[all-commits] [llvm/llvm-project] 033120: [DAGCombiner] Extend convertBuildVecZextToZext to ...

[Jim Lin via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 03312094b8243bb54b5bc8d89dea923fc09ce885
      https://github.com/llvm/llvm-project/commit/03312094b8243bb54b5bc8d89dea923fc09ce885
  Author: Jim Lin <jim at andestech.com>
  Date:   2026-04-17 (Fri, 17 Apr 2026)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    A llvm/test/CodeGen/RISCV/rvv/buildvec-sext.ll

  Log Message:
  -----------
  [DAGCombiner] Extend convertBuildVecZextToZext to sign extends (#192372)

Generalize the existing fold that collapses a BUILD_VECTOR of ZERO_EXTEND
(or ANY_EXTEND) of EXTRACT_VECTOR_ELTs into a single vector extend so that
it also handles SIGN_EXTEND. Mixed sign and zero extends remain unsupported
because their high-bit semantics differ, so the combine bails out in that
case.

---------

Co-authored-by: Claude Opus 4.6 (1M context) <noreply at anthropic.com>



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