[all-commits] [llvm/llvm-project] 34659d: [InstCombine][X86] simplifyX86immShift - convert v...

[Simon Pilgrim via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 34659de5fdd18468f062f301e64d7c883c9a5f14
      https://github.com/llvm/llvm-project/commit/34659de5fdd18468f062f301e64d7c883c9a5f14
  Author: Simon Pilgrim <llvm-dev at redking.me.uk>
  Date:   2020-03-20 (Fri, 20 Mar 2020)

  Changed paths:
    M llvm/include/llvm/Analysis/ValueTracking.h
    M llvm/lib/Analysis/ValueTracking.cpp
    M llvm/lib/Transforms/InstCombine/InstCombineCalls.cpp
    M llvm/test/Transforms/InstCombine/X86/x86-vector-shifts.ll

  Log Message:
  -----------
  [InstCombine][X86] simplifyX86immShift - convert variable in-range vector shift by scalar amounts to generic shifts (PR40391)

The sll/srl/sra scalar vector shifts can be replaced with generic shifts if the shift amount is known to be in range.

This also required public DemandedElts variants of llvm::computeKnownBits to be exposed (PR36319).