[all-commits] [llvm/llvm-project] fd159c: [BOLT] Fix ignored LP at fragment start

[Fabian Parzefall via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: fd159c23163e4c08df8a6f0147f4431d4c7504af
      https://github.com/llvm/llvm-project/commit/fd159c23163e4c08df8a6f0147f4431d4c7504af
  Author: Fabian Parzefall <parzefall at fb.com>
  Date:   2022-08-17 (Wed, 17 Aug 2022)

  Changed paths:
    M bolt/lib/Core/BinaryEmitter.cpp
    A bolt/test/runtime/X86/lp-fragment-start.s

  Log Message:
  -----------
  [BOLT] Fix ignored LP at fragment start

If the first block of a fragment is also a landing pad, the landing pad
is not used if an exception is thrown. This is because the landing pad
is at the same start address that the corresponding LSDA describes. In
that case, the offset in the call site records to refer to that landing
pad is zero, and a zero offset is interpreted by the personality
function as "no handler" and ignored.

Reviewed By: Amir

Differential Revision: https://reviews.llvm.org/D132053