Andrew Trick 6ea2b9608a Allocate local registers in order for optimal coloring. ... Also avoid locals evicting locals just because they want a cheaper register. Problem: MI Sched knows exactly how many registers we have and assumes they can be colored. In cases where we have large blocks, usually from unrolled loops, greedy coloring fails. This is a source of "regressions" from the MI Scheduler on x86. I noticed this issue on x86 where we have long chains of two-address defs in the same live range. It's easy to see this in matrix multiplication benchmarks like IRSmk and even the unit test misched-matmul.ll. A fundamental difference between the LLVM register allocator and conventional graph coloring is that in our model a live range can't discover its neighbors, it can only verify its neighbors. That's why we initially went for greedy coloring and added eviction to deal with the hard cases. However, for singly defined and two-address live ranges, we can optimally color without visiting neighbors simply by processing the live ranges in instruction order. Other beneficial side effects: It is much easier to understand and debug regalloc for large blocks when the live ranges are allocated in order. Yes, global allocation is still very confusing, but it's nice to be able to comprehend what happened locally. Heuristics could be added to bias register assignment based on instruction locality (think late register pairing, banks...). Intuituvely this will make some test cases that are on the threshold of register pressure more stable. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187139 91177308-0d34-0410-b5e6-96231b3b80d8		2013-07-25 18:35:14 +00:00
..
ADCE	Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.	2012-02-16 06:28:33 +00:00
ArgumentPromotion	Update some EH tests that were violating the new EH model.	2013-03-21 18:30:10 +00:00
BBVectorize	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
BlockPlacement	Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.	2012-02-16 06:28:33 +00:00
BranchFolding	Change tests from "opt %s" to "opt < %s" so that opt doesn't see the	2009-09-11 18:01:28 +00:00
CodeExtractor	Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.	2012-02-16 06:28:33 +00:00
CodeGenPrepare	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
ConstantMerge	Fix const merging when an alias of a const is llvm.used.	2013-05-06 01:48:55 +00:00
ConstProp	Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.	2013-07-14 01:50:49 +00:00
CorrelatedValuePropagation	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
DeadArgElim	Current batch of -disable-debug-info-verifier.	2013-07-25 17:16:05 +00:00
DeadStoreElimination	Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.	2013-07-14 01:50:49 +00:00
DebugIR	Adding tests for DebugIR pass	2013-06-28 20:37:20 +00:00
EarlyCSE	Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.	2013-07-14 01:50:49 +00:00
FunctionAttrs	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
GCOVProfiling	Revert "Revert "PR14606: debug info imported_module support""	2013-04-22 06:12:31 +00:00
GlobalDCE	Revert 179826. Tests were worthless.	2013-04-19 09:32:30 +00:00
GlobalOpt	Check that TD isn't NULL before dereferencing it down this path.	2013-07-25 02:55:14 +00:00
GVN	Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.	2013-07-14 01:50:49 +00:00
IndVarSimplify	Teach indvars to generate nsw/nuw flags when widening an induction variable.	2013-07-14 02:50:07 +00:00
Inline	Have InlineCost check constant fcmps	2013-07-20 04:09:00 +00:00
InstCombine	Current batch of -disable-debug-info-verifier.	2013-07-25 17:16:05 +00:00
InstSimplify	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
Internalize	Respect llvm.used in Internalize.	2013-07-25 03:23:25 +00:00
IPConstantProp	Use references to attribute groups on the call/invoke instructions.	2013-02-22 09:09:42 +00:00
JumpThreading	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
LCSSA	Convert all tests using TCL-style quoting to use shell-style quoting.	2012-07-02 12:47:22 +00:00
LICM	Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.	2013-07-14 01:50:49 +00:00
LoopDeletion	Modify the LLVM assembly output so that it uses references to represent function attributes.	2013-02-20 07:21:42 +00:00
LoopIdiom	add -disable-debug-info-verifier to 3 test to fix tests with pipefail.	2013-07-24 18:44:10 +00:00
LoopRotate	Update testing cases to pass debug info verifier.	2013-07-24 22:23:00 +00:00
LoopSimplify	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
LoopStrengthReduce	Allocate local registers in order for optimal coloring.	2013-07-25 18:35:14 +00:00
LoopUnroll	Fixup to r186268 and r186269: don't append -LABEL to CHECK-NOT. No functionality change.	2013-07-14 02:10:57 +00:00
LoopUnswitch	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
LoopVectorize	Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.	2013-07-14 01:50:49 +00:00
LowerAtomic	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
LowerExpectIntrinsic	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
LowerInvoke	Replace all instances of dg.exp file with lit.local.cfg, since all tests are run with LIT now and now Dejagnu. dg.exp is no longer needed.	2012-02-16 06:28:33 +00:00
LowerSwitch	PR1255 related changes (case ranges):	2012-05-24 09:33:20 +00:00
Mem2Reg	Current batch of -disable-debug-info-verifier.	2013-07-25 17:16:05 +00:00
MemCpyOpt	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
MergeFunc	TBAA: remove !tbaa from testing cases if not used.	2013-04-30 17:52:57 +00:00
MetaRenamer	Tests: rewrite 'opt ... %s' to 'opt ... < %s' so that opt does not emit a ModuleID	2013-01-01 13:57:25 +00:00
ObjCARC	Update testing cases to pass debug info verifier.	2013-07-24 22:23:00 +00:00
PhaseOrdering	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
PruneEH	The normal edge of an invoke is not allowed to branch to a block with a	2012-08-10 20:55:20 +00:00
Reassociate	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
Reg2Mem	Make sure we don't emit instructions before a landingpad instruction.	2013-01-08 10:51:32 +00:00
ScalarRepl	Current batch of -disable-debug-info-verifier.	2013-07-25 17:16:05 +00:00
SCCP	Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.	2013-07-14 01:50:49 +00:00
SimplifyCFG	add -disable-debug-info-verifier to 3 test to fix tests with pipefail.	2013-07-24 18:44:10 +00:00
Sink	Update Transforms tests to use CHECK-LABEL for easier debugging. No functionality change.	2013-07-14 01:42:54 +00:00
SLPVectorizer	When we vectorize across multiple basic blocks we may vectorize PHINodes that create a cycle. We already break the cycle on phi-nodes, but arithmetic operations are still uplicated. This patch adds code that checks if the operation that we are vectorizing was vectorized during the visit of the operands and uses this value if it can.	2013-07-22 22:18:07 +00:00
SROA	Fix a problem I introduced in r187029 where we would over-eagerly	2013-07-24 12:12:17 +00:00
StripSymbols	Debug Info: improve the Finder.	2013-07-24 17:10:09 +00:00
StructurizeCFG	Move StructurizeCFG out of R600 to generic Transforms.	2013-06-19 20:18:24 +00:00
TailCallElim	Catch more CHECK that can be converted to CHECK-LABEL in Transforms for easier debugging. No functionality change.	2013-07-14 01:50:49 +00:00
TailDup	Revert the test moves from 176733. Use "REQUIRES: asserts" instead.	2013-03-12 16:27:52 +00:00