David Greene
451d1a6ecd
Fix misue of iterator pointing to erased object. Uncovered by
...
_GLIBCXX_DEBUG.
llvm-svn: 37793
2007-06-29 02:45:24 +00:00
Evan Cheng
2afd702c20
Move CorrectExtraCFGEdges() from BranchFolding.cpp to a MachineBasicBlock method.
...
llvm-svn: 37633
2007-06-18 22:43:58 +00:00
Dale Johannesen
86798e5e11
Make throttle a hidden parameter, per review.
...
llvm-svn: 37511
2007-06-08 01:08:52 +00:00
Dale Johannesen
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
Dale Johannesen
0558dda319
Tail merging wasn't working for predecessors of landing pads. PR 1496.
...
llvm-svn: 37427
2007-06-04 23:52:54 +00:00
Evan Cheng
df75785594
Move ReplaceUsesOfBlockWith() out of BranchFolding into a MachineBasicBlock general facility.
...
llvm-svn: 37408
2007-06-04 06:44:01 +00:00
Dale Johannesen
6e7cdce773
Fix CorrectExtraCFGEdges to allow for multiple LandingPad targets.
...
llvm-svn: 37394
2007-06-02 00:08:15 +00:00
Dale Johannesen
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
Dale Johannesen
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
Dale Johannesen
d14ad078c6
Changed per review comment.
...
llvm-svn: 37355
2007-05-30 00:32:01 +00:00
Dale Johannesen
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
Dale Johannesen
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
Dale Johannesen
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
Dale Johannesen
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
Dale Johannesen
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
Dale Johannesen
f8956178af
Remove some unneeded branches. (spotted by Evan, thanks)
...
llvm-svn: 37198
2007-05-18 01:28:58 +00:00
Dale Johannesen
420a85d0cf
Remove extra CFG edges before doing these passes; it makes them happier.
...
llvm-svn: 37089
2007-05-15 21:19:17 +00:00
Dale Johannesen
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
Dale Johannesen
6e16d09252
Make tail merging handle many more cases (all it can, I think).
...
llvm-svn: 36966
2007-05-10 01:01:49 +00:00
Dale Johannesen
9a25b3afcd
Handle some non-exit blocks in tail merging.
...
llvm-svn: 36907
2007-05-07 20:57:21 +00:00
Devang Patel
8c78a0bff0
Drop 'const'
...
llvm-svn: 36662
2007-05-03 01:11:54 +00:00
Devang Patel
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
Devang Patel
09f162ca6a
Do not use typeinfo to identify pass in pass manager.
...
llvm-svn: 36632
2007-05-01 21:15:47 +00:00
Chris Lattner
4dbbace4ff
Fix PR1228 and CodeGen/Generic/2007-04-30-LandingPadBranchFolding.ll
...
llvm-svn: 36602
2007-04-30 23:35:00 +00:00
Dale Johannesen
d05a1a2ade
maintain LiveIn when splitting blocks (register scavenging needs it)
...
llvm-svn: 35226
2007-03-20 21:35:06 +00:00
Jim Laskey
9df1a1d8d8
Remove isAccessable.
...
llvm-svn: 34497
2007-02-22 16:39:03 +00:00
Jim Laskey
2dc5245c4a
Make branch folding behave in the presence of landing pads.
...
llvm-svn: 34476
2007-02-21 22:42:20 +00:00
Dale Johannesen
12920dda9e
Fixes PR 1200
...
llvm-svn: 34359
2007-02-17 00:44:34 +00:00
Jim Laskey
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
Jim Laskey
f9e5445ed4
Make LABEL a builtin opcode.
...
llvm-svn: 33537
2007-01-26 14:34:52 +00:00
Chris Lattner
aee775a6b7
Eliminate static ctors from Statistics
...
llvm-svn: 32698
2006-12-19 22:41:21 +00:00
Chris Lattner
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
Chris Lattner
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
Chris Lattner
56ec81ff73
Fix another case we *don't* want to do this xform.
...
llvm-svn: 31861
2006-11-18 21:56:39 +00:00
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Jeff Cohen
7d6f3db3e2
Unbreak VC++ build.
...
llvm-svn: 31464
2006-11-05 19:31:28 +00:00
Reid Spencer
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
3ac71b31f0
enable branch folding with an option
...
llvm-svn: 31335
2006-11-01 00:38:31 +00:00
Chris Lattner
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 $257, %ecx
jne LBB1_1 #label.0.no_exit.1_crit_edge.exitStub
jmp LBB1_2 #codeRepl5.exitStub
... which is much better layout :)
llvm-svn: 31282
2006-10-29 21:05:41 +00:00
Chris Lattner
c07657f59b
Teach branch folding to fold identical jump tables together and to delete
...
jump tables that are dead.
llvm-svn: 31273
2006-10-28 18:34:47 +00:00
Chris Lattner
af8383806b
improve deletion of blocks that just contain branches by knowing that
...
the pred block doesn't fall through into them if it's a jumptable.
llvm-svn: 31263
2006-10-28 17:32:47 +00:00
Chris Lattner
0d4479b77d
simplify code
...
llvm-svn: 31188
2006-10-25 22:21:37 +00:00
Chris Lattner
9feb308d51
turn off tail merging for now
...
llvm-svn: 31180
2006-10-25 18:08:50 +00:00
Chris Lattner
ceb51d8427
move single basic blocks that are neither fallen into nor fall out of into
...
a place more useful. In particular, if we can put them in a place where code
will be able to fall into it, do so. Otherwise, put it in a place it can fall
through into a successor. Otherwise, if preventing a fallthrough, move to the
end of the function, out of the way.
This deletes several hundred unconditional branches from spass.
llvm-svn: 31149
2006-10-24 01:12:32 +00:00
Chris Lattner
ebdb1d6724
Enable tail merging by default.
...
llvm-svn: 31140
2006-10-23 22:10:12 +00:00
Jim Laskey
5e1a34032b
More complete solution to deleting blocks and debug info.
...
llvm-svn: 31129
2006-10-23 14:56:37 +00:00
Chris Lattner
9f5a129543
don't break infinite loops
...
llvm-svn: 31102
2006-10-21 06:11:43 +00:00
Chris Lattner
28f17f45be
Use branch reversal to do stuff like this:
...
call L_strcmp$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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
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
Chris Lattner
47db29a405
disable this pass for now, it's causing issues
...
llvm-svn: 30951
2006-10-14 00:30:06 +00:00
Chris Lattner
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
Chris Lattner
3e8e57c771
disable some objectionable code, maybe we can bring this pass to life
...
llvm-svn: 30939
2006-10-13 20:43:10 +00:00
Misha Brukman
835702a094
Remove trailing whitespace
...
llvm-svn: 21420
2005-04-21 22:36:52 +00:00
Reid Spencer
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
Chris Lattner
356f5a13f5
Dereferencing end() is bad.
...
llvm-svn: 15402
2004-08-01 09:51:42 +00:00
Alkis Evlogimenos
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
Chris Lattner
0f1c2ed907
Next on a pointer increments the pointer, not an iterator
...
llvm-svn: 15375
2004-07-31 18:40:36 +00:00
Alkis Evlogimenos
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
Alkis Evlogimenos
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
Chris Lattner
25e48dd2e0
Implement a simple target-independent CFG cleanup pass
...
llvm-svn: 15368
2004-07-31 10:01:27 +00:00