[all-commits] [llvm/llvm-project] 1ee84e: [DebugInfo] Allow spill slots in call site paramet...

[Vedant Kumar via All-commits]

  Branch: refs/heads/master
  Home:   https://github.com/llvm/llvm-project
  Commit: 1ee84e5ab2a4b7e79b39d4b5130c749c6a7c08aa
      https://github.com/llvm/llvm-project/commit/1ee84e5ab2a4b7e79b39d4b5130c749c6a7c08aa
  Author: Vedant Kumar <vsk at apple.com>
  Date:   2019-11-14 (Thu, 14 Nov 2019)

  Changed paths:
    M llvm/lib/CodeGen/AsmPrinter/DwarfExpression.cpp
    M llvm/lib/CodeGen/TargetInstrInfo.cpp
    A llvm/test/DebugInfo/MIR/X86/dbg-call-site-spilled-arg.mir

  Log Message:
  -----------
  [DebugInfo] Allow spill slots in call site parameter descriptions

Allow call site paramter descriptions to reference spill slots. Spill
slots are not visible to high-level LLVM IR, so they can safely be
referenced during entry value evaluation (as they cannot be clobbered by
some other function).

This gives a 5% increase in the number of call site parameter DIEs in an
LTO x86_64 build of the xnu kernel.

This reverts commit eb4c98ca3d2590bad9f6542afbf3a7824d2b53fa (
[DebugInfo] Exclude memory location values as parameter entry values),
effectively reintroducing the portion of D60716 which dealt with memory
locations (authored by Djordje, Nikola, Ananth, and Ivan).

This partially addresses llvm.org/PR43343. However, not all memory
operands forwarded to callees live in spill slots. In the xnu build, it
may be possible to use an escape analysis to increase the number of call
site parameter by another 15% (more details in PR43343).

Differential Revision: https://reviews.llvm.org/D70254