29192d042e
Delete trivial landing pads that just continue unwinding the caught
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exception.
llvm-svn: 139117
2011-09-05 12:57:57 +00:00
0655b78ccc
Address review comments.
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- Reword comments.
- Allow undefined behavior interfering with undefined behavior.
- Add address space checks.
llvm-svn: 138619
2011-08-26 02:25:55 +00:00
fb212a6309
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.
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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.
llvm-svn: 138618
2011-08-26 01:22:29 +00:00
55d875fa1c
I think there was some confusion about what I meant. :-) Replacing the comment.
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llvm-svn: 137743
2011-08-16 20:41:17 +00:00
bd39703456
After talking with Bill, it seems like the LandingPad handling here is likely
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to be wrong (or at least somewhat suspect). Leave a FIXME for Bill.
llvm-svn: 137694
2011-08-16 00:41:37 +00:00
b8f30de527
Minor comment fixes.
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llvm-svn: 137693
2011-08-16 00:20:11 +00:00
0ffdf2ea0b
Update SimplifyCFG for atomic operations.
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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?
llvm-svn: 137691
2011-08-15 23:59:28 +00:00
229907cd11
land David Blaikie's patch to de-constify Type, with a few tweaks.
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llvm-svn: 135375
2011-07-18 04:54:35 +00:00
5bd375a6cc
Convert CallInst and InvokeInst APIs to use ArrayRef.
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llvm-svn: 135265
2011-07-15 08:37:34 +00:00
b10a0f223a
Add r134057 back, but splice the predecessor after the successors phi
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nodes.
Original message:
Let simplify cfg simplify bb with only debug and lifetime intrinsics.
llvm-svn: 134182
2011-06-30 20:14:24 +00:00
96ed721d9b
Temporarily revert r134057: "Let simplify cfg simplify bb with only debug and
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lifetime intrinsics" due to buildbot failures.
llvm-svn: 134071
2011-06-29 16:22:11 +00:00
4c0dfcec7e
Let simplify cfg simplify bb with only debug and lifetime intrinsics.
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llvm-svn: 134057
2011-06-29 05:25:47 +00:00
4ab4a8e63a
Fix PR10103: Less code for enum type translation.
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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.
llvm-svn: 133344
2011-06-18 10:28:47 +00:00
4f163dfed1
If the block that we're threading through is jumped to by an indirect branch,
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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
llvm-svn: 132638
2011-06-04 09:42:04 +00:00
ad964559ef
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.
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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.
llvm-svn: 131855
2011-05-22 16:24:18 +00:00
1407fb4bbe
Reapply r131605. This time with a fix, which is to use NoFolder.
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llvm-svn: 131673
2011-05-19 20:52:46 +00:00
964602d7ba
revert 131605 to fix PR9946.
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llvm-svn: 131620
2011-05-19 02:26:30 +00:00
3015a54813
Use IRBuilder.
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llvm-svn: 131609
2011-05-19 00:13:33 +00:00
31458a0002
Use IRBuilder while simplifying unreachable.
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llvm-svn: 131607
2011-05-19 00:09:21 +00:00
4b13f39b77
Use IRBuilder while simplifying conditional branch.
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llvm-svn: 131605
2011-05-18 23:59:51 +00:00
7de6c4bf75
Use IRBuilder while simplifying branch.
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llvm-svn: 131598
2011-05-18 23:18:47 +00:00
dd14e0f7fa
Use IRBuilder while simplifying return instruction.
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llvm-svn: 131580
2011-05-18 21:33:11 +00:00
583805530c
Spread use of IRBuilder even more.
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llvm-svn: 131571
2011-05-18 20:53:17 +00:00
a7ec47d23c
Use IRBuilder while simplifying switch instruction.
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llvm-svn: 131566
2011-05-18 20:35:38 +00:00
0b373dca1f
Use IRBuilder while simplifying unwind.
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llvm-svn: 131561
2011-05-18 20:01:18 +00:00
2c2ea226b7
Use IRBuilder while simplifying terminator.
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llvm-svn: 131552
2011-05-18 18:43:31 +00:00
767f6930bc
Use IRBuilder while simplifying unconditional branch.
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llvm-svn: 131551
2011-05-18 18:28:48 +00:00
5c810ce4a3
Use IRBuilder while folding two entry PHINode.
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llvm-svn: 131548
2011-05-18 18:16:44 +00:00
15ad6761da
Set up IRBuilder for use during simplification.
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llvm-svn: 131545
2011-05-18 18:01:27 +00:00
b849cd511b
Preseve line numbers while simplifying CFG.
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llvm-svn: 131508
2011-05-17 23:29:05 +00:00
d96205c4e5
SimplifyCFG: Use ComputeMaskedBits to prune dead cases from switch instructions.
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llvm-svn: 131345
2011-05-14 15:57:25 +00:00
616044acd5
SimplifyCFG: Expose phi node folding cost threshold as command line parameter
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llvm-svn: 130528
2011-04-29 18:47:38 +00:00
e3511e15e0
SimplifyCFG: Add CostRemaining parameter to DominatesMergePoint
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llvm-svn: 130527
2011-04-29 18:47:31 +00:00
61f6602acd
SimplifyCFG: Add Trunc, ZExt and SExt to the list of cheap instructions for phi node folding
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llvm-svn: 130526
2011-04-29 18:47:25 +00:00
fba5cdfce1
rework FoldBranchToCommonDest to exit earlier when there is a bonus
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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.
llvm-svn: 129502
2011-04-14 02:44:53 +00:00
7d4cdae564
comment cleanup, use moveBefore instead of removeFromParent+insertBefore.
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llvm-svn: 129319
2011-04-11 23:24:57 +00:00
bc3d8b212f
Do not let debug info interfer with branch folding.
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llvm-svn: 129114
2011-04-07 23:11:25 +00:00
197c35298a
While hoisting common code from if/else, hoist debug info intrinsics if they match.
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llvm-svn: 129078
2011-04-07 17:27:36 +00:00
e48ddf863b
Simplify. isIdenticalToWhenDefined() checks opcode.
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llvm-svn: 129041
2011-04-07 00:30:15 +00:00
d715ec82b4
While folding branch to a common destination into a predecessor, copy dbg values also.
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llvm-svn: 129035
2011-04-06 22:37:20 +00:00
52131344a2
Remove PHINode::reserveOperandSpace(). Instead, add a parameter to
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PHINode::Create() giving the (known or expected) number of operands.
llvm-svn: 128537
2011-03-30 11:28:46 +00:00
e0938d8a87
(Almost) always call reserveOperandSpace() on newly created PHINodes.
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llvm-svn: 128535
2011-03-30 11:19:20 +00:00
c4414c6e92
PR9450: Make switch optimization in SimplifyCFG not dependent on the ordering
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of pointers in an std::map.
llvm-svn: 127650
2011-03-15 02:23:35 +00:00
aac35b3fbb
PR9420; an instruction before an unreachable is guaranteed not to have any
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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.
llvm-svn: 127299
2011-03-09 00:48:33 +00:00
8ae07996c9
Teach SimplifyCFG that (switch (select cond, X, Y)) is better expressed as a branch.
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Based on a patch by Alistair Lynn.
llvm-svn: 126647
2011-02-28 09:44:07 +00:00
ceb5daa567
Revert "SimplifyCFG: GEPs with just one non-constant index are also cheap."
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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.
llvm-svn: 126481
2011-02-25 10:33:33 +00:00
dfdca1a14d
SimplifyCFG: GEPs with just one non-constant index are also cheap.
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llvm-svn: 126452
2011-02-24 23:26:09 +00:00
27361a7124
SimplifyCFG: GEPs with constant indices are cheap enough to be executed unconditionally.
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llvm-svn: 126445
2011-02-24 22:46:11 +00:00
8d6a8c130b
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.
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Also prevent the switch-to-icmp transform from creating identity adds, noticed by Marius Wachtler.
llvm-svn: 125056
2011-02-07 22:37:28 +00:00
62aa46b852
SimplifyCFG: Also transform switches that represent a range comparison but are not sorted into sub+icmp.
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This transforms another 1000 switches in gcc.c.
llvm-svn: 124826
2011-02-03 22:51:41 +00:00
Duncan Sands