Xun Li 10e1d5734d [Coroutines] Optimize the lifespan of temporary co_await object ... Summary: If we ever assign co_await to a temporary variable, such as foo(co_await expr), we generate AST that looks like this: MaterializedTemporaryExpr(CoawaitExpr(...)). MaterializedTemporaryExpr would emit an intrinsics that marks the lifetime start of the temporary storage. However such temporary storage will not be used until co_await is ready to write the result. Marking the lifetime start way too early causes extra storage to be put in the coroutine frame instead of the stack. As you can see from https://godbolt.org/z/zVx_eB, the frame generated for get_big_object2 is 12K, which contains a big_object object unnecessarily. After this patch, the frame size for get_big_object2 is now only 8K. There are still room for improvements, in particular, GCC has a 4K frame for this function. But that's a separate problem and not addressed in this patch. The basic idea of this patch is during CoroSplit, look for every local variable in the coroutine created through AllocaInst, identify all the lifetime start/end markers and the use of the variables, and sink the lifetime.start maker to the places as close to the first-ever use as possible. Reviewers: lewissbaker, modocache, junparser Reviewed By: junparser Subscribers: hiraditya, llvm-commits, rsmith, ChuanqiXu, cfe-commits Tags: #clang, #llvm Differential Revision: https://reviews.llvm.org/D82314		2020-06-28 10:18:15 -07:00
..
ArgAddr.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-alloc-with-param-O0.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-alloc-with-param-O2.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-catchswitch.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-cleanup-lowering.ll	[Coroutines][4/6] New pass manager: coro-cleanup	2020-02-19 00:30:27 -05:00
coro-cleanup.ll	[Coroutines][5/6] Add coroutine passes to pipeline	2020-02-19 00:57:14 -05:00
coro-debug-frame-variable.ll	[Coroutines] Use dbg.declare for frame variables	2020-03-03 17:13:46 -05:00
coro-debug.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-early.ll	[Coroutines][1/6] New pass manager: coro-early	2020-02-17 13:27:48 -05:00
coro-eh-aware-edge-split-00.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-eh-aware-edge-split-01.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-eh-aware-edge-split-02.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-elide.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-frame-arrayalloca.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-frame-unreachable.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-frame.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-heap-elide.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-materialize.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-padding.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-param-copy.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-retcon-alloca.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-retcon-frame.ll	CoroSplit: Fix coroutine splitting for retcon and retcon.once	2020-06-03 12:10:58 -07:00
coro-retcon-once-value2.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-retcon-once-value.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-retcon-resume-values2.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-retcon-resume-values.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-retcon-value.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-retcon.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-spill-after-phi.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-spill-corobegin.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
coro-split-00.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-split-01.ll	[Coroutines][5/6] Add coroutine passes to pipeline	2020-02-19 00:57:14 -05:00
coro-split-02.ll	[Coroutines] Optimize the lifespan of temporary co_await object	2020-06-28 10:18:15 -07:00
coro-split-alloc.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-split-dbg.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-split-eh-00.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-split-eh-01.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-split-hidden.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-split-musttail1.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-split-musttail2.ll	[Coroutines] Remove alignment check in shouldBeMustTail	2020-04-07 09:07:34 +08:00
coro-split-musttail3.ll	[Coroutines 2/2] Improve symmetric control transfer feature	2020-03-30 09:53:09 +08:00
coro-split-musttail.ll	Re-land new pass manager coro-split and coro-elide	2020-02-19 00:11:23 -05:00
coro-split-sink-lifetime.ll	[Coroutines] Optimize the lifespan of temporary co_await object	2020-06-28 10:18:15 -07:00
coro-swifterror.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
ex0.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
ex1.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
ex2.ll	[Coroutines][New pass manager] Move CoroElide pass to right position	2020-03-01 21:48:24 +08:00
ex3.ll	[Coroutines][New pass manager] Move CoroElide pass to right position	2020-03-01 21:48:24 +08:00
ex4.ll	[Coroutines][5/6] Add coroutine passes to pipeline	2020-02-19 00:57:14 -05:00
ex5.ll	Use optimal layout and preserve alloca alignment in coroutine frames.	2020-03-26 00:51:09 -04:00
no-suspend.ll	[Coroutines] Fix PR45130	2020-03-20 11:27:08 +08:00
phi-coro-end.ll	[Coroutines][5/6] Add coroutine passes to pipeline	2020-02-19 00:57:14 -05:00
restart-trigger.ll	[Coroutines][5/6] Add coroutine passes to pipeline	2020-02-19 00:57:14 -05:00
smoketest.ll	[Coroutines][5/6] Add coroutine passes to pipeline	2020-02-19 00:57:14 -05:00