSignedness()
+  case IITDescriptor::Integer:
+    return cir::IntType::get(context, descriptor.Integer_Width,
+                             /*isSigned=*/true);
+  default:
+    cgf.cgm.errorNYI("Unimplemented intrinsic type descriptor");
+    return cir::VoidType::get(context);
+  }
+}
+
+/// Helper function to correct integer signedness for intrinsic arguments and
+/// return type. IIT always returns signed integers, but the actual intrinsic
+/// may expect unsigned integers based on the AST FunctionDecl parameter types.
+static mlir::Type correctIntegerSignedness(mlir::Type iitType, QualType astType,
+                                           mlir::MLIRContext *context) {
+  auto intTy = dyn_cast<cir::IntType>(iitType);
+  if (!intTy)
+    return iitType;
+
+  if (astType->isUnsignedIntegerType())
+    return cir::IntType::get(context, intTy.getWidth(), /*isSigned=*/false);
+
+  return iitType;
+}
+
+static mlir::Value getCorrectedPtr(mlir::Value argValue, mlir::Type expectedTy,
+                                   CIRGenBuilderTy &builder) {
+  auto ptrType = mlir::dyn_cast<cir::PointerType>(argValue.getType());
+  assert(ptrType && "expected pointer type");
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andykaylor wrote:

Sorry. I missed that.

https://github.com/llvm/llvm-project/pull/179098