Juergen Ributzka fb282c68b7 Add Constant Hoisting Pass ... This pass identifies expensive constants to hoist and coalesces them to better prepare it for SelectionDAG-based code generation. This works around the limitations of the basic-block-at-a-time approach. First it scans all instructions for integer constants and calculates its cost. If the constant can be folded into the instruction (the cost is TCC_Free) or the cost is just a simple operation (TCC_BASIC), then we don't consider it expensive and leave it alone. This is the default behavior and the default implementation of getIntImmCost will always return TCC_Free. If the cost is more than TCC_BASIC, then the integer constant can't be folded into the instruction and it might be beneficial to hoist the constant. Similar constants are coalesced to reduce register pressure and materialization code. When a constant is hoisted, it is also hidden behind a bitcast to force it to be live-out of the basic block. Otherwise the constant would be just duplicated and each basic block would have its own copy in the SelectionDAG. The SelectionDAG recognizes such constants as opaque and doesn't perform certain transformations on them, which would create a new expensive constant. This optimization is only applied to integer constants in instructions and simple (this means not nested) constant cast experessions. For example: %0 = load i64* inttoptr (i64 big_constant to i64*) Reviewed by Eric git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@200022 91177308-0d34-0410-b5e6-96231b3b80d8		2014-01-24 18:23:08 +00:00
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ADT	Add operator!= for FoldingSetNodeID and FoldingSetNodeIDRef. Implementation in	2014-01-21 01:29:37 +00:00
Analysis	Add Constant Hoisting Pass	2014-01-24 18:23:08 +00:00
AsmParser	Move the LLVM IR asm writer header files into the IR directory, as they	2014-01-07 12:34:26 +00:00
Bitcode	Make parseBitcodeFile return an ErrorOr<Module *>.	2014-01-15 01:08:23 +00:00
CodeGen	Add Constant Hoisting Pass	2014-01-24 18:23:08 +00:00
Config	Remove the test for endianness in configure.ac and regenerate.	2014-01-09 01:09:57 +00:00
DebugInfo	llvm-dwarfdump: type unit dwo support	2014-01-09 05:08:24 +00:00
ExecutionEngine	Add target analysis passes to the codegen pipeline for MCJIT.	2014-01-23 19:23:28 +00:00
IR	MIPS: mark intrinsics IntrNoMem so all patterns using them are consistent.	2014-01-21 10:41:16 +00:00
IRReader	Split out the IRReader header and the utility functions it provides into	2013-03-26 02:25:37 +00:00
LTO	Adding new LTO APIs to parse metadata nodes and extract linker options and	2014-01-21 18:31:27 +00:00
MC	Move emitInlineAsmEnd to the AsmPrinter interface.	2014-01-24 15:47:54 +00:00
Object	[Object][ELF][Mips] Print symbol name for MIPS ELF relocations.	2014-01-23 15:05:45 +00:00
Option	Option parsing: support case-insensitive option matching.	2013-08-28 20:04:31 +00:00
Support	Fix known typos	2014-01-24 17:20:08 +00:00
TableGen	Speling fixes.	2013-10-22 15:18:03 +00:00
Target	Add a variable to track whether or not we've used a unique section,	2014-01-23 06:47:25 +00:00
Transforms	Add Constant Hoisting Pass	2014-01-24 18:23:08 +00:00
AutoUpgrade.h	Debug Info: drop debug info via upgrading path if version number does not match.	2013-12-02 21:29:56 +00:00
CMakeLists.txt	Move all of the header files which are involved in modelling the LLVM IR	2013-01-02 11:36:10 +00:00
DebugInfo.h	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
DIBuilder.h	typo	2014-01-18 02:12:10 +00:00
GVMaterializer.h	Use error_code in GVMaterializer.	2013-11-05 19:36:34 +00:00
InitializePasses.h	Add Constant Hoisting Pass	2014-01-24 18:23:08 +00:00
InstVisitor.h	Add addrspacecast instruction.	2013-11-15 01:34:59 +00:00
LinkAllIR.h	[cleanup] Move the Dominators.h and Verifier.h headers into the IR	2014-01-13 09:26:24 +00:00
LinkAllPasses.h	Add Constant Hoisting Pass	2014-01-24 18:23:08 +00:00
Linker.h	Add a 'deleteModule' method to the Linker class.	2013-10-16 08:59:57 +00:00
Pass.h	moves doInitialization and doFinalization to the Pass class and removes some unreachable code in MachineModuleInfo	2012-12-03 21:56:57 +00:00
PassAnalysisSupport.h	Fix include guards so they exactly match file names.	2013-01-10 00:45:19 +00:00
PassManager.h	Move the old pass manager infrastructure into a legacy namespace and	2013-11-09 12:26:54 +00:00
PassRegistry.h	Re-sort all of the includes with ./utils/sort_includes.py so that	2014-01-07 11:48:04 +00:00
PassSupport.h	[opt][PassInfo] Allow opt to run passes that need target machine.	2014-01-16 21:44:34 +00:00