[all-commits] [llvm/llvm-project] b27e54: [DAG] Convert truncstore(extend(x)) back to store(x)

[David Green via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: b27e5459d51fd5ba80a1182e5bd8c0fd5e2e6a49
      https://github.com/llvm/llvm-project/commit/b27e5459d51fd5ba80a1182e5bd8c0fd5e2e6a49
  Author: David Green <david.green at arm.com>
  Date:   2022-01-22 (Sat, 22 Jan 2022)

  Changed paths:
    M llvm/lib/CodeGen/SelectionDAG/DAGCombiner.cpp
    M llvm/lib/Target/X86/X86ISelLowering.cpp
    M llvm/test/CodeGen/AMDGPU/copy-illegal-type.ll

  Log Message:
  -----------
  [DAG] Convert truncstore(extend(x)) back to store(x)

Pulled out of D106237, this folds truncstore(extend(x)) back to store(x)
if the original store was legal. This can come up due to the order we
fold nodes. A fold from X86 needs to be adjusted to prevent infinite
loops, to have it pick the operand of a trunc more directly.

Differential Revision: https://reviews.llvm.org/D117901