Commit Graph

60 Commits

Author SHA1 Message Date
Chris Lattner
f478951b0e fix PR3217: fully cached queries need to be verified against the
visited set before they are used.  If used, their blocks need to be
added to the visited set so that subsequent queries don't use conflicting
pointer values in the cache result blocks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61080 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-16 07:10:09 +00:00
Chris Lattner
8f416f3afd Add a testcase for GCC PR 23455, which lpre handles now. Add some
comments about why we're not getting other cases.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61032 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15 07:49:24 +00:00
Chris Lattner
ef423ebdd1 gvn now hoists this load out of the hot non-call path.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61028 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15 06:34:48 +00:00
Chris Lattner
4807e07fff Adjust testcase to make it more stable across visitation order changes,
unbreaking it after r61024.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61025 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15 04:42:00 +00:00
Chris Lattner
f33131685b make GVN try to rename inputs to the resultant replaced values, which
cleans up the generated code a bit.  This should have the added benefit of
not randomly renaming functions/globals like my previous patch did. :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61023 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15 03:46:38 +00:00
Chris Lattner
9e59c64c14 Implement initial support for PHI translation in memdep. This means that
memdep keeps track of how PHIs affect the pointer in dep queries, which 
allows it to eliminate the load in cases like rle-phi-translate.ll, which
basically end up being:

BB1:
   X = load P
   br BB3
BB2:
   Y = load Q
   br BB3
BB3:
   R = phi [P] [Q]
   load R

turning "load R" into a phi of X/Y.  In addition to additional exposed
opportunities, this makes memdep safe in many cases that it wasn't before
(which is required for load PRE) and also makes it substantially more 
efficient.  For example, consider:


bb1:  // has many predecessors.
   P = some_operator()
   load P

In this example, previously memdep would scan all the predecessors of BB1
to see if they had something that would mustalias P.  In some cases (e.g.
test/Transforms/GVN/rle-must-alias.ll) it would actually find them and end
up eliminating something.  In many other cases though, it would scan and not
find anything useful.  MemDep now stops at a block if the pointer is defined
in that block and cannot be phi translated to predecessors.  This causes it
to miss the (rare) cases like rle-must-alias.ll, but makes it faster by not
scanning tons of stuff that is unlikely to be useful.  For example, this
speeds up GVN as a whole from 3.928s to 2.448s (60%)!.  IMO, scalar GVN 
should be enhanced to simplify the rle-must-alias pointer base anyway, which
would allow the loads to be eliminated.

In the future, this should be enhanced to phi translate through geps and 
bitcasts as well (as indicated by FIXMEs) making memdep even more powerful.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61022 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-15 03:35:32 +00:00
Chris Lattner
5c6d91c1d1 another random testcase that shouldn't crash gvn and is
good for coverage with future changes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@61011 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-14 21:20:46 +00:00
Chris Lattner
3f101bb1e7 RLE isn't smart enough to eliminate this safely yet.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60994 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-13 21:04:20 +00:00
Chris Lattner
4f118f0a20 rename some tests to be more uniform in naming convention.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60988 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-13 18:47:40 +00:00
Chris Lattner
c2f33f24af gvn should never crash on this.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60987 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-13 18:39:44 +00:00
Bill Wendling
8295e49e76 Temporarily revert r60973. It's inexplicably causing a failure when self-hosting LLVM:
llvm[2]: Linking Release executable opt (without symbols)
...
Undefined symbols:
  "llvm::APFloat::IEEEsingle", referenced from:
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(Constants.o)
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(AsmWriter.o)
      __ZN4llvm7APFloat10IEEEsingleE$non_lazy_ptr in libLLVMCore.a(ConstantFold.o)
  "llvm::APFloat::IEEEdouble", referenced from:
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(Constants.o)
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(AsmWriter.o)
      __ZN4llvm7APFloat10IEEEdoubleE$non_lazy_ptr in libLLVMCore.a(ConstantFold.o)
ld: symbol(s) not found

This is in release mode. To replicate, compile llvm and llvm-gcc in optimized
mode. Then build llvm, in optimized mode, with the newly created compiler.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60977 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-13 09:28:44 +00:00
Chris Lattner
879922932f make RLE preserve the name of the load that it replaces. This is just
a pretification of the IR.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60973 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-13 07:22:47 +00:00
Chris Lattner
5a45bf1b48 loosen up an assertion that isn't valid when called from
invalidateCachedPointerInfo.  Thanks to Bill for sending me
a testcase.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60805 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 22:45:32 +00:00
Chris Lattner
20d6f0982a Teach BasicAA::getModRefInfo(CallSite, CallSite) some
tricks based on readnone/readonly functions.

Teach memdep to look past readonly calls when analyzing
deps for a readonly call.  This allows elimination of a
few more calls from 403.gcc:

before:
     63 gvn    - Number of instructions PRE'd
 153986 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

after:
     63 gvn    - Number of instructions PRE'd
 153991 gvn    - Number of instructions deleted
  50069 gvn    - Number of loads deleted

5 calls isn't much, but this adds plumbing for the next change.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60794 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-09 21:19:42 +00:00
Chris Lattner
7f7c736682 Fix test/Transforms/GVN/pre-load.ll
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60594 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-05 17:04:12 +00:00
Chris Lattner
c89c6a964c Implement PRE of loads in the GVN pass with a pretty cheap and
straight-forward implementation.  This does not require any extra
alias analysis queries beyond what we already do for non-local loads.

Some programs really really like load PRE.  For example, SPASS triggers
this ~1000 times, ~300 times in 255.vortex, and ~1500 times on 403.gcc.

The biggest limitation to the implementation is that it does not split
critical edges.  This is a huge killer on many programs and should be
addressed after the initial patch is enabled by default.

The implementation of this should incidentally speed up rejection of 
non-local loads because it avoids creating the repl densemap in cases 
when it won't be used for fully redundant loads.

This is currently disabled by default.
Before I turn this on, I need to fix a couple of miscompilations in
the testsuite, look at compile time performance numbers, and look at
perf impact.  This is pretty close to ready though.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60408 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-02 08:16:11 +00:00
Owen Anderson
e209d9a3e6 Add a test for my previous PRE fix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60394 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-02 04:25:42 +00:00
Chris Lattner
67afda6c1e testcase for my previous commit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60315 91177308-0d34-0410-b5e6-96231b3b80d8
2008-12-01 01:42:03 +00:00
Chris Lattner
cae30afc34 don't require GVN to work on dead values, just make the
test return the loaded value.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@60252 91177308-0d34-0410-b5e6-96231b3b80d8
2008-11-29 21:21:48 +00:00
Owen Anderson
f2aa160b35 A better fix for PR2503 that doesn't pessimize GVN in the presence of unreachable blocks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@53032 91177308-0d34-0410-b5e6-96231b3b80d8
2008-07-02 17:20:16 +00:00
Owen Anderson
3987f8e1ac Use the -enable-pre flag so this test doesn't fail.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52784 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-26 17:03:28 +00:00
Owen Anderson
b230372437 Add local PRE to GVN. This only operates in cases where it would not increase code size, namely when the instantiated expression
would only need to be created in one predecessor.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@52471 91177308-0d34-0410-b5e6-96231b3b80d8
2008-06-18 21:41:49 +00:00
Gabor Greif
f6cadc440c sabre brings to my attention that the 'tr' suffix is also obsolete
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51349 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 21:00:03 +00:00
Gabor Greif
722243bd40 Rename the last test with .llx extension to .ll, resolve duplicate test by renaming to isnan2. Now that no test has llx ending there is no need to search for them from dg.exp too.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51328 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-20 19:52:04 +00:00
Owen Anderson
6513c1bf90 Add a testcase for non-local CSE of read-only calls.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@51025 91177308-0d34-0410-b5e6-96231b3b80d8
2008-05-13 08:17:44 +00:00
Owen Anderson
c008c5e08c Add testcase for PR2213.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49517 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-11 05:13:32 +00:00
Owen Anderson
a723d1e48f Factor a bunch of functionality related to memcpy and memset transforms out of
GVN and into its own pass.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@49419 91177308-0d34-0410-b5e6-96231b3b80d8
2008-04-09 08:23:16 +00:00
Chris Lattner
f83e13ae0a add a testcase for forming memset from noncontiguous stores.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48938 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-29 04:51:35 +00:00
Chris Lattner
0b26a31ae6 apparently tclsh doesn't lex like bash. Weird.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48732 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-24 17:41:57 +00:00
Chris Lattner
263250b131 pass the option so this test tests the right thing.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48731 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-24 17:36:38 +00:00
Owen Anderson
856254026f Use normal naming convention for test.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48693 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-22 21:08:33 +00:00
Chris Lattner
b017c9e89c implement an initial hack at a straight-line store -> memset optimization.
This fires dozens of times across spec and multisource, but I don't know
if it actually speeds stuff up.  Hopefully the testers will show something
nice :)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48680 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-22 05:37:16 +00:00
Owen Anderson
8a97fddbc2 Fix a bug in GVN that Duncan noticed, where we potentially need to insert a
pointer bitcast when performing return slot optimization.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48343 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-13 22:07:10 +00:00
Owen Anderson
6bb0bd52ec Improve the return slot optimization to be both more aggressive (not limited to sret parameters), and
safer (when the passed pointer might be invalid).  Thanks to Duncan and Chris for the idea behind this, 
and extra thanks to Duncan for helping me work out the trap-safety.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@48280 91177308-0d34-0410-b5e6-96231b3b80d8
2008-03-12 07:37:44 +00:00
Owen Anderson
bf931bb094 Add PR number to testcase.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47640 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-26 23:16:11 +00:00
Owen Anderson
77db50f68f Fix an issue where GVN had the sizes of the two memcpy's reverse, resulting
in an invalid transformation.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47639 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-26 23:06:17 +00:00
Owen Anderson
c0808a7e1d Fix an issue where GVN was performing the return slot optimization when it was
not safe.  This is fixed by more aggressively checking that the return slot is
not used elsewhere in the function.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47544 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-25 04:08:09 +00:00
Owen Anderson
0f7ea1ab10 Fix an issue where GVN would try to use an instruction before its definition when performing return slot optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47541 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-25 00:40:41 +00:00
Chris Lattner
ea0415957d make this just a bit more strict.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47274 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18 17:33:10 +00:00
Owen Anderson
5aa4f2a085 Add support to GVN for performing sret return slot optimization. This means that, if an sret function tail calls
another sret function, it should pass its own sret parameter to the tail callee, allowing it to fill in the correct
return value.  llvm-gcc does not emit this by default.  Instead, it allocates space in the caller for the sret of
the tail call and then uses memcpy to copy the result into the caller's sret parameter.  This optimization detects
and optimizes that case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47265 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-18 09:24:53 +00:00
Nick Lewycky
c91b49b890 Testcase for PR2032.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47113 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-14 07:15:11 +00:00
Eli Friedman
35327b3e57 Add a note pointing to PR1996.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47055 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 07:56:04 +00:00
Eli Friedman
261c704da1 Add test for PR1996. (This is my first time adding a test for a
transform, so please review.)



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47050 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-13 06:55:57 +00:00
Owen Anderson
30b4bd4d10 Re-apply the patch to improve the optimizations of memcpy's, with several
bugs fixed.  This now passes PPC bootstrap.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@47026 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-12 21:15:18 +00:00
Bill Wendling
e00fec554b Temporarily reverting:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20080128/057882.html

This is causing a miscompilation on PPC G5 and just now seeing it on iMac x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46822 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-06 20:03:07 +00:00
Owen Anderson
d02c0bc984 Make this test more aggressive, to cover recent improvements.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46695 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-04 04:55:24 +00:00
Owen Anderson
6f7a52d300 Allow GVN to hack on memcpy's, making them open to further optimization.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@46693 91177308-0d34-0410-b5e6-96231b3b80d8
2008-02-04 02:59:58 +00:00
Dan Gohman
28beeeac4d Convert tests using "| wc -l | grep ..." to use the count script.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@41097 91177308-0d34-0410-b5e6-96231b3b80d8
2007-08-15 13:36:28 +00:00
Owen Anderson
b95f9d565f Fix a failure I accidentally caused in my last commit by mishandling the
removal of redundant phis.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40650 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-31 20:18:28 +00:00
Owen Anderson
054ab94bff Fix a misoptimization in aha.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@40642 91177308-0d34-0410-b5e6-96231b3b80d8
2007-07-31 17:43:14 +00:00