Commit Graph

237 Commits

Author SHA1 Message Date
Owen Anderson b1dc1d44f8 Add LCSSA as a requirement for LoopUnswitch, and assert that LoopUnswitch preserves
LCSSA.

llvm-svn: 28739
2006-06-09 18:40:32 +00:00
Chris Lattner 5821a6a17a add the actual cost to the debug info
llvm-svn: 27051
2006-03-24 07:14:00 +00:00
Chris Lattner e5521db5bc 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.

llvm-svn: 26320
2006-02-22 23:55:00 +00:00
Chris Lattner 8a5a324dac Add some comments, simplify some code, and fix a bug that caused rewriting
to rewrite with the wrong value.

llvm-svn: 26311
2006-02-22 06:37:14 +00:00
Chris Lattner c2e3a7a4ce improved support for branch folding, still not enabled.
llvm-svn: 26289
2006-02-18 07:57:38 +00:00
Chris Lattner 19fa8ac938 Implement deletion of dead blocks, currently disabled.
llvm-svn: 26285
2006-02-18 02:42:34 +00:00
Chris Lattner cb853de534 a previous patch completely disabled trivial unswitching, this fixees it.
Thanks to nate for pointing this out :)

llvm-svn: 26280
2006-02-18 01:32:04 +00:00
Chris Lattner 29f771ba21 initial trivial support for folding branches that have now-constant destinations.
llvm-svn: 26279
2006-02-18 01:27:45 +00:00
Chris Lattner 8e44ff50b0 When unswitching a loop, make sure to update loop info with exit blocks in
the right loop.

llvm-svn: 26277
2006-02-18 00:55:32 +00:00
Chris Lattner baddba41c7 Fix loops where the header has an exit, fixing a loop-unswitch crash on crafty
llvm-svn: 26258
2006-02-17 06:39:56 +00:00
Chris Lattner 6fd136239b start of some new simplification code, not thoroughly tested, use at your own
risk :)

llvm-svn: 26248
2006-02-17 00:31:07 +00:00
Chris Lattner fa335f6083 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.

llvm-svn: 26235
2006-02-16 19:36:22 +00:00
Jeff Cohen 55f63f1b53 Fix VC++ warning.
llvm-svn: 26228
2006-02-16 04:07:37 +00:00
Chris Lattner ff42e81028 fix a bug where we unswitched the wrong way
llvm-svn: 26225
2006-02-16 01:24:41 +00:00
Chris Lattner fdff0bb43e 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
    }
  }
}

llvm-svn: 26223
2006-02-15 22:52:05 +00:00
Chris Lattner e5cb76d744 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.

llvm-svn: 26220
2006-02-15 22:03:36 +00:00
Chris Lattner 65152d80ec Checking the wrong value. This caused us to emit silly code like
Y = seteq bool X, true
instead of just using X :)

llvm-svn: 26215
2006-02-15 19:05:52 +00:00
Chris Lattner 01db04efb0 more refactoring, no functionality change.
llvm-svn: 26194
2006-02-15 01:44:42 +00:00
Chris Lattner b0cbe7106e pull some code out into a function
llvm-svn: 26191
2006-02-15 00:07:43 +00:00
Chris Lattner 0b8ec1a132 Use statistics to keep track of what flavors of loops we are unswitching
llvm-svn: 26157
2006-02-14 01:01:41 +00:00
Chris Lattner fbadd7e1ee implement unswitching of loops with switch stmts and selects in them
llvm-svn: 26114
2006-02-11 00:43:37 +00:00
Chris Lattner f1b151684d Update PHI nodes in successors of exit blocks.
llvm-svn: 26113
2006-02-10 23:26:14 +00:00
Chris Lattner fe4151efe7 Reform the unswitching code in terms of edge splitting, not block splitting.
llvm-svn: 26112
2006-02-10 23:16:39 +00:00
Chris Lattner ec6b40a093 Fix a case where UnswitchTrivialCondition broke critical edges with
phi's in the successors

llvm-svn: 26108
2006-02-10 19:08:15 +00:00
Chris Lattner 6e263155a6 add some notes, move some code around. Implement unswitching of loops
with branches on partially invariant computations.

llvm-svn: 26104
2006-02-10 02:30:37 +00:00
Chris Lattner 4935417a84 Move code around to be more logical, no functionality change.
llvm-svn: 26103
2006-02-10 02:01:22 +00:00
Chris Lattner 3fc3148b85 When unswitching a trivial loop, do admit we are doing it! :)
llvm-svn: 26102
2006-02-10 01:36:35 +00:00
Chris Lattner ed7a67b0de 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.

llvm-svn: 26101
2006-02-10 01:24:09 +00:00
Chris Lattner 4f0e66df6a Simplify control flow a bit, note that unswitch preserves canonical loop form
llvm-svn: 26098
2006-02-09 22:15:42 +00:00
Chris Lattner 8976219850 Make the threshold a parameter
llvm-svn: 26093
2006-02-09 20:15:48 +00:00
Chris Lattner 2826e0511b 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.

llvm-svn: 26089
2006-02-09 19:14:52 +00:00
Chris Lattner c597b8a55e Make iostream #inclusion explicit
llvm-svn: 25514
2006-01-22 23:32:06 +00:00
Misha Brukman b1c9317bb4 Remove trailing whitespace
llvm-svn: 21427
2005-04-21 23:48:37 +00:00
Jeff Cohen eca0d0f2da Put createLoopUnswitchPass() into proper namespace
llvm-svn: 19306
2005-01-06 05:47:18 +00:00
Alkis Evlogimenos a5c04ee50f Fixes to make LLVM compile with vc7.1.
Patch contributed by Paolo Invernizzi!

llvm-svn: 16152
2004-09-03 18:19:51 +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 f48f777d4c 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.

llvm-svn: 13068
2004-04-19 18:07:02 +00:00