271 Commits

Author SHA1 Message Date
Chris Lattner
979b8f1d8c refactor the speculative execution logic to be factored into the cond branch code instead of
doing a cfg search for every block simplified.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121686 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:26:52 +00:00
Chris Lattner
eff7edf126 simplify a bunch of code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121685 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:20:28 +00:00
Chris Lattner
ef5002ba85 move HoistThenElseCodeToIf up to a more logical and efficient-to-handle place.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121684 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:15:29 +00:00
Chris Lattner
ddb97a2bf1 move 'MergeBlocksIntoPredecessor' call earlier. Use
getSinglePredecessor to simplify code.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121683 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:10:48 +00:00
Chris Lattner
97fdb898f5 factor new code out to a SimplifyBranchOnICmpChain helper function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121681 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 05:03:41 +00:00
Chris Lattner
7312a22ed6 enhance the "change or icmp's into switch" xform to handle one value in an
'or sequence' that it doesn't understand.  This allows us to optimize
something insane like this:

int crud (unsigned char c, unsigned x)
 {
   if(((((((((( (int) c <= 32 ||
                    (int) c == 46) || (int) c == 44)
                  || (int) c == 58) || (int) c == 59) || (int) c == 60)
               || (int) c == 62) || (int) c == 34) || (int) c == 92)
            || (int) c == 39) != 0)
     foo();
 }

into:

define i32 @crud(i8 zeroext %c, i32 %x) nounwind ssp noredzone {
entry:
  %cmp = icmp ult i8 %c, 33
  br i1 %cmp, label %if.then, label %switch.early.test

switch.early.test:                                ; preds = %entry
  switch i8 %c, label %if.end [
    i8 39, label %if.then
    i8 44, label %if.then
    i8 58, label %if.then
    i8 59, label %if.then
    i8 60, label %if.then
    i8 62, label %if.then
    i8 46, label %if.then
    i8 92, label %if.then
    i8 34, label %if.then
  ]

by pulling the < comparison out ahead of the newly formed switch.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121680 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:50:38 +00:00
Chris Lattner
0aa749bde7 merge two very similar functions into one that has a bool argument.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121678 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:26:26 +00:00
Chris Lattner
662269d2ab don't bother handling non-canonical icmp's
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121676 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:18:32 +00:00
Chris Lattner
803a29d19f inline a function, making the result much simpler.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121675 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 04:15:19 +00:00
Chris Lattner
abf706703f Fix my previous patch to handle a degenerate case that the llvm-gcc
bootstrap buildbot tripped over.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121674 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 03:43:57 +00:00
Chris Lattner
28acc13548 convert some methods to be static functions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121673 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 03:30:12 +00:00
Chris Lattner
fca20f507c zap two more std::sorts.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121672 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 03:24:30 +00:00
Chris Lattner
61c77449c7 fix a fairly serious oversight with switch formation from
or'd conditions.  Previously we'd compile something like this:

int crud (unsigned char c) {
   return c == 62 || c == 34 || c == 92;
}

into:

  switch i8 %c, label %lor.rhs [
    i8 62, label %lor.end
    i8 34, label %lor.end
  ]

lor.rhs:                                          ; preds = %entry
  %cmp8 = icmp eq i8 %c, 92
  br label %lor.end

lor.end:                                          ; preds = %entry, %entry, %lor.rhs
  %0 = phi i1 [ true, %entry ], [ %cmp8, %lor.rhs ], [ true, %entry ]
  %lor.ext = zext i1 %0 to i32
  ret i32 %lor.ext

which failed to merge the compare-with-92 into the switch.  With this patch
we simplify this all the way to:

  switch i8 %c, label %lor.rhs [
    i8 62, label %lor.end
    i8 34, label %lor.end
    i8 92, label %lor.end
  ]

lor.rhs:                                          ; preds = %entry
  br label %lor.end

lor.end:                                          ; preds = %entry, %entry, %entry, %lor.rhs
  %0 = phi i1 [ true, %entry ], [ false, %lor.rhs ], [ true, %entry ], [ true, %entry ]
  %lor.ext = zext i1 %0 to i32
  ret i32 %lor.ext

which is much better for codegen's switch lowering stuff.  This kicks in 33 times
on 176.gcc (for example) cutting 103 instructions off the generated code.





git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121671 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 03:18:54 +00:00
Chris Lattner
6d4d21e29d convert an std::sort to array_pod_sort.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121669 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 02:00:58 +00:00
Chris Lattner
cd4b709d73 move the "br (X == 0 | X == 1), T, F" -> switch optimization to a new
location in simplifycfg.  In the old days, SimplifyCFG was never run on
the entry block, so we had to scan over all preds of the BB passed into
simplifycfg to do this xform, now we can just check blocks ending with
a condbranch.  This avoids a scan over all preds of every simplified 
block, which should be a significant compile-time perf win on functions
with lots of edges.  No functionality change.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121668 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 01:57:34 +00:00
Chris Lattner
9a2b72acc9 reduce indentation and generally simplify code, no functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121667 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 01:47:07 +00:00
Chris Lattner
dcb54ce3da use getFirstNonPHIOrDbg to simplify this code.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121664 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 01:28:06 +00:00
Frits van Bommel
7ac40c3ffa Teach SimplifyCFG to turn
(indirectbr (select cond, blockaddress(@fn, BlockA),
                            blockaddress(@fn, BlockB)))
into
  (br cond, BlockA, BlockB).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120943 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-05 18:29:03 +00:00
Duncan Sands
5f28475b30 Fix PR8445: a block with no predecessors may be the entry block, in which case
it isn't unreachable and should not be zapped.  The check for the entry block
was missing in one case: a block containing a unwind instruction.  While there,
do some small cleanups: "M" is not a great name for a Function* (it would be
more appropriate for a Module*), change it to "Fn"; use Fn in more places.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@117224 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-24 12:23:30 +00:00
Dan Gohman
7a4994356b Instead, teach SimplifyCFG to trim non-address-taken blocks from
indirectbr destination lists.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111122 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-16 14:41:14 +00:00
Dan Gohman
e2c6d131d1 Teach SimplifyCFG how to simplify indirectbr instructions.
- Eliminate redundant successors.
 - Convert an indirectbr with one successor into a direct branch.

Also, generalize SimplifyCFG to be able to be run on a function entry block.
It knows quite a few simplifications which are applicable to the entry
block, and it only needs a few checks to avoid trouble with the entry block.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@111060 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-14 00:29:42 +00:00
Gabor Greif
20361b9d4d pass dereferenced iterator to dyn_cast
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@109098 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-22 11:43:44 +00:00
Owen Anderson
2722dfa75d Remove unneeded check, and correct style.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108427 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-15 16:38:22 +00:00
Owen Anderson
e84178a0bd Extend SimplifyCFG's common-destination folding heuristic to allow a single
"bonus" instruction to be speculatively executed.  Add a heuristic to
ensure we're not tripping up out-of-order execution by checking that this bonus
instruction only uses values that were already guaranteed to be available.

This allows us to eliminate the short circuit in (x&1)&&(x&2).


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108351 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-14 19:52:16 +00:00
Gabor Greif
625398343e cache dereferenced iterators
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@108133 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-12 10:59:23 +00:00
Gabor Greif
5896935423 cache result of operator*
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@107974 91177308-0d34-0410-b5e6-96231b3b80d8
2010-07-09 15:25:09 +00:00
Dan Gohman
4bb31bfaa3 Fix a grammaro.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99917 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-30 20:04:57 +00:00
Gabor Greif
bd44314c67 fix two cases where the arguments were extracted from the wrong range out of the InvokeInst
spotted by baldrick -- thanks\!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@99914 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-30 19:20:53 +00:00
Bill Wendling
c69b4a5b8b Make returns more consistent with others.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@98490 91177308-0d34-0410-b5e6-96231b3b80d8
2010-03-14 10:40:28 +00:00
Duncan Sands
1df9859c40 There are two ways of checking for a given type, for example isa<PointerType>(T)
and T->isPointerTy().  Convert most instances of the first form to the second form.
Requested by Chris.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96344 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-16 11:11:14 +00:00
Duncan Sands
b0bc6c361d Uniformize the names of type predicates: rather than having isFloatTy and
isInteger, we now have isFloatTy and isIntegerTy.  Requested by Chris!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@96223 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-15 16:12:20 +00:00
Jakob Stoklund Olesen
58e9ee85fd Teach SimplifyCFG about magic pointer constants.
Weird code sometimes uses pointer constants other than null. This patch
teaches SimplifyCFG to build switch instructions in those cases.

Code like this:

void f(const char *x) {
  if (!x)
    puts("null");
  else if ((uintptr_t)x == 1)
    puts("one");
  else if (x == (char*)2 || x == (char*)3)
    puts("two");
  else if ((intptr_t)x == 4)
    puts("four");
  else
    puts(x);
}

Now becomes a switch:

define void @f(i8* %x) nounwind ssp {
entry:
  %magicptr23 = ptrtoint i8* %x to i64            ; <i64> [#uses=1]
  switch i64 %magicptr23, label %if.else16 [
    i64 0, label %if.then
    i64 1, label %if.then2
    i64 2, label %if.then9
    i64 3, label %if.then9
    i64 4, label %if.then14
  ]

Note that LLVM's own DenseMap uses magic pointers.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@95439 91177308-0d34-0410-b5e6-96231b3b80d8
2010-02-05 22:03:18 +00:00
Benjamin Kramer
11acaa374c Convert a ton of simple integer type equality tests to the new predicate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92760 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 20:07:06 +00:00
Benjamin Kramer
f012705c7e Avoid going through the LLVMContext for type equality where it's safe to dereference the type pointer.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92726 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 13:12:22 +00:00
David Greene
89d6fd36a2 Change errs() to dbgs().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92604 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 01:26:52 +00:00
Devang Patel
44a29e066a Remove dead debug info intrinsics.
Intrinsic::dbg_stoppoint
 Intrinsic::dbg_region_start 
 Intrinsic::dbg_region_end 
 Intrinsic::dbg_func_start
AutoUpgrade simply ignores these intrinsics now.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@92557 91177308-0d34-0410-b5e6-96231b3b80d8
2010-01-05 01:10:40 +00:00
Jim Grosbach
43a8241b65 Move EliminateDuplicatePHINodes() from SimplifyCFG.cpp to Local.cpp
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@90324 91177308-0d34-0410-b5e6-96231b3b80d8
2009-12-02 17:06:45 +00:00
Jim Grosbach
20f4d34fe3 Make EliminateDuplicatePHINodes() available as a utility function
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89297 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-19 02:02:10 +00:00
Chris Lattner
dce94d92df refactor TryToSimplifyUncondBranchFromEmptyBlock out of SimplifyCFG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86666 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-10 05:59:26 +00:00
Chris Lattner
7b550ccfc5 remove a bunch of extraneous LLVMContext arguments
from various APIs, addressing PR5325.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@86231 91177308-0d34-0410-b5e6-96231b3b80d8
2009-11-06 04:27:31 +00:00
Dan Gohman
0e747beb3c Add a comment about a missed opportunity.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85635 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-30 23:15:43 +00:00
Dan Gohman
2c63566e40 Teach SimplifyCFG how to eliminate duplicate PHI nodes within a block.
This reduces codesize on a variety of codes by 1-2% on x86-64. It also
helps clean up after SSAUpdater.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@85626 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-30 22:39:04 +00:00
Chris Lattner
11f15dbb28 change simplifycfg to not duplicate 'unwind' instructions. Hopefully
this will increase the likelihood of common code getting sunk towards
the unwind.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@83996 91177308-0d34-0410-b5e6-96231b3b80d8
2009-10-13 18:13:05 +00:00
Nick Lewycky
6776064d19 Instruction::clone does not need to take an LLVMContext&. Remove that and
update all the callers.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@82889 91177308-0d34-0410-b5e6-96231b3b80d8
2009-09-27 07:38:41 +00:00
Dan Gohman
58cfa3b137 Rename Instruction::isIdenticalTo to Instruction::isIdenticalToWhenDefined,
and introduce a new Instruction::isIdenticalTo which tests for full
identity, including the SubclassOptionalData flags. Also, fix the
Instruction::clone implementations to preserve the SubclassOptionalData
flags. Finally, teach several optimizations how to handle
SubclassOptionalData correctly, given these changes.

This fixes the counterintuitive behavior of isIdenticalTo not comparing
the full value, and clone not returning an identical clone, as well as
some subtle bugs that could be caused by these.

Thanks to Nick Lewycky for reporting this, and for an initial patch!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@80038 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-25 22:11:20 +00:00
Daniel Dunbar
e317bcc74c Fix -Asserts warnings.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79849 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-23 10:29:55 +00:00
Chris Lattner
bdff548e4d eliminate the "Value" printing methods that print to a std::ostream.
This required converting a bunch of stuff off DOUT and other cleanups.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79819 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-23 04:37:46 +00:00
Eli Friedman
12bb766ae9 Fix for PR3016: detect the tricky case, where there are
unfoldable references to a PHI node in the block being folded, and disable
the transformation in that case.  The correct transformation of such PHI
nodes depends on whether BB dominates Succ, and dominance is expensive 
to compute here.  (Alternatively, it's possible to check whether any 
uses are live, but that's also essentially a dominance calculation. 
Another alternative is to use reg2mem, but it probably isn't a good idea to
use that in simplifycfg.)

Also, remove some incorrect code from CanPropagatePredecessorsForPHIs 
which is made unnecessary with this patch: it didn't consider the case 
where a PHI node in BB has multiple uses.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@79174 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-16 04:23:49 +00:00
Owen Anderson
1d0be15f89 Push LLVMContexts through the IntegerType APIs.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78948 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-13 21:58:54 +00:00
Dan Gohman
4ae5126d04 Remove a bunch more now-unnecessary Context arguments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@78809 91177308-0d34-0410-b5e6-96231b3b80d8
2009-08-12 16:23:25 +00:00