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path: root/lib/Transforms/Utils/SimplifyCFG.cpp
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2012-12-03Use the new script to sort the includes of every file under lib.Chandler Carruth
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
2012-11-30Fix non-determinism introduced in r168970 and pointed out by Duncan.Chandler Carruth
We're iterating over a non-deterministically ordered container looking for two saturating flags. To do this correctly, we have to saturate both, and only stop looping if both saturate to their final value. Otherwise, which flag we see first changes the result. This is also a micro-optimization of the previous version as now we don't go into the (possibly expensive) test logic once the first violation of either constraint is detected. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168989 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-30Rearrange the comments, control flow, and variable names; noChandler Carruth
functionality changed. Evan's commit r168970 moved the code that the primary comment in this function referred to to the other end of the function without moving the comment, and there has been a steady creep of "boolean" logic in it that is simpler if handled via early exit. That way each special case can have its own comments. I've also made the variable name a bit more explanatory than "AllFit". This is in preparation to fix the non-deterministic output of this function. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168988 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-30Fix logic to determine whether to turn a switch into a lookup table. WhenEvan Cheng
the tables cannot fit in registers (i.e. bitmap), do not emit the table if it's using an illegal type. rdar://12779436 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168970 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-16SimplifyCFG: Don't assume non-null ScalarTargetTransformInfo.Hans Wennborg
Patch by Pekka Jääskeläinen! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168176 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-15misspellAndrew Trick
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168058 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-15whitespaceAndrew Trick
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@168057 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-07Only do switch-to-lookup table transformation when TargetTransformInfoHans Wennborg
is available. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167552 91177308-0d34-0410-b5e6-96231b3b80d8
2012-11-01Revert the series of commits starting with r166578 which introduced theChandler Carruth
getIntPtrType support for multiple address spaces via a pointer type, and also introduced a crasher bug in the constant folder reported in PR14233. These commits also contained several problems that should really be addressed before they are re-committed. I have avoided reverting various cleanups to the DataLayout APIs that are reasonable to have moving forward in order to reduce the amount of churn, and minimize the number of commits that were reverted. I've also manually updated merge conflicts and manually arranged for the getIntPtrType function to stay in DataLayout and to be defined in a plausible way after this revert. Thanks to Duncan for working through this exact strategy with me, and Nick Lewycky for tracking down the really annoying crasher this triggered. (Test case to follow in its own commit.) After discussing with Duncan extensively, and based on a note from Micah, I'm going to continue to back out some more of the more problematic patches in this series in order to ensure we go into the LLVM 3.2 branch with a reasonable story here. I'll send a note to llvmdev explaining what's going on and why. Summary of reverted revisions: r166634: Fix a compiler warning with an unused variable. r166607: Add some cleanup to the DataLayout changes requested by Chandler. r166596: Revert "Back out r166591, not sure why this made it through since I cancelled the command. Bleh, sorry about this! r166591: Delete a directory that wasn't supposed to be checked in yet. r166578: Add in support for getIntPtrType to get the pointer type based on the address space. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167221 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-31Remove fixme about unreachable cases from SwitchToLookupTableHans Wennborg
SimplifyCFG will have removed those cases for us. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167132 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-31Address Duncan's comments on r167121.Hans Wennborg
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167130 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-31Address Duncan's comments on r167115Hans Wennborg
- Use 0 instead of NULL - Helper function for "dyn_cast, else lookup in the constant pool". git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167121 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-31Fix false -> NULL conversion from r167115 spotted by Benjamin Kramer.Hans Wennborg
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167117 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-31Do simple constant propagation in lookup table formation for switchesHans Wennborg
By propagating the value for the switch condition, LLVM can now build lookup tables for code such as: switch (x) { case 1: return 5; case 2: return 42; case 3: case 4: case 5: return x - 123; default: return 123; } Given that x is known for each case, "x - 123" becomes a constant for cases 3, 4, and 5. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167115 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-30Use TargetTransformInfo to control switch-to-lookup table transformationHans Wennborg
When the switch-to-lookup tables transform landed in SimplifyCFG, it was pointed out that this could be inappropriate for some targets. Since there was no way at the time for the pass to know anything about the target, an awkward reverse-transform was added in CodeGenPrepare that turned lookup tables back into switches for some targets. This patch uses the new TargetTransformInfo to determine if a switch should be transformed, and removes CodeGenPrepare::ConvertLoadToSwitch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@167011 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-29Remove a wrapper around getIntPtrType added to GVN by Hal in commit 166624 (theDuncan Sands
wrapper returns a vector of integers when passed a vector of pointers) by having getIntPtrType itself return a vector of integers in this case. Outside of this wrapper, I didn't find anywhere in the codebase that was relying on the old behaviour for vectors of pointers, so give this a whirl through the buildbots. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166939 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-25Also optimize large switch statements.Jakob Stoklund Olesen
The isValueEqualityComparison() guard at the top of SimplifySwitch() only applies to some of the possible transformations. The newer transformations work just fine on large switches, and the check on predecessor count is nonsensical. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166710 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-24Add in support for getIntPtrType to get the pointer type based on the ↵Micah Villmow
address space. This checkin also adds in some tests that utilize these paths and updates some of the clients. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166578 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-14Simplify code. No functionality change.Benjamin Kramer
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165904 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-11PGO: create metadata for switch only if it has more than one targets.Manman Ren
When all cases of a switch statement are dead, the weights vector only has one element, and we will get an ssertion failure when calling createBranchWeights. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165759 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08Move TargetData to DataLayout.Micah Villmow
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165402 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-04SimplifyCFG: Enhance the "remove CFG edge that leads to null pointer ↵Benjamin Kramer
dereference" optimization to also handle instructions with multiple uses. We conservatively only check the first use to avoid walking long use chains. This catches the common case of having both a load and a store to a pointer supplied by a PHI node. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165232 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-01SimplifyCFG: Don't crash when forming a switch bitmap with an undef default ↵Benjamin Kramer
value. Fixes PR13985. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164934 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-30SimplifyCFG: Enumerating all predecessors of a BB can be expensive ↵Benjamin Kramer
(switches), avoid it if possible. No functionality change. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164923 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-27Fix a integer overflow in SimplifyCFG's look up table formation logic.Benjamin Kramer
If the width is very large it gets truncated from uint64_t to uint32_t when passed to TD->fitsInLegalInteger. The truncated value can fit in a register. This manifested in massive memory usage or crashes (PR13946). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164784 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26Address Duncan's comments on r164684:Hans Wennborg
- Put statistics in alphabetical order - Don't use getZextValue when building TableInt, just use APInts - Introduce Create{Z,S}ExtOrTrunc in IRBuilder. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164696 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26Address Duncan's comments on r164682:Hans Wennborg
- Finish assert messages with exclamation mark - Move overflow checking into ShouldBuildLookupTable. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164692 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26SimplifyCFG: Make the switch-to-lookup table transformation store theHans Wennborg
tables in bitmaps when they fit in a target-legal register. This saves some space, and it also allows for building tables that would otherwise be deemed too sparse. One interesting case that this hits is example 7 from http://blog.regehr.org/archives/320. We currently generate good code for this when lowering the switch to the selection DAG: we build a bitmask to decide whether to jump to one block or the other. My patch will result in the same bitmask, but it removes the need for the jump, as the return value can just be retrieved from the mask. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164684 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-26SimplifyCFG: Refactor the switch-to-lookup table transformation byHans Wennborg
breaking out the building of lookup tables into a separate class. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164682 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-20SimplifyCFG: sink common codes from IF, ELSE blocks down to END block.Manman Ren
We already have HoistThenElseCodeToIf, this patch implements SinkThenElseCodeToEnd. When END block has only two predecessors and each predecessor terminates with unconditional branches, we compare instructions in IF and ELSE blocks backwards and check whether we can sink the common instructions down. rdar://12191395 git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164325 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-19SimplifyCFG: Don't generate invalid code for switch used to initializeHans Wennborg
two variables where the first variable is returned and the second ignored. I don't think this occurs in practice (other passes should have cleaned up the unused phi node), but it should still be handled correctly. Also make the logic for determining if we should return early less sketchy. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164225 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-18PGO: preserve branch-weight metadata when simplifying Switch to a sub, an icmpManman Ren
and a conditional branch; also when removing dead cases from a switch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164084 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-17PGO: preserve branch-weight metadata when simplifying SwitchManman Ren
Hanlde the case when we split the default edge if the default target has "icmp" and unconditinal branch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164076 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-17PGO: preserve branch-weight metadata when simplifying SwitchOnSelect.Manman Ren
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164068 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-17PGO: preserve branch-weight metadata when simplifying two branches with a commonManman Ren
destination in SimplifyCondBranchToCondBranch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164054 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-17Fix a few vars that can end up being used without initialization.Axel Naumann
The cases where no initialization happens should still be checked for logic flaws. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164032 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-15PGO: preserve branch-weight metadata when simplifying two branches with a commonManman Ren
destination. Updated previous implementation to fix a case not covered: // PBI: br i1 %x, TrueDest, BB // BI: br i1 %y, TrueDest, FalseDest The other case was handled correctly. // PBI: br i1 %x, BB, FalseDest // BI: br i1 %y, TrueDest, FalseDest Also tried to use 64-bit arithmetic instead of APInt with scale to simplify the computation. Let me know if you have other opinions about this. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163954 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14PGO: preserve branch-weight metadata when simplifying a switch with a singleManman Ren
case to a conditional branch and when removing dead cases. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163942 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14Try to fix the bots by detecting inconsistant branch-weight metadata.Manman Ren
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163926 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-14PGO: preserve branch-weight metadata when merging two switches whereManman Ren
the default target of the first switch is not the basic block the second switch is in (PredDefault != BB). git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163916 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-11SimplifyCFG: preserve branch-weight metadata when creating a new switch fromManman Ren
a pair of switch/branch where both depend on the value of the same variable and the default case of the first switch/branch goes to the second switch/branch. Code clean up and fixed a few issues: 1> handling the case where some cases of the 2nd switch are invalidated 2> correctly calculate the weight for the 2nd switch when it is a conditional eq Testing case is modified from Alastair's original patch. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163635 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-10Fix style issues from r163302 pointed out by Evan.Hans Wennborg
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163491 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-08Remove an incorrect assert during branch weight propagation.Andrew Trick
Patch and test case by Alastair Murray! git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163437 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-07SimplifyCFG: ValidLookupTableConstant should be staticHans Wennborg
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163378 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06Fix switch_to_lookup_table.ll test from r163302.Hans Wennborg
The lookup tables did not get built in a deterministic order. This makes them get built in the order that the corresponding phi nodes were found. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163305 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-06Build lookup tables for switches (PR884)Hans Wennborg
This adds a transformation to SimplifyCFG that attemps to turn switch instructions into loads from lookup tables. It works on switches that are only used to initialize one or more phi nodes in a common successor basic block, for example: int f(int x) { switch (x) { case 0: return 5; case 1: return 4; case 2: return -2; case 5: return 7; case 6: return 9; default: return 42; } This speeds up the code by removing the hard-to-predict jump, and reduces code size by removing the code for the jump targets. git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163302 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-05Stop casting away const qualifier needlessly.Roman Divacky
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163258 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-30testMichael Ilseman
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162914 91177308-0d34-0410-b5e6-96231b3b80d8
2012-08-29Preserve branch profile metadata during switch formation.Andrew Trick
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
2012-08-29whitespaceAndrew Trick
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162867 91177308-0d34-0410-b5e6-96231b3b80d8