Commit Graph

353 Commits

Author SHA1 Message Date
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
Devang Patel
0b4ccdc98c Use IRBuilder while simplifying conditional branch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131605 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 23:59:51 +00:00
Devang Patel
02dd5418d2 Use IRBuilder while simplifying branch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131598 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 23:18:47 +00:00
Devang Patel
176ec40cb1 Use IRBuilder while simplifying return instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131580 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 21:33:11 +00:00
Devang Patel
b55d924b1e Spread use of IRBuilder even more.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131571 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 20:53:17 +00:00
Devang Patel
007349dafd Use IRBuilder while simplifying switch instruction.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131566 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 20:35:38 +00:00
Devang Patel
d46ba26a6b Use IRBuilder while simplifying unwind.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131561 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 20:01:18 +00:00
Devang Patel
d3372b85e6 Use IRBuilder while simplifying terminator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131552 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 18:43:31 +00:00
Devang Patel
a23812cfbd Use IRBuilder while simplifying unconditional branch.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131551 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 18:28:48 +00:00
Devang Patel
f60364de44 Use IRBuilder while folding two entry PHINode.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131548 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 18:16:44 +00:00
Devang Patel
3e410c6607 Set up IRBuilder for use during simplification.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131545 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-18 18:01:27 +00:00
Devang Patel
d80e8ed2fa Preseve line numbers while simplifying CFG.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131508 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-17 23:29:05 +00:00
Benjamin Kramer
10fcfb53fd SimplifyCFG: Use ComputeMaskedBits to prune dead cases from switch instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@131345 91177308-0d34-0410-b5e6-96231b3b80d8
2011-05-14 15:57:25 +00:00
Peter Collingbourne
57808b3da0 SimplifyCFG: Expose phi node folding cost threshold as command line parameter
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130528 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-29 18:47:38 +00:00
Peter Collingbourne
f15907fead SimplifyCFG: Add CostRemaining parameter to DominatesMergePoint
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130527 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-29 18:47:31 +00:00
Peter Collingbourne
8a70192b51 SimplifyCFG: Add Trunc, ZExt and SExt to the list of cheap instructions for phi node folding
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@130526 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-29 18:47:25 +00:00
Chris Lattner
3c6e746b5f rework FoldBranchToCommonDest to exit earlier when there is a bonus
instruction around, reducing work.

Greatly simplify handling of debug instructions.  There is no need to
build up a vector of them and then move them into the one predecessor
if we're processing a block.  Instead just rescan the block and *copy*
them into the pred.  If a block gets merged into multiple preds, this
will retain more debug info.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129502 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-14 02:44:53 +00:00
Chris Lattner
c8fbc34869 comment cleanup, use moveBefore instead of removeFromParent+insertBefore.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129319 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-11 23:24:57 +00:00
Devang Patel
60d490cdc7 Do not let debug info interfer with branch folding.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129114 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-07 23:11:25 +00:00
Devang Patel
949666ea16 While hoisting common code from if/else, hoist debug info intrinsics if they match.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129078 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-07 17:27:36 +00:00
Devang Patel
ae6c95b58e Simplify. isIdenticalToWhenDefined() checks opcode.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129041 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-07 00:30:15 +00:00
Devang Patel
d418194036 While folding branch to a common destination into a predecessor, copy dbg values also.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129035 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-06 22:37:20 +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
Eli Friedman
b1a6eab655 PR9450: Make switch optimization in SimplifyCFG not dependent on the ordering
of pointers in an std::map.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127650 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-15 02:23:35 +00:00
Eli Friedman
2adc5b6a17 PR9420; an instruction before an unreachable is guaranteed not to have any
reachable uses, but there still might be uses in dead blocks.  Use the
standard solution of replacing all the uses with undef.  This is
a rare case because it's very sensitive to phase ordering in SimplifyCFG.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@127299 91177308-0d34-0410-b5e6-96231b3b80d8
2011-03-09 00:48:33 +00:00
Frits van Bommel
f7b2a9d7df Teach SimplifyCFG that (switch (select cond, X, Y)) is better expressed as a branch.
Based on a patch by Alistair Lynn.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126647 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-28 09:44:07 +00:00
Benjamin Kramer
278be783b5 Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."
Yes, there are other types than i8* and GEPs on them can produce an add+multiply.
We don't consider that cheap enough to be speculatively executed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126481 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-25 10:33:33 +00:00
Benjamin Kramer
9ae59e3444 SimplifyCFG: GEPs with just one non-constant index are also cheap.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126452 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-24 23:26:09 +00:00
Benjamin Kramer
9b61c550c2 SimplifyCFG: GEPs with constant indices are cheap enough to be executed unconditionally.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@126445 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-24 22:46:11 +00:00
Benjamin Kramer
33828bcb24 SimplifyCFG: Track the number of used icmps when turning a icmp chain into a switch. If we used only one icmp, don't turn it into a switch.
Also prevent the switch-to-icmp transform from creating identity adds, noticed by Marius Wachtler.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@125056 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-07 22:37:28 +00:00
Benjamin Kramer
042b27f40e SimplifyCFG: Also transform switches that represent a range comparison but are not sorted into sub+icmp.
This transforms another 1000 switches in gcc.c.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@124826 91177308-0d34-0410-b5e6-96231b3b80d8
2011-02-03 22:51:41 +00:00