Commit Graph

34 Commits

Author SHA1 Message Date
Evan Cheng
0490dcb1b7 Add a smarter heuristic to determine when to coalesce a virtual register with a physical one. More specifically, it avoid tying a virtual register in the loop with a physical register defined / used outside the loop. When it determines it's not profitable, it will use the physical register as the allocation preference instead.
This is *not* turned on by default. Testing indicates this is just as likely to pessimize code. The main issue seems to be allocation preference doesn't work effectively. That will change once I've taught register allocator "swapping".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@70503 91177308-0d34-0410-b5e6-96231b3b80d8
2009-04-30 18:39:57 +00:00
Evan Cheng
961154f2db ReMaterializeTrivialDef need to trim the live interval to the last kill if the copy kills the source register. This fixes uint64tof64.ll after ARM::MOVi is marked as isAsCheapAsAMove.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@63853 91177308-0d34-0410-b5e6-96231b3b80d8
2009-02-05 08:45:04 +00:00
Evan Cheng
8c08d8c77c Cross register class coalescing. Not yet enabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62832 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-23 02:15:19 +00:00
Evan Cheng
e08eb9ca1d Refactor code. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@62573 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-20 06:44:16 +00:00
Dan Gohman
d68a07650c Tidy up #includes, deleting a bunch of unnecessary #includes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61715 91177308-0d34-0410-b5e6-96231b3b80d8
2009-01-05 17:59:02 +00:00
Evan Cheng
b3990d5e94 Remove val# defined by a remat'ed def that is now dead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@58294 91177308-0d34-0410-b5e6-96231b3b80d8
2008-10-27 23:21:01 +00:00
Evan Cheng
20580a1cf6 Re-materalized definition instructions may be dead. Whack them.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56352 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-19 17:38:47 +00:00
Evan Cheng
8db866808c Fix PR2748. Avoid coalescing physical register with virtual register which would create illegal extract_subreg. e.g.
vr1024 = extract_subreg vr1025, 1
...
vr1024 = mov8rr AH
If vr1024 is coalesced with AH, the extract_subreg is now illegal since AH does not have a super-reg whose sub-register 1 is AH.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@56118 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-11 20:07:10 +00:00
Dan Gohman
ae73dc1448 Tidy up several unbeseeming casts from pointer to intptr_t.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55779 91177308-0d34-0410-b5e6-96231b3b80d8
2008-09-04 17:05:41 +00:00
Evan Cheng
cd04708f59 Re-apply 55467 with fix. If copy is being replaced by remat'ed def, transfer the implicit defs onto the remat'ed instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55564 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-30 09:09:33 +00:00
Dan Gohman
f641395435 Revert r55467; it causes regressions in UnitTests/Vector/divides,
Benchmarks/sim/sim, and others on x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55475 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-28 17:22:54 +00:00
Evan Cheng
9242cb8b82 If a copy isn't coalesced, but its src is defined by trivial computation. Re-materialize the src to replace the copy.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@55467 91177308-0d34-0410-b5e6-96231b3b80d8
2008-08-28 07:53:51 +00:00
Owen Anderson
496bac5b08 Fix a compile-time regression introduced by my heuristic-changing patch. I forgot
to multiply the instruction count by a constant factor in a few places, which
caused the register allocator to require many more iterations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53959 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-23 19:47:27 +00:00
Owen Anderson
a1566f2e12 Change the heuristics used in the coalescer, register allocator, and within
live intervals itself to use an instruction count approximation that is 
not affected by inserting empty indices.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53937 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-22 22:46:49 +00:00
Evan Cheng
e00f5de361 Coalesce copy from one register class to a sub register class. e.g. X86::MOV16to16_.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52480 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-19 01:39:21 +00:00
Owen Anderson
dbb8137c11 The coalescer doesn't need LiveVariables now that we have register use iterators.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51790 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-30 22:37:27 +00:00
Evan Cheng
9c1e06e187 After reading memory that's already freed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49810 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-16 20:24:25 +00:00
Evan Cheng
f0785153e5 Add comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49469 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-10 08:03:14 +00:00
Evan Cheng
7e073baedb - More aggressively coalescing away copies whose source is defined by an implicit_def.
- Added insert_subreg coalescing support.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49448 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-09 20:57:25 +00:00
Evan Cheng
db9b1c3329 - Turn copies of implicit_def into implicit_def instructions.
- Be smarter about coalescing copies from implicit_def.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49168 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-03 16:41:54 +00:00
Evan Cheng
3c88d742d4 Rewrite code that propagate isDead information after a dead copy is coalesced. This remove some ugly spaghetti code and fixed a number of subtle bugs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48490 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-18 08:26:47 +00:00
Evan Cheng
4ff3f1cc57 - Fix a subtle bug in RemoveCopyByCommutingDef. ALR is the live range where the source is defined; BLR is the live range which is defined by the copy.
If ALR and BLR overlaps and end of BLR extends beyond end of ALR, e.g.                                                                                                 
 A = or A, B                                                                                                                                                            
 ...                                                                                                                                                                    
 B = A                                                                                                                                                                  
 ...                                                                                                                                                                    
 C = A<kill>                                                                                                                                                            
 ...                                                                                                                                                                    
   = B                                                                                                                                                                  
                                                                                                                                                                        
then do not add kills of A to the newly created B interval.
- Also fix some kill info update bug.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48141 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-10 08:11:32 +00:00
Evan Cheng
ecb2a8b9bc Fix a coalescer bug wrt how dead copy interval is shortened.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47966 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-05 22:09:42 +00:00
Evan Cheng
6130f66eaa Refactor code. Remove duplicated functions that basically do the same thing as
findRegisterUseOperandIdx, findRegisterDefOperandIndx. Fix some naming inconsistencies.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47927 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-05 00:59:57 +00:00
Evan Cheng
bec2c0c7e1 No need for coalescer to update kills. Only copies are coalesced and those instructions will be deleted. Doh.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47749 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-29 02:50:03 +00:00
Evan Cheng
559f4224d6 Refactor some code; check if commuteInstruction is able to commute the instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47208 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-16 02:32:17 +00:00
Evan Cheng
c8d044e4f7 - Removing the infamous r2rMap_ and rep() method. Now the coalescer will update
register defs and uses after each successful coalescing.
- Also removed a number of hacks and fixed some subtle kill information bugs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47167 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-15 18:24:29 +00:00
Evan Cheng
70071434ae Initial support for copy elimination by commuting its definition MI.
PR1877.
A3 = op A2 B0<kill>                                                                                                                                                                            
...                                                                                                                                                                                     
B1 = A3      <- this copy                                                                                                                                                                      
...                                                                                                                                                                                          
   = op A3   <- more uses                                                                                                                                                                      
                                                                                                                                                                                                 
==>                                                                                                                                                                                             
                                                                                                                                                                                            
B2 = op B0 A2<kill>                                                                                                                                                                            
...                                                                                                                                                                                          
B1 = B2      <- now an identify copy                                                                                                                                                           
...                                                                                                                                                                                          
   = op B2   <- more uses

This speeds up FreeBench/neural by 29%, Olden/bh by 12%, oopack_v1p8 by 53%.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47046 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 03:01:43 +00:00
Dan Gohman
6f0d024a53 Rename MRegisterInfo to TargetRegisterInfo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46930 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-10 18:45:23 +00:00
Chris Lattner
4ee451de36 Remove attribution from file headers, per discussion on llvmdev.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45418 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-29 20:36:04 +00:00
Dan Gohman
ded2b0d0fb Add explicit keywords, and fix a minor typo that they uncovered.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@45034 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-14 15:41:34 +00:00
Evan Cheng
22f07ffd27 Switch over to MachineLoopInfo.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@44838 91177308-0d34-0410-b5e6-96231b3b80d8
2007-12-11 02:09:15 +00:00
Evan Cheng
8fc9a10221 First step towards moving the coalescer to priority_queue based machinery.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43764 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-06 08:52:21 +00:00
Evan Cheng
a461c4d75b Move SimpleRegisterCoalescing.h to lib/CodeGen since there is now a common
register coalescer interface: RegisterCoalescing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@43714 91177308-0d34-0410-b5e6-96231b3b80d8
2007-11-05 17:41:38 +00:00