[clang] [CIR] Add rotate operation (PR #148426)

[Henrich Lauko via cfe-commits]

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@@ -57,6 +57,20 @@ static RValue emitBuiltinBitOp(CIRGenFunction &cgf, const CallExpr *e,
   return RValue::get(result);
 }
 
+RValue CIRGenFunction::emitRotate(const CallExpr *e, bool isRotateLeft) {
+  mlir::Value input = emitScalarExpr(e->getArg(0));
+  mlir::Value amount = emitScalarExpr(e->getArg(1));
+
+  // The builtin's amount parameter may have a different type than the input
+  // argument, but the CIR op uses the same type for all values.
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xlauko wrote:

why? This just creates unnecessary int cast. 

https://github.com/llvm/llvm-project/pull/148426