Commit Graph

230 Commits

Author SHA1 Message Date
Lei Huang 34e6621724 Update branch coalescing to be a PowerPC specific pass
Implementing this pass as a PowerPC specific pass.  Branch coalescing utilizes
the analyzeBranch method which currently does not include any implicit operands.
This is not an issue on PPC but must be handled on other targets.

Pass is currently off by default. Enabled via -enable-ppc-branch-coalesce.

Differential Revision : https: // reviews.llvm.org/D32776

llvm-svn: 313061
2017-09-12 18:39:11 +00:00
Eric Christopher e42ac21499 Temporarily revert "Update branch coalescing to be a PowerPC specific pass"
From comments and code review it wasn't intended to be enabled by default yet.

This reverts commit r311588.

llvm-svn: 312214
2017-08-31 05:56:16 +00:00
Lei Huang 0cb591fc4c Update branch coalescing to be a PowerPC specific pass
Implementing this pass as a PowerPC specific pass.  Branch coalescing utilizes
the analyzeBranch method which currently does not include any implicit operands.
This is not an issue on PPC but must be handled on other targets.

Differential Revision : https: // reviews.llvm.org/D32776

llvm-svn: 311588
2017-08-23 19:25:04 +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
Florian Hahn 5f746c8e27 Recommit rL305677: [CodeGen] Add generic MacroFusion pass
Use llvm::make_unique to avoid ambiguity with MSVC.

This patch adds a generic MacroFusion pass, that is used on X86 and
AArch64, which both define target-specific shouldScheduleAdjacent
functions. This generic pass should make it easier for other targets to
implement macro fusion and I intend to add macro fusion for ARM shortly.

Differential Revision: https://reviews.llvm.org/D34144

llvm-svn: 305690
2017-06-19 12:53:31 +00:00
Florian Hahn e16d3106f3 Revert r305677 [CodeGen] Add generic MacroFusion pass.
This causes Windows buildbot failures do an ambiguous call.

llvm-svn: 305681
2017-06-19 11:26:15 +00:00
Florian Hahn ee1b096f8a [CodeGen] Add generic MacroFusion pass.
Summary:
This patch adds a generic MacroFusion pass, that is used on X86 and
AArch64, which both define target-specific shouldScheduleAdjacent
functions. This generic pass should make it easier for other targets to
implement macro fusion and I intend to add macro fusion for ARM shortly.

Reviewers: craig.topper, evandro, t.p.northover, atrick, MatzeB

Reviewed By: MatzeB

Subscribers: atrick, aemerson, mgorny, javed.absar, kristof.beyls, llvm-commits

Differential Revision: https://reviews.llvm.org/D34144

llvm-svn: 305677
2017-06-19 10:51:38 +00:00
Dehao Chen 6b737ddce7 Add LiveRangeShrink pass to shrink live range within BB.
Summary: LiveRangeShrink pass moves instruction right after the definition with the same BB if the instruction and its operands all have more than one use. This pass is inexpensive and guarantees optimal live-range within BB.

Reviewers: davidxl, wmi, hfinkel, MatzeB, andreadb

Reviewed By: MatzeB, andreadb

Subscribers: hiraditya, jyknight, sanjoy, skatkov, gberry, jholewinski, qcolombet, javed.absar, krytarowski, atrick, spatel, RKSimon, andreadb, MatzeB, mehdi_amini, mgorny, efriedma, davide, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D32563

llvm-svn: 304371
2017-05-31 23:25:25 +00:00
Hans Wennborg b00ffd8cb7 Revert r302938 "Add LiveRangeShrink pass to shrink live range within BB."
This also reverts follow-ups r303292 and r303298.

It broke some Chromium tests under MSan, and apparently also internal
tests at Google.

llvm-svn: 303369
2017-05-18 18:50:05 +00:00
Ayman Musa c5490e5a29 [X86] Relocate code of replacement of subtarget unsupported masked memory intrinsics to run also on -O0 option.
Currently, when masked load, store, gather or scatter intrinsics are used, we check in CodeGenPrepare pass if the subtarget support these intrinsics, if not we replace them with scalar code - this is a functional transformation not an optimization (not optional).

CodeGenPrepare pass does not run when the optimization level is set to CodeGenOpt::None (-O0).

Functional transformation should run with all optimization levels, so here I created a new pass which runs on all optimization levels and does no more than this transformation.

Differential Revision: https://reviews.llvm.org/D32487

llvm-svn: 303050
2017-05-15 11:30:54 +00:00
Dehao Chen 65dd23e273 Add LiveRangeShrink pass to shrink live range within BB.
Summary: LiveRangeShrink pass moves instruction right after the definition with the same BB if the instruction and its operands all have more than one use. This pass is inexpensive and guarantees optimal live-range within BB.

Reviewers: davidxl, wmi, hfinkel, MatzeB, andreadb

Reviewed By: MatzeB, andreadb

Subscribers: hiraditya, jyknight, sanjoy, skatkov, gberry, jholewinski, qcolombet, javed.absar, krytarowski, atrick, spatel, RKSimon, andreadb, MatzeB, mehdi_amini, mgorny, efriedma, davide, dberlin, llvm-commits

Differential Revision: https://reviews.llvm.org/D32563

llvm-svn: 302938
2017-05-12 19:29:27 +00:00
Amara Emerson 836b0f48c1 Add a late IR expansion pass for the experimental reduction intrinsics.
This pass uses a new target hook to decide whether or not to expand a particular
intrinsic to the shuffevector sequence.

Differential Revision: https://reviews.llvm.org/D32245

llvm-svn: 302631
2017-05-10 09:42:49 +00:00
Matthias Braun e4e14ae507 MachineFrameInfo: Move implementation to an own file; NFC
Move implementation of the MachineFrameInfo class into
MachineFrameInfo.cpp

llvm-svn: 301494
2017-04-26 23:36:58 +00:00
Jessica Paquette 596f483a5e [Outliner] Fixed Asan bot failure in r296418
Fixed the asan bot failure which led to the last commit of the outliner being reverted.
The change is in lib/CodeGen/MachineOutliner.cpp in the SuffixTree's constructor. LeafVector
is no longer initialized using reserve but just a standard constructor.

llvm-svn: 297081
2017-03-06 21:31:18 +00:00
Nemanja Ivanovic b223cfabcc Improve scheduling with branch coalescing
This patch adds a MachineSSA pass that coalesces blocks that branch
on the same condition.

Committing on behalf of Lei Huang.

Differential Revision: https://reviews.llvm.org/D28249

llvm-svn: 296670
2017-03-01 20:29:34 +00:00
Matthias Braun 81f68ec3a9 Revert "Add MIR-level outlining pass"
Revert Machine Outliner for now, as it breaks the asan bot.

This reverts commit r296418.

llvm-svn: 296426
2017-02-28 02:24:30 +00:00
Matthias Braun d36410945f Add MIR-level outlining pass
This is a patch for the outliner described in the RFC at:
http://lists.llvm.org/pipermail/llvm-dev/2016-August/104170.html

The outliner is a code-size reduction pass which works by finding
repeated sequences of instructions in a program, and replacing them with
calls to functions. This is useful to people working in low-memory
environments, where sacrificing performance for space is acceptable.

This adds an interprocedural outliner directly before printing assembly.
For reference on how this would work, this patch also includes X86
target hooks and an X86 test.

The outliner is run like so:

clang -mno-red-zone -mllvm -enable-machine-outliner file.c

Patch by Jessica Paquette<jpaquette@apple.com>!

rdar://29166825

Differential Revision: https://reviews.llvm.org/D26872

llvm-svn: 296418
2017-02-28 00:33:32 +00:00
Adam Nemet bbb141c734 Add new pass LazyMachineBlockFrequencyInfo
And use it in MachineOptimizationRemarkEmitter.  A test will follow on top of
Justin's changes to enable MachineORE in AsmPrinter.

The approach is similar to the IR-level pass.  It's a bit simpler because BPI
is immutable at the Machine level so we don't need to make that lazy.

Because of this, a new function mapping is introduced (BPIPassTrait::getBPI).
This function extracts BPI from the pass.  In case of the lazy pass, this is
when the calculation of the BFI occurs.  For Machine-level, this is the
identity function.

Differential Revision: https://reviews.llvm.org/D29836

llvm-svn: 295072
2017-02-14 17:21:09 +00:00
Eric Fiselier 87c87f4c30 [CMake] Fix pthread handling for out-of-tree builds
LLVM defines `PTHREAD_LIB` which is used by AddLLVM.cmake and various projects
to correctly link the threading library when needed. Unfortunately
`PTHREAD_LIB` is defined by LLVM's `config-ix.cmake` file which isn't installed
and therefore can't be used when configuring out-of-tree builds. This causes
such builds to fail since `pthread` isn't being correctly linked.

This patch attempts to fix that problem by renaming and exporting
`LLVM_PTHREAD_LIB` as part of`LLVMConfig.cmake`. I renamed `PTHREAD_LIB`
because It seemed likely to cause collisions with downstream users of
`LLVMConfig.cmake`.

llvm-svn: 294690
2017-02-10 01:59:20 +00:00
Nirav Dave a7c041d147 [X86] Implement -mfentry
Summary: Insert calls to __fentry__ at function entry.

Reviewers: hfinkel, craig.topper

Subscribers: mgorny, llvm-commits

Differential Revision: https://reviews.llvm.org/D28000

llvm-svn: 293648
2017-01-31 17:00:27 +00:00
Adam Nemet a964066705 New OptimizationRemarkEmitter pass for MIR
This allows MIR passes to emit optimization remarks with the same level
of functionality that is available to IR passes.

It also hooks up the greedy register allocator to report spills.  This
allows for interesting use cases like increasing interleaving on a loop
until spilling of registers is observed.

I still need to experiment whether reporting every spill scales but this
demonstrates for now that the functionality works from llc
using -pass-remarks*=<pass>.

Differential Revision: https://reviews.llvm.org/D29004

llvm-svn: 293110
2017-01-25 23:20:33 +00:00
Matthias Braun 710a4c1f3d CodeGen: Add/Factor out LiveRegUnits class; NFCI
This is a set of register units intended to track register liveness, it
is similar in spirit to LivePhysRegs.
You can also think of this as the liveness tracking parts of the
RegisterScavenger factored out into an own class.

This was proposed in http://llvm.org/PR27609

Differential Revision: http://reviews.llvm.org/D21916

llvm-svn: 292542
2017-01-20 00:16:14 +00:00
Daniel Jasper 0f77869d58 Move DwarfGenerator.cpp to unittests
So far it creates a test helper and so it should be moved there. It also
create a layering cycle between CodeGen and CodeGen/AsmPrinter, which
should be avoided.

Review: https://reviews.llvm.org/D27570
llvm-svn: 289044
2016-12-08 12:45:29 +00:00
Greg Clayton 3462a420d1 Make a DWARF generator so we can unit test DWARF APIs with gtest.
The only tests we have for the DWARF parser are the tests that use llvm-dwarfdump and expect output from textual dumps.

More DWARF parser modification are coming in the next few weeks and I wanted to add tests that can verify that we can encode and decode all form types, as well as test some other basic DWARF APIs where we ask DIE objects for their children and siblings.

DwarfGenerator.cpp was added in the lib/CodeGen directory. This file contains the code necessary to easily create DWARF for tests:

dwarfgen::Generator DG;
Triple Triple("x86_64--");
bool success = DG.init(Triple, Version);
if (!success)
  return;
dwarfgen::CompileUnit &CU = DG.addCompileUnit();
dwarfgen::DIE CUDie = CU.getUnitDIE();

CUDie.addAttribute(DW_AT_name, DW_FORM_strp, "/tmp/main.c");
CUDie.addAttribute(DW_AT_language, DW_FORM_data2, DW_LANG_C);

dwarfgen::DIE SubprogramDie = CUDie.addChild(DW_TAG_subprogram);
SubprogramDie.addAttribute(DW_AT_name, DW_FORM_strp, "main");
SubprogramDie.addAttribute(DW_AT_low_pc, DW_FORM_addr, 0x1000U);
SubprogramDie.addAttribute(DW_AT_high_pc, DW_FORM_addr, 0x2000U);

dwarfgen::DIE IntDie = CUDie.addChild(DW_TAG_base_type);
IntDie.addAttribute(DW_AT_name, DW_FORM_strp, "int");
IntDie.addAttribute(DW_AT_encoding, DW_FORM_data1, DW_ATE_signed);
IntDie.addAttribute(DW_AT_byte_size, DW_FORM_data1, 4);

dwarfgen::DIE ArgcDie = SubprogramDie.addChild(DW_TAG_formal_parameter);
ArgcDie.addAttribute(DW_AT_name, DW_FORM_strp, "argc");
// ArgcDie.addAttribute(DW_AT_type, DW_FORM_ref4, IntDie);
ArgcDie.addAttribute(DW_AT_type, DW_FORM_ref_addr, IntDie);

StringRef FileBytes = DG.generate();
MemoryBufferRef FileBuffer(FileBytes, "dwarf");
auto Obj = object::ObjectFile::createObjectFile(FileBuffer);
EXPECT_TRUE((bool)Obj);
DWARFContextInMemory DwarfContext(*Obj.get());
This code is backed by the AsmPrinter code that emits DWARF for the actual compiler.

While adding unit tests it was discovered that DIEValue that used DIEEntry as their values had bugs where DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref8, and DW_FORM_ref_udata forms were not supported. These are all now supported. Added support for DW_FORM_string so we can emit inlined C strings.

Centralized the code to unique abbreviations into a new DIEAbbrevSet class and made both the dwarfgen::Generator and the llvm::DwarfFile classes use the new class.

Fixed comments in the llvm::DIE class so that the Offset is known to be the compile/type unit offset.

DIEInteger now supports more DW_FORM values.

There are also unit tests that cover:

Encoding and decoding all form types and values
Encoding and decoding all reference types (DW_FORM_ref1, DW_FORM_ref2, DW_FORM_ref4, DW_FORM_ref8, DW_FORM_ref_udata, DW_FORM_ref_addr) including cross compile unit references with that go forward one compile unit and backward on compile unit.

Differential Revision: https://reviews.llvm.org/D27326

llvm-svn: 289010
2016-12-08 01:03:48 +00:00
Matthias Braun 7f423442d1 TargetSubtargetInfo: Move implementation to lib/CodeGen; NFC
TargetSubtargetInfo is filled with CodeGen specific interfaces nowadays
(getInstrInfo(), getFrameLowering(), getSelectionDAGInfo()) most of the
tuning flags like enablePostRAScheduler(), getAntiDepBreakMode(),
enableRALocalReassignment(), ... also do not seem to be universal enough
to make sense outside of CodeGen.

Differential Revision: https://reviews.llvm.org/D26948

llvm-svn: 287708
2016-11-22 22:09:03 +00:00
Chris Bieneman 05c279fc4b [CMake] NFC. Updating CMake dependency specifications
This patch updates a bunch of places where add_dependencies was being explicitly called to add dependencies on intrinsics_gen to instead use the DEPENDS named parameter. This cleanup is needed for a patch I'm working on to add a dependency debugging mode to the build system.

llvm-svn: 287206
2016-11-17 04:36:50 +00:00
Matt Arsenault 36919a4f7c Move AArch64BranchRelaxation to generic code
llvm-svn: 283459
2016-10-06 15:38:53 +00:00
Hal Finkel 40d7f5c277 Add a counter-function insertion pass
As discussed in https://reviews.llvm.org/D22666, our current mechanism to
support -pg profiling, where we insert calls to mcount(), or some similar
function, is fundamentally broken. We insert these calls in the frontend, which
means they get duplicated when inlining, and so the accumulated execution
counts for the inlined-into functions are wrong.

Because we don't want the presence of these functions to affect optimizaton,
they should be inserted in the backend. Here's a pass which would do just that.
The knowledge of the name of the counting function lives in the frontend, so
we're passing it here as a function attribute. Clang will be updated to use
this mechanism.

Differential Revision: https://reviews.llvm.org/D22825

llvm-svn: 280347
2016-09-01 09:42:39 +00:00
Quentin Colombet 374796d678 [GlobalISel] Add a fallback path to SDISel.
When global-isel fails on a MachineFunction MF, MF will be cleaned up
and given to SDISel.
Thanks to this fallback, we can already perform correctness test even if
we support only a small portion of the functions in a test.

llvm-svn: 279891
2016-08-27 00:18:31 +00:00
Matthias Braun 733fe3676c CodeGen: Remove MachineFunctionAnalysis => Enable (Machine)ModulePasses
Re-apply this patch, hopefully I will get away without any warnings
in the constructor now.

This patch removes the MachineFunctionAnalysis. Instead we keep a
map from IR Function to MachineFunction in the MachineModuleInfo.

This allows the insertion of ModulePasses into the codegen pipeline
without breaking it because the MachineFunctionAnalysis gets dropped
before a module pass.

Peak memory should stay unchanged without a ModulePass in the codegen
pipeline: Previously the MachineFunction was freed at the end of a codegen
function pipeline because the MachineFunctionAnalysis was dropped; With
this patch the MachineFunction is freed after the AsmPrinter has
finished.

Differential Revision: http://reviews.llvm.org/D23736

llvm-svn: 279602
2016-08-24 01:52:46 +00:00
Richard Smith 8c3fbdc6c4 Revert r279564. It introduces undefined behavior (binding a reference to a
dereferenced null pointer) in MachineModuleInfo::MachineModuleInfo that causes
-Werror builds (including several buildbots) to fail.

llvm-svn: 279580
2016-08-23 22:08:27 +00:00
Matthias Braun 4c1f1f120c CodeGen: Remove MachineFunctionAnalysis => Enable (Machine)ModulePasses
Re-apply this commit with the deletion of a MachineFunction delegated to
a separate pass to avoid use after free when doing this directly in
AsmPrinter.

This patch removes the MachineFunctionAnalysis. Instead we keep a
map from IR Function to MachineFunction in the MachineModuleInfo.

This allows the insertion of ModulePasses into the codegen pipeline
without breaking it because the MachineFunctionAnalysis gets dropped
before a module pass.

Peak memory should stay unchanged without a ModulePass in the codegen
pipeline: Previously the MachineFunction was freed at the end of a codegen
function pipeline because the MachineFunctionAnalysis was dropped; With
this patch the MachineFunction is freed after the AsmPrinter has
finished.

Differential Revision: http://reviews.llvm.org/D23736

llvm-svn: 279564
2016-08-23 20:58:29 +00:00
Matthias Braun 7f66202d38 Revert "(HEAD -> master, origin/master, origin/HEAD) CodeGen: Remove MachineFunctionAnalysis => Enable (Machine)ModulePasses"
Reverting while tracking down a use after free.

This reverts commit r279502.

llvm-svn: 279503
2016-08-23 05:17:11 +00:00
Matthias Braun fd936841eb CodeGen: Remove MachineFunctionAnalysis => Enable (Machine)ModulePasses
This patch removes the MachineFunctionAnalysis. Instead we keep a
map from IR Function to MachineFunction in the MachineModuleInfo.

This allows the insertion of ModulePasses into the codegen pipeline
without breaking it because the MachineFunctionAnalysis gets dropped
before a module pass.

Peak memory should stay unchanged without a ModulePass in the codegen
pipeline: Previously the MachineFunction was freed at the end of a codegen
function pipeline because the MachineFunctionAnalysis was dropped; With
this patch the MachineFunction is freed after the AsmPrinter has
finished.

Differential Revision: http://reviews.llvm.org/D23736

llvm-svn: 279502
2016-08-23 03:20:09 +00:00
Matthias Braun fdc4c6b426 Revert "RegScavenging: Add scavengeRegisterBackwards()"
The ppc64 multistage bot fails on this.

This reverts commit r279124.

Also Revert "CodeGen: Add/Factor out LiveRegUnits class; NFCI" because it depends on the previous change
This reverts commit r279171.

llvm-svn: 279199
2016-08-19 03:03:24 +00:00
Matthias Braun 91f95f0201 CodeGen: Add/Factor out LiveRegUnits class; NFCI
This is a set of register units intended to track register liveness, it
is similar in spirit to LivePhysRegs.
You can also think of this as the liveness tracking parts of the
RegisterScavenger factored out into an own class.

This was proposed in http://llvm.org/PR27609

Differential Revision: http://reviews.llvm.org/D21916

llvm-svn: 279171
2016-08-18 22:11:28 +00:00
Brendon Cahoon 254f889dc5 MachinePipeliner pass that implements Swing Modulo Scheduling
Software pipelining is an optimization for improving ILP by
overlapping loop iterations. Swing Modulo Scheduling (SMS) is
an implementation of software pipelining that attempts to
reduce register pressure and generate efficient pipelines with
a low compile-time cost.

This implementaion of SMS is a target-independent back-end pass.
When enabled, the pass should run just prior to the register
allocation pass, while the machine IR is in SSA form. If the pass
is successful, then the original loop is replaced by the optimized
loop. The optimized loop contains one or more prolog blocks, the
pipelined kernel, and one or more epilog blocks.

This pass is enabled for Hexagon only. To enable for other targets,
a couple of target specific hooks must be implemented, and the
pass needs to be called from the target's TargetMachine
implementation.

Differential Review: http://reviews.llvm.org/D16829

llvm-svn: 277169
2016-07-29 16:44:44 +00:00
Tim Northover 62ae568bbb GlobalISel: implement low-level type with just size & vector lanes.
This should be all the low-level instruction selection needs to determine how
to implement an operation, with the remaining context taken from the opcode
(e.g. G_ADD vs G_FADD) or other flags not based on type (e.g. fast-math).

llvm-svn: 276158
2016-07-20 19:09:30 +00:00
Dean Michael Berris 52735fc435 XRay: Add entry and exit sleds
Summary:
In this patch we implement the following parts of XRay:

- Supporting a function attribute named 'function-instrument' which currently only supports 'xray-always'. We should be able to use this attribute for other instrumentation approaches.
- Supporting a function attribute named 'xray-instruction-threshold' used to determine whether a function is instrumented with a minimum number of instructions (IR instruction counts).
- X86-specific nop sleds as described in the white paper.
- A machine function pass that adds the different instrumentation marker instructions at a very late stage.
- A way of identifying which return opcode is considered "normal" for each architecture.

There are some caveats here:

1) We don't handle PATCHABLE_RET in platforms other than x86_64 yet -- this means if IR used PATCHABLE_RET directly instead of a normal ret, instruction lowering for that platform might do the wrong thing. We think this should be handled at instruction selection time to by default be unpacked for platforms where XRay is not availble yet.

2) The generated section for X86 is different from what is described from the white paper for the sole reason that LLVM allows us to do this neatly. We're taking the opportunity to deviate from the white paper from this perspective to allow us to get richer information from the runtime library.

Reviewers: sanjoy, eugenis, kcc, pcc, echristo, rnk

Subscribers: niravd, majnemer, atrick, rnk, emaste, bmakam, mcrosier, mehdi_amini, llvm-commits

Differential Revision: http://reviews.llvm.org/D19904

llvm-svn: 275367
2016-07-14 04:06:33 +00:00
Evgeniy Stepanov a5da256f92 StackColoring for SafeStack.
This is a fix for PR27842.

An IR-level implementation of stack coloring tailored to work with
SafeStack. It is a bit weaker than the MI implementation in that it
does not the "lifetime start at first access" logic. This can be
improved in the future.

This patch also replaces the naive implementation of stack frame
layout with a greedy algorithm that can split existing stack slots
and even fit small objects inside the alignment padding of other
objects.

llvm-svn: 274162
2016-06-29 20:37:43 +00:00
Mehdi Amini 1d396832d3 Interprocedural Register Allocation (IPRA): add a Transformation Pass
Adds a MachineFunctionPass that scans the body to find calls, and
update the register mask with the one saved by the
RegUsageInfoCollector analysis in PhysicalRegisterUsageInfo.

Patch by Vivek Pandya <vivekvpandya@gmail.com>

Differential Revision: http://reviews.llvm.org/D21180

llvm-svn: 272414
2016-06-10 18:37:21 +00:00
Mehdi Amini bbacddfe92 Interprocedural Register Allocation (IPRA) Analysis
Add an option to enable the analysis of MachineFunction register
usage to extract the list of clobbered registers.

When enabled, the CodeGen order is changed to be bottom up on the Call
Graph.

The analysis is split in two parts, RegUsageInfoCollector is the
MachineFunction Pass that runs post-RA and collect the list of
clobbered registers to produce a register mask.

An immutable pass, RegisterUsageInfo, stores the RegMask produced by
RegUsageInfoCollector, and keep them available. A future tranformation
pass will use this information to update every call-sites after
instruction selection.

Patch by Vivek Pandya <vivekvpandya@gmail.com>

Differential Revision: http://reviews.llvm.org/D20769

llvm-svn: 272403
2016-06-10 16:19:46 +00:00
Matthias Braun f9acacaa92 CodeGen: Refactor renameDisconnectedComponents() as a pass
Refactor LiveIntervals::renameDisconnectedComponents() to be a pass.
Also change the name to "RenameIndependentSubregs":

- renameDisconnectedComponents() worked on a MachineFunction at a time
  so it is a natural candidate for a machine function pass.

- The algorithm is testable with a .mir test now.

- This also fixes a problem where the lazy renaming as part of the
  MachineScheduler introduced IMPLICIT_DEF instructions after the number
  of a nodes in a region were counted leading to a mismatch.

Differential Revision: http://reviews.llvm.org/D20507

llvm-svn: 271345
2016-05-31 22:38:06 +00:00
Matthias Braun 31d19d43c7 CodeGen: Move TargetPassConfig from Passes.h to an own header; NFC
Many files include Passes.h but only a fraction needs to know about the
TargetPassConfig class. Move it into an own header. Also rename
Passes.cpp to TargetPassConfig.cpp while we are at it.

llvm-svn: 269011
2016-05-10 03:21:59 +00:00
Matthias Braun fbe85ae12e CodeGen: Add DetectDeadLanes pass.
The DetectDeadLanes pass performs a dataflow analysis of used/defined
subregister lanes across COPY instructions and instructions that will
get lowered to copies. It detects dead definitions and uses reading
undefined values which are obscured by COPY and subregister usage.

These dead definitions cause trouble in the register coalescer which
cannot deal with definitions suddenly becoming dead after coalescing
COPY instructions.

For now the pass only adds dead and undef flags to machine operands. It
should be possible to extend it in the future to remove the dead
instructions and redo the analysis for the affected virtual
registers.

Differential Revision: http://reviews.llvm.org/D18427

llvm-svn: 267851
2016-04-28 03:07:16 +00:00
Peter Collingbourne 7dd8dbf486 Introduce llvm.load.relative intrinsic.
This intrinsic takes two arguments, ``%ptr`` and ``%offset``. It loads
a 32-bit value from the address ``%ptr + %offset``, adds ``%ptr`` to that
value and returns it. The constant folder specifically recognizes the form of
this intrinsic and the constant initializers it may load from; if a loaded
constant initializer is known to have the form ``i32 trunc(x - %ptr)``,
the intrinsic call is folded to ``x``.

LLVM provides that the calculation of such a constant initializer will
not overflow at link time under the medium code model if ``x`` is an
``unnamed_addr`` function. However, it does not provide this guarantee for
a constant initializer folded into a function body. This intrinsic can be
used to avoid the possibility of overflows when loading from such a constant.

Differential Revision: http://reviews.llvm.org/D18367

llvm-svn: 267223
2016-04-22 21:18:02 +00:00
Tom Stellard ee34680bb0 CodeGen: Add a stand-alone hazard recognizer pass
Summary:
This new pass allows targets to use the hazard recognizer without having
to also run one of the schedulers.  This is useful when compiling with
optimizations disabled for targets that still need noop hazards
to be handled correctly.

Reviewers: hfinkel, atrick

Subscribers: arsenm, llvm-commits

Differential Revision: http://reviews.llvm.org/D18594

llvm-svn: 267156
2016-04-22 14:43:50 +00:00
Sanjoy Das c0441c29df Introduce a "patchable-function" function attribute
Summary:
The `"patchable-function"` attribute can be used by an LLVM client to
influence LLVM's code generation in ways that makes the generated code
easily patchable at runtime (for instance, to redirect control).
Right now only one patchability scheme is supported,
`"prologue-short-redirect"`, but this can be expanded in the future.

Reviewers: joker.eph, rnk, echristo, dberris

Subscribers: joker.eph, echristo, mcrosier, llvm-commits

Differential Revision: http://reviews.llvm.org/D19046

llvm-svn: 266715
2016-04-19 05:24:47 +00:00
Kyle Butt 3232dbbf02 Codegen: Factor tail duplication into a utility class. NFC
This is in preparation for tail duplication during block placement. See D18226.
This needs to be a utility class for 2 reasons. No passes may run after block
placement, and also, tail-duplication affects subsequent layout decisions, so
it must be interleaved with placement, and can't be separated out into its own
pass. The original pass is still useful, and now runs by delegating to the
utility class.

llvm-svn: 265842
2016-04-08 20:35:01 +00:00