[clang] [RISCV][clang] Add Zvfbfwma C intrinsics support (PR #79615)

[Craig Topper via cfe-commits]

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@@ -1730,12 +1730,26 @@ let ManualCodegen = [{
     defm vfwnmacc : RVVFloatingWidenTerBuiltinSetRoundingMode;
     defm vfwmsac  : RVVFloatingWidenTerBuiltinSetRoundingMode;
     defm vfwnmsac : RVVFloatingWidenTerBuiltinSetRoundingMode;
+
+    // Vector BF16 widening multiply-accumulate
+    let Log2LMUL = [-2, -1, 0, 1, 2],
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topperc wrote:

Do we need a RequiredFeatures for this?

https://github.com/llvm/llvm-project/pull/79615