[PATCH] D53877: [IR] Strawman for dedicated FNeg IR instruction

[Roman Lebedev via Phabricator via llvm-commits]

lebedev.ri added a comment.

> with the intention of adding more Unary operations in the future. E.g. integer Neg (and maybe Abs, Copysign, etc.).

While there are very clear reasons for `FNeg` to exist, this isn't so true for any of the others listed here..



================
Comment at: include/llvm-c/Core.h:64
   LLVMInvoke         = 5,
   /* removed 6 due to API changes */
   LLVMUnreachable    = 7,
----------------
This strongly suggests that you can not reorder/renumber the existing enumerators.


================
Comment at: lib/Bitcode/Writer/BitcodeWriter.cpp:521
+  default: llvm_unreachable("Unknown binary instruction!");
+  // TODO: Handle integer Neg?
+  case Instruction::FNeg: return bitc::UNOP_NEG;
----------------
There is no integer neg opcode to handle.


Repository:
  rL LLVM

https://reviews.llvm.org/D53877