Commit Graph

35 Commits

Author SHA1 Message Date
Chris Lattner
f8bf116f80 Fix Regression/Transforms/LoopUnswitch/2006-02-22-UnswitchCrash.ll, which
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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26320 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-22 23:55:00 +00:00
Chris Lattner
bd28e3f8ef Add some comments, simplify some code, and fix a bug that caused rewriting
to rewrite with the wrong value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26311 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-22 06:37:14 +00:00
Chris Lattner
a6fc94b71e improved support for branch folding, still not enabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26289 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-18 07:57:38 +00:00
Chris Lattner
db41024a85 Implement deletion of dead blocks, currently disabled.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26285 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-18 02:42:34 +00:00
Chris Lattner
caf4893536 a previous patch completely disabled trivial unswitching, this fixees it.
Thanks to nate for pointing this out :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26280 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-18 01:32:04 +00:00
Chris Lattner
f4412d890d initial trivial support for folding branches that have now-constant destinations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26279 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-18 01:27:45 +00:00
Chris Lattner
25cae0fd1c When unswitching a loop, make sure to update loop info with exit blocks in
the right loop.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26277 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-18 00:55:32 +00:00
Chris Lattner
0017d480cc Fix loops where the header has an exit, fixing a loop-unswitch crash on crafty
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26258 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-17 06:39:56 +00:00
Chris Lattner
52221f7b16 start of some new simplification code, not thoroughly tested, use at your own
risk :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26248 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-17 00:31:07 +00:00
Chris Lattner
10cd9bbde7 Change SplitBlock to increment a BasicBlock::iterator, not an Instruction*. Apparently they do different things :)
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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26235 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-16 19:36:22 +00:00
Jeff Cohen
21c107ab0f Fix VC++ warning.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26228 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-16 04:07:37 +00:00
Chris Lattner
f17c42d409 fix a bug where we unswitched the wrong way
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26225 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-16 01:24:41 +00:00
Chris Lattner
a48654ef23 Implement trivial unswitching for switch stmts. This allows us to trivial
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
    }
  }
}


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26223 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-15 22:52:05 +00:00
Chris Lattner
4e1323969c make "trivial" unswitching significantly more general. It can now handle
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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26220 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-15 22:03:36 +00:00
Chris Lattner
3fdde110eb Checking the wrong value. This caused us to emit silly code like
Y = seteq bool X, true
instead of just using X :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26215 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-15 19:05:52 +00:00
Chris Lattner
6d9d13d2e4 more refactoring, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26194 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-15 01:44:42 +00:00
Chris Lattner
fed5d9dbd3 pull some code out into a function
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26191 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-15 00:07:43 +00:00
Chris Lattner
3dd4c402de Use statistics to keep track of what flavors of loops we are unswitching
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26157 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-14 01:01:41 +00:00
Chris Lattner
c23580969f implement unswitching of loops with switch stmts and selects in them
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26114 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-11 00:43:37 +00:00
Chris Lattner
e825593bf2 Update PHI nodes in successors of exit blocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26113 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-10 23:26:14 +00:00
Chris Lattner
b2bc315eac Reform the unswitching code in terms of edge splitting, not block splitting.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26112 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-10 23:16:39 +00:00
Chris Lattner
81be2e961b Fix a case where UnswitchTrivialCondition broke critical edges with
phi's in the successors


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26108 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-10 19:08:15 +00:00
Chris Lattner
708e1a5c9c add some notes, move some code around. Implement unswitching of loops
with branches on partially invariant computations.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26104 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-10 02:30:37 +00:00
Chris Lattner
dd3ee6d086 Move code around to be more logical, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26103 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-10 02:01:22 +00:00
Chris Lattner
4d1ca946ea When unswitching a trivial loop, do admit we are doing it! :)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26102 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-10 01:36:35 +00:00
Chris Lattner
4c41d49a92 Implement unconditional unswitching of 'trivial' loops, those loops that contain
branches in their entry block that control whether or not the loop is a noop or not.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26101 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-10 01:24:09 +00:00
Chris Lattner
f4f5f4e56f Simplify control flow a bit, note that unswitch preserves canonical loop form
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26098 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-09 22:15:42 +00:00
Chris Lattner
e487abbfbf Make the threshold a parameter
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26093 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-09 20:15:48 +00:00
Chris Lattner
2f4b898e8c Simplify the loop-unswitch pass, by not even trying to unswitch loops with
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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@26089 91177308-0d34-0410-b5e6-96231b3b80d8
2006-02-09 19:14:52 +00:00
Chris Lattner
dac58ad983 Make iostream #inclusion explicit
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@25514 91177308-0d34-0410-b5e6-96231b3b80d8
2006-01-22 23:32:06 +00:00
Misha Brukman
fd93908ae8 Remove trailing whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@21427 91177308-0d34-0410-b5e6-96231b3b80d8
2005-04-21 23:48:37 +00:00
Jeff Cohen
f5e58f8f43 Put createLoopUnswitchPass() into proper namespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@19306 91177308-0d34-0410-b5e6-96231b3b80d8
2005-01-06 05:47:18 +00:00
Alkis Evlogimenos
20aa474f8f Fixes to make LLVM compile with vc7.1.
Patch contributed by Paolo Invernizzi!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16152 91177308-0d34-0410-b5e6-96231b3b80d8
2004-09-03 18:19:51 +00:00
Reid Spencer
551ccae044 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/.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@16137 91177308-0d34-0410-b5e6-96231b3b80d8
2004-09-01 22:55:40 +00:00
Chris Lattner
18f16094c2 Initial checkin of a simple loop unswitching pass. It still needs work,
but it's a start, and seems to do it's basic job.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@13068 91177308-0d34-0410-b5e6-96231b3b80d8
2004-04-19 18:07:02 +00:00