Chris Lattner 7e598096ea Sink noop copies into the basic block that uses them. This reduces the number ... of cross-block live ranges, and allows the bb-at-a-time selector to always coallesce these away, at isel time. This reduces the load on the coallescer and register allocator. For example on a codec on X86, we went from: 1643 asm-printer - Number of machine instrs printed 419 liveintervals - Number of loads/stores folded into instructions 1144 liveintervals - Number of identity moves eliminated after coalescing 1022 liveintervals - Number of interval joins performed 282 liveintervals - Number of intervals after coalescing 1304 liveintervals - Number of original intervals 86 regalloc - Number of times we had to backtrack 1.90232 regalloc - Ratio of intervals processed over total intervals 40 spiller - Number of values reused 182 spiller - Number of loads added 121 spiller - Number of stores added 132 spiller - Number of register spills 6 twoaddressinstruction - Number of instructions commuted to coalesce 360 twoaddressinstruction - Number of two-address instructions to: 1636 asm-printer - Number of machine instrs printed 403 liveintervals - Number of loads/stores folded into instructions 1155 liveintervals - Number of identity moves eliminated after coalescing 1033 liveintervals - Number of interval joins performed 279 liveintervals - Number of intervals after coalescing 1312 liveintervals - Number of original intervals 76 regalloc - Number of times we had to backtrack 1.88998 regalloc - Ratio of intervals processed over total intervals 1 spiller - Number of copies elided 41 spiller - Number of values reused 191 spiller - Number of loads added 114 spiller - Number of stores added 128 spiller - Number of register spills 4 twoaddressinstruction - Number of instructions commuted to coalesce 356 twoaddressinstruction - Number of two-address instructions On this testcase, this change provides a modest reduction in spill code, regalloc iterations, and total instructions emitted. It increases the number of register coallesces. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@28115 91177308-0d34-0410-b5e6-96231b3b80d8		2006-05-05 01:04:50 +00:00
..
DAGCombiner.cpp	Remove a bogus transformation. This fixes SingleSource/UnitTests/2006-01-23-InitializedBitField.c	2006-04-28 23:33:20 +00:00
LegalizeDAG.cpp	Refactor TargetMachine, pushing handling of TargetData into the target-specific subclasses. This has one caller-visible change: getTargetData() now returns a pointer instead of a reference.	2006-05-03 01:29:57 +00:00
Makefile	Change Library Names Not To Conflict With Others When Installed	2004-10-27 23:18:45 +00:00
ScheduleDAG.cpp	Remove and simplify some more machineinstr/machineoperand stuff.	2006-05-04 18:16:01 +00:00
ScheduleDAGList.cpp	Initial support for register pressure aware scheduling. The register reduction	2006-05-04 19:16:39 +00:00
ScheduleDAGSimple.cpp	Move simple-selector-specific types to the simple selector.	2006-03-10 07:51:18 +00:00
SelectionDAG.cpp	Fix Regression/CodeGen/Generic/2006-04-26-SetCCAnd.ll and	2006-04-27 05:01:07 +00:00
SelectionDAGISel.cpp	Sink noop copies into the basic block that uses them. This reduces the number	2006-05-05 01:04:50 +00:00
SelectionDAGPrinter.cpp	print arbitrary constant pool entries	2006-03-05 09:38:03 +00:00
TargetLowering.cpp	Refactor TargetMachine, pushing handling of TargetData into the target-specific subclasses. This has one caller-visible change: getTargetData() now returns a pointer instead of a reference.	2006-05-03 01:29:57 +00:00