[all-commits] [llvm/llvm-project] 5918f6: [InstCombine] Infer zext nneg flag (#71534)

[Nikita Popov via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 5918f62301788b53e7d3a23f3203c483e9d4d791
      https://github.com/llvm/llvm-project/commit/5918f62301788b53e7d3a23f3203c483e9d4d791
  Author: Nikita Popov <npopov at redhat.com>
  Date:   2023-11-08 (Wed, 08 Nov 2023)

  Changed paths:
    M clang/test/Headers/wasm.c
    M llvm/lib/Transforms/InstCombine/InstCombineCasts.cpp
    M llvm/test/Transforms/InstCombine/2010-11-01-lshr-mask.ll
    M llvm/test/Transforms/InstCombine/X86/x86-vector-shifts-inseltpoison.ll
    M llvm/test/Transforms/InstCombine/X86/x86-vector-shifts.ll
    M llvm/test/Transforms/InstCombine/adjust-for-minmax.ll
    M llvm/test/Transforms/InstCombine/and-narrow.ll
    M llvm/test/Transforms/InstCombine/and-xor-or.ll
    M llvm/test/Transforms/InstCombine/and.ll
    M llvm/test/Transforms/InstCombine/assoc-cast-assoc.ll
    M llvm/test/Transforms/InstCombine/binop-cast.ll
    M llvm/test/Transforms/InstCombine/cast-mul-select.ll
    M llvm/test/Transforms/InstCombine/cast.ll
    M llvm/test/Transforms/InstCombine/ctpop.ll
    M llvm/test/Transforms/InstCombine/cttz.ll
    M llvm/test/Transforms/InstCombine/fmul.ll
    M llvm/test/Transforms/InstCombine/freeze.ll
    M llvm/test/Transforms/InstCombine/load-bitcast-select.ll
    M llvm/test/Transforms/InstCombine/lshr.ll
    M llvm/test/Transforms/InstCombine/minmax-fold.ll
    M llvm/test/Transforms/InstCombine/minmax-intrinsics.ll
    M llvm/test/Transforms/InstCombine/narrow-math.ll
    M llvm/test/Transforms/InstCombine/negated-bitmask.ll
    M llvm/test/Transforms/InstCombine/overflow-mul.ll
    M llvm/test/Transforms/InstCombine/reduction-add-sext-zext-i1.ll
    M llvm/test/Transforms/InstCombine/reduction-xor-sext-zext-i1.ll
    M llvm/test/Transforms/InstCombine/rem.ll
    M llvm/test/Transforms/InstCombine/select-bitext-bitwise-ops.ll
    M llvm/test/Transforms/InstCombine/select-bitext.ll
    M llvm/test/Transforms/InstCombine/select-cmp-cttz-ctlz.ll
    M llvm/test/Transforms/InstCombine/select-ctlz-to-cttz.ll
    M llvm/test/Transforms/InstCombine/select-obo-peo-ops.ll
    M llvm/test/Transforms/InstCombine/select-with-bitwise-ops.ll
    M llvm/test/Transforms/InstCombine/shift-amount-reassociation-in-bittest-with-truncation-shl.ll
    M llvm/test/Transforms/InstCombine/shift.ll
    M llvm/test/Transforms/InstCombine/trunc-inseltpoison.ll
    M llvm/test/Transforms/InstCombine/trunc.ll
    M llvm/test/Transforms/InstCombine/udiv-simplify.ll
    M llvm/test/Transforms/InstCombine/udivrem-change-width.ll
    M llvm/test/Transforms/InstCombine/vector-casts-inseltpoison.ll
    M llvm/test/Transforms/InstCombine/vector-casts.ll
    M llvm/test/Transforms/InstCombine/wcslen-1.ll
    M llvm/test/Transforms/InstCombine/wcslen-3.ll
    M llvm/test/Transforms/InstCombine/zeroext-and-reduce.ll
    M llvm/test/Transforms/InstCombine/zext-or-icmp.ll
    M llvm/test/Transforms/InstCombine/zext.ll
    M llvm/test/Transforms/LoopVectorize/ARM/mve-reductions.ll
    M llvm/test/Transforms/LoopVectorize/reduction-inloop.ll

  Log Message:
  -----------
  [InstCombine] Infer zext nneg flag (#71534)

Use KnownBits to infer the nneg flag on zext instructions.

Currently we only set nneg when converting sext -> zext, but don't set
it when we have a zext in the first place. If we want to use it in
optimizations, we should make sure the flag inference is consistent.