Chandler Carruth 6b980541df Refactor the interface to recursively simplifying instructions to be tad ... bit simpler by handling a common case explicitly. Also, refactor the implementation to use a worklist based walk of the recursive users, rather than trying to use value handles to detect and recover from RAUWs during the recursive descent. This fixes a very subtle bug in the previous implementation where degenerate control flow structures could cause mutually recursive instructions (PHI nodes) to collapse in just such a way that From became equal to To after some amount of recursion. At that point, we hit the inf-loop that the assert at the top attempted to guard against. This problem is defined away when not using value handles in this manner. There are lots of comments claiming that the WeakVH will protect against just this sort of error, but they're not accurate about the actual implementation of WeakVHs, which do still track RAUWs. I don't have any test case for the bug this fixes because it requires running the recursive simplification on unreachable phi nodes. I've no way to either run this or easily write an input that triggers it. It was found when using instruction simplification inside the inliner when running over the nightly test-suite. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153393 91177308-0d34-0410-b5e6-96231b3b80d8		2012-03-24 21:11:24 +00:00
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Analysis	Refactor the interface to recursively simplifying instructions to be tad	2012-03-24 21:11:24 +00:00
Archive	Include cstdio in a few place that depended on getting it transitively through StringExtras.h	2012-03-23 11:35:30 +00:00
AsmParser	Convert assert(0) to llvm_unreachable	2012-02-07 05:05:23 +00:00
Bitcode	llvm::SwitchInst	2012-03-11 06:09:17 +00:00
CodeGen	Add the ability to promote legal integer VAARGs. This is required for the PPC64 SVR4 ABI.	2012-03-24 03:53:52 +00:00
DebugInfo	More dead code removal (using -Wunreachable-code)	2012-01-20 21:51:11 +00:00
ExecutionEngine	Make it feasible for clients using EngineBuilder to capture the TargetMachine that is created as part of selecting the appropriate target.	2012-03-23 17:40:56 +00:00
Linker	It's possible for two types, which are isomorphic, to be added to the	2012-03-23 23:17:38 +00:00
MC	Add a hook in MCELFObjectTargetWriter to allow targets to sort relocation	2012-03-23 23:06:45 +00:00
Object	[Object/COFF]: Expose getSectionContents.	2012-03-19 20:27:37 +00:00
Support	[PathV2]: Fix bug in create_directories which caused infinite recursion on	2012-03-21 23:09:14 +00:00
TableGen	Fix infinite loop in nested multiclasses.	2012-03-07 16:39:35 +00:00
Target	Fix small-integer VAARG on SVR4 ABI PPC64.	2012-03-24 03:53:55 +00:00
Transforms	Refactor the interface to recursively simplifying instructions to be tad	2012-03-24 21:11:24 +00:00
VMCore	Remove always true variable.	2012-03-24 20:02:25 +00:00
CMakeLists.txt	Move TableGen's parser and entry point into a library	2011-10-01 16:41:13 +00:00
LLVMBuild.txt	LLVMBuild: Introduce a common section which currently has a list of the	2011-12-12 22:45:54 +00:00
Makefile	Remove more of llvmc and dependencies.	2011-09-20 00:34:27 +00:00