Commit Graph

384 Commits

Author SHA1 Message Date
Michael Ilseman
749807852b test
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162914 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-30 15:45:16 +00:00
Andrew Trick
b1b97833ae Preserve branch profile metadata during switch formation.
Patch by Michael Ilseman!
This fixes SimplifyCFGOpt::FoldValueComparisonIntoPredecessors to preserve metata when folding conditional branches into switches.

void foo(int x) {
  if (x == 0)
    bar(1);
  else if (__builtin_expect(x == 10, 1))
    bar(2);
  else if (x == 20)
    bar(3);
}

CFG:

B0
|  \
|   X0
B10
|  \
|   X10
B20
|  \
E   X20

Merge B0-B10:
w(B0-X0) = w(B0-X0)*sum-weights(B10) = w(B0-X0) * (w(B10-X10) + w(B10-B20))
w(B0-X10) = w(B0-B10) * w(B10-X10)
w(B0-B20) = w(B0-B10) * w(B10-B20)

B0 __
| \  \
| X10 X0
B20
|  \
E  X20

Merge B0-B20:
w(B0-X0) = w(B0-X0) * sum-weights(B20) = w(B0-X0) * (w(B20-E) + w(B20-X20))
w(B0-X10) = w(B0-X10) * sum-weights(B20) = ...
w(B0-X20) = w(B0-B20) * w(B20-X20)
w(B0-E) = w(B0-B20) * w(B20-E)

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162868 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-29 21:46:38 +00:00
Andrew Trick
6b01438dec whitespace
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162867 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-29 21:46:36 +00:00
Sylvestre Ledru
c8e41c5917 Fix a typo (the the => the)
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160621 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-23 08:51:15 +00:00
Chandler Carruth
0baa4809a8 Move llvm/Support/MDBuilder.h to llvm/MDBuilder.h, to live with
IRBuilder, DIBuilder, etc.

This is the proper layering as MDBuilder can't be used (or implemented)
without the Core Metadata representation.

Patches to Clang and Dragonegg coming up.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160237 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-15 23:26:50 +00:00
Benjamin Kramer
23d3622e76 Make helper functions static.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160173 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-13 13:25:15 +00:00
Eric Christopher
c723eb1aef Revert "IntRange:" as it appears to be breaking self hosting.
This reverts commit b2833d9dcb.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159618 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-02 23:22:21 +00:00
Stepan Dyatkovskiy
b2833d9dcb IntRange:
- Changed isSingleNumber method behaviour. Now this flag is calculated on demand.
IntegersSubsetMapping
  - Optimized diff operation.
  - Replaced type of Items field from std::list with std::map.
  - Added new methods:
    bool isOverlapped(self &RHS)
    void add(self& RHS, SuccessorClass *S)
    void detachCase(self& NewMapping, SuccessorClass *Succ)
    void removeCase(SuccessorClass *Succ)
    SuccessorClass *findSuccessor(const IntTy& Val)
    const IntTy* getCaseSingleNumber(SuccessorClass *Succ)
IntegersSubsetTest
  - DiffTest: Added checks for successors.
SimplifyCFG
  Updated SwitchInst usage (now it is case-ragnes compatible) for
    - SimplifyEqualityComparisonWithOnlyPredecessor
    - FoldValueComparisonIntoPredecessors



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159527 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-02 13:02:18 +00:00
Chandler Carruth
06cb8ed006 Move llvm/Support/IRBuilder.h -> llvm/IRBuilder.h
This was always part of the VMCore library out of necessity -- it deals
entirely in the IR. The .cpp file in fact was already part of the VMCore
library. This is just a mechanical move.

I've tried to go through and re-apply the coding standard's preferred
header sort, but at 40-ish files, I may have gotten some wrong. Please
let me know if so.

I'll be committing the corresponding updates to Clang and Polly, and
Duncan has DragonEgg.

Thanks to Bill and Eric for giving the green light for this bit of cleanup.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159421 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-29 12:38:19 +00:00
Nick Lewycky
edb5842b7c Remove dyn_cast + dereference pattern by replacing it with a cast and changing
the safety check to look for the same type we're going to actually cast to.
Fixes PR13180!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159110 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-24 10:15:42 +00:00
Manman Ren
ee28e0fdd1 SimplifyCFG: fold unconditional branch to its predecessor if profitable.
This patch extends FoldBranchToCommonDest to fold unconditional branches.
For unconditional branches, we fold them if it is easy to update the phi nodes 
in the common successors.

rdar://10554090


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@158392 91177308-0d34-0410-b5e6-96231b3b80d8
2012-06-13 05:43:29 +00:00
Benjamin Kramer
3e933ecb74 SimplifyCFG: Turn the ad-hoc std::pair that represents switch cases into an explicit struct.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157516 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-26 14:29:37 +00:00
Benjamin Kramer
937338cf64 Add support for branch weight metadata to MDBuilder and use it in various places.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@157515 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-26 13:59:43 +00:00
Rafael Espindola
26c8dcc692 Always compute all the bits in ComputeMaskedBits.
This allows us to keep passing reduced masks to SimplifyDemandedBits, but
know about all the bits if SimplifyDemandedBits fails. This allows instcombine
to simplify cases like the one in the included testcase.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154011 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-04 12:51:34 +00:00
Stepan Dyatkovskiy
3d3abe0852 llvm::SwitchInst
Renamed methods caseBegin, caseEnd and caseDefault with case_begin, case_end, and case_default.
Added some notes relative to case iterators.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152532 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-11 06:09:17 +00:00
Stepan Dyatkovskiy
c10fa6c801 Taken into account Duncan's comments for r149481 dated by 2nd Feb 2012:
http://lists.cs.uiuc.edu/pipermail/llvm-commits/Week-of-Mon-20120130/136146.html

Implemented CaseIterator and it solves almost all described issues: we don't need to mix operand/case/successor indexing anymore. Base iterator class is implemented as a template since it may be initialized either from "const SwitchInst*" or from "SwitchInst*".

ConstCaseIt is just a read-only iterator.
CaseIt is read-write iterator; it allows to change case successor and case value.

Usage of iterator allows totally remove resolveXXXX methods. All indexing convertions done automatically inside the iterator's getters.

Main way of iterator usage looks like this:
SwitchInst *SI = ... // intialize it somehow

for (SwitchInst::CaseIt i = SI->caseBegin(), e = SI->caseEnd(); i != e; ++i) {
  BasicBlock *BB = i.getCaseSuccessor();
  ConstantInt *V = i.getCaseValue();
  // Do something.
}

If you want to convert case number to TerminatorInst successor index, just use getSuccessorIndex iterator's method.
If you want initialize iterator from TerminatorInst successor index, use CaseIt::fromSuccessorIndex(...) method.

There are also related changes in llvm-clients: klee and clang.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152297 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-08 07:06:20 +00:00
Bill Wendling
aa5abe88d6 [unwind removal] We no longer have 'unwind' instructions being generated, so
remove the code that handles them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149901 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-06 21:16:41 +00:00
Stepan Dyatkovskiy
24473120a2 SwitchInst refactoring.
The purpose of refactoring is to hide operand roles from SwitchInst user (programmer). If you want to play with operands directly, probably you will need lower level methods than SwitchInst ones (TerminatorInst or may be User). After this patch we can reorganize SwitchInst operands and successors as we want.

What was done:

1. Changed semantics of index inside the getCaseValue method:
getCaseValue(0) means "get first case", not a condition. Use getCondition() if you want to resolve the condition. I propose don't mix SwitchInst case indexing with low level indexing (TI successors indexing, User's operands indexing), since it may be dangerous.
2. By the same reason findCaseValue(ConstantInt*) returns actual number of case value. 0 means first case, not default. If there is no case with given value, ErrorIndex will returned.
3. Added getCaseSuccessor method. I propose to avoid usage of TerminatorInst::getSuccessor if you want to resolve case successor BB. Use getCaseSuccessor instead, since internal SwitchInst organization of operands/successors is hidden and may be changed in any moment.
4. Added resolveSuccessorIndex and resolveCaseIndex. The main purpose of these methods is to see how case successors are really mapped in TerminatorInst.
4.1 "resolveSuccessorIndex" was created if you need to level down from SwitchInst to TerminatorInst. It returns TerminatorInst's successor index for given case successor.
4.2 "resolveCaseIndex" converts low level successors index to case index that curresponds to the given successor.

Note: There are also related compatability fix patches for dragonegg, klee, llvm-gcc-4.0, llvm-gcc-4.2, safecode, clang.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149481 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-01 07:49:51 +00:00
Nick Lewycky
6c00c6a181 Gracefully degrade precision in branch probability numbers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148946 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-25 09:43:14 +00:00
Nick Lewycky
f460bf8cd8 Actually, this code handles wrapped sets just fine. Noticed by inspection.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@148487 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-19 18:19:42 +00:00
Dan Gohman
3b205175ea Fix SpeculativelyExecuteBB to either speculate all or none of the phis
present in the bottom of the CFG triangle, as the transformation isn't
ever valuable if the branch can't be eliminated.

Also, unify some heuristics between SimplifyCFG's multiple
if-converters, for consistency.

This fixes rdar://10627242.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147630 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-05 23:58:56 +00:00
Dan Gohman
dd35df15a2 Revert r56315. When the instruction to speculate is a load, this
code can incorrectly move the load across a store. This never
happens in practice today, but only because the current
heuristics accidentally preclude it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147623 91177308-0d34-0410-b5e6-96231b3b80d8
2012-01-05 22:54:35 +00:00
Nick Lewycky
8da7ddf2d2 Demystify this comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147307 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-28 06:57:32 +00:00
Nick Lewycky
91968489d7 Use false not zero, as a bool.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147292 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-27 18:27:22 +00:00
Nick Lewycky
06cc66f65a Teach simplifycfg to recompute branch weights when merging some branches, and
to discard weights when appropriate. Still more to do (and a new TODO), but
it's a start!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147286 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-27 04:31:52 +00:00
Nick Lewycky
c9a1aed7fe Update the branch weight metadata when reversing the order of a branch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147280 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-26 20:54:14 +00:00
Nick Lewycky
9d52310222 Sort includes, canonicalize whitespace, fix typos. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147279 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-26 20:37:40 +00:00
Nick Lewycky
8369687576 Make some intrinsics safe to speculatively execute.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@147036 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-21 05:52:02 +00:00
Kevin Enderby
67005b311c Revert r146822 at Pete Cooper's request as it broke clang self hosting.
Hope I did this correctly :)


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146834 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-17 19:48:52 +00:00
Pete Cooper
93ca12299f SimplifyCFG now predicts some conditional branches to true or false depending on previous branch on same comparison operands.
For example, 

if (a == b) {
    if (a > b) // this is false
    
Fixes some of the issues on <rdar://problem/10554090>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146822 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-17 06:32:38 +00:00
Dan Gohman
f042660197 Move Instruction::isSafeToSpeculativelyExecute out of VMCore and
into Analysis as a standalone function, since there's no need for
it to be in VMCore. Also, update it to use isKnownNonZero and
other goodies available in Analysis, making it more precise,
enabling more aggressive optimization.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146610 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-14 23:49:11 +00:00
Duncan Sands
ad99ef8bf5 Delete trivial landing pads that just continue unwinding the caught
exception.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139117 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-05 12:57:57 +00:00
Benjamin Kramer
9bb5488dbd Address review comments.
- Reword comments.
- Allow undefined behavior interfering with undefined behavior.
- Add address space checks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138619 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-26 02:25:55 +00:00
Benjamin Kramer
98d6d2372f SimplifyCFG: If we have a PHI node that can evaluate to NULL and do a load or store to the address returned by the PHI node then we can consider this incoming value as dead and remove the edge pointing there, unless there are instructions that can affect control flow executed in between.
In theory this could be extended to other instructions, eg. division by zero, but it's likely that it will "miscompile" some code because people depend on div by zero not trapping. NULL pointer dereference usually leads to a crash so we should be on the safe side.

This shrinks the size of a Release clang by 16k on x86_64.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138618 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-26 01:22:29 +00:00
Bill Wendling
23b49ba6d5 I think there was some confusion about what I meant. :-) Replacing the comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137743 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-16 20:41:17 +00:00
Eli Friedman
6437f2c2e2 After talking with Bill, it seems like the LandingPad handling here is likely
to be wrong (or at least somewhat suspect).  Leave a FIXME for Bill.




git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137694 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-16 00:41:37 +00:00
Eli Friedman
33cb445fb6 Minor comment fixes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137693 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-16 00:20:11 +00:00
Eli Friedman
8176388d65 Update SimplifyCFG for atomic operations.
This commit includes a mention of the landingpad instruction, but it's not
changing the behavior around it.  I think the current behavior is correct,
though.  Bill, can you double-check that?



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@137691 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-15 23:59:28 +00:00
Chris Lattner
db125cfaf5 land David Blaikie's patch to de-constify Type, with a few tweaks.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135375 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-18 04:54:35 +00:00
Jay Foad
a3efbb15dd Convert CallInst and InvokeInst APIs to use ArrayRef.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135265 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-15 08:37:34 +00:00
Rafael Espindola
77a2c372fa Add r134057 back, but splice the predecessor after the successors phi
nodes.

Original message:
Let simplify cfg simplify bb with only debug and lifetime intrinsics.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134182 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-30 20:14:24 +00:00
Chad Rosier
ce77aa3edc Temporarily revert r134057: "Let simplify cfg simplify bb with only debug and
lifetime intrinsics" due to buildbot failures.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134071 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-29 16:22:11 +00:00
Rafael Espindola
0fb7dcd48f Let simplify cfg simplify bb with only debug and lifetime intrinsics.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134057 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-29 05:25:47 +00:00
Hans Wennborg
448da519cc Fix PR10103: Less code for enum type translation.
In cases such as the attached test, where the case value for a switch
destination is used in a phi node that follows the destination, it
might be better to replace that value with the condition value of the
switch, so that more blocks can be folded away with
TryToSimplifyUncondBranchFromEmptyBlock because there are less
conflicts in the phi node.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133344 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-18 10:28:47 +00:00
Bill Wendling
6a648b8538 If the block that we're threading through is jumped to by an indirect branch,
then we don't want to set the destination in the indirect branch to the
destination. This is because the indirect branch needs its destinations to have
had their block addresses taken. This isn't so of the new critical edge that's
split during this process. If it turns out that the destination block has only
one predecessor, and that being a BB with an indirect branch, then it won't be
marked as 'used' and may be removed.
PR10072


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@132638 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-04 09:42:04 +00:00
Frits van Bommel
5649ba70fb Add a parameter to ConstantFoldTerminator() that callers can use to ask it to also clean up the condition of any conditional terminator it folds to be unconditional, if that turns the condition into dead code. This just means it calls RecursivelyDeleteTriviallyDeadInstructions() in strategic spots. It defaults to the old behavior.
I also changed -simplifycfg, -jump-threading and -codegenprepare to use this to produce slightly better code without any extra cleanup passes (AFAICT this was the only place in -simplifycfg where now-dead conditions of replaced terminators weren't being cleaned up). The only other user of this function is -sccp, but I didn't read that thoroughly enough to figure out whether it might be holding pointers to instructions that could be deleted by this.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131855 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-22 16:24:18 +00:00
Devang Patel
d3a1788da1 Reapply r131605. This time with a fix, which is to use NoFolder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131673 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-19 20:52:46 +00:00
Rafael Espindola
216dde91d1 revert 131605 to fix PR9946.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131620 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-19 02:26:30 +00:00
Devang Patel
1f5812bd99 Use IRBuilder.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131609 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-19 00:13:33 +00:00
Devang Patel
1aa89a2f91 Use IRBuilder while simplifying unreachable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131607 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-19 00:09:21 +00:00