[PATCH] D95588: [RISCV] Implement the MC layer support of P extension

[Craig Topper via Phabricator via cfe-commits]

craig.topper added inline comments.


================
Comment at: llvm/lib/Target/RISCV/RISCVInstrInfoP.td:599
+               Sched<[]>;
+def SMBB32   : RVPBinary<0b0000100, 0b010, "smbb32">,
+               Sched<[]>;
----------------
It looks like the 0.9.3 spec lists this as an alias of MULSR64 and does not give it an encoding.


================
Comment at: llvm/lib/Target/RISCV/RISCVInstrInfoP.td:737
+               Sched<[]>;
+def KMADA32  : RVPTernary<0b0100100, 0b010, "kmada32">,
+               Sched<[]>;
----------------
0.9.3 spec has this as an alias of KMAR64


================
Comment at: llvm/lib/Target/RISCV/RISCVInstrInfoP.td:835
+    Predicates = [HasStdExtZpn] in
+def INSB : RVInstR<0b1010110, 0b000, OPC_OP_P, (outs GPR:$rd),
+                   (ins GPR:$rs2, GPR:$rs1, uimmlog2xlenbytes:$shamt),
----------------
I believe way this has been done on other extensions is to have `(outs GPR:$rd_wb), (ins GPR:$rd, GPR:$rs1, uimmlog2xlenbytes:$shamt)` and `let Constraints = "$rd = $rd_wb"`

And I don't think it should inherit from RVInstR since it doesn't have a real rs2.


Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D95588/new/

https://reviews.llvm.org/D95588