[clang] [PowerPC] Fix use of FPSCR builtins in smmintrin.h (PR #67299)

[Qiu Chaofan via cfe-commits]

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@@ -11595,6 +11595,50 @@ SDValue PPCTargetLowering::LowerFP_EXTEND(SDValue Op, SelectionDAG &DAG) const {
   llvm_unreachable("ERROR:Should return for all cases within swtich.");
 }
 
+// Lower mffsl intrinsic with mffs in targets without ISA 3.0
+static SDValue lowerMFFSL(SDValue Op, SelectionDAG &DAG,
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ecnelises wrote:

> The reason mffsl exists is because it is a lightweight version of mffs.

Thanks, according to the 'lightweight' meaning, this sounds reasonable. I don't have strong preference to align with GCC behavior. We have builtins only for P9 which can't be or haven't been emulated.

https://github.com/llvm/llvm-project/pull/67299