Atmn Patel bf30fa7425 [LoopDeletion] Allows deletion of possibly infinite side-effect free loops ... From C11 and C++11 onwards, a forward-progress requirement has been introduced for both languages. In the case of C, loops with non-constant conditionals that do not have any observable side-effects (as defined by 6.8.5p6) can be assumed by the implementation to terminate, and in the case of C++, this assumption extends to all functions. The clang frontend will emit the `mustprogress` function attribute for C++ functions (D86233, D85393, D86841) and emit the loop metadata `llvm.loop.mustprogress` for every loop in C11 or later that has a non-constant conditional. This patch modifies LoopDeletion so that only loops with the `llvm.loop.mustprogress` metadata or loops contained in functions that are required to make progress (`mustprogress` or `willreturn`) are checked for observable side-effects. If these loops do not have an observable side-effect, then we delete them. Loops without observable side-effects that do not satisfy the above conditions will not be deleted. Reviewed By: jdoerfert Differential Revision: https://reviews.llvm.org/D86844		2021-01-05 09:56:16 -05:00
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llvm	[LoopDeletion] Allows deletion of possibly infinite side-effect free loops	2021-01-05 09:56:16 -05:00
llvm-c	[X86] Add x86_amx type for intel AMX.	2020-12-30 13:52:13 +08:00