summaryrefslogtreecommitdiffstats
path: root/llvm/lib/CodeGen/TailDuplicator.cpp
Commit message (Collapse)AuthorAgeFilesLines
* Rename DEBUG macro to LLVM_DEBUG.Nicola Zaghen2018-05-141-10/+10
| | | | | | | | | | | | | | | | The DEBUG() macro is very generic so it might clash with other projects. The renaming was done as follows: - git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g' - git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM - Manual change to APInt - Manually chage DOCS as regex doesn't match it. In the transition period the DEBUG() macro is still present and aliased to the LLVM_DEBUG() one. Differential Revision: https://reviews.llvm.org/D43624 llvm-svn: 332240
* [DWARF] Allow duplication of tails with CFI instructionsPetar Jovanovic2018-01-311-2/+16
| | | | | | | | | | | | | | | | | | This commit came as a result for revert of patch r317579 (originally committed as r317100). The patch made CFI instructions duplicable, because their existence in the epilogue block was affecting the Tail duplication pass. However, duplicating blocks with CFI instructions was an issue for compact unwind info on Darwin, which is why the patch was reverted. This patch allows duplicating tails with CFI instructions, though they are not duplicable, by copying them 'manually'. Patch by Djordje Kovacevic. Differential Revision: https://reviews.llvm.org/D40979 llvm-svn: 323883
* MachineFunction: Return reference from getFunction(); NFCMatthias Braun2017-12-151-1/+1
| | | | | | The Function can never be nullptr so we can return a reference. llvm-svn: 320884
* [CodeGen] Unify MBB reference format in both MIR and debug outputFrancis Visoiu Mistrih2017-12-041-10/+13
| | | | | | | | | | | | | | | | As part of the unification of the debug format and the MIR format, print MBB references as '%bb.5'. The MIR printer prints the IR name of a MBB only for block definitions. * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)->getNumber\(\)/" << printMBBReference(*\1)/g' * find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#" << ([a-zA-Z0-9_]+)\.getNumber\(\)/" << printMBBReference(\1)/g' * find . \( -name "*.txt" -o -name "*.s" -o -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" \) -type f -print0 | xargs -0 sed -i '' -E 's/BB#([0-9]+)/%bb.\1/g' * grep -nr 'BB#' and fix Differential Revision: https://reviews.llvm.org/D40422 llvm-svn: 319665
* Fix a bunch more layering of CodeGen headers that are in TargetDavid Blaikie2017-11-171-2/+2
| | | | | | | | All these headers already depend on CodeGen headers so moving them into CodeGen fixes the layering (since CodeGen depends on Target, not the other way around). llvm-svn: 318490
* Revert "Correct dwarf unwind information in function epilogue for X86"Reid Kleckner2017-11-081-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This reverts r317579, originally committed as r317100. There is a design issue with marking CFI instructions duplicatable. Not all targets support the CFIInstrInserter pass, and targets like Darwin can't cope with duplicated prologue setup CFI instructions. The compact unwind info emission fails. When the following code is compiled for arm64 on Mac at -O3, the CFI instructions end up getting tail duplicated, which causes compact unwind info emission to fail: int a, c, d, e, f, g, h, i, j, k, l, m; void n(int o, int *b) { if (g) f = 0; for (; f < o; f++) { m = a; if (l > j * k > i) j = i = k = d; h = b[c] - e; } } We get assembly that looks like this: ; BB#1: ; %if.then Lloh3: adrp x9, _f@GOTPAGE Lloh4: ldr x9, [x9, _f@GOTPAGEOFF] mov w8, wzr Lloh5: str wzr, [x9] stp x20, x19, [sp, #-16]! ; 8-byte Folded Spill .cfi_def_cfa_offset 16 .cfi_offset w19, -8 .cfi_offset w20, -16 cmp w8, w0 b.lt LBB0_3 b LBB0_7 LBB0_2: ; %entry.if.end_crit_edge Lloh6: adrp x8, _f@GOTPAGE Lloh7: ldr x8, [x8, _f@GOTPAGEOFF] Lloh8: ldr w8, [x8] stp x20, x19, [sp, #-16]! ; 8-byte Folded Spill .cfi_def_cfa_offset 16 .cfi_offset w19, -8 .cfi_offset w20, -16 cmp w8, w0 b.ge LBB0_7 LBB0_3: ; %for.body.lr.ph Note the multiple .cfi_def* directives. Compact unwind info emission can't handle that. llvm-svn: 317726
* Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layeringDavid Blaikie2017-11-081-3/+3
| | | | | | | | This header includes CodeGen headers, and is not, itself, included by any Target headers, so move it into CodeGen to match the layering of its implementation. llvm-svn: 317647
* Reland "Correct dwarf unwind information in function epilogue for X86"Petar Jovanovic2017-11-071-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Reland r317100 with minor fix regarding ComputeCommonTailLength function in BranchFolding.cpp. Skipping top CFI instructions block needs to executed on several more return points in ComputeCommonTailLength(). Original r317100 message: "Correct dwarf unwind information in function epilogue for X86" This patch aims to provide correct dwarf unwind information in function epilogue for X86. It consists of two parts. The first part inserts CFI instructions that set appropriate cfa offset and cfa register in emitEpilogue() in X86FrameLowering. This part is X86 specific. The second part is platform independent and ensures that: - CFI instructions do not affect code generation - Unwind information remains correct when a function is modified by different passes. This is done in a late pass by analyzing information about cfa offset and cfa register in BBs and inserting additional CFI directives where necessary. Changed CFI instructions so that they: - are duplicable - are not counted as instructions when tail duplicating or tail merging - can be compared as equal Added CFIInstrInserter pass: - analyzes each basic block to determine cfa offset and register valid at its entry and exit - verifies that outgoing cfa offset and register of predecessor blocks match incoming values of their successors - inserts additional CFI directives at basic block beginning to correct the rule for calculating CFA Having CFI instructions in function epilogue can cause incorrect CFA calculation rule for some basic blocks. This can happen if, due to basic block reordering, or the existence of multiple epilogue blocks, some of the blocks have wrong cfa offset and register values set by the epilogue block above them. CFIInstrInserter is currently run only on X86, but can be used by any target that implements support for adding CFI instructions in epilogue. Patch by Violeta Vukobrat. llvm-svn: 317579
* Revert "Correct dwarf unwind information in function epilogue for X86"Petar Jovanovic2017-11-011-2/+2
| | | | | | | This reverts r317100 as it introduced sanitizer-x86_64-linux-autoconf buildbot failure (build #15606). llvm-svn: 317136
* Correct dwarf unwind information in function epilogue for X86Petar Jovanovic2017-11-011-2/+2
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This patch aims to provide correct dwarf unwind information in function epilogue for X86. It consists of two parts. The first part inserts CFI instructions that set appropriate cfa offset and cfa register in emitEpilogue() in X86FrameLowering. This part is X86 specific. The second part is platform independent and ensures that: - CFI instructions do not affect code generation - Unwind information remains correct when a function is modified by different passes. This is done in a late pass by analyzing information about cfa offset and cfa register in BBs and inserting additional CFI directives where necessary. Changed CFI instructions so that they: - are duplicable - are not counted as instructions when tail duplicating or tail merging - can be compared as equal Added CFIInstrInserter pass: - analyzes each basic block to determine cfa offset and register valid at its entry and exit - verifies that outgoing cfa offset and register of predecessor blocks match incoming values of their successors - inserts additional CFI directives at basic block beginning to correct the rule for calculating CFA Having CFI instructions in function epilogue can cause incorrect CFA calculation rule for some basic blocks. This can happen if, due to basic block reordering, or the existence of multiple epilogue blocks, some of the blocks have wrong cfa offset and register values set by the epilogue block above them. CFIInstrInserter is currently run only on X86, but can be used by any target that implements support for adding CFI instructions in epilogue. Patch by Violeta Vukobrat. Differential Revision: https://reviews.llvm.org/D35844 llvm-svn: 317100
* Add test case for r311511Matthias Braun2017-08-231-2/+2
| | | | | | | | This also changes the TailDuplicator to be configured explicitely pre/post regalloc rather than relying on the isSSA() flag. This was necessary to have `llc -run-pass` work reliably. llvm-svn: 311520
* TargetInstrInfo: Change duplicate() to work on bundles.Matthias Braun2017-08-221-8/+5
| | | | | | | | | | | | | | Adds infrastructure to clone whole instruction bundles rather than just single instructions. This fixes a bug where tail duplication would unbundle instructions while cloning. This should unbreak the "Clang Stage 1: cmake, RA, with expensive checks enabled" build on greendragon. The bot broke with r311139 hitting this pre-existing bug. A proper testcase will come next. llvm-svn: 311511
* Revert "r306529 - [X86] Correct dwarf unwind information in function epilogue"Daniel Jasper2017-06-291-8/+2
| | | | | | | | | | I am 99% sure that this breaks the PPC ASAN build bot: http://lab.llvm.org:8011/builders/sanitizer-ppc64be-linux/builds/3112/steps/64-bit%20check-asan/logs/stdio If it doesn't go back to green, we can recommit (and fix the original commit message at the same time :) ). llvm-svn: 306676
* [X86] Correct dwarf unwind information in function epiloguePetar Jovanovic2017-06-281-2/+8
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | CFI instructions that set appropriate cfa offset and cfa register are now inserted in emitEpilogue() in X86FrameLowering. Majority of the changes in this patch: 1. Ensure that CFI instructions do not affect code generation. 2. Enable maintaining correct information about cfa offset and cfa register in a function when basic blocks are reordered, merged, split, duplicated. These changes are target independent and described below. Changed CFI instructions so that they: 1. are duplicable 2. are not counted as instructions when tail duplicating or tail merging 3. can be compared as equal Add information to each MachineBasicBlock about cfa offset and cfa register that are valid at its entry and exit (incoming and outgoing CFI info). Add support for updating this information when basic blocks are merged, split, duplicated, created. Add a verification pass (CFIInfoVerifier) that checks that outgoing cfa offset and register of predecessor blocks match incoming values of their successors. Incoming and outgoing CFI information is used by a late pass (CFIInstrInserter) that corrects CFA calculation rule for a basic block if needed. That means that additional CFI instructions get inserted at basic block beginning to correct the rule for calculating CFA. Having CFI instructions in function epilogue can cause incorrect CFA calculation rule for some basic blocks. This can happen if, due to basic block reordering, or the existence of multiple epilogue blocks, some of the blocks have wrong cfa offset and register values set by the epilogue block above them. Patch by Violeta Vukobrat. Differential Revision: https://reviews.llvm.org/D18046 llvm-svn: 306529
* [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use ↵Eugene Zelenko2017-06-071-14/+24
| | | | | | warnings; other minor fixes (NFC). llvm-svn: 304954
* [CodeGen] Fix uninitialized variables exposed by r303084Vitaly Buka2017-05-221-2/+2
| | | | | | | All other calls of analyzeBranch reset PredTBB and PredFBB, so I assume it's expected behavior. llvm-svn: 303581
* [TailDuplicator] Maintain DebugLoc for branch instructionsTaewook Oh2017-02-271-1/+2
| | | | | | | | | | | | | | Summary: Existing implementation of duplicateSimpleBB function drops DebugLoc metadata of branch instructions during the transformation. This patch addresses this issue by making newly created branch instructions to keep the metadata of replaced branch instructions. Reviewers: qcolombet, craig.topper, aprantl, MatzeB, sanjoy, dblaikie Reviewed By: dblaikie Subscribers: dblaikie, llvm-commits Differential Revision: https://reviews.llvm.org/D30026 llvm-svn: 296371
* [MachineBlockPlacement] Don't make blocks "uneditable"Sanjoy Das2016-12-151-7/+7
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | Summary: This fixes an issue with MachineBlockPlacement due to a badly timed call to `analyzeBranch` with `AllowModify` set to true. The timeline is as follows: 1. `MachineBlockPlacement::maybeTailDuplicateBlock` calls `TailDup.shouldTailDuplicate` on its argument, which in turn calls `analyzeBranch` with `AllowModify` set to true. 2. This `analyzeBranch` call edits the terminator sequence of the block based on the physical layout of the machine function, turning an unanalyzable non-fallthrough block to a unanalyzable fallthrough block. Normally MBP bails out of rearranging such blocks, but this block was unanalyzable non-fallthrough (and thus rearrangeable) the first time MBP looked at it, and so it goes ahead and decides where it should be placed in the function. 3. When placing this block MBP fails to analyze and thus update the block in keeping with the new physical layout. Concretely, before (1) we have something like: ``` LBL0: < unknown terminator op that may branch to LBL1 > jmp LBL1 LBL1: ... A LBL2: ... B ``` In (2), analyze branch simplifies this to ``` LBL0: < unknown terminator op that may branch to LBL2 > ;; jmp LBL1 <- redundant jump removed LBL1: ... A LBL2: ... B ``` In (3), MachineBlockPlacement goes ahead with its plan of putting LBL2 after the first block since that is profitable. ``` LBL0: < unknown terminator op that may branch to LBL2 > ;; jmp LBL1 <- redundant jump LBL2: ... B LBL1: ... A ``` and the program now has incorrect behavior (we no longer fall-through from `LBL0` to `LBL1`) because MBP can no longer edit LBL0. There are several possible solutions, but I went with removing the teeth off of the `analyzeBranch` calls in TailDuplicator. That makes thinking about the result of these calls easier, and breaks nothing in the lit test suite. I've also added some bookkeeping to the MachineBlockPlacement pass and used that to write an assert that would have caught this. Reviewers: chandlerc, gberry, MatzeB, iteratee Subscribers: mcrosier, llvm-commits Differential Revision: https://reviews.llvm.org/D27783 llvm-svn: 289764
* Codegen: Tail-duplicate during placement.Kyle Butt2016-10-111-13/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tail duplication pass uses an assumed layout when making duplication decisions. This is fine, but passes up duplication opportunities that may arise when blocks are outlined. Because we want the updated CFG to affect subsequent placement decisions, this change must occur during placement. In order to achieve this goal, TailDuplicationPass is split into a utility class, TailDuplicator, and the pass itself. The pass delegates nearly everything to the TailDuplicator object, except for looping over the blocks in a function. This allows the same code to be used for tail duplication in both places. This change, in concert with outlining optional branches, allows triangle shaped code to perform much better, esepecially when the taken/untaken branches are correlated, as it creates a second spine when the tests are small enough. Issue from previous rollback fixed, and a new test was added for that case as well. Issue was worklist/scheduling/taildup issue in layout. Issue from 2nd rollback fixed, with 2 additional tests. Issue was tail merging/loop info/tail-duplication causing issue with loops that share a header block. Issue with early tail-duplication of blocks that branch to a fallthrough predecessor fixed with test case: tail-dup-branch-to-fallthrough.ll Differential revision: https://reviews.llvm.org/D18226 llvm-svn: 283934
* Revert "Codegen: Tail-duplicate during placement."Daniel Jasper2016-10-111-50/+13
| | | | | | | | | This reverts commit r283842. test/CodeGen/X86/tail-dup-repeat.ll causes and llc crash with our internal testing. I'll share a link with you. llvm-svn: 283857
* Codegen: Tail-duplicate during placement.Kyle Butt2016-10-111-13/+50
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tail duplication pass uses an assumed layout when making duplication decisions. This is fine, but passes up duplication opportunities that may arise when blocks are outlined. Because we want the updated CFG to affect subsequent placement decisions, this change must occur during placement. In order to achieve this goal, TailDuplicationPass is split into a utility class, TailDuplicator, and the pass itself. The pass delegates nearly everything to the TailDuplicator object, except for looping over the blocks in a function. This allows the same code to be used for tail duplication in both places. This change, in concert with outlining optional branches, allows triangle shaped code to perform much better, esepecially when the taken/untaken branches are correlated, as it creates a second spine when the tests are small enough. Issue from previous rollback fixed, and a new test was added for that case as well. Issue was worklist/scheduling/taildup issue in layout. Issue from 2nd rollback fixed, with 2 additional tests. Issue was tail merging/loop info/tail-duplication causing issue with loops that share a header block. Issue with early tail-duplication of blocks that branch to a fallthrough predecessor fixed with test case: tail-dup-branch-to-fallthrough.ll Differential revision: https://reviews.llvm.org/D18226 llvm-svn: 283842
* Revert "Codegen: Tail-duplicate during placement."Kyle Butt2016-10-081-46/+13
| | | | | | This reverts commit 71c312652c10f1855b28d06697c08d47e7a243e4. llvm-svn: 283647
* Codegen: Tail-duplicate during placement.Kyle Butt2016-10-071-13/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | The tail duplication pass uses an assumed layout when making duplication decisions. This is fine, but passes up duplication opportunities that may arise when blocks are outlined. Because we want the updated CFG to affect subsequent placement decisions, this change must occur during placement. In order to achieve this goal, TailDuplicationPass is split into a utility class, TailDuplicator, and the pass itself. The pass delegates nearly everything to the TailDuplicator object, except for looping over the blocks in a function. This allows the same code to be used for tail duplication in both places. This change, in concert with outlining optional branches, allows triangle shaped code to perform much better, esepecially when the taken/untaken branches are correlated, as it creates a second spine when the tests are small enough. Issue from previous rollback fixed, and a new test was added for that case as well. Issue was worklist/scheduling/taildup issue in layout. Issue from 2nd rollback fixed, with 2 additional tests. Issue was tail merging/loop info/tail-duplication causing issue with loops that share a header block. Differential revision: https://reviews.llvm.org/D18226 llvm-svn: 283619
* Revert "Codegen: Tail-duplicate during placement."Kyle Butt2016-10-051-46/+13
| | | | | | | | | | This reverts commit 062ace9764953e9769142c1099281a345f9b6bdc. Issue with loop info and block removal revealed by polly. I have a fix for this issue already in another patch, I'll re-roll this together with that fix, and a test case. llvm-svn: 283292
* Codegen: Tail-duplicate during placement.Kyle Butt2016-10-041-13/+46
| | | | | | | | | | | | | | | | | | | | | | | | | | The tail duplication pass uses an assumed layout when making duplication decisions. This is fine, but passes up duplication opportunities that may arise when blocks are outlined. Because we want the updated CFG to affect subsequent placement decisions, this change must occur during placement. In order to achieve this goal, TailDuplicationPass is split into a utility class, TailDuplicator, and the pass itself. The pass delegates nearly everything to the TailDuplicator object, except for looping over the blocks in a function. This allows the same code to be used for tail duplication in both places. This change, in concert with outlining optional branches, allows triangle shaped code to perform much better, esepecially when the taken/untaken branches are correlated, as it creates a second spine when the tests are small enough. Issue from previous rollback fixed, and a new test was added for that case as well. Differential revision: https://reviews.llvm.org/D18226 llvm-svn: 283274
* Revert "Codegen: Tail-duplicate during placement."Kyle Butt2016-10-041-46/+13
| | | | | | | | This reverts commit ff234efbe23528e4f4c80c78057b920a51f434b2. Causing crashes on aarch64 build. llvm-svn: 283172
* Codegen: Tail-duplicate during placement.Kyle Butt2016-10-041-13/+46
| | | | | | | | | | | | | | | | | | | | | The tail duplication pass uses an assumed layout when making duplication decisions. This is fine, but passes up duplication opportunities that may arise when blocks are outlined. Because we want the updated CFG to affect subsequent placement decisions, this change must occur during placement. In order to achieve this goal, TailDuplicationPass is split into a utility class, TailDuplicator, and the pass itself. The pass delegates nearly everything to the TailDuplicator object, except for looping over the blocks in a function. This allows the same code to be used for tail duplication in both places. This change, in concert with outlining optional branches, allows triangle shaped code to perform much better, esepecially when the taken/untaken branches are correlated, as it creates a second spine when the tests are small enough. llvm-svn: 283164
* Finish renaming remaining analyzeBranch functionsMatt Arsenault2016-09-141-2/+2
| | | | llvm-svn: 281535
* Make analyzeBranch family of instruction names consistentMatt Arsenault2016-09-141-1/+1
| | | | | | | analyzeBranch was renamed to use lowercase first, rename the related set to match. llvm-svn: 281506
* TailDuplication: Extract Indirect-Branch block limit as option. NFCKyle Butt2016-08-301-3/+9
| | | | | | | | The existing code hard-coded a limit of 20 instructions for duplication when a block ended with an indirect branch. Extract this as an option. No functional change intended. llvm-svn: 280125
* TailDuplication: Record blocks that received the duplicated block. NFC.Kyle Butt2016-08-261-2/+10
| | | | | | | This will allow tail duplication during layout to handle the cfg changes more cleanly. llvm-svn: 279858
* TailDuplication: Don't pass MMI separately from MF. NFCKyle Butt2016-08-251-2/+1
| | | | | | | MMI must match the function passed, and MF has a handle on MMI. Use that instead of accepting it as separate argument. No Functional Change. llvm-svn: 279701
* TailDuplication: Save MF and reduce number of parameters. NFCKyle Butt2016-08-251-22/+21
| | | | | | | | Save the function in the class, and then don't pass it around. This reduces the number of parameters and makes calls to member functions simpler. No Functional Change. llvm-svn: 279700
* TailDuplicator: Fix crash after r278974Matthias Braun2016-08-181-1/+1
| | | | | | | | Some inputs would after r278974 without this fix (see http://lab.llvm.org:8080/green/job/clang-stage2-cmake-RgSan_build/2733/console for an example) llvm-svn: 279022
* Tail Duplication: Accept explicit threshold for duplicating.Kyle Butt2016-08-171-4/+8
| | | | | | | | This will allow tail duplication and tail merging during layout to have a shared threshold to make sure that they don't overlap. No observable change intended. llvm-svn: 278981
* TailDuplicator: Use optForSize instead of hasFnAttribute.Kyle Butt2016-08-171-1/+1
| | | | | | | This will cause minsize functions to have the same threshold as optsize functions, but otherwise should have no effects. llvm-svn: 278980
* Codegen: Don't tail-duplicate blocks with un-analyzable fallthrough.Kyle Butt2016-08-161-0/+10
| | | | | | | | | | | | If AnalyzeBranch can't analyze a block and it is possible to fallthrough, then duplicating the block doesn't make sense, as only one block can be the layout predecessor for the un-analyzable fallthrough. Submitted wit a test case, but NOTE: the test case doesn't currently fail. However, the test case fails with D20505 and would have saved me some time debugging. llvm-svn: 278866
* TailDuplicator: Use range loopsMatt Arsenault2016-08-161-42/+23
| | | | llvm-svn: 278847
* Revert "Codegen: Don't tail-duplicate blocks with un-analyzable fallthrough."Diana Picus2016-08-141-10/+0
| | | | | | | | | This reverts commit r278288. r278287 broke the clang-cmake-thumbv7-a15-full-sh bot. Revert this so we can get to r278287. llvm-svn: 278620
* Use the range variant of find instead of unpacking begin/endDavid Majnemer2016-08-111-1/+1
| | | | | | | | | If the result of the find is only used to compare against end(), just use is_contained instead. No functionality change is intended. llvm-svn: 278433
* Codegen: Don't tail-duplicate blocks with un-analyzable fallthrough.Kyle Butt2016-08-101-0/+10
| | | | | | | | | | | | If AnalyzeBranch can't analyze a block and it is possible to fallthrough, then duplicating the block doesn't make sense, as only one block can be the layout predecessor for the un-analyzable fallthrough. Submitted wit a test case, but NOTE: the test case doesn't currently fail. However, the test case fails with D20505 and would have saved me some time debugging. llvm-svn: 278288
* Codegen: Tail Duplication: Only duplicate into layout pred if it is a CFG Pred.Kyle Butt2016-07-201-0/+2
| | | | | | | | | Add a check that the layout predecessor of a block is an actual CFG predecssor of the block as well. No current code fails this check, but upcoming patches can trigger this, and it makes sense to separate it out. llvm-svn: 276066
* Codegen: Factor out canTailDuplicateKyle Butt2016-07-191-9/+19
| | | | | | | | canTailDuplicate accepts two blocks and returns true if the first can be duplicated into the second successfully. Use this function to encapsulate the heuristic. llvm-svn: 276062
* Rename AnalyzeBranch* to analyzeBranch*.Jacques Pienaar2016-07-151-5/+5
| | | | | | | | | | | | Summary: NFC. Rename AnalyzeBranch/AnalyzeBranchPredicate to analyzeBranch/analyzeBranchPredicate to follow LLVM coding style and be consistent with TargetInstrInfo's analyzeCompare and analyzeSelect. Reviewers: tstellarAMD, mcrosier Subscribers: mcrosier, jholewinski, jfb, arsenm, dschuff, jyknight, dsanders, nemanjai Differential Revision: https://reviews.llvm.org/D22409 llvm-svn: 275564
* TailDuplicator: Remove live-in updating logicMatthias Braun2016-07-061-18/+0
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This logic was introduced in r157663 and does not make any sense to me. The motivating example in rdar://11538365 looks like this: This is the tail: BB#16: derived from LLVM BB %if.end68 Live Ins: %R0 %R4 %R5 Predecessors according to CFG: BB#15 BB#5 tBLXi pred:14, pred:%noreg, <ga:@CFRelease>, %R0<kill>, <regmask>, %LR<imp-def,dead>, %SP<imp-use>, %SP<imp-def> t2B <BB#20>, pred:14, pred:%noreg Successors according to CFG: BB#20 This is the predBB: BB#5: Live Ins: %R5 Predecessors according to CFG: BB#4 %R4<def> = t2MOVi 0, pred:14, pred:%noreg, opt:%noreg t2B <BB#16>, pred:14, pred:%noreg Successors according to CFG: BB#16 However this is invalid machine code to begin with, if %R0 is live-in to BB#16 then it must be live-in to BB#5 as well if BB#5 does not define it. We should not need logic to retroactively fix broken machine code and in fact the example from r157663 passes cleanly with the code removed and I do not see any (newly) failing tests with the machine verifier enabled. Differential Revision: http://reviews.llvm.org/D22031 llvm-svn: 274655
* CodeGen: Use MachineInstr& in TargetInstrInfo, NFCDuncan P. N. Exon Smith2016-06-301-1/+1
| | | | | | | | | | | | | | | | | | | | | | | | | | | | | | This is mostly a mechanical change to make TargetInstrInfo API take MachineInstr& (instead of MachineInstr* or MachineBasicBlock::iterator) when the argument is expected to be a valid MachineInstr. This is a general API improvement. Although it would be possible to do this one function at a time, that would demand a quadratic amount of churn since many of these functions call each other. Instead I've done everything as a block and just updated what was necessary. This is mostly mechanical fixes: adding and removing `*` and `&` operators. The only non-mechanical change is to split ARMBaseInstrInfo::getOperandLatencyImpl out from ARMBaseInstrInfo::getOperandLatency. Previously, the latter took a `MachineInstr*` which it updated to the instruction bundle leader; now, the latter calls the former either with the same `MachineInstr&` or the bundle leader. As a side effect, this removes a bunch of MachineInstr* to MachineBasicBlock::iterator implicit conversions, a necessary step toward fixing PR26753. Note: I updated WebAssembly, Lanai, and AVR (despite being off-by-default) since it turned out to be easy. I couldn't run tests for AVR since llc doesn't link with it turned on. llvm-svn: 274189
* [TailDuplication] Split up NumInstrDups statistic.Geoff Berry2016-06-141-3/+6
| | | | | | | | | | | | Summary: Split NumInstrDups statistic into separate added/removed counts to avoid negative stat being printed as unsigned. Subscribers: mcrosier, llvm-commits Differential Revision: http://reviews.llvm.org/D21335 llvm-svn: 272700
* Pass DebugLoc and SDLoc by const ref.Benjamin Kramer2016-06-121-1/+1
| | | | | | | | This used to be free, copying and moving DebugLocs became expensive after the metadata rewrite. Passing by reference eliminates a ton of track/untrack operations. No functionality change intended. llvm-svn: 272512
* [Tail duplication] Handle source registers with subregistersKrzysztof Parzyszek2016-04-261-34/+80
| | | | | | | | | | | | | | When a block is tail-duplicated, the PHI nodes from that block are replaced with appropriate COPY instructions. When those PHI nodes contained use operands with subregisters, the subregisters were dropped from the COPY instructions, resulting in incorrect code. Keep track of the subregister information and use this information when remapping instructions from the duplicated block. Differential Revision: http://reviews.llvm.org/D19337 llvm-svn: 267583
* CodeGen: Fix a use-after-free in TailDuplicationJustin Bogner2016-04-111-2/+0
| | | | | | | | | | The call to processPHI already erased MI from its parent, so MI isn't even valid here, making the getParent() call a use-after-free in addition to being redundant. Found by ASan with the ArrayRecycler changes in llvm.org/pr26808. llvm-svn: 266008
OpenPOWER on IntegriCloud