Dale Johannesen
b306dfb861
Changed per review comment.
...
llvm-svn: 37355
2007-05-30 00:32:01 +00:00
Dale Johannesen
1ba04f7d87
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
86fb3a132a
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
ecaa8a0fb4
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
d0b7bbe261
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
fe0fe14411
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
ca37006ffb
Remove some unneeded branches. (spotted by Evan, thanks)
...
llvm-svn: 37198
2007-05-18 01:28:58 +00:00
Dale Johannesen
78ae2e1acb
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
2f28ffc5fd
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
4f9661688c
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
c884abe112
Handle some non-exit blocks in tail merging.
...
llvm-svn: 36907
2007-05-07 20:57:21 +00:00
Devang Patel
cd45427a87
Drop 'const'
...
llvm-svn: 36662
2007-05-03 01:11:54 +00:00
Devang Patel
8ee9065162
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
38a66bc82e
Do not use typeinfo to identify pass in pass manager.
...
llvm-svn: 36632
2007-05-01 21:15:47 +00:00
Chris Lattner
8da69f853c
Fix PR1228 and CodeGen/Generic/2007-04-30-LandingPadBranchFolding.ll
...
llvm-svn: 36602
2007-04-30 23:35:00 +00:00
Dale Johannesen
50a22f6fe6
maintain LiveIn when splitting blocks (register scavenging needs it)
...
llvm-svn: 35226
2007-03-20 21:35:06 +00:00
Jim Laskey
8c79f0f892
Remove isAccessable.
...
llvm-svn: 34497
2007-02-22 16:39:03 +00:00
Jim Laskey
b56b6a7042
Make branch folding behave in the presence of landing pads.
...
llvm-svn: 34476
2007-02-21 22:42:20 +00:00
Dale Johannesen
960bd79f88
Fixes PR 1200
...
llvm-svn: 34359
2007-02-17 00:44:34 +00:00
Jim Laskey
64f4242072
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
23ed7d2625
Make LABEL a builtin opcode.
...
llvm-svn: 33537
2007-01-26 14:34:52 +00:00
Chris Lattner
a975b95adb
Eliminate static ctors from Statistics
...
llvm-svn: 32698
2006-12-19 22:41:21 +00:00
Chris Lattner
a531ce882e
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
4946ae54df
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
b101c06bce
Fix another case we *don't* want to do this xform.
...
llvm-svn: 31861
2006-11-18 21:56:39 +00:00
Chris Lattner
514fc3de5c
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
bddc114cfb
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
f71921c79d
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
e1003da1a2
Unbreak VC++ build.
...
llvm-svn: 31464
2006-11-05 19:31:28 +00:00
Reid Spencer
4bafa71dc1
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
f20968bc33
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
b459c08384
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
5651528580
enable branch folding with an option
...
llvm-svn: 31335
2006-11-01 00:38:31 +00:00
Chris Lattner
e1b2b2127b
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 $257, %ecx
jne LBB1_1 #label.0.no_exit.1_crit_edge.exitStub
jmp LBB1_2 #codeRepl5.exitStub
... which is much better layout :)
llvm-svn: 31282
2006-10-29 21:05:41 +00:00
Chris Lattner
95eed3bd09
Teach branch folding to fold identical jump tables together and to delete
...
jump tables that are dead.
llvm-svn: 31273
2006-10-28 18:34:47 +00:00
Chris Lattner
af9b4c33c2
improve deletion of blocks that just contain branches by knowing that
...
the pred block doesn't fall through into them if it's a jumptable.
llvm-svn: 31263
2006-10-28 17:32:47 +00:00
Chris Lattner
2258020df2
simplify code
...
llvm-svn: 31188
2006-10-25 22:21:37 +00:00
Chris Lattner
df59442a74
turn off tail merging for now
...
llvm-svn: 31180
2006-10-25 18:08:50 +00:00
Chris Lattner
533b205309
move single basic blocks that are neither fallen into nor fall out of into
...
a place more useful. In particular, if we can put them in a place where code
will be able to fall into it, do so. Otherwise, put it in a place it can fall
through into a successor. Otherwise, if preventing a fallthrough, move to the
end of the function, out of the way.
This deletes several hundred unconditional branches from spass.
llvm-svn: 31149
2006-10-24 01:12:32 +00:00
Chris Lattner
0c3fabc9a4
Enable tail merging by default.
...
llvm-svn: 31140
2006-10-23 22:10:12 +00:00
Jim Laskey
f6a28d7161
More complete solution to deleting blocks and debug info.
...
llvm-svn: 31129
2006-10-23 14:56:37 +00:00
Chris Lattner
9e7d74961b
don't break infinite loops
...
llvm-svn: 31102
2006-10-21 06:11:43 +00:00
Chris Lattner
210d322b1f
Use branch reversal to do stuff like this:
...
call L_strcmp$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
cf7f500cfd
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
d4cb8dc857
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
52a4558cf2
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
cd00328fad
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
ef7c2e1dc8
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
8464c7e3e1
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
c4be6ee8b8
disable this pass for now, it's causing issues
...
llvm-svn: 30951
2006-10-14 00:30:06 +00:00