[PATCH] D123693: Transform illegal intrinsics to V_ILLEGAL

[Brendon Cahoon via Phabricator via llvm-commits]

bcahoon added a comment.

The rationale is for library code that looks like:
void example(float *p, float v) {

  if (_ISA_verison == 9008 || __ISA_verison == 9010)
     global_atomic_fadd(p, v);
  else
     generic_atomic_fadd(p, v);

}

At optimization levels > 0, the dead code is eliminated, but at optimization level 0, the dead code remain and the compiler attempts to generate an instruction. That instruction would never be executed due to the condition, but it still needs to be generated. In these cases, we don't have multilibs (target specific libraries).


Repository:
  rG LLVM Github Monorepo

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  https://reviews.llvm.org/D123693/new/

https://reviews.llvm.org/D123693