[PATCH] D81765: Don't hoist very large static allocas to the entry block during inlining

[Pierre Habouzit via Phabricator via llvm-commits]

MadCoder added inline comments.


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Comment at: llvm/include/llvm/Analysis/InlineCost.h:54
+/// size is above this amount in bytes.
+const unsigned MaxStaticAllocaSizeToMove = 65536;
 } // namespace InlineConstants
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jfb wrote:
> @MadCoder does this size limit make sense to you, or would you recommend something smaller?
64k is wayyyy too large.

a kernel stack is 16k.

and we've seen that cause explosions in ioctl() kind of syscalls that have a large switch going in their various implementations where one of the functions has a large stack buffer and is a leaf and another path has no stack allocations but will go in a deep stack.

the threshold for the kernel is likely something like 1 or 2k


Repository:
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CHANGES SINCE LAST ACTION
  https://reviews.llvm.org/D81765/new/

https://reviews.llvm.org/D81765