67 Commits

Author SHA1 Message Date
Duncan Sands
8864383748 Handle the case of a tail recursion in which the tail call is followed
by a return that returns a constant, while elsewhere in the function
another return instruction returns a different constant.  This is a
special case of accumulator recursion, so just generalize the existing
logic a bit.

llvm-svn: 108241
2010-07-13 15:41:41 +00:00
Gabor Greif
5c94fddae4 cache dereferenced iterators
llvm-svn: 108131
2010-07-12 10:36:48 +00:00
Duncan Sands
954c75c560 The accumulator tail recursion transform claims to work for any associative
operation, but the way it's implemented requires the operation to also be
commutative.  So add a check for commutativity (and tweak the corresponding
comments).  This makes no difference in practice since every associative
LLVM instruction is also commutative!  Here's an example to show the need
for commutativity: the accum_recursion.ll testcase calculates the factorial
function.  Before the transformation the result of a call is
  ((((1*1)*2)*3)...)*x
while afterwards it is
  (((1*x)*(x-1))...*2)*1
which clearly requires both associativity and commutativity of * to be equal
to the original.

llvm-svn: 108056
2010-07-10 20:31:42 +00:00
Duncan Sands
68f39e00a4 Fix PR7328: when turning a tail recursion into a loop, need to preserve
the returned value after the tail call if it differs from other return
values.  The optimal thing to do would be to introduce a phi node for
the return value, but for the moment just fix the miscompile.

llvm-svn: 106947
2010-06-26 12:53:31 +00:00
Gabor Greif
39ff38468c use getNumArgOperands
llvm-svn: 106709
2010-06-24 00:48:48 +00:00
Gabor Greif
1d1526999b use ArgOperand API
llvm-svn: 106707
2010-06-24 00:44:01 +00:00
Dan Gohman
0d7d3faf8e Move FindAvailableLoadedValue isSafeToLoadUnconditionally out of
lib/Transforms/Utils and into lib/Analysis so that Analysis passes
can use them.

llvm-svn: 104949
2010-05-28 16:19:17 +00:00
Eric Christopher
e78496e5f1 Revert 101465, it broke internal OpenGL testing.
Probably the best way to know that all getOperand() calls have been handled
is to replace that API instead of updating.

llvm-svn: 101579
2010-04-16 23:37:20 +00:00
Dan Gohman
f0457a82fa Refine the detection of seemingly infinitely recursive calls where the
callee is expected to be expanded to something else by codegen, so that
normal infinitely recursive calls are still transformed.

llvm-svn: 101468
2010-04-16 15:57:50 +00:00
Gabor Greif
e7d6812008 reapply r101434
with a fix for self-hosting

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101465
2010-04-16 15:33:14 +00:00
Gabor Greif
cd116e8c6a back out r101423 and r101397, they break llvm-gcc self-host on darwin10
llvm-svn: 101434
2010-04-16 01:16:20 +00:00
Gabor Greif
2e18d34d80 reapply r101364, which has been backed out in r101368
with a fix

rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101397
2010-04-15 20:51:13 +00:00
Gabor Greif
6022150477 back out r101364, as it trips the linux nightlybot on some clang C++ tests
llvm-svn: 101368
2010-04-15 12:46:56 +00:00
Gabor Greif
428ca23bbd rotate CallInst operands, i.e. move callee to the back
of the operand array

the motivation for this patch are laid out in my mail to llvm-commits:
more efficient access to operands and callee, faster callgraph-construction,
smaller compiler binary

llvm-svn: 101364
2010-04-15 10:49:53 +00:00
Evan Cheng
e273e42195 Revert 94937 and move the noreturn check to codegen.
llvm-svn: 95198
2010-02-03 03:55:59 +00:00
Evan Cheng
c2f3c20680 Do not mark no-return calls tail calls. It'll screw up special calls like longjmp and it doesn't make much sense for performance reason. If my logic is faulty, please let me know.
llvm-svn: 94937
2010-01-31 00:59:31 +00:00
Bob Wilson
0f04082970 Check alignment of loads when deciding whether it is safe to execute them
unconditionally.  Besides checking the offset, also check that the underlying
object is aligned as much as the load itself.

llvm-svn: 94875
2010-01-30 04:42:39 +00:00
Nick Lewycky
2b3ac2b1a7 Improve tail call elimination to handle the switch statement.
llvm-svn: 86403
2009-11-07 21:10:15 +00:00
Nick Lewycky
f49c373c13 Oops, FunctionContainsEscapingAllocas is really used to mean two different
things. Back out part of r86349 for a moment.

llvm-svn: 86353
2009-11-07 07:42:38 +00:00
Nick Lewycky
a2b0965613 Dust off tail recursion elimination. Fix a fixme by applying CaptureTracking
and add a .ll to demo the new capability.

llvm-svn: 86349
2009-11-07 07:10:01 +00:00
Chris Lattner
5f54c5bd1c eliminate VISIBILITY_HIDDEN from Transforms/Scalar. PR4861
llvm-svn: 80766
2009-09-02 06:11:42 +00:00
Owen Anderson
9df206d02d Push LLVMContexts through the IntegerType APIs.
llvm-svn: 78948
2009-08-13 21:58:54 +00:00
Chris Lattner
8ddc06469c Improve tail call elim to move loads above readonly calls
when it allows forming a tail call.  Patch by Frits van
Bommel.  This implements PR4323.

llvm-svn: 73752
2009-06-19 04:22:16 +00:00
Duncan Sands
880eaf5278 Allow readonly functions to unwind exceptions. Teach
the optimizers about this.  For example, a readonly
function with no uses cannot be removed unless it is
also marked nounwind.

llvm-svn: 71071
2009-05-06 06:49:50 +00:00
Dan Gohman
e1f9be27bc Tidy up several unbeseeming casts from pointer to intptr_t.
llvm-svn: 55779
2008-09-04 17:05:41 +00:00
Chris Lattner
f9d43c9853 Fix a case where tailcallelim wouldn't set the changed bit when it made a change.
llvm-svn: 52267
2008-06-14 00:49:48 +00:00
Gabor Greif
48ffb6c7dc Fix a bunch of 80col violations that arose from the Create API change. Tweak makefile targets to find these better.
llvm-svn: 51143
2008-05-15 10:04:30 +00:00
Dan Gohman
bab18cae46 Clean up the use of static and anonymous namespaces. This turned up
several things that were neither in an anonymous namespace nor static
but not intended to be global.

llvm-svn: 51017
2008-05-13 00:00:25 +00:00
Gabor Greif
6c6b8a57f3 API changes for class Use size reduction, wave 1.
Specifically, introduction of XXX::Create methods
for Users that have a potentially variable number of
Uses.

llvm-svn: 49277
2008-04-06 20:25:17 +00:00
Devang Patel
cb8f342ea8 Become multiple return value aware.
Right now, the pass does not optimize tail recursions 
involving multiple return values.

llvm-svn: 48228
2008-03-11 17:33:32 +00:00
Anton Korobeynikov
fd6b669c80 Make Transforms to be 4.3 warnings-clean
llvm-svn: 47371
2008-02-20 11:26:25 +00:00
Chris Lattner
ad9a6ccb83 Remove attribution from file headers, per discussion on llvmdev.
llvm-svn: 45418
2007-12-29 20:36:04 +00:00
Chris Lattner
ab8aa7d61a Prevent tailcallelim from breaking "recursive" calls to builtins.
llvm-svn: 41804
2007-09-10 20:58:55 +00:00
Nick Lewycky
c2306ff5b4 Fix typo in comment.
llvm-svn: 36873
2007-05-06 13:37:16 +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
Dan Gohman
d0a0ea9916 Change uses of Function::front to Function::getEntryBlock for readability.
llvm-svn: 35265
2007-03-22 16:38:57 +00:00
Chris Lattner
b131b3e07e Simplify code by using value::takename
llvm-svn: 34176
2007-02-11 01:23:03 +00:00
Reid Spencer
8749d297f5 Apply the VISIBILITY_HIDDEN field to the remaining anonymous classes in
the Transforms library. This reduces debug library size by 132 KB, debug
binary size by 376 KB, and reduces link time for llvm tools slightly.

llvm-svn: 33939
2007-02-05 23:32:05 +00:00
Chris Lattner
9e7640cf02 Switch over Transforms/Scalar to use the STATISTIC macro. For each statistic
converted, we lose a static initializer.  This also allows GCC to emit warnings
about unused statistics.

llvm-svn: 32690
2006-12-19 21:40:18 +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
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
51e762d4cb Add a workaround for PR962, disabling the more aggressive form of this
transformation.  This speeds up a C++ app 2.25x.

llvm-svn: 31113
2006-10-22 18:42:26 +00:00
Chris Lattner
a39dcb5377 eliminate RegisterOpt. It does the same thing as RegisterPass.
llvm-svn: 29925
2006-08-27 22:42:52 +00:00
Chris Lattner
0bd3e3230c Implement Transforms/TailCallElim/return-undef.ll, a trivial case
that has been sitting in my inbox since May 18. :)

llvm-svn: 24194
2005-11-05 08:21:11 +00:00
Chris Lattner
c6571e5c64 Use the new 'moveBefore' method to simplify some code. Really, which is
easier to understand?  :)

llvm-svn: 22706
2005-08-08 19:11:57 +00:00
Chris Lattner
427319ff4b Fix typoCVS: ----------------------------------------------------------------------
llvm-svn: 22692
2005-08-07 07:00:52 +00:00
Chris Lattner
5b499da0a7 * Use the new PHINode::hasConstantValue method to simplify some code
* Teach this code to move allocas out of the loop when tail call eliminating
  a call marked 'tail'.  This implements TailCallElim/move_alloca_for_tail_call.ll
* Do not perform this transformation if a call is marked 'tail' and if there
  are allocas that we cannot move out of the loop in #2.  Doing so would increase
  the stack usage of the function.  This implements fixes
  PR615 and TailCallElim/dont-tce-tail-marked-call.ll.

llvm-svn: 22690
2005-08-07 04:27:41 +00:00
Jeff Cohen
bd51ec7461 Eliminate all remaining tabs and trailing spaces.
llvm-svn: 22523
2005-07-27 06:12:32 +00:00