Sanjoy Das 9b70f16033 Reimplement depedency tracking in the ImplicitNullChecks pass ... Summary: This change rewrites a core component in the ImplicitNullChecks pass for greater simplicity since the original design was over-complicated for no good reason. Please review this as essentially a new pass. The change is almost NFC and I've added a test case for a scenario that this new code handles that wasn't handled earlier. The implicit null check pass, at its core, is a code hoisting transform. It differs from "normal" code transforms in that it speculates potentially faulting instructions (by design), but a lot of the usual hazard detection logic (register read-after-write etc.) still applies. We previously detected hazards by keeping track of registers defined and used by machine instructions over an instruction range, but that was unwieldy and did not actually confer any performance benefits. The intent was to have linear time complexity over the number of machine instructions considered, but it ended up being N^2 is practice. This new version is more obviously O(N^2) (with N capped to 8 by default) in hazard detection. It does not attempt to be clever in tracking register uses or defs (the previous cleverness here was a source of bugs). Once this is checked in, I'll extract out the `IsSuitableMemoryOp` and `CanHoistLoadInst` lambda into member functions (they're too complicated to be inline lambdas) and do some other related NFC cleanups. Reviewers: reames, anna, atrick Subscribers: mcrosier, llvm-commits Differential Revision: https://reviews.llvm.org/D27592 llvm-svn: 290394		2016-12-23 00:41:21 +00:00
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Analysis	[X86][SSE] Improve lowering of vXi64 multiplies	2016-12-21 20:00:10 +00:00
Assembler	[LLParser] Make the line field of DIMacro(File) optional.	2016-12-22 00:29:00 +00:00
Bindings
Bitcode	IR: Function summary representation for type tests.	2016-12-21 23:03:45 +00:00
BugPoint
CodeGen	Reimplement depedency tracking in the ImplicitNullChecks pass	2016-12-23 00:41:21 +00:00
DebugInfo	Fix an assertion in DwarfExpression when emitting fragments in vector registers	2016-12-22 06:10:41 +00:00
Examples
ExecutionEngine	Fix R_AARCH64_MOVW_UABS_G3 relocation	2016-12-15 22:36:53 +00:00
Feature
FileCheck	[FileCheck] Fix --strict-whitespace --match-full-lines -- add test-case	2016-12-18 21:04:47 +00:00
Instrumentation	Renumber testcase metadata nodes after r290153.	2016-12-22 00:45:21 +00:00
Integer
JitListener
LibDriver	LibDriver: Allow resource files to be archive members.	2016-12-15 19:37:46 +00:00
Linker	Renumber testcase metadata nodes after r290153.	2016-12-22 00:45:21 +00:00
LTO	Renumber testcase metadata nodes after r290153.	2016-12-22 00:45:21 +00:00
MC	AMDGPU: Fix missing 16-bit cmpx instructions	2016-12-22 16:27:14 +00:00
Object
ObjectYAML	[ObjectYAML] Support for DWARF debug_info section	2016-12-22 22:44:27 +00:00
Other	[PM] Loosen the check ever so slightly -- MSVC appears to not include	2016-12-22 07:53:20 +00:00
SymbolRewriter
TableGen
ThinLTO/X86	Renumber testcase metadata nodes after r290153.	2016-12-22 00:45:21 +00:00
tools	[sancov] hash prefix results in huge merge files, use shorter prefix	2016-12-21 22:09:57 +00:00
Transforms	[cfi] Emit jump tables as a function-level inline asm.	2016-12-22 22:22:35 +00:00
Unit
Verifier	[IR] Remove the DIExpression field from DIGlobalVariable.	2016-12-20 02:09:43 +00:00
YAMLParser
.clang-format
CMakeLists.txt
lit.cfg
lit.site.cfg.in
TestRunner.sh