[PATCH] D151313: [RISCV][BF16] Make backend type bf16 to follow the psABI

[Craig Topper via Phabricator via llvm-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:428
     setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::f16, Expand);
+    setLoadExtAction(ISD::EXTLOAD, MVT::f32, MVT::bf16, Expand);
     setTruncStoreAction(MVT::f32, MVT::f16, Expand);
----------------
This wasn't needed by D151663? Is there a test case missing from D151663 that requires this?


================
Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:432
+    setOperationAction(ISD::FP_TO_BF16, MVT::f32, Custom);
+    setOperationAction(ISD::BF16_TO_FP, MVT::f32, Custom);
     setOperationAction(ISD::IS_FPCLASS, MVT::f32, Custom);
----------------
D151663 uses 

```
    setOperationAction(ISD::FP_TO_BF16, MVT::f32,
                       Subtarget.isSoftFPABI() ? LibCall : Custom);
```

Is that difference important?


================
Comment at: llvm/lib/Target/RISCV/RISCVISelLowering.cpp:2461
+  if (Op.getOperand(0).getValueType() == MVT::bf16) {
+    Op0 =
+        DAG.getNode(ISD::ANY_EXTEND, DL, XLenVT,
----------------
Why wasn't this part needed in D151663?


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D151313/new/

https://reviews.llvm.org/D151313