Commit Graph

376 Commits

Author SHA1 Message Date
Reid Kleckner 05da2fe521 Sink all InitializePasses.h includes
This file lists every pass in LLVM, and is included by Pass.h, which is
very popular. Every time we add, remove, or rename a pass in LLVM, it
caused lots of recompilation.

I found this fact by looking at this table, which is sorted by the
number of times a file was changed over the last 100,000 git commits
multiplied by the number of object files that depend on it in the
current checkout:
  recompiles    touches affected_files  header
  342380        95      3604    llvm/include/llvm/ADT/STLExtras.h
  314730        234     1345    llvm/include/llvm/InitializePasses.h
  307036        118     2602    llvm/include/llvm/ADT/APInt.h
  213049        59      3611    llvm/include/llvm/Support/MathExtras.h
  170422        47      3626    llvm/include/llvm/Support/Compiler.h
  162225        45      3605    llvm/include/llvm/ADT/Optional.h
  158319        63      2513    llvm/include/llvm/ADT/Triple.h
  140322        39      3598    llvm/include/llvm/ADT/StringRef.h
  137647        59      2333    llvm/include/llvm/Support/Error.h
  131619        73      1803    llvm/include/llvm/Support/FileSystem.h

Before this change, touching InitializePasses.h would cause 1345 files
to recompile. After this change, touching it only causes 550 compiles in
an incremental rebuild.

Reviewers: bkramer, asbirlea, bollu, jdoerfert

Differential Revision: https://reviews.llvm.org/D70211
2019-11-13 16:34:37 -08:00
Jeremy Morse ec32dff0b0 [BranchFolding] skip debug instr to avoid code change
Use the existing helper function in BranchFolding, "countsAsInstruction",
to skip over non-instructions. Otherwise debug instructions can be
identified as the last real instruction in a block, leading to different
codegen decisions when debug is enabled as demonstrated by the test case.

Patch by: yechunliang (Chris Ye)!

Differential Revision: https://reviews.llvm.org/D66467
2019-10-29 11:45:38 +00:00
Nikola Prica 98603a8153 [DebugInfo][If-Converter] Update call site info during the optimization
During the If-Converter optimization pay attention when copying or
deleting call instructions in order to keep call site information in
valid state.

Reviewers: aprantl, vsk, efriedma

Reviewed By: vsk, efriedma

Differential Revision: https://reviews.llvm.org/D66955

llvm-svn: 374068
2019-10-08 15:43:12 +00:00
Simon Pilgrim f609c0a303 BranchFolding - IsBetterFallthrough - assert non-null pointers. NFCI.
Silences static analyzer null dereference warnings.

llvm-svn: 373823
2019-10-05 13:20:30 +00:00
Yuanfang Chen cc382cf727 [NewPM] Port MachineModuleInfo to the new pass manager.
Existing clients are converted to use MachineModuleInfoWrapperPass. The
new interface is for defining a new pass manager API in CodeGen.

Reviewers: fedor.sergeev, philip.pfaffe, chandlerc, arsenm

Reviewed By: arsenm, fedor.sergeev

Differential Revision: https://reviews.llvm.org/D64183

llvm-svn: 373240
2019-09-30 17:54:50 +00:00
Daniel Sanders 0c47611131 Apply llvm-prefer-register-over-unsigned from clang-tidy to LLVM
Summary:
This clang-tidy check is looking for unsigned integer variables whose initializer
starts with an implicit cast from llvm::Register and changes the type of the
variable to llvm::Register (dropping the llvm:: where possible).

Partial reverts in:
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
X86FixupLEAs.cpp - Some functions return unsigned and arguably should be MCRegister
X86FrameLowering.cpp - Some functions return unsigned and arguably should be MCRegister
HexagonBitSimplify.cpp - Function takes BitTracker::RegisterRef which appears to be unsigned&
MachineVerifier.cpp - Ambiguous operator==() given MCRegister and const Register
PPCFastISel.cpp - No Register::operator-=()
PeepholeOptimizer.cpp - TargetInstrInfo::optimizeLoadInstr() takes an unsigned&
MachineTraceMetrics.cpp - MachineTraceMetrics lacks a suitable constructor

Manual fixups in:
ARMFastISel.cpp - ARMEmitLoad() now takes a Register& instead of unsigned&
HexagonSplitDouble.cpp - Ternary operator was ambiguous between unsigned/Register
HexagonConstExtenders.cpp - Has a local class named Register, used llvm::Register instead of Register.
PPCFastISel.cpp - PPCEmitLoad() now takes a Register& instead of unsigned&

Depends on D65919

Reviewers: arsenm, bogner, craig.topper, RKSimon

Reviewed By: arsenm

Subscribers: RKSimon, craig.topper, lenary, aemerson, wuzish, jholewinski, MatzeB, qcolombet, dschuff, jyknight, dylanmckay, sdardis, nemanjai, jvesely, wdng, nhaehnle, sbc100, jgravelle-google, kristof.beyls, hiraditya, aheejin, kbarton, fedor.sergeev, javed.absar, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, tpr, PkmX, jocewei, jsji, Petar.Avramovic, asbirlea, Jim, s.egerton, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D65962

llvm-svn: 369041
2019-08-15 19:22:08 +00:00
Daniel Sanders 2bea69bf65 Finish moving TargetRegisterInfo::isVirtualRegister() and friends to llvm::Register as started by r367614. NFC
llvm-svn: 367633
2019-08-01 23:27:28 +00:00
David Bolvansky 896ece41e4 [Codegen] Merge tail blocks with no successors after block placement
Summary:
I found the following case having tail blocks with no successors merging opportunities after block placement.

Before block placement:

bb0:
    ...
    bne a0, 0, bb2:

bb1:
    mv a0, 1
    ret 

bb2:
    ...

bb3:
    mv a0, 1
    ret

bb4:
    mv a0, -1
    ret

The conditional branch bne in bb0 is opposite to beq.

After block placement:

bb0:
    ...
    beq a0, 0, bb1

bb2:
    ...

bb4:
    mv a0, -1
    ret

bb1:
    mv a0, 1
    ret

bb3:
    mv a0, 1
    ret

After block placement, that appears new tail merging opportunity, bb1 and bb3 can be merged as one block. So the conditional constraint for merging tail blocks with no successors should be removed. In my experiment for RISC-V, it decreases code size.


Author of original patch: Jim Lin

Reviewers: haicheng, aheejin, craig.topper, rnk, RKSimon, Jim, dmgreen

Reviewed By: Jim, dmgreen

Subscribers: xbolva00, dschuff, javed.absar, sbc100, jgravelle-google, aheejin, kito-cheng, dmgreen, PkmX, llvm-commits

Tags: #llvm

Differential Revision: https://reviews.llvm.org/D54411

llvm-svn: 363284
2019-06-13 18:11:32 +00:00
Evandro Menezes 85bd3978ae [IR] Refactor attribute methods in Function class (NFC)
Rename the functions that query the optimization kind attributes.

Differential revision: https://reviews.llvm.org/D60287

llvm-svn: 357731
2019-04-04 22:40:06 +00:00
Craig Topper 428c14d1db [BranchFolding] Remove dead code for handling EHPad blocks
Summary: This code tries to handle the case where IBB is an EHPad, but there's an earlier check that uses PBB->hasEHPadSuccessor(). Where PBB is a predecessor of IBB. The hasEHPadSuccessor function would have visited IBB and seen that it was an EHPad and returned false. This would prevent us from reaching this code with IBB as an EHPad.

Looks like this code was originally added in rL37427 (ancient) and made dead in rL143001.

Reviewers: rnk, void, efriedma

Reviewed By: rnk

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D57358

llvm-svn: 353375
2019-02-07 06:21:28 +00:00
Chandler Carruth 2946cd7010 Update the file headers across all of the LLVM projects in the monorepo
to reflect the new license.

We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.

Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.

llvm-svn: 351636
2019-01-19 08:50:56 +00:00
Hsiangkai Wang 957578ddf7 [CodeGen] Fix bugs in BranchFolderPass when debug labels are generated.
Skip DBG_VALUE and DBG_LABEL in branch folding algorithms.

The bug is reported in
https://bugs.chromium.org/p/chromium/issues/detail?id=898160.

Differential Revision: https://reviews.llvm.org/D54199

llvm-svn: 347964
2018-11-30 08:07:29 +00:00
Chandler Carruth c73c0307fe [MI] Change the array of `MachineMemOperand` pointers to be
a generically extensible collection of extra info attached to
a `MachineInstr`.

The primary change here is cleaning up the APIs used for setting and
manipulating the `MachineMemOperand` pointer arrays so chat we can
change how they are allocated.

Then we introduce an extra info object that using the trailing object
pattern to attach some number of MMOs but also other extra info. The
design of this is specifically so that this extra info has a fixed
necessary cost (the header tracking what extra info is included) and
everything else can be tail allocated. This pattern works especially
well with a `BumpPtrAllocator` which we use here.

I've also added the basic scaffolding for putting interesting pointers
into this, namely pre- and post-instruction symbols. These aren't used
anywhere yet, they're just there to ensure I've actually gotten the data
structure types correct. I'll flesh out support for these in
a subsequent patch (MIR dumping, parsing, the works).

Finally, I've included an optimization where we store any single pointer
inline in the `MachineInstr` to avoid the allocation overhead. This is
expected to be the overwhelmingly most common case and so should avoid
any memory usage growth due to slightly less clever / dense allocation
when dealing with >1 MMO. This did require several ergonomic
improvements to the `PointerSumType` to reasonably support the various
usage models.

This also has a side effect of freeing up 8 bits within the
`MachineInstr` which could be repurposed for something else.

The suggested direction here came largely from Hal Finkel. I hope it was
worth it. ;] It does hopefully clear a path for subsequent extensions
w/o nearly as much leg work. Lots of thanks to Reid and Justin for
careful reviews and ideas about how to do all of this.

Differential Revision: https://reviews.llvm.org/D50701

llvm-svn: 339940
2018-08-16 21:30:05 +00:00
Krzysztof Parzyszek 358a916aa8 Initialize LiveRegs once in BranchFolder::mergeCommonTails
llvm-svn: 335365
2018-06-22 16:38:38 +00:00
Karl-Johan Karlsson abb11f805f [BranchFolding] Fix live-in's when hoisting code
Summary:
When the branch folder hoist code into a predecessor it adjust live-in's
in the blocks it hoist code from. However it fail to handle hoisted code
that contain a defed register that originally is live-in in the block
through a super register.

This is fixed by replacing the live-in handling code with calls to
utility functions in LivePhysRegs.

Reviewers: kparzysz, gberry, MatzeB, uweigand, aprantl

Reviewed By: kparzysz

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47529

llvm-svn: 334163
2018-06-07 07:20:33 +00:00
Heejin Ahn d69acf3b4c Change ambiguous uses of term 'funclet' to 'EH scopes'. NFC.
Summary:
`getEHScopeMembership()` function is used not only for funclet-based
EHs; they apply to all EH schemes that use the scoped IR
(catchpad/cleanuppad/...). D47005 (rL333045) changed some of the uses of
the term 'funclet' to 'EH scopes' in case they apply to all scoped EH,
and this fixes more of them. For `FuncletLayout` pass, I left it as is
because the pass is only used for funclet-based EH.

Reviewers: majnemer

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D47611

llvm-svn: 333711
2018-06-01 00:03:21 +00:00
Heejin Ahn 1e4d35044f [WebAssembly] Add functions for EHScopes
Summary:
There are functions using the term 'funclet' to refer to both
1. an EH scopes, the structure of BBs that starts with
catchpad/cleanuppad and ends with catchret/cleanupret, and
2. a small function that gets outlined in AsmPrinter, which is the
original meaning of 'funclet'.

So far the two have been the same thing; EH scopes are always outlined
in AsmPrinter as funclets at the end of the compilation pipeline. But
now wasm also uses scope-based EH but does not outline those, so we now
need to correctly distinguish those two use cases in functions.

This patch splits `MachineBasicBlock::isFuncletEntry` into
`isFuncletEntry` and `isEHScopeEntry`, and
`MachineFunction::hasFunclets` into `hasFunclets` and `hasEHScopes`, in
order to distinguish the two different use cases. And this also changes
some uses of the term 'funclet' to 'scope' in `getFuncletMembership` and
change the function name to `getEHScopeMembership` because this function
is not about outlined funclets but about EH scope memberships.

This change is in the same vein as D45559.

Reviewers: majnemer, dschuff

Subscribers: sbc100, jgravelle-google, sunfish, llvm-commits

Differential Revision: https://reviews.llvm.org/D47005

llvm-svn: 333045
2018-05-23 00:32:46 +00:00
Geoff Berry 64a2ea41ea [BranchFolding] Allow hoisting to block with a single conditional branch.
Summary:
The BranchFolding pass is currently missing opportunities to hoist
common code if the hoisted-to block contains a single conditional branch
that has register uses.  This occurs somewhat frequently on AArch64 with
CBZ/TBZ opcodes.

This change also eliminates some code differences when debug info is
present since the presence of e.g. DBG_VALUE instructions in the
hoisted-to block can enable hoisting that wouldn't have occurred without
them.

Reviewers: MatzeB, rnk, kparzysz, twoh, aprantl, javed.absar

Subscribers: kristof.beyls, JDevlieghere, mcrosier, llvm-commits

Differential Revision: https://reviews.llvm.org/D46324

llvm-svn: 332265
2018-05-14 17:31:18 +00:00
Nicola Zaghen d34e60ca85 Rename DEBUG macro to LLVM_DEBUG.
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
2018-05-14 12:53:11 +00:00
Shiva Chen 801bf7ebbe [DebugInfo] Examine all uses of isDebugValue() for debug instructions.
Because we create a new kind of debug instruction, DBG_LABEL, we need to
check all passes which use isDebugValue() to check MachineInstr is debug
instruction or not. When expelling debug instructions, we should expel
both DBG_VALUE and DBG_LABEL. So, I create a new function,
isDebugInstr(), in MachineInstr to check whether the MachineInstr is
debug instruction or not.

This patch has no new test case. I have run regression test and there is
no difference in regression test.

Differential Revision: https://reviews.llvm.org/D45342

Patch by Hsiangkai Wang.

llvm-svn: 331844
2018-05-09 02:42:00 +00:00
Bjorn Pettersson 9a8483a4b2 [BranchFolding] Salvage DBG_VALUE instructions from empty blocks
Summary:
This patch will introduce copying of DBG_VALUE instructions
from an otherwise empty basic block to predecessor/successor
blocks in case the empty block is eliminated/bypassed. It
is currently only done in one identified situation in the
BranchFolding pass, before optimizing on empty block.
It can be seen as a light variant of the propagation done
by the LiveDebugValues pass, which unfortunately is executed
after the BranchFolding pass.

We only propagate (copy) DBG_VALUE instructions in a limited
number of situations:
 a) If the empty BB is the only predecessor of a successor
    we can copy the DBG_VALUE instruction to the beginning of
    the successor (because the DBG_VALUE instruction is always
    part of the flow between the blocks).
 b) If the empty BB is the only successor of a predecessor
    we can copy the DBG_VALUE instruction to the end of the
    predecessor (because the DBG_VALUE instruction is always
    part of the flow between the blocks). In this case we add
    the DBG_VALUE just before the first terminator (assuming
    that the terminators do not impact the DBG_VALUE).

A future solution, to handle more situations, could perhaps
be to run the LiveDebugValues pass before branch folding?

This fix is related to PR37234. It is expected to resolve
the problem seen, when applied together with the fix in
SelectionDAG from here: https://reviews.llvm.org/D46129

Reviewers: #debug-info, aprantl, rnk

Reviewed By: #debug-info, aprantl

Subscribers: ormris, gbedwell, llvm-commits

Differential Revision: https://reviews.llvm.org/D46184

llvm-svn: 331183
2018-04-30 14:37:46 +00:00
Petar Jovanovic e2bfcd6394 Correct dwarf unwind information in function epilogue
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 (they are not counted as
  instructions when tail duplicating or tail merging)
* 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.

Added CFIInstrInserter pass:

* analyzes each basic block to determine cfa offset and register are 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/D42848

llvm-svn: 330706
2018-04-24 10:32:08 +00:00
Matthias Braun f1caa2833f MachineFunction: Return reference from getFunction(); NFC
The Function can never be nullptr so we can return a reference.

llvm-svn: 320884
2017-12-15 22:22:58 +00:00
Francis Visoiu Mistrih a8a83d150f [CodeGen] Use MachineOperand::print in the MIRPrinter for MO_Register.
Work towards the unification of MIR and debug output by refactoring the
interfaces.

For MachineOperand::print, keep a simple version that can be easily called
from `dump()`, and a more complex one which will be called from both the
MIRPrinter and MachineInstr::print.

Add extra checks inside MachineOperand for detached operands (operands
with getParent() == nullptr).

https://reviews.llvm.org/D40836

* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+)<def> ([^ ]+)/kill: \1 def \2 \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/kill: def ([^ ]+) ([^ ]+) ([^ ]+)<def>/kill: def \1 \2 def \3/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/<def>//g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<kill>/killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use,kill>/implicit killed \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<def[ ]*,[ ]*dead>/dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def[ ]*,[ ]*dead>/implicit-def dead \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-def>/implicit-def \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<imp-use>/implicit \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<internal>/internal \1/g'
* find . \( -name "*.mir" -o -name "*.cpp" -o -name "*.h" -o -name "*.ll" -o -name "*.s" \) -type f -print0 | xargs -0 sed -i '' -E 's/([^ ]+)<undef>/undef \1/g'

llvm-svn: 320022
2017-12-07 10:40:31 +00:00
Francis Visoiu Mistrih 25528d6de7 [CodeGen] Unify MBB reference format in both MIR and debug output
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
2017-12-04 17:18:51 +00:00
David Blaikie b3bde2ea50 Fix a bunch more layering of CodeGen headers that are in Target
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
2017-11-17 01:07:10 +00:00
Reid Kleckner 7adb2fdbba Revert "Correct dwarf unwind information in function epilogue for X86"
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
2017-11-08 21:31:14 +00:00
David Blaikie 3f833edc7c Target/TargetInstrInfo.h -> CodeGen/TargetInstrInfo.h to match layering
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
2017-11-08 01:01:31 +00:00
Petar Jovanovic e2a585dddc Reland "Correct dwarf unwind information in function epilogue for X86"
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
2017-11-07 14:40:27 +00:00
Petar Jovanovic bb5c84fb57 Revert "Correct dwarf unwind information in function epilogue for X86"
This reverts r317100 as it introduced sanitizer-x86_64-linux-autoconf
buildbot failure (build #15606).

llvm-svn: 317136
2017-11-01 23:05:52 +00:00
Petar Jovanovic f2faee92aa 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.

Differential Revision: https://reviews.llvm.org/D35844

llvm-svn: 317100
2017-11-01 16:04:11 +00:00
Eugene Zelenko 149178d92b [CodeGen] Fix some Clang-tidy modernize and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 315380
2017-10-10 22:33:29 +00:00
Matthias Braun c9056b834d Insert IMPLICIT_DEFS for undef uses in tail merging
Tail merging can convert an undef use into a normal one when creating a
common tail. Doing so can make the register live out from a block which
previously contained the undef use. To keep the liveness up-to-date,
insert IMPLICIT_DEFs in such blocks when necessary.

To enable this patch the computeLiveIns() function which used to
compute live-ins for a block and set them immediately is split into new
functions:
- computeLiveIns() just computes the live-ins in a LivePhysRegs set.
- addLiveIns() applies the live-ins to a block live-in list.
- computeAndAddLiveIns() is a convenience function combining the other
  two functions and behaving like computeLiveIns() before this patch.

Based on a patch by Krzysztof Parzyszek <kparzysz@codeaurora.org>

Differential Revision: https://reviews.llvm.org/D37034

llvm-svn: 312668
2017-09-06 20:45:24 +00:00
Reid Kleckner 9be82c3169 Fix conditional tail call branch folding when both edges are the same
The conditional tail call logic did the wrong thing when both
destinations of a conditional branch were the same:

BB#1: derived from LLVM BB %entry
    Live Ins: %EFLAGS
    Predecessors according to CFG: BB#0
        JE_1 <BB#5>, %EFLAGS<imp-use,kill>
        JMP_1 <BB#5>

BB#5: derived from LLVM BB %sw.epilog
    Predecessors according to CFG: BB#1
        TCRETURNdi64 <ga:@mergeable_conditional_tailcall>, 0, ...

We would fold the JE_1 to a TCRETURNdi64cc, and then remove our BB#5
successor. Then BB#5 would be deleted as it had no predecessors, leaving
a dangling "JMP_1 <BB#5>" reference behind to cause assertions later.

This patch checks that both conditional branch destinations are
different before doing the transform. The standard branch folding logic
is able to remove both the JMP_1 and the JE_1, and for my test case we
end up forming a better conditional tail call later.

Fixes PR33980

llvm-svn: 309422
2017-07-28 19:48:40 +00:00
Daniel Jasper 559aa75382 Revert "r306529 - [X86] Correct dwarf unwind information in function epilogue"
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
2017-06-29 13:58:24 +00:00
Petar Jovanovic 7b3a38ec30 [X86] Correct dwarf unwind information in function epilogue
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
2017-06-28 10:21:17 +00:00
Eugene Zelenko fb69e66cff [CodeGen] Fix some Clang-tidy modernize-use-using and Include What You Use warnings; other minor fixes (NFC).
llvm-svn: 304839
2017-06-06 22:22:41 +00:00
Chandler Carruth 6bda14b313 Sort the remaining #include lines in include/... and lib/....
I did this a long time ago with a janky python script, but now
clang-format has built-in support for this. I fed clang-format every
line with a #include and let it re-sort things according to the precise
LLVM rules for include ordering baked into clang-format these days.

I've reverted a number of files where the results of sorting includes
isn't healthy. Either places where we have legacy code relying on
particular include ordering (where possible, I'll fix these separately)
or where we have particular formatting around #include lines that
I didn't want to disturb in this patch.

This patch is *entirely* mechanical. If you get merge conflicts or
anything, just ignore the changes in this patch and run clang-format
over your #include lines in the files.

Sorry for any noise here, but it is important to keep these things
stable. I was seeing an increasing number of patches with irrelevant
re-ordering of #include lines because clang-format was used. This patch
at least isolates that churn, makes it easy to skip when resolving
conflicts, and gets us to a clean baseline (again).

llvm-svn: 304787
2017-06-06 11:49:48 +00:00
Matthias Braun e51c435c07 LivePhysRegs: Skip reserved regs in computeLiveIns; NFCI
Re-commit r303937 + r303949 as they were not the cause for the build
failures.

We do not track liveness of reserved registers so adding them to the
liveins list in computeLiveIns() was completely unnecessary.

llvm-svn: 303970
2017-05-26 06:32:31 +00:00
Matthias Braun f56a6d84b6 Revert "LivePhysRegs: Skip reserved regs in computeLiveIns; NFCI"
Tentatively revert, suspecting that it caused breakage in stage2
buildbots.

This reverts commit r303949.
This reverts commit r303937.

llvm-svn: 303955
2017-05-26 01:29:32 +00:00
Matthias Braun 9512dd5ffd LivePhysRegs: Skip reserved regs in computeLiveIns; NFCI
We do not track liveness of reserved registers so adding them to the
liveins list in computeLiveIns() was completely unnecessary.

llvm-svn: 303937
2017-05-25 23:39:33 +00:00
Matthias Braun 1527baab0c CodeGen: Rename DEBUG_TYPE to match passnames
Rename the DEBUG_TYPE to match the names of corresponding passes where
it makes sense. Also establish the pattern of simply referencing
DEBUG_TYPE instead of repeating the passname where possible.

llvm-svn: 303921
2017-05-25 21:26:32 +00:00
Krzysztof Parzyszek 31d4b3b247 Remove stale live-ins in the branch folder
Hoisting common code can cause registers that live-in in the successor
blocks to no longer be live-in. The live-in information needs to be
updated to reflect this, or otherwise incorrect code can be generated
later on.

Differential Revision: https://reviews.llvm.org/D32661

llvm-svn: 302228
2017-05-05 12:20:07 +00:00
Kyle Butt a12bd756e4 CodeGen: BranchFolding: Merge identical blocks, even if they are short.
Merging identical blocks when it doesn't reduce fallthrough. It is common for
the blocks created from critical edge splitting to be identical. We would like
to merge these blocks whenever doing so would not reduce fallthrough.

llvm-svn: 299890
2017-04-10 22:28:12 +00:00
Taewook Oh 1b192336d8 NFC: Reformats comments according to the coding guildelines.
llvm-svn: 297808
2017-03-15 06:29:23 +00:00
Taewook Oh fb1833efeb [BranchFolding] Merge debug locations from common tail instead of removing
Summary: D25742 improved the precision of debug locations for PGO by removing debug locations from common tail when tail-merging. However, if identical insturctions that are merged into a common tail have the same debug locations, there's no need to remove them. This patch creates a merged debug location of identical instructions across SameTails and assign it to the instruction in the common tail, so that the debug locations are maintained if they are same across identical instructions.

Reviewers: aprantl, probinson, MatzeB, rob.lougher

Reviewed By: aprantl

Subscribers: andreadb, llvm-commits

Differential Revision: https://reviews.llvm.org/D30226

llvm-svn: 297805
2017-03-15 05:44:59 +00:00
Taewook Oh 4cf5c1087c [BranchFolding] Update debug location along with the update of branch instruction.
Summary:
Currently, BranchFolder drops DebugLoc for branch instructions in some places. For example, for the test code attached, the branch instruction of 'entry' block has a DILocation of

```
!12 = !DILocation(line: 6, column: 3, scope: !11)
```

, but this information is gone when then block is lowered because BranchFolder misses it. This patch is a fix for this issue.

Reviewers: qcolombet, aprantl, craig.topper, MatzeB

Reviewed By: aprantl

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29902

llvm-svn: 295684
2017-02-21 00:12:38 +00:00
Hans Wennborg a468601e0e [X86] Re-enable conditional tail calls and fix PR31257.
This reverts r294348, which removed support for conditional tail calls
due to the PR above. It fixes the PR by marking live registers as
implicitly used and defined by the now predicated tailcall. This is
similar to how IfConversion predicates instructions.

Differential Revision: https://reviews.llvm.org/D29856

llvm-svn: 295262
2017-02-16 00:04:05 +00:00
Xinliang David Li 538d666814 include function name in dot filename
Differential Revision: http://reviews.llvm.org/D29975

llvm-svn: 295220
2017-02-15 19:21:04 +00:00
Reid Kleckner a622fc9bdf [BranchFolding] Tail common all identical unreachable blocks
Summary:
Blocks ending in unreachable are typically cold because they end the
program or throw an exception, so merging them with other identical
blocks is usually profitable because it reduces the size of cold code.
MachineBlockPlacement generally does not arrange to fall through to such
blocks, so commoning these blocks will not introduce additional
unconditional branches.

Reviewers: hans, iteratee, haicheng

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D29153

llvm-svn: 295105
2017-02-14 21:02:24 +00:00