18e816f356
Switch to a very conservative heuristic for determining when loop-unswitching
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will be profitable. This is mainly to remove some cases where excessive
unswitching would result in long compile times and/or huge generated code.
Once someone comes up with a better heuristic that avoids these cases, this
should be switched out.
llvm-svn: 28962
2006-06-28 17:47:50 +00:00
0a2e11260e
Don't unswitch really large loops even if they are mostly filled with empty
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blocks.
llvm-svn: 28959
2006-06-28 16:38:55 +00:00
bb3ae5eb8f
Fix for 2006-06-27-DeadSwitchCase.ll
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Be more careful when updating Phi nodes after eliminating dead switch cases. Fix
proposed by Chris.
llvm-svn: 28947
2006-06-27 22:26:09 +00:00
f52351e50f
Make LoopUnswitch able to unswitch loops with live-out values by taking advantage
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of LCSSA. This results several times the number of unswitchings occurring on
tests such and timberwolfmc, unix-tbl, and ldecod.
llvm-svn: 28912
2006-06-26 07:44:36 +00:00
0c4f5a655a
Fix Transforms/LoopUnswitch/2006-06-13-SingleEntryPHI.ll, a loop unswitch
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bug exposed by the recent lcssa work.
llvm-svn: 28779
2006-06-14 04:46:17 +00:00
fd0a3d6e5c
Reapply my 6/9 changes. The bug Evan saw no longer occurs.
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llvm-svn: 28759
2006-06-12 21:49:21 +00:00
1b6e310e6f
Back out Owen's 6/9 changes. They broke MultiSource/Benchmarks/Prolangs-C/bison (and perhaps others).
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llvm-svn: 28747
2006-06-11 09:32:57 +00:00
b1dc1d44f8
Add LCSSA as a requirement for LoopUnswitch, and assert that LoopUnswitch preserves
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LCSSA.
llvm-svn: 28739
2006-06-09 18:40:32 +00:00
5821a6a17a
add the actual cost to the debug info
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llvm-svn: 27051
2006-03-24 07:14:00 +00:00
e5521db5bc
Fix Regression/Transforms/LoopUnswitch/2006-02-22-UnswitchCrash.ll, which
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caused SPASS to fail building last night.
We can't trivially unswitch a loop if the exit block has phi nodes in it,
because we don't know which predecessor to use.
llvm-svn: 26320
2006-02-22 23:55:00 +00:00
8a5a324dac
Add some comments, simplify some code, and fix a bug that caused rewriting
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to rewrite with the wrong value.
llvm-svn: 26311
2006-02-22 06:37:14 +00:00
c2e3a7a4ce
improved support for branch folding, still not enabled.
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llvm-svn: 26289
2006-02-18 07:57:38 +00:00
19fa8ac938
Implement deletion of dead blocks, currently disabled.
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llvm-svn: 26285
2006-02-18 02:42:34 +00:00
cb853de534
a previous patch completely disabled trivial unswitching, this fixees it.
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Thanks to nate for pointing this out :)
llvm-svn: 26280
2006-02-18 01:32:04 +00:00
29f771ba21
initial trivial support for folding branches that have now-constant destinations.
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llvm-svn: 26279
2006-02-18 01:27:45 +00:00
8e44ff50b0
When unswitching a loop, make sure to update loop info with exit blocks in
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the right loop.
llvm-svn: 26277
2006-02-18 00:55:32 +00:00
baddba41c7
Fix loops where the header has an exit, fixing a loop-unswitch crash on crafty
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llvm-svn: 26258
2006-02-17 06:39:56 +00:00
6fd136239b
start of some new simplification code, not thoroughly tested, use at your own
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risk :)
llvm-svn: 26248
2006-02-17 00:31:07 +00:00
fa335f6083
Change SplitBlock to increment a BasicBlock::iterator, not an Instruction*. Apparently they do different things :)
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This fixes a testcase that nate reduced from spass.
Also included are a couple minor code changes that don't affect the generated
code at all.
llvm-svn: 26235
2006-02-16 19:36:22 +00:00
55f63f1b53
Fix VC++ warning.
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llvm-svn: 26228
2006-02-16 04:07:37 +00:00
ff42e81028
fix a bug where we unswitched the wrong way
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llvm-svn: 26225
2006-02-16 01:24:41 +00:00
fdff0bb43e
Implement trivial unswitching for switch stmts. This allows us to trivial
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unswitch this loop on 2 before sweating to unswitch on 1/3.
void test4(int N, int i, int C, int*P, int*Q) {
int j;
for (j = 0; j < N; ++j) {
switch (C) { // general unswitching.
default: P[i+j] = 0; break;
case 1: Q[i+j] = 0; break;
case 3: P[i+j] = Q[i+j]; break;
case 2: break; // TRIVIAL UNSWITCH on C==2
}
}
}
llvm-svn: 26223
2006-02-15 22:52:05 +00:00
e5cb76d744
make "trivial" unswitching significantly more general. It can now handle
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this for example:
for (j = 0; j < N; ++j) { // trivial unswitch
if (C)
P[i+j] = 0;
}
turning it into the obvious code without bothering to duplicate an empty loop.
llvm-svn: 26220
2006-02-15 22:03:36 +00:00
65152d80ec
Checking the wrong value. This caused us to emit silly code like
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Y = seteq bool X, true
instead of just using X :)
llvm-svn: 26215
2006-02-15 19:05:52 +00:00
01db04efb0
more refactoring, no functionality change.
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llvm-svn: 26194
2006-02-15 01:44:42 +00:00
b0cbe7106e
pull some code out into a function
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llvm-svn: 26191
2006-02-15 00:07:43 +00:00
0b8ec1a132
Use statistics to keep track of what flavors of loops we are unswitching
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llvm-svn: 26157
2006-02-14 01:01:41 +00:00
fbadd7e1ee
implement unswitching of loops with switch stmts and selects in them
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llvm-svn: 26114
2006-02-11 00:43:37 +00:00
f1b151684d
Update PHI nodes in successors of exit blocks.
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llvm-svn: 26113
2006-02-10 23:26:14 +00:00
fe4151efe7
Reform the unswitching code in terms of edge splitting, not block splitting.
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llvm-svn: 26112
2006-02-10 23:16:39 +00:00
ec6b40a093
Fix a case where UnswitchTrivialCondition broke critical edges with
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phi's in the successors
llvm-svn: 26108
2006-02-10 19:08:15 +00:00
6e263155a6
add some notes, move some code around. Implement unswitching of loops
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with branches on partially invariant computations.
llvm-svn: 26104
2006-02-10 02:30:37 +00:00
4935417a84
Move code around to be more logical, no functionality change.
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llvm-svn: 26103
2006-02-10 02:01:22 +00:00
3fc3148b85
When unswitching a trivial loop, do admit we are doing it! :)
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llvm-svn: 26102
2006-02-10 01:36:35 +00:00
ed7a67b0de
Implement unconditional unswitching of 'trivial' loops, those loops that contain
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branches in their entry block that control whether or not the loop is a noop or not.
llvm-svn: 26101
2006-02-10 01:24:09 +00:00
4f0e66df6a
Simplify control flow a bit, note that unswitch preserves canonical loop form
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llvm-svn: 26098
2006-02-09 22:15:42 +00:00
8976219850
Make the threshold a parameter
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llvm-svn: 26093
2006-02-09 20:15:48 +00:00
2826e0511b
Simplify the loop-unswitch pass, by not even trying to unswitch loops with
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uses of loop values outside the loop. We need loop-closed SSA form to do
this right, or to use SSA rewriting if we really care.
llvm-svn: 26089
2006-02-09 19:14:52 +00:00
c597b8a55e
Make iostream #inclusion explicit
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llvm-svn: 25514
2006-01-22 23:32:06 +00:00
b1c9317bb4
Remove trailing whitespace
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llvm-svn: 21427
2005-04-21 23:48:37 +00:00
eca0d0f2da
Put createLoopUnswitchPass() into proper namespace
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llvm-svn: 19306
2005-01-06 05:47:18 +00:00
a5c04ee50f
Fixes to make LLVM compile with vc7.1.
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Patch contributed by Paolo Invernizzi!
llvm-svn: 16152
2004-09-03 18:19:51 +00:00
7c16caa336
Changes For Bug 352
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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
f48f777d4c
Initial checkin of a simple loop unswitching pass. It still needs work,
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but it's a start, and seems to do it's basic job.
llvm-svn: 13068
2004-04-19 18:07:02 +00:00
Owen Anderson