[all-commits] [llvm/llvm-project] eb5425: [RISCV] Return false from shouldFormOverflowOp whe...

[Liao Chunyu via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: eb54254b6e09afd726feefbebd1a74a4bc028722
      https://github.com/llvm/llvm-project/commit/eb54254b6e09afd726feefbebd1a74a4bc028722
  Author: LiaoChunyu <chunyu at iscas.ac.cn>
  Date:   2023-03-14 (Tue, 14 Mar 2023)

  Changed paths:
    M llvm/lib/Target/RISCV/RISCVISelLowering.h
    M llvm/test/CodeGen/RISCV/overflow-intrinsics.ll

  Log Message:
  -----------
  [RISCV] Return false from shouldFormOverflowOp when type is i8 and i16

i8 and i16 are not using overflow.
Reduce the number of zero extension instructions.

To reduce the uncertainty of the unknown,
most of the checks of the virtual function are kept

Reviewed By: craig.topper

Differential Revision: https://reviews.llvm.org/D143646