[RISCV][MC] Fix encoding for vfwmaccbf16

[asb]

Summary

The encoding matched the one given in the bf16 extension specification PDF, but per https://github.com/riscv/riscv-bfloat16/issues/45 it seems this encoding was not the one that is intended and was incorrectly modified due to an issue in the PDF generation process. This patch corrects the opcode to 111011 from 100011.

[craig.topper]

LGTM

[reames]

It looks like the PDF has been updated, so LGTM by me as well.

llvm/lib/Target/RISCV/RISCVInstrInfoZvfbf.td

 let RVVConstraint = WidenCvt in
 defm VFWCVTBF16_F_F_V : VWCVTF_FV_VS2<"vfwcvtbf16.f.f.v", 0b010010, 0b01101>;
 let Uses = [FRM] in
 defm VFNCVTBF16_F_F_W : VNCVTF_FV_VS2<"vfncvtbf16.f.f.w", 0b010010, 0b11101>;
 }
 
 let Predicates = [HasStdExtZvfbfwma], Constraints = "@earlyclobber $vd",
     RVVConstraint = WidenV, Uses = [FRM], mayRaiseFPException = true in {
-defm VFWMACCBF16_V : VWMAC_FV_V_F<"vfwmaccbf16", 0b100011>;
+defm VFWMACCBF16_V : VWMAC_FV_V_F<"vfwmaccbf16", 0b111011>;
 }

llvm/test/MC/RISCV/rvv/zvfbfwma.s

 # RUN:   | FileCheck %s --check-prefix=CHECK-ERROR
 # RUN: llvm-mc -triple=riscv64 -filetype=obj -mattr=+experimental-zvfbfwma %s \
 # RUN:    | llvm-objdump -d --mattr=+experimental-zvfbfwma - \
 # RUN:    | FileCheck %s --check-prefix=CHECK-INST
 # RUN: llvm-mc -triple=riscv64 -filetype=obj -mattr=+experimental-zvfbfwma %s \
 # RUN:    | llvm-objdump -d - | FileCheck %s --check-prefix=CHECK-UNKNOWN
 
 # CHECK-INST: vfwmaccbf16.vv v8, v20, v4, v0.t
-# CHECK-ENCODING: [0x57,0x14,0x4a,0x8c]
+# CHECK-ENCODING: [0x57,0x14,0x4a,0xec]
 # CHECK-ERROR: instruction requires the following: 'Zvfbfwma' (Vector BF16 widening mul-add){{$}}
-# CHECK-UNKNOWN: 57 14 4a 8c <unknown>
+# CHECK-UNKNOWN: 57 14 4a ec <unknown>
 vfwmaccbf16.vv v8, v20, v4, v0.t
 
 # CHECK-INST: vfwmaccbf16.vv v8, v20, v4
-# CHECK-ENCODING: [0x57,0x14,0x4a,0x8e]
+# CHECK-ENCODING: [0x57,0x14,0x4a,0xee]
 # CHECK-ERROR: instruction requires the following: 'Zvfbfwma' (Vector BF16 widening mul-add){{$}}
-# CHECK-UNKNOWN: 57 14 4a 8e <unknown>
+# CHECK-UNKNOWN: 57 14 4a ee <unknown>
 vfwmaccbf16.vv v8, v20, v4
 
 # CHECK-INST: vfwmaccbf16.vf v8, fa0, v4, v0.t
-# CHECK-ENCODING: [0x57,0x54,0x45,0x8c]
+# CHECK-ENCODING: [0x57,0x54,0x45,0xec]
 # CHECK-ERROR: instruction requires the following: 'Zvfbfwma' (Vector BF16 widening mul-add){{$}}
-# CHECK-UNKNOWN: 57 54 45 8c <unknown>
+# CHECK-UNKNOWN: 57 54 45 ec <unknown>
 vfwmaccbf16.vf v8, fa0, v4, v0.t
 
 # CHECK-INST: vfwmaccbf16.vf v8, fa0, v4
-# CHECK-ENCODING: [0x57,0x54,0x45,0x8e]
+# CHECK-ENCODING: [0x57,0x54,0x45,0xee]
 # CHECK-ERROR: instruction requires the following: 'Zvfbfwma' (Vector BF16 widening mul-add){{$}}
-# CHECK-UNKNOWN: 57 54 45 8e <unknown>
+# CHECK-UNKNOWN: 57 54 45 ee <unknown>
 vfwmaccbf16.vf v8, fa0, v4
 
 # Check scalar half FP load/store/move included in this extension.
 
 # CHECK-INST: flh ft0, 12(a0)
 # CHECK-ENCODING: [0x07,0x10,0xc5,0x00]
 # CHECK-ERROR: instruction requires the following: 'Zfh' (Half-Precision Floating-Point) or 'Zfhmin' (Half-Precision Floating-Point Minimal) or 'Zfbfmin' (Scalar BF16 Converts) or 'Zvfbfwma' (Vector BF16 widening mul-add){{$}}
 # CHECK-UNKNOWN: 07 10 c5 00 <unknown>