[all-commits] [llvm/llvm-project] 02e7e6: [LoongArch] Fix invalid VEXTH combines for unsuppo...

[hev via All-commits]

  Branch: refs/heads/users/hev/fix-207316
  Home:   https://github.com/llvm/llvm-project
  Commit: 02e7e6f78843b5874d453f52db7502e6db1ce122
      https://github.com/llvm/llvm-project/commit/02e7e6f78843b5874d453f52db7502e6db1ce122
  Author: WANG Rui <wangrui at loongson.cn>
  Date:   2026-07-16 (Thu, 16 Jul 2026)

  Changed paths:
    M llvm/lib/Target/LoongArch/LoongArchISelLowering.cpp
    A llvm/test/CodeGen/LoongArch/lasx/issue207316.ll
    M llvm/test/CodeGen/LoongArch/lasx/xvexth.ll
    M llvm/test/CodeGen/LoongArch/lsx/vexth.ll

  Log Message:
  -----------
  [LoongArch] Fix invalid VEXTH combines for unsupported type extensions

`performEXTENDCombine` could form `VEXTH`/`VEXTH_U` nodes for unsupported
type combinations, such as extending `v8i8` to `v8i32` or `v2i64` to `v2i128`.
These illegal nodes would later reach instruction selection and trigger
backend failures:

* `Cannot select: LoongArchISD::VEXTH`
* `Don't know how to legalize this operation`

Prevent these combines from firing by verifying that the destination type
is legal and has exactly twice the total bit width of the source before
forming a `VEXTH`/`VEXTH_U` node.

Apply the same checks to `performSHLCombine` for consistency.



To unsubscribe from these emails, change your notification settings at https://github.com/llvm/llvm-project/settings/notifications