b28a17c346
Rewrite a loop to avoid using iterators pointing to
...
elements that have been erased. Based on a patch
by Nicolas Capens.
llvm-svn: 51485
2008-05-23 17:19:02 +00:00
d78c400b5b
Clean up the use of static and anonymous namespaces. This turned up
...
several things that were neither in an anonymous namespace nor static
but not intended to be global.
llvm-svn: 51017
2008-05-13 00:00:25 +00:00
9d29283fc7
Be more aggressive about tail-merging small blocks
...
if those blocks consist entirely of common instructions;
merging will not add an extra branch in this case.
llvm-svn: 51006
2008-05-12 22:53:12 +00:00
c4c4d8e1f7
Further rework of tail merge algorithm. Not quite
...
semantically identical, but little difference in
either results or execution speed; but it's much
easier to read, at least IMO.
llvm-svn: 50999
2008-05-12 20:33:57 +00:00
66da8b5334
Remove an evil vector bool. Cosmetic refactoring,
...
no functional change.
llvm-svn: 50921
2008-05-09 23:28:24 +00:00
cff7df201c
Rewrite tail merging algorithm to handle the
...
case where there are multiple blocks with a large
number of common tail instructions more efficiently
(compile time optimization).
llvm-svn: 50916
2008-05-09 21:24:35 +00:00
6a2da37c0e
Make several variable declarations static.
...
llvm-svn: 50696
2008-05-06 01:53:16 +00:00
9d339849ee
Teach branch folding pass about implicit_def instructions. Unfortunately we can't just eliminate them since register scavenger expects every register use to be defined. However, we can delete them when there are no intra-block uses. Carefully removing some implicit def's which enable more blocks to be optimized away.
...
llvm-svn: 49461
2008-04-10 02:32:10 +00:00
c799065cc3
Add a quick and dirty "loop aligner pass". x86 uses it to align its loops to 16-byte boundaries.
...
llvm-svn: 47703
2008-02-28 00:43:03 +00:00
3266ff9a6f
PR1909: Tail merging pass ran wild. It makes no sense to merge blocks in order to save a single instruction since a branch will be inserted for each BB.
...
llvm-svn: 47301
2008-02-19 02:09:37 +00:00
3a4be0fdef
Rename MRegisterInfo to TargetRegisterInfo.
...
llvm-svn: 46930
2008-02-10 18:45:23 +00:00
70de4cb1cd
Use empty() instead of comparing size() with zero.
...
llvm-svn: 46514
2008-01-29 13:02:09 +00:00
03ad885039
rename TargetInstrDescriptor -> TargetInstrDesc.
...
Make MachineInstr::getDesc return a reference instead
of a pointer, since it can never be null.
llvm-svn: 45695
2008-01-07 07:27:27 +00:00
a98c679de0
Rename MachineInstr::getInstrDescriptor -> getDesc(), which reflects
...
that it is cheap and efficient to get.
Move a variety of predicates from TargetInstrInfo into
TargetInstrDescriptor, which makes it much easier to query a predicate
when you don't have TII around. Now you can use MI->getDesc()->isBranch()
instead of going through TII, and this is much more efficient anyway. Not
all of the predicates have been moved over yet.
Update old code that used MI->getInstrDescriptor()->Flags to use the
new predicates in many places.
llvm-svn: 45674
2008-01-07 01:56:04 +00:00
a4ce4f6987
rename isLoad -> isSimpleLoad due to evan's desire to have such a predicate.
...
llvm-svn: 45667
2008-01-06 23:38:27 +00:00
10324d0175
rename isStore -> mayStore to more accurately reflect what it captures.
...
llvm-svn: 45656
2008-01-06 08:36:04 +00:00
a5bb370aa4
Add new shorter predicates for testing machine operands for various types:
...
e.g. MO.isMBB() instead of MO.isMachineBasicBlock(). I don't plan on
switching everything over, so new clients should just start using the
shorter names.
Remove old long accessors, switching everything over to use the short
accessor: getMachineBasicBlock() -> getMBB(),
getConstantPoolIndex() -> getIndex(), setMachineBasicBlock -> setMBB(), etc.
llvm-svn: 45464
2007-12-30 23:10:15 +00:00
f3ebc3f3d2
Remove attribution from file headers, per discussion on llvmdev.
...
llvm-svn: 45418
2007-12-29 20:36:04 +00:00
d202e03fe5
Improve branch folding by recgonizing that explict successor relationships impact the value of fall-through choices.
...
llvm-svn: 44785
2007-12-10 07:24:06 +00:00
f73340efb9
Changed XXX to FIXME, and added comment to the README file
...
llvm-svn: 43359
2007-10-25 19:49:32 +00:00
5f7ed00d44
Added comment explaining why we are doing this check.
...
llvm-svn: 43353
2007-10-25 18:23:45 +00:00
ac5c93040f
Don't branch fold inline asm statements.
...
llvm-svn: 43191
2007-10-19 21:09:55 +00:00
5f6a9da530
More explicit keywords.
...
llvm-svn: 40757
2007-08-02 21:21:54 +00:00
d5ea194b6c
If assertions are not enabled, we should return False here.
...
llvm-svn: 38535
2007-07-11 08:47:55 +00:00
d9034f717a
Make this work with GLIBCXX_DEBUG.
...
llvm-svn: 38516
2007-07-10 22:00:30 +00:00
451d1a6ecd
Fix misue of iterator pointing to erased object. Uncovered by
...
_GLIBCXX_DEBUG.
llvm-svn: 37793
2007-06-29 02:45:24 +00:00
2afd702c20
Move CorrectExtraCFGEdges() from BranchFolding.cpp to a MachineBasicBlock method.
...
llvm-svn: 37633
2007-06-18 22:43:58 +00:00
86798e5e11
Make throttle a hidden parameter, per review.
...
llvm-svn: 37511
2007-06-08 01:08:52 +00:00
52fcf022f7
Throttle tail merging; handling blocks with large numbers of predecessors
...
is too slow.
llvm-svn: 37509
2007-06-08 00:34:27 +00:00
0558dda319
Tail merging wasn't working for predecessors of landing pads. PR 1496.
...
llvm-svn: 37427
2007-06-04 23:52:54 +00:00
df75785594
Move ReplaceUsesOfBlockWith() out of BranchFolding into a MachineBasicBlock general facility.
...
llvm-svn: 37408
2007-06-04 06:44:01 +00:00
6e7cdce773
Fix CorrectExtraCFGEdges to allow for multiple LandingPad targets.
...
llvm-svn: 37394
2007-06-02 00:08:15 +00:00
3c0a13762d
Implement smarter algorithm for choosing which blocks to tail-merge.
...
See test/CodeGen/X86/test-pic-jtbl.ll for a case where it works well;
shaves another 10K off our favorite benchmark. I was hesitant about
this because of compile speed, but seems to do OK on a bootstrap.
llvm-svn: 37392
2007-06-01 23:02:45 +00:00
1a401e68a8
Arrange for only 1 of multiple branches to landing pad to be kept.
...
Do not remove empty landing pads (EH table needs to be updated)
llvm-svn: 37375
2007-05-31 21:54:00 +00:00
d14ad078c6
Changed per review comment.
...
llvm-svn: 37355
2007-05-30 00:32:01 +00:00
a69ebdbebc
Make stable_sort in tail merging actually be stable (it never was, but didn't
...
matter until my last change). Reenable tail merging by default.
llvm-svn: 37354
2007-05-29 23:47:50 +00:00
1409b6a59b
Blocks that cond-br and uncond-br/fallthrough to same block should have
...
only one successor.
llvm-svn: 37324
2007-05-24 18:31:55 +00:00
1af8c870c7
Fix for PR1444: do not create two successors to the same block.
...
Temporarily, this breaks CodeGen/Generic/2006-02-12-InsertLibraryCall.ll
by exposing an unrelated latent problem; working on that.
llvm-svn: 37323
2007-05-24 17:39:32 +00:00
f4a77d2481
Two tail merging improvements:
...
When considering blocks with more than 2 predecessors, merge the block with
the largest number of matching insns, rather than the first block found.
Considering that 1 matching insn is enough to show a win for candidates that
already end with a branch.
llvm-svn: 37315
2007-05-23 21:07:20 +00:00
82810c8a13
Make tail merging the default, except on powerPC. There was no prior art
...
for a target-dependent default with a command-line override; this way
should be generally usable.
llvm-svn: 37285
2007-05-22 17:14:46 +00:00
f8956178af
Remove some unneeded branches. (spotted by Evan, thanks)
...
llvm-svn: 37198
2007-05-18 01:28:58 +00:00
420a85d0cf
Remove extra CFG edges before doing these passes; it makes them happier.
...
llvm-svn: 37089
2007-05-15 21:19:17 +00:00
cc8f571bc8
Do not generate branches to entry block. This fixes several test suite
...
failures on PPC (can happen only when prologue code is null)
llvm-svn: 36979
2007-05-10 23:59:23 +00:00
6e16d09252
Make tail merging handle many more cases (all it can, I think).
...
llvm-svn: 36966
2007-05-10 01:01:49 +00:00
9a25b3afcd
Handle some non-exit blocks in tail merging.
...
llvm-svn: 36907
2007-05-07 20:57:21 +00:00
8c78a0bff0
Drop 'const'
...
llvm-svn: 36662
2007-05-03 01:11:54 +00:00
e95c6ad802
Use 'static const char' instead of 'static const int'.
...
Due to darwin gcc bug, one version of darwin linker coalesces
static const int, which defauts PassID based pass identification.
llvm-svn: 36652
2007-05-02 21:39:20 +00:00
09f162ca6a
Do not use typeinfo to identify pass in pass manager.
...
llvm-svn: 36632
2007-05-01 21:15:47 +00:00
4dbbace4ff
Fix PR1228 and CodeGen/Generic/2007-04-30-LandingPadBranchFolding.ll
...
llvm-svn: 36602
2007-04-30 23:35:00 +00:00
d05a1a2ade
maintain LiveIn when splitting blocks (register scavenging needs it)
...
llvm-svn: 35226
2007-03-20 21:35:06 +00:00
9df1a1d8d8
Remove isAccessable.
...
llvm-svn: 34497
2007-02-22 16:39:03 +00:00
2dc5245c4a
Make branch folding behave in the presence of landing pads.
...
llvm-svn: 34476
2007-02-21 22:42:20 +00:00
12920dda9e
Fixes PR 1200
...
llvm-svn: 34359
2007-02-17 00:44:34 +00:00
c56315c2b5
Change the MachineDebugInfo to MachineModuleInfo to better reflect usage
...
for debugging and exception handling.
llvm-svn: 33550
2007-01-26 21:22:28 +00:00
f9e5445ed4
Make LABEL a builtin opcode.
...
llvm-svn: 33537
2007-01-26 14:34:52 +00:00
aee775a6b7
Eliminate static ctors from Statistics
...
llvm-svn: 32698
2006-12-19 22:41:21 +00:00
700b873130
Detemplatize the Statistic class. The only type it is instantiated with
...
is 'unsigned'.
llvm-svn: 32279
2006-12-06 17:46:33 +00:00
ea017f66f7
Don't transform in another bad case: if the block is empty, it should be
...
simplified before we do this xform so that our cost model is accurate.
llvm-svn: 31864
2006-11-18 22:25:39 +00:00
56ec81ff73
Fix another case we *don't* want to do this xform.
...
llvm-svn: 31861
2006-11-18 21:56:39 +00:00
7acdc17fe4
make the previous change more aggressive, moving any block with no fallthrough.
...
This speeds up yacr2 by 7% on a core2.
llvm-svn: 31856
2006-11-18 21:30:35 +00:00
47ce26158f
Minor code layout tweak: if we have something like this:
...
if (cond) goto BB2
BB1:
...
return;
BB2:
...
Move BB1 to the end of the function so that the code falls through in the
non-return case. This has the effect of moving assert (and other no-return
call) bodies and return blocks out of loops.
llvm-svn: 31855
2006-11-18 20:47:54 +00:00
bf3b57f221
optimize single MBB loops better. In particular, produce:
...
LBB1_57: #bb207.i
movl 72(%esp), %ecx
movb (%ecx,%eax), %cl
movl 80(%esp), %edx
movb %cl, 1(%edx,%eax)
incl %eax
cmpl $143, %eax
jne LBB1_57 #bb207.i
jmp LBB1_64 #cond_next255.i
intead of:
LBB1_57: #bb207.i
movl 72(%esp), %ecx
movb (%ecx,%eax), %cl
movl 80(%esp), %edx
movb %cl, 1(%edx,%eax)
incl %eax
cmpl $143, %eax
je LBB1_64 #cond_next255.i
jmp LBB1_57 #bb207.i
This eliminates a branch per iteration of the loop. This hurted PPC
particularly, because the extra branch meant another dispatch group for each
iteration of the loop.
llvm-svn: 31530
2006-11-08 01:03:21 +00:00
7d6f3db3e2
Unbreak VC++ build.
...
llvm-svn: 31464
2006-11-05 19:31:28 +00:00
de46e48420
For PR786:
...
Turn on -Wunused and -Wno-unused-parameter. Clean up most of the resulting
fall out by removing unused variables. Remaining warnings have to do with
unused functions (I didn't want to delete code without review) and unused
variables in generated code. Maintainers should clean up the remaining
issues when they see them. All changes pass DejaGnu tests and Olden.
llvm-svn: 31380
2006-11-02 20:25:50 +00:00
7cee6ddcd8
give branch folding a simple heuristic to decide which block to split so that
...
it inserts an uncond branch where it is less likely to cause a problem. This
fixes some perf issues on ppc.
llvm-svn: 31354
2006-11-01 19:36:29 +00:00
f505a5a063
make tail merging more aggressive. If two blocks share a common tail, but the
...
tail is not an entire block for either of them, pick one, split it, then
merge the common part.
llvm-svn: 31336
2006-11-01 01:16:12 +00:00
3ac71b31f0
enable branch folding with an option
...
llvm-svn: 31335
2006-11-01 00:38:31 +00:00
504eeda365
Make CanFallThrough more intelligent (so it can handle blocks with (e.g.) no
...
successors), and make island block movement more general.
This compiles CodeGen/X86/2006-04-27-ISelFoldingBug.ll to:
_loadAndRLEsource_no_exit_2E_1_label_2E_0:
subl $8, %esp
movl %esi, 4(%esp)
movl %ebx, (%esp)
movl 16(%esp), %eax
movl 12(%esp), %ecx
LBB1_3: #label.0
movl _last, %edx
movl %edx, %esi
incl %esi
movl %esi, _last
movl %ecx, %ebx
# TRUNCATE movb %bl, %bl
movl _block, %esi
movb %bl, 1(%esi,%edx)
cmpl %eax, _last
jge LBB1_2 #codeRepl5.exitStub
LBB1_4: #label.0
cmpl $257, %ecx
je LBB1_2 #codeRepl5.exitStub
LBB1_1: #label.0.no_exit.1_crit_edge.exitStub
movl $1, %eax
movl (%esp), %ebx
movl 4(%esp), %esi
addl $8, %esp
ret
LBB1_2: #codeRepl5.exitStub
xorl %eax, %eax
movl (%esp), %ebx
movl 4(%esp), %esi
addl $8, %esp
ret
instead of:
_loadAndRLEsource_no_exit_2E_1_label_2E_0:
subl $8, %esp
movl %esi, 4(%esp)
movl %ebx, (%esp)
movl 16(%esp), %eax
movl 12(%esp), %ecx
jmp LBB1_3 #label.0
LBB1_1: #label.0.no_exit.1_crit_edge.exitStub
movl $1, %eax
movl (%esp), %ebx
movl 4(%esp), %esi
addl $8, %esp
ret
LBB1_2: #codeRepl5.exitStub
xorl %eax, %eax
movl (%esp), %ebx
movl 4(%esp), %esi
addl $8, %esp
ret
LBB1_3: #label.0
movl _last, %edx
movl %edx, %esi
incl %esi
movl %esi, _last
movl %ecx, %ebx
# TRUNCATE movb %bl, %bl
movl _block, %esi
movb %bl, 1(%esi,%edx)
cmpl %eax, _last
jge LBB1_2 #codeRepl5.exitStub
LBB1_4: #label.0
cmpl $257, %ecx
jne LBB1_1 #label.0.no_exit.1_crit_edge.exitStub
jmp LBB1_2 #codeRepl5.exitStub
... which is much better layout :)
llvm-svn: 31282
2006-10-29 21:05:41 +00:00
c07657f59b
Teach branch folding to fold identical jump tables together and to delete
...
jump tables that are dead.
llvm-svn: 31273
2006-10-28 18:34:47 +00:00
af8383806b
improve deletion of blocks that just contain branches by knowing that
...
the pred block doesn't fall through into them if it's a jumptable.
llvm-svn: 31263
2006-10-28 17:32:47 +00:00
0d4479b77d
simplify code
...
llvm-svn: 31188
2006-10-25 22:21:37 +00:00
9feb308d51
turn off tail merging for now
...
llvm-svn: 31180
2006-10-25 18:08:50 +00:00
ceb51d8427
move single basic blocks that are neither fallen into nor fall out of into
...
a place more useful. In particular, if we can put them in a place where code
will be able to fall into it, do so. Otherwise, put it in a place it can fall
through into a successor. Otherwise, if preventing a fallthrough, move to the
end of the function, out of the way.
This deletes several hundred unconditional branches from spass.
llvm-svn: 31149
2006-10-24 01:12:32 +00:00
ebdb1d6724
Enable tail merging by default.
...
llvm-svn: 31140
2006-10-23 22:10:12 +00:00
5e1a34032b
More complete solution to deleting blocks and debug info.
...
llvm-svn: 31129
2006-10-23 14:56:37 +00:00
9f5a129543
don't break infinite loops
...
llvm-svn: 31102
2006-10-21 06:11:43 +00:00
28f17f45be
Use branch reversal to do stuff like this:
...
call L_strcmp$stub
testl %eax, %eax
- jne LBB26_208 #cond_true6020
- jmp LBB26_227 #bb7119
+ je LBB26_227 #bb7119
LBB26_208: #cond_true6020
movl $l31_str14, 4(%esp)
testl %eax, %eax
- jne LBB26_704 #cond_true13042
- jmp LBB26_713 #bb13151
+ je LBB26_713 #bb13151
LBB26_704: #cond_true13042
movl $_str52, 4(%esp)
cmpl 76(%ecx), %eax
- jge LBB26_1628 #cond_false63.i.i
- jmp LBB26_1769 #_Z8makeGridP13mrSurfaceListidiidd.exit.i
+ jl LBB26_1769 #_Z8makeGridP13mrSurfaceListidiidd.exit.i
LBB26_1628: #cond_false63.i.i
movl $0, 48964(%esp)
llvm-svn: 31100
2006-10-21 05:54:00 +00:00
3ca52185af
Transform code like:
...
jle FOO
jmp BAR
BAR:
into:
jle FOO
BAR:
... whoa!
llvm-svn: 31098
2006-10-21 05:43:30 +00:00
4fe01c42ca
Three changes:
...
1. Remove a bunch of ifdef'd code.
2. When a block just contains an uncond branch, change all blocks branching
to it to jump to the destination instead.
3. If branch analysis tells us some edges in the machinecfg are not actually
possible, remove them.
#2 triggers a suprisingly large number of times.
llvm-svn: 31094
2006-10-21 05:08:28 +00:00
60c9d4dc76
Add an experimental cross-jumping implementation.
...
This is currently disabled by default and limited in several ways, but does
have a positive effect.
llvm-svn: 31090
2006-10-21 00:47:49 +00:00
73da320e50
Teach the branch folder to update debug info if it removes blocks with line
...
# notes in it.
llvm-svn: 31026
2006-10-17 23:17:27 +00:00
bca3e297fe
Enable deleting branches to successor blocks. With the previous patches,
...
branch folding can now compile stuff like this:
void foo(int W, int X, int Y, int Z) {
if (W & 1) {
for (; X;--X) bar();
} else if (W & 2) {
for (; Y;--Y) bar();
} else if (W & 4) {
for (; Z;--Z) bar();
} else if (W & 8) {
for (; W;--W) bar();
}
if (W) {
bar();
}
}
contrived testcase where loops exits all end up merging together. To have
the loop merges be:
...
cmplw cr0, r30, r27
bne cr0, LBB1_14 ;bb38
LBB1_16: ;cond_next48.loopexit
mr r27, r29
LBB1_20: ;cond_next48
cmplwi cr0, r27, 0
beq cr0, LBB1_22 ;UnifiedReturnBlock
...
instead of:
...
cmplw cr0, r30, r27
bne cr0, LBB1_14 ;bb38
LBB1_16: ;cond_next48.loopexit
mr r27, r29
b LBB1_20 ;cond_next48
LBB1_17: ;cond_next48.loopexit1
b LBB1_20 ;cond_next48
LBB1_18: ;cond_next48.loopexit2
b LBB1_20 ;cond_next48
LBB1_19: ;cond_next48.loopexit3
LBB1_20: ;cond_next48
cmplwi cr0, r27, 0
beq cr0, LBB1_22 ;UnifiedReturnBlock
...
This is CodeGen/PowerPC/branch-opt.ll
llvm-svn: 31006
2006-10-17 18:16:40 +00:00
56c9d2597e
Reenable this pass, fixing the bugs in it.
...
It now correctly deletes unreachable blocks and blocks that are empty.
llvm-svn: 31000
2006-10-17 17:13:52 +00:00
47db29a405
disable this pass for now, it's causing issues
...
llvm-svn: 30951
2006-10-14 00:30:06 +00:00
3218e0eed5
falling off the end of a function is ok with an unreachable instruction.
...
llvm-svn: 30950
2006-10-14 00:21:48 +00:00
3e8e57c771
disable some objectionable code, maybe we can bring this pass to life
...
llvm-svn: 30939
2006-10-13 20:43:10 +00:00
835702a094
Remove trailing whitespace
...
llvm-svn: 21420
2005-04-21 22:36:52 +00:00
7c16caa336
Changes For Bug 352
...
Move include/Config and include/Support into include/llvm/Config,
include/llvm/ADT and include/llvm/Support. From here on out, all LLVM
public header files must be under include/llvm/.
llvm-svn: 16137
2004-09-01 22:55:40 +00:00
356f5a13f5
Dereferencing end() is bad.
...
llvm-svn: 15402
2004-08-01 09:51:42 +00:00
62c979ba07
Make OptimizeBlock take a MachineFunction::iterator instead of a
...
MachineBasicBlock* as a parameter so that nxext() and prior() helper
functions can work naturally on it.
llvm-svn: 15376
2004-07-31 19:24:41 +00:00
0f1c2ed907
Next on a pointer increments the pointer, not an iterator
...
llvm-svn: 15375
2004-07-31 18:40:36 +00:00
2303d3f660
Use next() helper to make code more readable. Use
...
MachineFunction::iterator instead of MachineBasicBlock* to avoid
dereferencing end iterators.
llvm-svn: 15373
2004-07-31 15:14:29 +00:00
1e8d8fd81f
Use MachineFunction::iterator instead of a MachineBasicBlock* because
...
FallThrough maybe == to MF.end().
llvm-svn: 15372
2004-07-31 15:03:52 +00:00
25e48dd2e0
Implement a simple target-independent CFG cleanup pass
...
llvm-svn: 15368
2004-07-31 10:01:27 +00:00
Dale Johannesen