2 Commits

Author SHA1 Message Date
Guozhi Wei
6599961c17 [TwoAddressInstructionPass] Improve the SrcRegMap and DstRegMap computation
This patch contains following enhancements to SrcRegMap and DstRegMap:

  1 In findOnlyInterestingUse not only check if the Reg is two address usage,
    but also check after commutation can it be two address usage.

  2 If a physical register is clobbered, remove SrcRegMap entries that are
    mapped to it.

  3 In processTiedPairs, when create a new COPY instruction, add a SrcRegMap
    entry only when the COPY instruction is coalescable. (The COPY src is
    killed)

With these enhancements isProfitableToCommute can do better commute decision,
and finally more register copies are removed.

Differential Revision: https://reviews.llvm.org/D108731
2021-10-11 15:28:31 -07:00
Melanie Blower
931e95687d [llvm][clang][fpenv] Create new intrinsic llvm.arith.fence to control FP optimization at expression level
This intrinsic blocks floating point transformations by the optimizer.

Author: Pengfei

Reviewed By: LuoYuanke, Andy Kaylor, Craig Topper, kpn

Differential Revision: https://reviews.llvm.org/D99675
2021-06-28 12:26:52 -04:00