[all-commits] [llvm/llvm-project] 41ba39: [WebAssembly] Don't do SjLj transformation when th...

[Heejin Ahn via All-commits]

  Branch: refs/heads/main
  Home:   https://github.com/llvm/llvm-project
  Commit: 41ba39dfcd0a765f238561ce1b52f843c825ff9a
      https://github.com/llvm/llvm-project/commit/41ba39dfcd0a765f238561ce1b52f843c825ff9a
  Author: Heejin Ahn <aheejin at gmail.com>
  Date:   2021-08-05 (Thu, 05 Aug 2021)

  Changed paths:
    M llvm/lib/Target/WebAssembly/WebAssemblyLowerEmscriptenEHSjLj.cpp
    M llvm/test/CodeGen/WebAssembly/lower-em-sjlj-alias.ll
    M llvm/test/CodeGen/WebAssembly/lower-em-sjlj.ll

  Log Message:
  -----------
  [WebAssembly] Don't do SjLj transformation when there's only setjmp

When there is a `setjmp` call in a function, we transform every callsite
of `setjmp` to record its information by calling `saveSetjmp` function,
and we also transform every callsite of a function that can longjmp to
to check if a longjmp occurred and if so jump to the corresponding
post-setjmp BB. Currently we are doing this for every function that
contains a call to `setjmp`, but if there is no other function call
within that function that can longjmp, this transformation of `setjmp`
callsite and all the preparation of `setjmpTable` in the entry of the
function are not necessary.

This checks if a setjmp-calling function has any other calls that can
longjmp, and if not, skips the function for the SjLj transformation.

Reviewed By: dschuff

Differential Revision: https://reviews.llvm.org/D107530