Bruno Cardoso Lopes c2183ae743 [MemoryDepAnalysis] Fix compile time slowdown ... - Problem One program takes ~3min to compile under -O2. This happens after a certain function A is inlined ~700 times in a function B, inserting thousands of new BBs. This leads to 80% of the compilation time spent in GVN::processNonLocalLoad and MemoryDependenceAnalysis::getNonLocalPointerDependency, while searching for nonlocal information for basic blocks. Usually, to avoid spending a long time to process nonlocal loads, GVN bails out if it gets more than 100 deps as a result from MD->getNonLocalPointerDependency. However this only happens *after* all nonlocal information for BBs have been computed, which is the bottleneck in this scenario. For instance, there are 8280 times where getNonLocalPointerDependency returns deps with more than 100 bbs and from those, 600 times it returns more than 1000 blocks. - Solution Bail out early during the nonlocal info computation whenever we reach a specified threshold. This patch proposes a 100 BBs threshold, it also reduces the compile time from 3min to 23s. - Testing The test-suite presented no compile nor execution time regressions. Some numbers from my machine (x86_64 darwin): - 17s under -Oz (which avoids inlining). - 1.3s under -O1. - 2m51s under -O2 ToT *** 23s under -O2 w/ Result.size() > 100 - 1m54s under -O2 w/ Result.size() > 500 With NumResultsLimit = 100, GVN yields the same outcome as in the unlimited 3min version. http://reviews.llvm.org/D5532 rdar://problem/18188041 llvm-svn: 218792		2014-10-01 20:07:13 +00:00
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Analysis	[MemoryDepAnalysis] Fix compile time slowdown	2014-10-01 20:07:13 +00:00
AsmParser	Make CallingConv::ID an alias of "unsigned".	2014-09-10 18:00:17 +00:00
Bitcode	Do not destroy external linkage when deleting function body	2014-09-23 12:54:19 +00:00
CodeGen	Move the complex address expression out of DIVariable and into an extra	2014-10-01 18:55:02 +00:00
DebugInfo	Store TypeUnits in a SmallVector<DWARFUnitSection> instead of a single DWARFUnitSection.	2014-09-29 13:56:39 +00:00
ExecutionEngine	[MCJIT] Turn the getSymbolAddress free function created in r218626 into a static	2014-10-01 04:11:13 +00:00
IR	Move the complex address expression out of DIVariable and into an extra	2014-10-01 18:55:02 +00:00
IRReader	Pass a && to getLazyBitcodeModule.	2014-09-03 17:31:46 +00:00
LineEditor
Linker	Merge alignment of common GlobalValue.	2014-09-09 17:48:18 +00:00
LTO	LTO: Ignore disabled diagnostic remarks	2014-10-01 18:36:03 +00:00
MC	Extend C disassembler API to allow specifying target features	2014-09-30 16:31:40 +00:00
Object	Object: BSS/virtual sections don't have contents	2014-09-26 22:32:16 +00:00
Option	Add an overload of getLastArgNoClaim taking two OptSpecifiers.	2014-09-12 19:42:53 +00:00
ProfileData	llvm-cov: Use the number of executed functions for the function coverage metric.	2014-09-30 12:45:13 +00:00
Support	Move the complex address expression out of DIVariable and into an extra	2014-10-01 18:55:02 +00:00
TableGen	Refactoring: raw pointer -> unique_ptr	2014-09-25 19:55:58 +00:00
Target	Don't repeat function/variable name in comment. NFC.	2014-10-01 19:39:32 +00:00
Transforms	Move the complex address expression out of DIVariable and into an extra	2014-10-01 18:55:02 +00:00
CMakeLists.txt
LLVMBuild.txt
Makefile