[PATCH] D86525: [ARM][CostModel] CodeSize costs for i1 arith ops

Mon Sep 7 01:21:10 PDT 2020

samparker added inline comments.

================
Comment at: llvm/lib/Target/ARM/ARMTargetTransformInfo.cpp:1043
+  int ISDOpcode = TLI->InstructionOpcodeToISD(Opcode);
+  if (ST->isThumb() && CostKind == TTI::TCK_CodeSize && Ty->isIntegerTy(1)) {
+    // Make operations on i1 relatively expensive as this often involves
----------------
SjoerdMeijer wrote:
> I was wondering if this should be ST->isThumb2() perhaps? Or does it not matter, this didn't show unexpected regressions?
I've included Thumb too because these operations would be even more expensive without IT support. There were some cases of increases in code size, see D86526, but overall this is a win.

Repository:
  rG LLVM Github Monorepo

CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D86525/new/

https://reviews.llvm.org/D86525