[all-commits] [llvm/llvm-project] a3cab1: [X86][MC] Support encoding/decoding for PUSHP/POPP...

[Shengchen Kan via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: a3cab1fa17ebf29b01fcb566648e2f3fb2955993
      https://github.com/llvm/llvm-project/commit/a3cab1fa17ebf29b01fcb566648e2f3fb2955993
  Author: Shengchen Kan <shengchen.kan at intel.com>
  Date:   2023-11-23 (Thu, 23 Nov 2023)

  Changed paths:
    M llvm/lib/Target/X86/Disassembler/X86Disassembler.cpp
    M llvm/lib/Target/X86/X86InstrMisc.td
    A llvm/test/MC/Disassembler/X86/apx/pushp-popp.txt
    A llvm/test/MC/X86/apx/pushp-popp-att.s
    A llvm/test/MC/X86/apx/pushp-popp-intel.s

  Log Message:
  -----------
  [X86][MC] Support encoding/decoding for PUSHP/POPP (#73092)

A PUSH and its corresponding POP may be marked with a 1-bit Push-Pop Acceleration (PPX)
hint to indicate that the POP reads the value written by the PUSH from the stack. The PPX hint
is encoded by setting REX2.W = 1 and is applicable only to PUSH with opcode 0x50+rd and POP
with opcode 0x58+rd in the legacy space. It is not applicable to any other variants of PUSH and POP.