Commit Graph

186 Commits

Author SHA1 Message Date
Bill Wendling
3e033f2923 Don't eliminate a partially redundant load if it's in a landing pad.
A landing pad can be jumped to only by the unwind edge of an invoke
instruction. If we eliminate a partially redundant load in a landing pad, it
will create a basic block that violates this constraint. It then leads to other
problems down the line if it tries to merge that basic block with the landing
pad. Avoid this by not eliminating the load in a landing pad.

PR17621


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193064 91177308-0d34-0410-b5e6-96231b3b80d8
2013-10-21 04:09:17 +00:00
Benjamin Kramer
c11b107f21 JumpThreading: Turn a select instruction into branching if it allows to thread one half of the select.
This is a common pattern coming out of simplifycfg generating gross code.

a:                                       ; preds = %entry
  %sel = select i1 %cmp1, double %add, double 0.000000e+00
  br label %b

b:
  %cond5 = phi double [ %sel, %a ], [ %sub, %entry ]
  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
  br i1 %cmp6, label %if.then, label %if.end

becomes

a:
  br i1 %cmp1, label %b, label %if.then

b:
  %cond5 = phi double [ %sub, %entry ], [ %add, %a ]
  %cmp6 = fcmp oeq double %cond5, 0.000000e+00
  br i1 %cmp6, label %if.then, label %if.end

Skipping block b completely if possible.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187880 91177308-0d34-0410-b5e6-96231b3b80d8
2013-08-07 10:29:38 +00:00
Nick Lewycky
81e480463d Reimplement isPotentiallyReachable to make nocapture deduction much stronger.
Adds unit tests for it too.

Split BasicBlockUtils into an analysis-half and a transforms-half, and put the
analysis bits into a new Analysis/CFG.{h,cpp}. Promote isPotentiallyReachable
into llvm::isPotentiallyReachable and move it into Analysis/CFG.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187283 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-27 01:24:00 +00:00
Chandler Carruth
0b8c9a80f2 Move all of the header files which are involved in modelling the LLVM IR
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.

There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.

The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.

I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).

I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-02 11:36:10 +00:00
James Molloy
67ae135759 Add a new attribute, 'noduplicate'. If a function contains a noduplicate call, the call cannot be duplicated - Jump threading, loop unrolling, loop unswitching, and loop rotation are inhibited if they would duplicate the call.
Similarly inlining of the function is inhibited, if that would duplicate the call (in particular inlining is still allowed when there is only one callsite and the function has internal linkage).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170704 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-20 16:04:27 +00:00
Nadav Rotem
c69908695a Teach the jump threading optimization to stop scanning the basic block when calculating the cost after passing the threshold.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169135 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03 17:34:44 +00:00
Chandler Carruth
d04a8d4b33 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03 16:50:05 +00:00
Micah Villmow
3574eca1b0 Move TargetData to DataLayout.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165402 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 16:38:25 +00:00
Benjamin Kramer
8e0d1c03ca Make MemoryBuiltins aware of TargetLibraryInfo.
This disables malloc-specific optimization when -fno-builtin (or -ffreestanding)
is specified. This has been a problem for a long time but became more severe
with the recent memory builtin improvements.

Since the memory builtin functions are used everywhere, this required passing
TLI in many places. This means that functions that now have an optional TLI
argument, like RecursivelyDeleteTriviallyDeadFunctions, won't remove dead
mallocs anymore if the TLI argument is missing. I've updated most passes to do
the right thing.

Fixes PR13694 and probably others.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162841 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-29 15:32:21 +00:00
Nadav Rotem
a94d6e87c4 Clean whitespaces.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160668 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-24 10:51:42 +00:00
Richard Osborne
dd2fb6c10b Fix assertion in jump threading (PR13405).
GetBestDestForJumpOnUndef() assumes there is at least 1 successor, which isn't
true if the block ends in an indirect branch with no successors. Fix this by
bailing out earlier in this case.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160546 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-20 10:36:17 +00:00
Chris Lattner
5161de6ebb enhance jump threading to preserve TBAA information when PRE'ing loads,
fixing rdar://11039258, an issue that came up when inspecting clang's 
bootstrapped codegen.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@152635 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-13 18:07:41 +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
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
Jakub Staszak
2fac1d5d61 SplitBlockPredecessors uses ArrayRef instead of Data and Size.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146277 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-09 21:19:53 +00:00
Chad Rosier
aab8e28d5e Fix a few more places where TargetData/TargetLibraryInfo is not being passed.
Add FIXMEs to places that are non-trivial to fix.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145661 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-02 01:26:24 +00:00
Eli Friedman
2bc3d52b9a Change a bunch of isVolatile() checks to check for atomic load/store as well.
No tests; these changes aren't really interesting in the sense that the logic is the same for volatile and atomic.

I believe this completes all of the changes necessary for the optimizer to handle loads and stores correctly.  I'm going to try and come up with some additional testing, though.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@139533 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-12 20:23:13 +00:00
Jakub Staszak
f227b50a8e Calculate GetBestDestForJumpOnUndef correctly.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133946 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-27 21:51:12 +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
95a7de6b91 Preserve line number information while threading jumps.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130880 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-04 22:48:19 +00:00
Owen Anderson
f6832bbda0 Fix an infinite alternation in JumpThreading where two transforms would repeatedly undo each other. The solution is to perform more aggressive constant folding to make one of the edges just folded away rather than trying to thread it.
Fixes <rdar://problem/9284786>.

Discovered with CSmith.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129538 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-14 21:35:50 +00:00
Jay Foad
3ecfc861b4 Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
PHINode::Create() giving the (known or expected) number of operands.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128537 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-30 11:28:46 +00:00
Jay Foad
d8b4fb4aab (Almost) always call reserveOperandSpace() on newly created PHINodes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@128535 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-30 11:19:20 +00:00
Chris Lattner
78f7a25f98 prevent jump threading from merging blocks when their address is
taken (and used!).  This prevents merging the blocks (invalidating
the block addresses) in a case like this:

#define _THIS_IP_  ({ __label__ __here; __here: (unsigned long)&&__here; })

void foo() {
  printf("%p\n", _THIS_IP_);
  printf("%p\n", _THIS_IP_);
  printf("%p\n", _THIS_IP_);
}

which fixes PR4151.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125829 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-18 04:43:06 +00:00
Frits van Bommel
01abcf339f Fix a bug in the loop in JumpThreading::ProcessThreadableEdges() where it could falsely produce a MultipleDestSentinel value if the first predecessor ended with an 'indirectbr'. If that happened, it caused an unnecessary FindMostPopularDest() call.
This wasn't a correctness problem, but it broke the fast path for single-predecessor blocks.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121966 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-16 12:16:00 +00:00
Frits van Bommel
26e097ca4b Teach jump threading to "look through" a select when the branch direction of a terminator depends on it.
When it sees a promising select it now tries to figure out whether the condition of the select is known in any of the predecessors and if so it maps the operands appropriately.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121859 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-15 09:51:20 +00:00
Chris Lattner
e991b5fdd5 simplify code and reduce indentation
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121670 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-13 02:38:13 +00:00
Frits van Bommel
8e8cdc8fe0 Remove some dead code from the jump threading pass.
The last uses of these functions were removed in r113852 when LazyValueInfo was permanently enabled and removed the need for them.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121133 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-07 13:08:07 +00:00
Frits van Bommel
6033b346e2 Implement jump threading of 'indirectbr' by keeping track of whether we're looking for ConstantInt*s or BlockAddress*s.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@121066 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-06 23:36:56 +00:00
Frits van Bommel
ea388f217b Refactor jump threading.
Should have no functional change other than the order of two transformations that are mutually-exclusive and the exact formatting of debug output.
Internally, it now stores the ConstantInt*s as Constant*s, and actual undef values instead of nulls.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120946 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-05 19:06:41 +00:00
Frits van Bommel
6f9a8307e0 Remove trailing whitespace.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@120945 91177308-0d34-0410-b5e6-96231b3b80d8
2010-12-05 19:02:47 +00:00
Owen Anderson
081c34b725 Get rid of static constructors for pass registration. Instead, every pass exposes an initializeMyPassFunction(), which
must be called in the pass's constructor.  This function uses static dependency declarations to recursively initialize
the pass's dependencies.

Clients that only create passes through the createFooPass() APIs will require no changes.  Clients that want to use the
CommandLine options for passes will need to manually call the appropriate initialization functions in PassInitialization.h
before parsing commandline arguments.

I have tested this with all standard configurations of clang and llvm-gcc on Darwin.  It is possible that there are problems
with the static dependencies that will only be visible with non-standard options.  If you encounter any crash in pass
registration/creation, please send the testcase to me directly.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116820 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-19 17:21:58 +00:00
Owen Anderson
2ab36d3502 Begin adding static dependence information to passes, which will allow us to
perform initialization without static constructors AND without explicit initialization
by the client.  For the moment, passes are required to initialize both their
(potential) dependencies and any passes they preserve.  I hope to be able to relax
the latter requirement in the future.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@116334 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-12 19:48:12 +00:00
Owen Anderson
ce665bd2e2 Now with fewer extraneous semicolons!
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115996 91177308-0d34-0410-b5e6-96231b3b80d8
2010-10-07 22:25:06 +00:00
Owen Anderson
36c4debc94 Fix PR8247: JumpThreading can cause a block to become unreachable while still having predecessor, if it is part of a self-loop.
Because of this, we cannot use the Simplify* APIs, as they can assert-fail on unreachable code.  Since it's not easy to determine
if a given threading will cause a block to become unreachable, simply defer simplifying simplification to later InstCombine and/or
DCE passes.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@115082 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-29 20:34:41 +00:00
Owen Anderson
c809d90bca Remove the option to disable LazyValueInfo in JumpThreading, as it is now
on by default and has received significant testing.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113852 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-14 20:57:41 +00:00
Chris Lattner
bdabacdcca Change lower atomic pass to use IntrinsicInst to simplify it a bit.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113114 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-05 20:10:47 +00:00
Chris Lattner
906a675db8 eliminate some non-obvious casts. UndefValue isa Constant.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@113113 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-05 20:03:09 +00:00
Duncan Sands
fc6e29d4ab Reapply commit 112699, speculatively reverted by echristo, since
I'm sure it is harmless.  Original commit message:
If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory.  Instead, simply pass
in the type and name explicitly, which is all that was used anyway.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112810 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-02 08:14:03 +00:00
Owen Anderson
9bfa6fec06 JumpThreading keeps LazyValueInfo up to date, so we don't need to rerun it
if we schedule another LVI-using pass afterwards.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112722 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01 18:27:22 +00:00
Eric Christopher
adc581f5cb Speculatively revert 112699 and 112702, they seem to be causing
self host errors on clang-x86-64.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112719 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01 17:29:10 +00:00
Duncan Sands
4d588bceb0 If PrototypeValue is erased in the middle of using the SSAUpdator
then the SSAUpdator may access freed memory.  Instead, simply pass
in the type and name explicitly, which is all that was used anyway.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112699 91177308-0d34-0410-b5e6-96231b3b80d8
2010-09-01 10:29:33 +00:00
Owen Anderson
0eb355ab6b More cleanups of my JumpThreading transforms, including extracting some duplicated code into a helper function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112634 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31 20:26:04 +00:00
Owen Anderson
9ba353627a Add an RAII helper to make cleanup of the RecursionSet more fool-proof.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112628 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31 19:24:27 +00:00
Owen Anderson
c1bdac66ff Refactor my fix for PR5652 to terminate the predecessor lookups after the first failure.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112620 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31 18:48:48 +00:00
Owen Anderson
cb21190cbd More Chris-inspired JumpThreading fixes: use ConstantExpr to correctly constant-fold undef, and be more careful with its return value.
This actually exposed an infinite recursion bug in ComputeValueKnownInPredecessors which theoretically already existed (in JumpThreading's
handling of and/or of i1's), but never manifested before.  This patch adds a tracking set to prevent this case.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112589 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-31 07:36:34 +00:00
Owen Anderson
327ca7bec2 Re-apply r112539, being more careful to respect the return values of the constant folding methods. Additionally,
use the ConstantExpr::get*() methods to simplify some constant folding.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112550 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30 23:22:36 +00:00
Owen Anderson
d930f205db Revert r112539. It accidentally introduced a miscompilation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112543 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30 22:33:41 +00:00
Owen Anderson
1e35610f20 Fixes and cleanups pointed out by Chris. In general, be careful to handle 0 results from ComputeValueKnownInPredecessors
(indicating undef), and re-use existing constant folding APIs.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112539 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-30 22:07:52 +00:00
Owen Anderson
fc2fb17fb7 Fix typos in comments.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112286 91177308-0d34-0410-b5e6-96231b3b80d8
2010-08-27 20:32:56 +00:00