[PATCH] D91677: Avoid simplification of library functions when callee has an implementation

[Siddhesh Poyarekar via Phabricator via llvm-commits]

siddhesh added inline comments.


================
Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:3023-3027
   // TODO: Split out the code below that operates on FP calls so that
   //       we can all non-FP calls with the StrictFP attribute to be
   //       optimized.
   if (CI->isNoBuiltin())
     return nullptr;
----------------
lebedev.ri wrote:
> Isn't the problem that you need to mark your `@bcopy` with `nobuiltin` attribute?
`nobuiltin` is clang-specific and to make this effective, all inline versions of bcopy would have to be marked `nobuiltin`.  There's no precedence for that in glibc, I'm not sure about other libraries.


================
Comment at: llvm/lib/Transforms/Utils/SimplifyLibCalls.cpp:3076-3079
+  // Simplification is for external library calls, so bail out if the callee
+  // has an implementation.
+  if (!Callee->empty())
+    return nullptr;
----------------
lebedev.ri wrote:
> And if it happens to be in another TU?
It does the simplification; it is not relevant for fortify-source since those implementations are always inline.


CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D91677/new/

https://reviews.llvm.org/D91677