[all-commits] [llvm/llvm-project] 842a67: [X86] LowerTRUNCATE - improve handling during type...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 842a6728d95057b5b048453f75139be6c7c18f93
      https://github.com/llvm/llvm-project/commit/842a6728d95057b5b048453f75139be6c7c18f93
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2023-07-11 (Tue, 11 Jul 2023)

  Changed paths:
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/X86/bitcast-and-setcc-256.ll
    M llvm/test/CodeGen/X86/bitcast-and-setcc-512.ll
    M llvm/test/CodeGen/X86/bitcast-vector-bool.ll
    M llvm/test/CodeGen/X86/cast-vsel.ll
    M llvm/test/CodeGen/X86/masked_store.ll
    M llvm/test/CodeGen/X86/masked_store_trunc.ll
    M llvm/test/CodeGen/X86/masked_store_trunc_usat.ll
    M llvm/test/CodeGen/X86/psubus.ll
    M llvm/test/CodeGen/X86/vector-reduce-and-bool.ll
    M llvm/test/CodeGen/X86/vector-reduce-or-bool.ll
    M llvm/test/CodeGen/X86/vector-reduce-xor-bool.ll
    M llvm/test/CodeGen/X86/vector-trunc-math.ll
    M llvm/test/CodeGen/X86/vector-trunc-packus.ll
    M llvm/test/CodeGen/X86/vector-trunc-usat.ll
    M llvm/test/CodeGen/X86/vector-trunc.ll

  Log Message:
  -----------
  [X86] LowerTRUNCATE - improve handling during type legalization to PACKSS/PACKUS patterns

Extend coverage for lowering wide vector types during type legalization to allow us to use PACKSS/PACKUS patterns instead of dropping down to shuffle lowering.

First step towards avoiding premature folds of TRUNCATE to PACKSS/PACKUS nodes as described on Issue #63710 - which causes a large number of regressions on D152928 - we will next need to tweak the TRUNCATE widening in ReplaceNodeResults

Differential Revision: https://reviews.llvm.org/D154592