Commit Graph

19718 Commits

Author SHA1 Message Date
Matthias Braun 97d0ffbe06 ScheduleDAGInstrs: Rework schedule graph builder.
Re-comitting with a change that avoids undefined uses getting put into
the VRegUses list.

The new algorithm remembers the uses encountered while walking backwards
until a matching def is found. Contrary to the previous version this:
- Works without LiveIntervals being available
- Allows to increase the precision to subregisters/lanemasks
  (not used for now)

The changes in the AMDGPU tests are necessary because the R600 scheduler
is not stable with respect to the order of nodes in the ready queues.

Differential Revision: http://reviews.llvm.org/D9068

llvm-svn: 254683
2015-12-04 01:51:19 +00:00
Matthias Braun c07cbc8d3c raw_ostream: << operator for callables with raw_ostream argument
This is a revised version of r254655 which uses a Printable wrapper
class to avoid ambiguous overload problems.

Differential Revision: http://reviews.llvm.org/D14348

llvm-svn: 254681
2015-12-04 01:31:59 +00:00
Evgeniy Stepanov 2bb9c5ca22 Emit function alias to data as a function symbol.
CFI emits jump slots for indirect functions as a byte array
constant, and declares function-typed aliases to these constants.

This change fixes AsmPrinter to emit these aliases as function
symbols and not data symbols.

llvm-svn: 254674
2015-12-04 00:45:43 +00:00
JF Bastien 1ac69947b6 CodeGen peephole: fold redundant phys reg copies
Code generation often exposes redundant physical register copies through
virtual registers such as:

  %vreg = COPY %PHYSREG
  ...
  %PHYSREG = COPY %vreg

There are cases where no intervening clobber of %PHYSREG occurs, and the
later copy could therefore be removed. In some cases this further allows
us to remove the initial copy.

This patch contains a motivating example which comes from the x86 build
of Chrome, specifically cc::ResourceProvider::UnlockForRead uses
libstdc++'s implementation of hash_map. That example has two tests live
at the same time, and after machine sinking LLVM has confused itself
enough and things spilling EFLAGS is a great idea even though it's
never restored and the comparison results are both live.

Before this patch we have:
  DEC32m %RIP, 1, %noreg, <ga:@L>, %noreg, %EFLAGS<imp-def>
  %vreg1<def> = COPY %EFLAGS; GR64:%vreg1
  %EFLAGS<def> = COPY %vreg1; GR64:%vreg1
  JNE_1 <BB#1>, %EFLAGS<imp-use>

Both copies are useless. This patch tries to eliminate the later copy in
a generic manner.

dec is especially confusing to LLVM when compared with sub.

I wrote this patch to treat all physical registers generically, but only
remove redundant copies of non-allocatable physical registers because
the allocatable ones caused issues (e.g. when calling conventions weren't
properly modeled) and should be handled later by the register allocator
anyways.

The following tests used to failed when the patch also replaced allocatable
registers:
  CodeGen/X86/StackColoring.ll
  CodeGen/X86/avx512-calling-conv.ll
  CodeGen/X86/copy-propagation.ll
  CodeGen/X86/inline-asm-fpstack.ll
  CodeGen/X86/musttail-varargs.ll
  CodeGen/X86/pop-stack-cleanup.ll
  CodeGen/X86/preserve_mostcc64.ll
  CodeGen/X86/tailcallstack64.ll
  CodeGen/X86/this-return-64.ll
This happens because COPY has other special meaning for e.g. dependency
breakage and x87 FP stack.

Note that all other backends' tests pass.

Reviewers: qcolombet
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D15157

llvm-svn: 254665
2015-12-03 23:43:56 +00:00
Justin Bogner 8d6f4e36e8 AsmPrinter: Simplify emitting FP elements in sequential data. NFC
Use APFloat APIs here Rather than manually type-punning through
unions.

llvm-svn: 254664
2015-12-03 23:28:35 +00:00
Matthias Braun 149b859c55 Revert "raw_ostream: << operator for callables with raw_stream argument"
This commit provoked "error C2593: 'operator <<' is ambiguous" on MSVC.

This reverts commit r254655.

llvm-svn: 254661
2015-12-03 23:00:28 +00:00
Matthias Braun e957a9bb1b raw_ostream: << operator for callables with raw_stream argument
This allows easier construction of print helpers. Example:

Printable PrintLaneMask(unsigned LaneMask) {
  return Printable([LaneMask](raw_ostream &OS) {
    OS << format("%08X", LaneMask);
  });
}

// Usage:
OS << PrintLaneMask(Mask);

Differential Revision: http://reviews.llvm.org/D14348

llvm-svn: 254655
2015-12-03 22:17:26 +00:00
Chih-Hung Hsieh ed7d81e5d4 [X86] Part 1 to fix x86-64 fp128 calling convention.
Almost all these changes are conditioned and only apply to the new
x86-64 f128 type configuration, which will be enabled in a follow up
patch. They are required together to make new f128 work. If there is
any error, we should fix or revert them as a whole.
These changes should have no impact to current configurations.

* Relax type legalization checks to accept new f128 type configuration,
  whose TypeAction is TypeSoftenFloat, not TypeLegal, but also has
  TLI.isTypeLegal true.
* Relax GetSoftenedFloat to return in some cases f128 type SDValue,
  which is TLI.isTypeLegal but not "softened" to i128 node.
* Allow customized FABS, FNEG, FCOPYSIGN on new f128 type configuration,
  to generate optimized bitwise operators for libm functions.
* Enhance related Lower* functions to handle f128 type.
* Enhance DAGTypeLegalizer::run, SoftenFloatResult, and related functions
  to keep new f128 type in register, and convert f128 operators to library calls.
* Fix Combiner, Emitter, Legalizer routines that did not handle f128 type.
* Add ExpandConstant to handle i128 constants, ExpandNode
  to handle ISD::Constant node.
* Add one more parameter to getCommonSubClass and firstCommonClass,
  to guarantee that returned common sub class will contain the specified
  simple value type.
  This extra parameter is used by EmitCopyFromReg in InstrEmitter.cpp.
* Fix infinite loop in getTypeLegalizationCost when f128 is the value type.
* Fix printOperand to handle null operand.
* Enhance ISD::BITCAST node to handle f128 constant.
* Expand new f128 type for BR_CC, SELECT_CC, SELECT, SETCC nodes.
* Enhance X86AsmPrinter to emit f128 values in comments.

Differential Revision: http://reviews.llvm.org/D15134

llvm-svn: 254653
2015-12-03 22:02:40 +00:00
Andrew Kaylor 9efb2332e2 [WinEH] Avoid infinite loop in BranchFolding for multiple single block funclets
Differential Revision: http://reviews.llvm.org/D14996

llvm-svn: 254629
2015-12-03 18:55:28 +00:00
Matthias Braun 2fd672a221 Revert "ScheduleDAGInstrs: Rework schedule graph builder."
This works mostly fine but breaks some stage 1 builders when compiling
compiler-rt on i386. Revert for further investigation as I can't see an
obvious cause/fix.

This reverts commit r254577.

llvm-svn: 254586
2015-12-03 03:01:10 +00:00
Matthias Braun d35fe3d984 ScheduleDAGInstrs: Rework schedule graph builder.
The new algorithm remembers the uses encountered while walking backwards
until a matching def is found. Contrary to the previous version this:
- Works without LiveIntervals being available
- Allows to increase the precision to subregisters/lanemasks
  (not used for now)

The changes in the AMDGPU tests are necessary because the R600 scheduler
is not stable with respect to the order of nodes in the ready queues.

Differential Revision: http://reviews.llvm.org/D9068

llvm-svn: 254577
2015-12-03 02:05:27 +00:00
Matthias Braun b0083608b4 RegisterPressure: Use range based for, fix else style; NFC
llvm-svn: 254575
2015-12-03 01:44:45 +00:00
David Majnemer 70497c696a Move EH-specific helper functions to a more appropriate place
No functionality change is intended.

llvm-svn: 254562
2015-12-02 23:06:39 +00:00
Reid Kleckner 1f11b4e3a7 Use std::string instead of strdup() and free() in WinCodeViewLineTables
llvm-svn: 254557
2015-12-02 22:34:30 +00:00
Kyle Butt cf6a8bfe51 [CodeGen]: Fix bad interaction with AntiDep breaking and inline asm.
AggressiveAntiDepBreaker was renaming registers specified by the user
for inline assembly. While this will work for compiler-specified
registers, it won't work for user-specified registers, and at the time
this runs, I don't currently see a way to distinguish them.

llvm-svn: 254532
2015-12-02 18:58:51 +00:00
Fiona Glaser 1075f6323f Fix accidental off by one change
Didn't break any tests, but did unnecessary extra work.

llvm-svn: 254529
2015-12-02 18:46:23 +00:00
Fiona Glaser e25b06fa23 Scheduler / Regalloc: use unique_ptr[] instead of std::vector
vector.resize() is significantly slower than memset in many STLs
and the cost of initializing these vectors is significant on targets
with many registers. Since we don't need the overhead of a vector,
use a simple unique_ptr instead.

llvm-svn: 254526
2015-12-02 18:32:59 +00:00
Tim Northover f520eff782 AArch64: use ldxp/stxp pair to implement 128-bit atomic loads.
The ARM ARM is clear that 128-bit loads are only guaranteed to have been atomic
if there has been a corresponding successful stxp. It's less clear for AArch32, so
I'm leaving that alone for now.

llvm-svn: 254524
2015-12-02 18:12:57 +00:00
Cong Hou cb07d7016a Fix a bug in IfConversion.cpp.
The bug is introduced in r254377 which failed some tests on ARM, where a new
probability is assigned to a successor but the provided BB may not be a
successor.

llvm-svn: 254463
2015-12-01 21:50:20 +00:00
Sanjay Patel 0b2a94916d use range-based for loops; NFCI
llvm-svn: 254453
2015-12-01 19:57:43 +00:00
Sanjay Patel b53791e5a7 don't repeat function/variable names in comments; NFC
llvm-svn: 254445
2015-12-01 19:32:35 +00:00
Sanjay Patel 96824deebc fix typo; NFC
llvm-svn: 254442
2015-12-01 19:19:18 +00:00
Elena Demikhovsky 0781d7b2b4 Fixed a failure in cost calculation for vector GEP
Cost calculation for vector GEP failed with due to invalid cast to GEP index operand.
The bug is fixed, added a test.

http://reviews.llvm.org/D14976

llvm-svn: 254408
2015-12-01 12:08:36 +00:00
Yury Gribov d7dbb66eb8 Introduce new @llvm.get.dynamic.area.offset.i{32, 64} intrinsics.
The @llvm.get.dynamic.area.offset.* intrinsic family is used to get the offset
from native stack pointer to the address of the most recent dynamic alloca on
the caller's stack. These intrinsics are intendend for use in combination with
@llvm.stacksave and @llvm.restore to get a pointer to the most recent dynamic
alloca. This is useful, for example, for AddressSanitizer's stack unpoisoning
routines.

Patch by Max Ostapenko.

Differential Revision: http://reviews.llvm.org/D14983

llvm-svn: 254404
2015-12-01 11:40:55 +00:00
Cong Hou 4aef7ef881 Allow known and unknown probabilities coexist in MBB's successor list.
Previously it is not allowed for each MBB to have successors with both known and
unknown probabilities. However, this may be too strict as at this stage we could
not always guarantee that. It is better to remove this restriction now, and I
will work on validating MBB's successors' probabilities first (for example,
check if the sum is approximate one).

llvm-svn: 254402
2015-12-01 11:05:39 +00:00
Cong Hou d97c100dc4 Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces.
(This is the second attempt to submit this patch. The first caused two assertion
 failures and was reverted. See https://llvm.org/bugs/show_bug.cgi?id=25687)

The patch in http://reviews.llvm.org/D13745 is broken into four parts:

1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.

This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.

All uses of weight-based interfaces are now updated to use probability-based
ones.


Differential revision: http://reviews.llvm.org/D14973

llvm-svn: 254377
2015-12-01 05:29:22 +00:00
Matthias Braun 50f7f585ed RegisterPressure: If we do not collect dead defs the list must be empty
llvm-svn: 254372
2015-12-01 04:20:06 +00:00
Matthias Braun ba6b225bf9 RegisterPressure: Remove support for recede()/advance() at MBB boundaries
Nobody was checking the returnvalue of recede()/advance() so we can
simply replace this code with asserts.

llvm-svn: 254371
2015-12-01 04:20:04 +00:00
Matthias Braun f9f8b92d93 RegisterPressure: Split RegisterOperands analysis code from result object; NFC
This is in preparation to expose the RegisterOperands class as
RegisterPressure API.

llvm-svn: 254368
2015-12-01 04:19:56 +00:00
Hans Wennborg 1dbaf67537 Revert r254348: "Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces."
and the follow-up r254356: "Fix a bug in MachineBlockPlacement that may cause assertion failure during BranchProbability construction."

Asserts were firing in Chromium builds. See PR25687.

llvm-svn: 254366
2015-12-01 03:49:42 +00:00
Cong Hou 1ccca9e673 Fix a bug in MachineBlockPlacement that may cause assertion failure during BranchProbability construction.
The root cause is the rounding behavior in BranchProbability construction. We may consider to use truncation instead in the future.

llvm-svn: 254356
2015-12-01 00:55:42 +00:00
Evgeniy Stepanov fd07995363 Extend debug info for function parameters in SDAG.
SDAG currently can emit debug location for function parameters when
an llvm.dbg.declare points to either a function argument SSA temp,
or to an AllocaInst. This change extends this logic by adding a
fallback case when neither of the above is true.

This is required for SafeStack, which may copy the contents of a
byval function argument into something that is not an alloca, and
then describe the target as the new location of the said argument.

llvm-svn: 254352
2015-12-01 00:34:30 +00:00
Cong Hou fa1917c673 Replace all weight-based interfaces in MBB with probability-based interfaces, and update all uses of old interfaces.
The patch in http://reviews.llvm.org/D13745 is broken into four parts:

1. New interfaces without functional changes (http://reviews.llvm.org/D13908).
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights (http://reviews.llvm.org/D14361).
3. Use new interfaces in all other passes.
4. Remove old interfaces.

This patch is 3+4 above. In this patch, MBB won't provide weight-based
interfaces any more, which are totally replaced by probability-based ones.
The interface addSuccessor() is redesigned so that the default probability is
unknown. We allow unknown probabilities but don't allow using it together
with known probabilities in successor list. That is to say, we either have a
list of successors with all known probabilities, or all unknown
probabilities. In the latter case, we assume each successor has 1/N
probability where N is the number of successors. An assertion checks if the
user is attempting to add a successor with the disallowed mixed use as stated
above. This can help us catch many misuses.

All uses of weight-based interfaces are now updated to use probability-based
ones.


Differential revision: http://reviews.llvm.org/D14973

llvm-svn: 254348
2015-12-01 00:02:51 +00:00
Paul Robinson a2550a6da3 Have 'optnone' respect the -fast-isel=false option.
This is primarily useful for debugging optnone v. ISel issues.

Differential Revision: http://reviews.llvm.org/D14792

llvm-svn: 254335
2015-11-30 21:56:16 +00:00
Craig Topper 6066164454 Use a lambda instead of std::bind and std::mem_fn I introduced in r254242. NFC
llvm-svn: 254260
2015-11-29 18:05:22 +00:00
Craig Topper d0573179dc [SelectionDAG] Use std::any_of instead of a manually coded loop. NFC
llvm-svn: 254242
2015-11-29 04:37:11 +00:00
Jonas Paulsson f12b925bb1 [Stack realignment] Handling of aligned allocas.
This patch implements dynamic realignment of stack objects for targets
with a non-realigned stack pointer. Behaviour in FunctionLoweringInfo
is changed so that for a target that has StackRealignable set to
false, over-aligned static allocas are considered to be variable-sized
objects and are handled with DYNAMIC_STACKALLOC nodes.

It would be good to group aligned allocas into a single big alloca as
an optimization, but this is yet todo.

SystemZ benefits from this, due to its stack frame layout.

New tests SystemZ/alloca-03.ll for aligned allocas, and
SystemZ/alloca-04.ll for "no-realign-stack" attribute on functions.

Review and help from Ulrich Weigand and Hal Finkel.

llvm-svn: 254227
2015-11-28 11:02:32 +00:00
Artyom Skrobov 314ee04268 Expose isXxxConstant() functions from SelectionDAGNodes.h (NFC)
Summary:
Many target lowerings copy-paste the code to test SDValues for known constants.
This code can instead be shared in SelectionDAG.cpp, and reused in the targets.

Reviewers: MatzeB, andreadb, tstellarAMD

Subscribers: arsenm, jyknight, llvm-commits

Differential Revision: http://reviews.llvm.org/D14945

llvm-svn: 254085
2015-11-25 19:41:11 +00:00
Eric Christopher 4675c439aa Fix some places where we were assuming that memory type had been legalized
to a simple type when lowering a truncating store of a vector type. In this
case for an EVT we'll return Expand as we should in all of the cases anyhow.

The testcase triggered at the one in VectorLegalizer::LegalizeOp, inspection
found the rest.

llvm-svn: 254061
2015-11-25 09:11:53 +00:00
Matthias Braun 147110da84 LiveVariables should not clobber MachineOperand::IsDead, ::IsKill on reserved physical registers
Patch by Nick Johnson <Nicholas.Paul.Johnson@deshawresearch.com>

Differential Revision: http://reviews.llvm.org/D14875

llvm-svn: 254012
2015-11-24 20:06:56 +00:00
Cong Hou 1938f2eb98 Let SelectionDAG start to use probability-based interface to add successors.
The patch in http://reviews.llvm.org/D13745 is broken into four parts:

1. New interfaces without functional changes.
2. Use new interfaces in SelectionDAG, while in other passes treat probabilities
as weights.
3. Use new interfaces in all other passes.
4. Remove old interfaces.

This the second patch above. In this patch SelectionDAG starts to use
probability-based interfaces in MBB to add successors but other MC passes are
still using weight-based interfaces. Therefore, we need to maintain correct
weight list in MBB even when probability-based interfaces are used. This is
done by updating weight list in probability-based interfaces by treating the
numerator of probabilities as weights. This change affects many test cases
that check successor weight values. I will update those test cases once this
patch looks good to you.


Differential revision: http://reviews.llvm.org/D14361

llvm-svn: 253965
2015-11-24 08:51:23 +00:00
Davide Italiano c304a0ddc1 [DIE] Make DIE.h NDEBUG conditional-free.
Switch dump()/print() method definitions to LLVM_DUMP_METHOD instead.

llvm-svn: 253945
2015-11-24 02:21:43 +00:00
Andrew Kaylor d0430e8580 [WinEH] Fix problem where CodeGenPrepare incorrectly sinks a bitcast into an EH pad.
Differential Revision: http://reviews.llvm.org/D14842

llvm-svn: 253902
2015-11-23 19:16:15 +00:00
Simon Pilgrim 1dfe53e180 Remove duplicate getValueType() calls. NFCI.
llvm-svn: 253823
2015-11-22 16:49:38 +00:00
Krzysztof Parzyszek 6753f33388 Avoid dependency between TableGen and CodeGen
Duplicate a few common definitions between DFAPacketizer.cpp and
DFAPacketizerEmitter.cpp to avoid including files from CodeGen
in TableGen.

llvm-svn: 253820
2015-11-22 15:20:19 +00:00
Krzysztof Parzyszek b46557292c Hexagon V60/HVX DFA scheduler support
Extended DFA tablegen to:
  - added "-debug-only dfa-emitter" support to llvm-tblgen

  - defined CVI_PIPE* resources for the V60 vector coprocessor

  - allow specification of multiple required resources
    - supports ANDs of ORs
    - e.g. [SLOT2, SLOT3], [CVI_MPY0, CVI_MPY1] means:
           (SLOT2 OR SLOT3) AND (CVI_MPY0 OR CVI_MPY1)

  - added support for combo resources
    - allows specifying ORs of ANDs
    - e.g. [CVI_XLSHF, CVI_MPY01] means:
           (CVI_XLANE AND CVI_SHIFT) OR (CVI_MPY0 AND CVI_MPY1)

  - increased DFA input size from 32-bit to 64-bit
    - allows for a maximum of 4 AND'ed terms of 16 resources

  - supported expressions now include:

    expression     => term [AND term] [AND term] [AND term]
    term           => resource [OR resource]*
    resource       => one_resource | combo_resource
    combo_resource => (one_resource [AND one_resource]*)

Author: Dan Palermo <dpalermo@codeaurora.org>

kparzysz: Verified AMDGPU codegen to be unchanged on all llc
tests, except those dealing with instruction encodings.

Reapply the previous patch, this time without circular dependencies.

llvm-svn: 253793
2015-11-21 20:00:45 +00:00
Krzysztof Parzyszek 4ca21fc1aa Revert r253790: it breaks all builds for some reason.
llvm-svn: 253791
2015-11-21 17:38:33 +00:00
Krzysztof Parzyszek 220a9bc018 Hexagon V60/HVX DFA scheduler support
Extended DFA tablegen to:
  - added "-debug-only dfa-emitter" support to llvm-tblgen

  - defined CVI_PIPE* resources for the V60 vector coprocessor

  - allow specification of multiple required resources
    - supports ANDs of ORs
    - e.g. [SLOT2, SLOT3], [CVI_MPY0, CVI_MPY1] means:
           (SLOT2 OR SLOT3) AND (CVI_MPY0 OR CVI_MPY1)

  - added support for combo resources
    - allows specifying ORs of ANDs
    - e.g. [CVI_XLSHF, CVI_MPY01] means:
           (CVI_XLANE AND CVI_SHIFT) OR (CVI_MPY0 AND CVI_MPY1)

  - increased DFA input size from 32-bit to 64-bit
    - allows for a maximum of 4 AND'ed terms of 16 resources

  - supported expressions now include:

    expression     => term [AND term] [AND term] [AND term]
    term           => resource [OR resource]*
    resource       => one_resource | combo_resource
    combo_resource => (one_resource [AND one_resource]*)

Author: Dan Palermo <dpalermo@codeaurora.org>

kparzysz: Verified AMDGPU codegen to be unchanged on all llc
tests, except those dealing with instruction encodings.

llvm-svn: 253790
2015-11-21 17:23:52 +00:00
Jonas Paulsson 8f0d2b7f1f [DAGCombiner] Bugfix for lost chain depenedency.
When MergeConsecutiveStores() combines two loads and two stores into
wider loads and stores, the chain users of both of the original loads
must be transfered to the new load, because it may be that a chain
user only depends on one of the loads.

New test case: test/CodeGen/SystemZ/dag-combine-01.ll

Reviewed by James Y Knight.

Bugzilla: https://llvm.org/bugs/show_bug.cgi?id=25310#c6
llvm-svn: 253779
2015-11-21 13:25:07 +00:00
Geoff Berry 5256fcada0 [CodeGenPrepare] Create more extloads and fewer ands
Summary:
Add and instructions immediately after loads that only have their low
bits used, assuming that the (and (load x) c) will be matched as a
extload and the ands/truncs fed by the extload will be removed by isel.

Reviewers: mcrosier, qcolombet, ab

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14584

llvm-svn: 253722
2015-11-20 22:34:39 +00:00
Arnaud A. de Grandmaison 4e89e9f846 [ShrinkWrap] Teach ShrinkWrap to handle targets requiring a register scavenger.
The included test only checks for a compiler crash for now. Several people are
facing this issue, so we first resolve the crash, and will increase shrinkwrap's
coverage later in a follow-up patch.

llvm-svn: 253718
2015-11-20 21:54:27 +00:00
Daniel Sanders b700203c8b Partially revert r253662: some unrelated work was accidentally committed with it.
Sorry.

llvm-svn: 253663
2015-11-20 13:16:35 +00:00
Daniel Sanders be9db3c00a Revert the revert 253497 and 253539 - These commits aren't the cause of the clang-cmake-mips failures.
Sorry for the noise.

llvm-svn: 253662
2015-11-20 13:13:53 +00:00
Tobias Edler von Koch 4d45090659 [LTO] Add option to emit assembly from LTOCodeGenerator
This adds a new API, LTOCodeGenerator::setFileType, to choose the output file
format for LTO CodeGen. A corresponding change to use this new API from
llvm-lto and a test case is coming in a separate commit.

Differential Revision: http://reviews.llvm.org/D14554

llvm-svn: 253622
2015-11-19 23:59:24 +00:00
Reid Kleckner cc2f6c35a3 [WinEH] Disable most forms of demotion
Now that the register allocator knows about the barriers on funclet
entry and exit, testing has shown that this is unnecessary.

We still demote PHIs on unsplittable blocks due to the differences
between the IR CFG and the Machine CFG.

llvm-svn: 253619
2015-11-19 23:23:33 +00:00
Krzysztof Parzyszek df537b97b1 Expand subregisters in MachineFrameInfo::getPristineRegs
http://reviews.llvm.org/D14719

llvm-svn: 253600
2015-11-19 21:18:52 +00:00
Sanjay Patel 4699b8ab6a [CGP] despeculate expensive cttz/ctlz intrinsics
This is another step towards allowing SimplifyCFG to speculate harder, but then have 
CGP clean things up if the target doesn't like it.

Previous patches in this series:
http://reviews.llvm.org/D12882
http://reviews.llvm.org/D13297

D13297 should catch most expensive ops, but speculation of cttz/ctlz requires special
handling because of weirdness in the intrinsic definition for handling a zero input 
(that definition can probably be blamed on x86).

For example, if we have the usual speculated-by-select expensive op pattern like this:

  %tobool = icmp eq i64 %A, 0
  %0 = tail call i64 @llvm.cttz.i64(i64 %A, i1 true)   ; is_zero_undef == true
  %cond = select i1 %tobool, i64 64, i64 %0
  ret i64 %cond

There's an instcombine that will turn it into:

  %0 = tail call i64 @llvm.cttz.i64(i64 %A, i1 false)   ; is_zero_undef == false

This CGP patch is looking for that case and despeculating it back into:

  entry:
    %tobool = icmp eq i64 %A, 0
    br i1 %tobool, label %cond.end, label %cond.true

  cond.true:
    %0 = tail call i64 @llvm.cttz.i64(i64 %A, i1 true)    ; is_zero_undef == true
    br label %cond.end

  cond.end:
    %cond = phi i64 [ %0, %cond.true ], [ 64, %entry ]
    ret i64 %cond

This unfortunately may lead to poorer codegen (see the changes in the existing x86 test), 
but if we increase speculation in SimplifyCFG (the next step in this patch series), then
we should avoid those kinds of cases in the first place.

The need for this patch was originally mentioned here:
http://reviews.llvm.org/D7506
with follow-up here:
http://reviews.llvm.org/D7554

Differential Revision: http://reviews.llvm.org/D14630

llvm-svn: 253573
2015-11-19 16:37:10 +00:00
Hans Wennborg dcc2500452 X86: More efficient legalization of wide integer compares
In particular, this makes the code for 64-bit compares on 32-bit targets
much more efficient.

Example:

  define i32 @test_slt(i64 %a, i64 %b) {
  entry:
    %cmp = icmp slt i64 %a, %b
    br i1 %cmp, label %bb1, label %bb2
  bb1:
    ret i32 1
  bb2:
    ret i32 2
  }

Before this patch:

  test_slt:
          movl    4(%esp), %eax
          movl    8(%esp), %ecx
          cmpl    12(%esp), %eax
          setae   %al
          cmpl    16(%esp), %ecx
          setge   %cl
          je      .LBB2_2
          movb    %cl, %al
  .LBB2_2:
          testb   %al, %al
          jne     .LBB2_4
          movl    $1, %eax
          retl
  .LBB2_4:
          movl    $2, %eax
          retl

After this patch:

  test_slt:
          movl    4(%esp), %eax
          movl    8(%esp), %ecx
          cmpl    12(%esp), %eax
          sbbl    16(%esp), %ecx
          jge     .LBB1_2
          movl    $1, %eax
          retl
  .LBB1_2:
          movl    $2, %eax
          retl

Differential Revision: http://reviews.llvm.org/D14496

llvm-svn: 253572
2015-11-19 16:35:08 +00:00
Pete Cooper 67cf9a723b Revert "Change memcpy/memset/memmove to have dest and source alignments."
This reverts commit r253511.

This likely broke the bots in
http://lab.llvm.org:8011/builders/clang-ppc64-elf-linux2/builds/20202
http://bb.pgr.jp/builders/clang-3stage-i686-linux/builds/3787

llvm-svn: 253543
2015-11-19 05:56:52 +00:00
Pete Cooper 72bc23ef02 Change memcpy/memset/memmove to have dest and source alignments.
Note, this was reviewed (and more details are in) http://lists.llvm.org/pipermail/llvm-commits/Week-of-Mon-20151109/312083.html

These intrinsics currently have an explicit alignment argument which is
required to be a constant integer.  It represents the alignment of the
source and dest, and so must be the minimum of those.

This change allows source and dest to each have their own alignments
by using the alignment attribute on their arguments.  The alignment
argument itself is removed.

There are a few places in the code for which the code needs to be
checked by an expert as to whether using only src/dest alignment is
safe.  For those places, they currently take the minimum of src/dest
alignments which matches the current behaviour.

For example, code which used to read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* %dest, i8* %src, i32 500, i32 8, i1 false)
will now read:
  call void @llvm.memcpy.p0i8.p0i8.i32(i8* align 8 %dest, i8* align 8 %src, i32 500, i1 false)

For out of tree owners, I was able to strip alignment from calls using sed by replacing:
  (call.*llvm\.memset.*)i32\ [0-9]*\,\ i1 false\)
with:
  $1i1 false)

and similarly for memmove and memcpy.

I then added back in alignment to test cases which needed it.

A similar commit will be made to clang which actually has many differences in alignment as now
IRBuilder can generate different source/dest alignments on calls.

In IRBuilder itself, a new argument was added.  Instead of calling:
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, /* isVolatile */ false)
you now call
  CreateMemCpy(Dst, Src, getInt64(Size), DstAlign, SrcAlign, /* isVolatile */ false)

There is a temporary class (IntegerAlignment) which takes the source alignment and rejects
implicit conversion from bool.  This is to prevent isVolatile here from passing its default
parameter to the source alignment.

Note, changes in future can now be made to codegen.  I didn't change anything here, but this
change should enable better memcpy code sequences.

Reviewed by Hal Finkel.

llvm-svn: 253511
2015-11-18 22:17:24 +00:00
Simon Pilgrim c1a46b729b [DAGCombiner] Vector constant folding for comparisons
This patch adds support for vector constant folding of integer/float comparisons.

This requires FoldConstantVectorArithmetic to support scalar constant operands (in this case ISD::CONDCASE). In future we should be able to support other scalar constant types as necessary (and possibly start calling FoldConstantVectorArithmetic for all node creations)

Differential Revision: http://reviews.llvm.org/D14683

llvm-svn: 253504
2015-11-18 21:17:19 +00:00
Betul Buyukkurt 6fac1741c9 [PGO] Value profiling support
This change introduces an instrumentation intrinsic instruction for
value profiling purposes, the lowering of the instrumentation intrinsic
and raw reader updates. The raw profile data files for llvm-profdata
testing are updated.

llvm-svn: 253484
2015-11-18 18:14:55 +00:00
Jonas Paulsson af722f8287 [SelectionDAGBuilder] Make sure DemoteReg ends up in right reg-class.
The virtual register containing the address for returned value on
stack should in the DAG be represented with a CopyFromReg node and not
a Register node. Otherwise, InstrEmitter will not make sure that it
ends up in the right register class for the target instruction.

SystemZ needs this, becuause the reg class for address registers is a
subset of the general 64 bit register class.

test/SystemZ/CodeGen/args-07.ll and args-04.ll updated to run with
-verify-machineinstrs.

Reviewed by Hal Finkel.

llvm-svn: 253461
2015-11-18 14:59:00 +00:00
Rafael Espindola 449711cb36 Stop producing .data.rel sections.
If a section is rw, it is irrelevant if the dynamic linker will write to
it or not.

It looks like llvm implemented this because gcc was doing it. It looks
like gcc implemented this in the hope that it would put all the
relocated items close together and speed up the dynamic linker.

There are two problem with this:
* It doesn't work. Both bfd and gold will map .data.rel to .data and
  concatenate the input sections in the order they are seen.
* If we want a feature like that, it can be implemented directly in the
  linker since it knowns where the dynamic relocations are.

llvm-svn: 253436
2015-11-18 06:02:15 +00:00
Cong Hou 136bc65ec8 Remove a redundant assertion in MachineBasicBlock.cpp. NFC.
llvm-svn: 253426
2015-11-18 01:55:56 +00:00
Cong Hou 11c1420173 Remove redundant code in MachineBasicBlock.cpp. NFC.
llvm-svn: 253425
2015-11-18 01:45:10 +00:00
Cong Hou 41cf1a5dfb Improving edge probabilities computation when choosing the best successor in machine block placement.
When looking for the best successor from the outer loop for a block
belonging to an inner loop, the edge probability computation can be
improved so that edges in the inner loop are ignored. For example,
suppose we are building chains for the non-loop part of the following
code, and looking for B1's best successor. Assume the true body is very
hot, then B3 should be the best candidate. However, because of the
existence of the back edge from B1 to B0, the probability from B1 to B3
can be very small, preventing B3 to be its successor. In this patch, when
computing the probability of the edge from B1 to B3, the weight on the
back edge B1->B0 is ignored, so that B1->B3 will have 100% probability.

if (...)
  do {
    B0;
    ... // some branches
    B1;
  } while(...);
else
  B2;
B3;


Differential revision: http://reviews.llvm.org/D10825

llvm-svn: 253414
2015-11-18 00:52:52 +00:00
David Blaikie 6196aa06c9 Generalize ownership/passing semantics to allow dsymutil to own abbreviations via unique_ptr
While still allowing CodeGen/AsmPrinter in llvm to own them using a bump
ptr allocator. (might be nice to replace the pointers there with
something that at least automatically calls their dtors, if that's
necessary/useful, rather than having it done explicitly (I think a typed
BumpPtrAllocator already does this, or maybe a unique_ptr with a custom
deleter, etc))

llvm-svn: 253409
2015-11-18 00:34:10 +00:00
Reid Kleckner c20276d0b2 [WinEH] Move WinEHFuncInfo from MachineModuleInfo to MachineFunction
Summary:
Now that there is a one-to-one mapping from MachineFunction to
WinEHFuncInfo, we don't need to use a DenseMap to select the right
WinEHFuncInfo for the current funclet.

The main challenge here is that X86WinEHStatePass is an IR pass that
doesn't have access to the MachineFunction. I gave it its own
WinEHFuncInfo object that it uses to calculate state numbers, which it
then throws away. As long as nobody creates or removes EH pads between
this pass and SDAG construction, we will get the same state numbers.

The other thing X86WinEHStatePass does is to mark the EH registration
node. Instead of communicating which alloca was the registration through
WinEHFuncInfo, I added the llvm.x86.seh.ehregnode intrinsic.  This
intrinsic generates no code and simply marks the alloca in use.

Reviewers: JCTremoulet

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14668

llvm-svn: 253378
2015-11-17 21:10:25 +00:00
Pat Gavlin c8ea157811 Lower statepoints with multi-def targets.
Statepoint lowering currently expects that the target method of a
statepoint only defines a single value. This precludes using
statepoints with ABIs that return values in multiple registers
(e.g. the SysV AMD64 ABI). This change adds support for lowering
statepoints with mutli-def targets.

llvm-svn: 253339
2015-11-17 16:04:21 +00:00
Dan Gohman 7aa4abac24 Use TargetRegisterInfo for printing MachineOperand register comments
Several places in AsmPrinter.cpp print comments describing MachineOperand
registers using MCRegisterInfo, which uses MCOperand-oriented names. This
doesn't work for targets that use virtual registers exclusively, as
WebAssembly does, since virtual registers are represented and printed
differently.

This patch preserves what seems to be the spirit of r229978, avoiding the
use of TM.getSubtargetImpl(), while still using MachineOperand-oriented
printing for MachineOperands.

Differential Revision: http://reviews.llvm.org/D14709

llvm-svn: 253338
2015-11-17 16:01:28 +00:00
Rafael Espindola 65e4902156 Drop prelink support.
The way prelink used to work was

* The compiler decides if a given section only has relocations that
are know to point to the same DSO. If so, it names it
.data.rel.ro.local<something>.
* The static linker puts all of these together.
* The prelinker program assigns addresses to each library and resolves
the local relocations.

There are many problems with this:
* It is incompatible with address space randomization.
* The information passed by the compiler is redundant. The linker
knows if a given relocation is in the same DSO or not. If could sort
by that if so desired.
* There are newer ways of speeding up DSO (gnu hash for example).
* Even if we want to implement this again in the compiler, the previous
  implementation is pretty broken. It talks about relocations that are
  "resolved by the static linker". If they are resolved, there are none
  left for the prelinker. What one needs to track is if an expression
  will require only dynamic relocations that point to the same DSO.

At this point it looks like the prelinker is an historical curiosity.
For example, fedora has retired it because it failed to build for two
releases
(http://pkgs.fedoraproject.org/cgit/prelink.git/commit/?id=eb43100a8331d91c801ee3dcdb0a0bb9babfdc1f)

This patch removes support for it. That is, it stops printing the
".local" sections.

llvm-svn: 253280
2015-11-17 00:51:23 +00:00
Matthias Braun fe9d6f211f Assume lane masks are always precise
Allowing imprecise lane masks in case of more than 32 sub register lanes
lead to some tricky corner cases, and I need another bugfix for another
one. Instead I rather declare lane masks as precise and let tablegen
abort if we do not have enough bits.

This does not affect any in-tree target, even AMDGPU only needs 16 lanes
at the moment. If the 32 lanes turn out to be a problem in the future,
then we can easily change the LaneBitmask typedef to uint64_t.

Differential Revision: http://reviews.llvm.org/D14557

llvm-svn: 253279
2015-11-17 00:50:55 +00:00
Keno Fischer b011c63d19 [DIBuilder] Make createReferenceType take size and align
Summary: Since we're passing references to dbg.value as pointers,
we need to have the frontend properly declare their sizes and
alignments (as it already does for regular pointers) in preparation
for my upcoming patch to have the verifer check that the sizes agree.

Also augment the backend logic that skips actually emitting this
information into DWARF such that it also handles reference types.

Reviewers: aprantl, dexonsmith, dblaikie

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D14275

llvm-svn: 253186
2015-11-16 07:57:32 +00:00
Akira Hatanaka b11ef0897c Reduce the size of MCRelaxableFragment.
MCRelaxableFragment previously kept a copy of MCSubtargetInfo and
MCInst to enable re-encoding the MCInst later during relaxation. A copy
of MCSubtargetInfo (instead of a reference or pointer) was needed
because the feature bits could be modified by the parser.

This commit replaces the MCSubtargetInfo copy in MCRelaxableFragment
with a constant reference to MCSubtargetInfo. The copies of
MCSubtargetInfo are kept in MCContext, and the target parsers are now
responsible for asking MCContext to provide a copy whenever the feature
bits of MCSubtargetInfo have to be toggled.
 
With this patch, I saw a 4% reduction in peak memory usage when I
compiled verify-uselistorder.lto.bc using llc.

rdar://problem/21736951

Differential Revision: http://reviews.llvm.org/D14346

llvm-svn: 253127
2015-11-14 06:35:56 +00:00
Quentin Colombet 2cdcfd23cd [ShrinkWrapping] Disable the optimization for functions with sanitize like
attribute.

Even if the target supports shrink-wrapping, the prologue and epilogue
must not move because a crash can happen anywhere and sanitizers need
to be able to unwind from the PC of the crash.

llvm-svn: 253116
2015-11-14 01:55:17 +00:00
Matthias Braun e6edd48d69 MachineScheduler: Print initial pressure in debug dump
llvm-svn: 253097
2015-11-13 22:30:31 +00:00
Matthias Braun 3b099db61d MachineScheduler: Improve debug output for "only one node in readyset"
When there is only 1 node left in the ready queue and it is picked call
the reason "ONLY1" instead of "NOCAND".

llvm-svn: 253096
2015-11-13 22:30:29 +00:00
James Molloy bb1dbf530a [SDAG] Fix expansion of BITREVERSE
Richard Trieu noted that UBSan detected an overflowing shift, and the obvious fix caused a crash.

What was happening was that the shiftee (1U) was indeed too small for the possible range of shifts it had to handle, but also we were using "VT.getSizeInBits()" to get the maximum type bitwidth, but we wanted "VT.getScalarSizeInBits()" to get the vector lane size instead of the entire vector size.

Use an APInt for the shift and VT.getScalarSizeInBits().

llvm-svn: 253023
2015-11-13 10:02:36 +00:00
Sanjoy Das ac9c5b1901 [ImplicitNulls] Add some clarifying comments; NFC
llvm-svn: 253020
2015-11-13 08:14:00 +00:00
Tom Stellard 0967c91e0c Revert "Remove unnecessary call to getAllocatableRegClass"
This reverts commit r252565.

This also includes the revert of the commit mentioned below in order to
avoid breaking tests in AMDGPU:

Revert "AMDGPU: Set isAllocatable = 0 on VS_32/VS_64"

This reverts commit r252674.

llvm-svn: 252956
2015-11-12 21:43:25 +00:00
Sanjoy Das e8b81649cf [ImplicitNulls] Fix wrapping by breaking up a condition, NFC
llvm-svn: 252947
2015-11-12 20:51:49 +00:00
Sanjoy Das edc394f1ed [ImplicitNull] Extract out a HazardDetector class, NFC
This will make later functional changes easier to follow.

llvm-svn: 252946
2015-11-12 20:51:44 +00:00
Quentin Colombet aeb85934b6 [ShrinkWrap] Fix a typo in a comment.
llvm-svn: 252918
2015-11-12 18:16:27 +00:00
Quentin Colombet 94dc1e0d34 [ShrinkWrap] Make sure we do not mess up with EH funclet lowering.
ShrinkWrapping does not understand exception handling constraints for now, so
make sure we do not mess with them by aborting on functions that use EH
funclets.

llvm-svn: 252917
2015-11-12 18:13:42 +00:00
Andrew Kaylor fb16a3ac9a [WinEH] Fix problem with removing an element from a SetVector while iterating.
Patch provided by Yaron Keren. (Thanks!)

llvm-svn: 252913
2015-11-12 17:36:03 +00:00
James Molloy 90111f79f9 [SDAG] Introduce a new BITREVERSE node along with a corresponding LLVM intrinsic
Several backends have instructions to reverse the order of bits in an integer. Conceptually matching such patterns is similar to @llvm.bswap, and it was mentioned in http://reviews.llvm.org/D14234 that it would be best if these patterns were matched in InstCombine instead of reimplemented in every different target.

This patch introduces an intrinsic @llvm.bitreverse.i* that operates similarly to @llvm.bswap. For plumbing purposes there is also a new ISD node ISD::BITREVERSE, with simple expansion and promotion support.

The intention is that InstCombine's BSWAP detection logic will be extended to support BITREVERSE too, and @llvm.bitreverse intrinsics emitted (if the backend supports lowering it efficiently).

llvm-svn: 252878
2015-11-12 12:29:09 +00:00
Matthias Braun b9610a6bc2 LegalizeDAG: Fix and improve FCOPYSIGN/FABS legalization
- Factor out code to query and modify the sign bit of a floatingpoint
  value as an integer. This also works if none of the targets integer
  types is big enough to hold all bits of the floatingpoint value.

- Legalize FABS(x) as FCOPYSIGN(x, 0.0) if FCOPYSIGN is available,
  otherwise perform bit manipulation on the sign bit. The previous code
  used "x >u 0 ? x : -x" which is incorrect for x being -0.0! It also
  takes 34 instructions on ARM Cortex-M4. With this patch we only
  require 5:
    vldr d0, LCPI0_0
    vmov r2, r3, d0
    lsrs r2, r3, #31
    bfi r1, r2, #31, #1
    bx lr
  (This could be further improved if the compiler would recognize that
   r2, r3 is zero).

- Only lower FCOPYSIGN(x, y) = sign(x) ? -FABS(x) : FABS(x) if FABS is
  available otherwise perform bit manipulation on the sign bit.

- Perform the sign(x) test by masking out the sign bit and comparing
  with 0 rather than shifting the sign bit to the highest position and
  testing for "<s 0". For x86 copysignl (on 80bit values) this gets us:
    testl $32768, %eax
  rather than:
    shlq $48, %rax
    sets %al
    testb %al, %al

Differential Revision: http://reviews.llvm.org/D11172

llvm-svn: 252839
2015-11-12 01:02:47 +00:00
Reid Kleckner b9204a584c [WinEH] Don't forward branches across empty EH pad BBs
For really simple SEH catchpads, we tried to forward the invoke unwind
edge across the empty block.

llvm-svn: 252822
2015-11-11 23:09:31 +00:00
Geoff Berry 2ddfc5e60f [DAGCombiner] Improve zextload optimization.
Summary:
Don't fold
  (zext (and (load x), cst)) -> (and (zextload x), (zext cst))
if
  (and (load x) cst)
will match as a zextload already and has additional users.

For example, the following IR:

  %load = load i32, i32* %ptr, align 8
  %load16 = and i32 %load, 65535
  %load64 = zext i32 %load16 to i64
  store i32 %load16, i32* %dst1, align 4
  store i64 %load64, i64* %dst2, align 8

used to produce the following aarch64 code:

	ldr		w8, [x0]
	and	w9, w8, #0xffff
	and	x8, x8, #0xffff
	str		w9, [x1]
	str		x8, [x2]

but with this change produces the following aarch64 code:

	ldrh		w8, [x0]
	str		w8, [x1]
	str		x8, [x2]

Reviewers: resistor, mcrosier

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14340

llvm-svn: 252789
2015-11-11 19:42:52 +00:00
Matt Arsenault d8fed1b793 Add target preference for GatherAllAliases max depth
llvm-svn: 252775
2015-11-11 18:44:33 +00:00
Dehao Chen 54511353e3 clang-format lib/CodeGen/AsmPrinter/DwarfCompileUnit.cpp
llvm-svn: 252769
2015-11-11 18:09:47 +00:00
Dehao Chen 72fdf444b7 Emit discriminator for inlined callsites.
Summary: Inlined callsites need to be emitted in debug info so that sample profile can be annotated to the correct inlined instance.

Reviewers: dnovillo, dblaikie

Subscribers: dblaikie, llvm-commits

Differential Revision: http://reviews.llvm.org/D14511

llvm-svn: 252768
2015-11-11 18:08:18 +00:00
Matthias Braun 2c98d0f477 MachineInstr: addRegisterDefReadUndef() => setRegisterDefReadUndef()
This way we can not only add but also remove read undef flags.

llvm-svn: 252678
2015-11-11 00:41:58 +00:00
Matthias Braun 4353b30542 TableGen: Emit LaneMask for register classes without subregisters as ~0u
This makes it slightly easier to handle classes with and without
subregister uniformly.

llvm-svn: 252671
2015-11-10 23:23:05 +00:00
Sanjay Patel 33ec5dbe35 less indent; NFCI
llvm-svn: 252643
2015-11-10 20:09:02 +00:00
Matt Arsenault aa118e299c LegalizeDAG: Implement promote for scalar_to_vector
This allows avoiding the default Expand behavior which
introduces stack usage. Bitcast the scalar and replace
the missing elements with undef.

This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.

llvm-svn: 252632
2015-11-10 18:48:11 +00:00
Matt Arsenault a46aa641f2 LegalizeDAG: Implement promote for insert_vector_elt
This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.

llvm-svn: 252631
2015-11-10 18:48:08 +00:00
Matt Arsenault 0b7958a59b LegalizeDAG: Implement promote for extract_vector_elt
This is for AMDGPU to implement v2i64 extract as extract of
half of a v4i32.

This is covered by existing tests and used by a future
commit which makes 64-bit vectors legal types on AMDGPU.

llvm-svn: 252630
2015-11-10 18:48:04 +00:00
Sanjay Patel 766589efdc add 'MustReduceDepth' as an objective/cost-metric for the MachineCombiner
This is one of the problems noted in PR25016:
https://llvm.org/bugs/show_bug.cgi?id=25016
and:
http://lists.llvm.org/pipermail/llvm-dev/2015-October/090998.html

The spilling problem is independent and not addressed by this patch.

The MachineCombiner was doing reassociations that don't improve or even worsen the critical path. 
This is caused by inclusion of the "slack" factor when calculating the critical path of the original
code sequence. If we don't add that, then we have a more conservative cost comparison of the old code
sequence vs. a new sequence. The more liberal calculation must be preserved, however, for the AArch64
MULADD patterns because benchmark regressions were observed without that.

The two failing test cases now have identical asm that does what we want:
a + b + c + d ---> (a + b) + (c + d)

Differential Revision: http://reviews.llvm.org/D13417

llvm-svn: 252616
2015-11-10 16:48:53 +00:00
Andy Ayers 809cbe9ea0 Support for emitting inline stack probes
For CoreCLR on Windows, stack probes must be emitted as inline sequences that probe successive stack pages
between the current stack limit and the desired new stack pointer location. This implements support for
the inline expansion on x64.

For in-body alloca probes, expansion is done during instruction lowering. For prolog probes, a stub call
is initially emitted during prolog creation, and expanded after epilog generation, to avoid complications
that arise when introducing new machine basic blocks during prolog and epilog creation.

Added a new test case, modified an existing one to exclude non-x64 coreclr (for now).

Add test case

Fix tests

llvm-svn: 252578
2015-11-10 01:50:49 +00:00
Matt Arsenault 6d87f28afd Remove unnecessary call to getAllocatableRegClass
I'm not sure what the point of this was. I'm not sure why
you would ever define an instruction that produces an unallocatable
register class. No tests fail with this removed, and it seems like
it should be a verifier error to define such an instruction.

This was problematic for AMDGPU because it would make bad decisions
by arbitrarily changing the register class when unsetting isAllocatable
for VS_32/VS_64, which is currently set as a workaround to this problem.

AMDGPU uses the VS_32/VS_64 register classes to represent operands which
can use either VGPRs or SGPRs. When  isAllocatable is unset for these,
this would need to pick  either the SGPR or VGPR class and insert either
a copy we don't want, or an illegal copy we would need to deal with
later. A semi-arbitrary register class ordering decision is made in tablegen,
which resulted in always picking a VGPR class because it happens to have
more registers than the SGPR register class. We really just want to
use whatever register class the original register had.

llvm-svn: 252565
2015-11-10 00:30:14 +00:00
Matthias Braun 7e624d5f11 MachineVerifier: Streamline live interval related error reporting
Simply perform additional report_context() calls after a report()
instead of adding more and more overloaded variations of report().  Also
improve several instances where information was output in an ad-hoc way
probably because no matching report() overload was available.

llvm-svn: 252552
2015-11-09 23:59:33 +00:00
Matthias Braun 716b43306b MachineVerifier: Add missing linebreak
MachineInstr::print() with SkipOppers==true does not produce a
linebreak, so we have to do that in MachineVerifier::report().

llvm-svn: 252551
2015-11-09 23:59:29 +00:00
Matthias Braun 45718db0a1 MachineVerifier: MI::print has no TargetMachine overload
The code was passing a target machine pointer which degraded to a true
operand to SkipOppers.

llvm-svn: 252550
2015-11-09 23:59:25 +00:00
Matthias Braun 42b4b63056 MachineVerifier: print list of live intervals if available
llvm-svn: 252549
2015-11-09 23:59:23 +00:00
Sanjay Patel 533c10c651 add a SelectionDAG method to check if no common bits are set in two nodes; NFCI
This was suggested in:
http://reviews.llvm.org/D13956

and is a follow-on to:
http://reviews.llvm.org/rL252515
http://reviews.llvm.org/rL252519

This lets us remove logically equivalent/duplicated code from DAGCombiner and X86ISelDAGToDAG.

A corresponding function for IR instructions already exists in ValueTracking.

llvm-svn: 252539
2015-11-09 23:31:38 +00:00
David Majnemer 2652b75700 [WinEH] Don't emit CATCHRET from visitCatchPad
Instead, emit a CATCHPAD node which will get selected to a target
specific sequence.

llvm-svn: 252528
2015-11-09 23:07:48 +00:00
Reid Kleckner 64b003f05d [WinEH] Tweak funclet prologue/epilogue insertion to pass verifier
For some reason we'd never run MachineVerifier on WinEH code, and you
explicitly have to ask for it with llc. I added it to a few test cases
to get some coverage.

Fixes PR25461.

llvm-svn: 252512
2015-11-09 21:04:00 +00:00
Andrew Kaylor fdd48fa1e1 [WinEH] Re-committing r252249 (Clone funclets with multiple parents) with additional fixes for determinism problems
Differential Revision: http://reviews.llvm.org/D14454

llvm-svn: 252508
2015-11-09 19:59:02 +00:00
Oliver Stannard 563585789c [CodeGen] Always promote f16 if not legal
We don't currently have any runtime library functions for operations on
f16 values (other than conversions to and from f32 and f64), so we
should always promote it to f32, even if that is not a legal type. In
that case, the f32 values would be softened to f32 library calls.

SoftenFloatRes_FP_EXTEND now needs to check the promoted operand's type,
as it may ne a no-op or require a different library call.

getCopyFromParts and getCopyToParts now need to cope with a
floating-point value stored in a larger integer part, as is the case for
any target that needs to store an f16 value in a 32-bit integer
register.

Differential Revision: http://reviews.llvm.org/D12856

llvm-svn: 252459
2015-11-09 11:03:18 +00:00
Yaron Keren 9ffee46d45 Erase unused FunctionDIs variables after r252219.
llvm-svn: 252401
2015-11-07 10:21:25 +00:00
Joseph Tremoulet f748c8937e [WinEH] Update exception pointer registers
Summary:
The CLR's personality routine passes these in rdx/edx, not rax/eax.

Make getExceptionPointerRegister a virtual method parameterized by
personality function to allow making this distinction.

Similarly make getExceptionSelectorRegister a virtual method parameterized
by personality function, for symmetry.


Reviewers: pgavlin, majnemer, rnk

Subscribers: jyknight, dsanders, llvm-commits

Differential Revision: http://reviews.llvm.org/D14344

llvm-svn: 252383
2015-11-07 01:11:31 +00:00
Tom Stellard 05691a678e DAGCombiner: Check shouldReduceLoadWidth before combining (and (load), x) -> extload
Reviewers: resistor, arsenm

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D13805

llvm-svn: 252349
2015-11-06 21:58:37 +00:00
Quentin Colombet 9a8efc08d3 [ShrinkWrapping] Teach shrink-wrapping how to analyze RegMask.
Previously we were conservatively assuming that RegMask operands clobber
callee saved registers.

llvm-svn: 252341
2015-11-06 21:00:13 +00:00
Matthias Braun 9198c671e8 MachineScheduler: Add regpressure information to debug dump
llvm-svn: 252340
2015-11-06 20:59:02 +00:00
Reid Kleckner b8fd162fc5 [WinEH] Mark funclet entries and exits as clobbering all registers
Summary:
In this implementation, LiveIntervalAnalysis invents a few register
masks on basic block boundaries that preserve no registers. The nice
thing about this is that it prevents the prologue inserter from thinking
it needs to spill all XMM CSRs, because it doesn't see any explicit
physreg defs in the MI.

Reviewers: MatzeB, qcolombet, JosephTremoulet, majnemer

Subscribers: MatzeB, llvm-commits

Differential Revision: http://reviews.llvm.org/D14407

llvm-svn: 252318
2015-11-06 17:06:38 +00:00
NAKAMURA Takumi 9947cacebf Revert r252249 (and r252255, r252258), "[WinEH] Clone funclets with multiple parents"
It behaved flaky due to iterating pointer key values on std::set and std::map.

llvm-svn: 252279
2015-11-06 10:07:33 +00:00
Reid Kleckner e535c1f856 Range-for some LiveIntervals code under review
llvm-svn: 252267
2015-11-06 02:01:02 +00:00
Andrew Kaylor f477585a2b Fix build warnings
llvm-svn: 252255
2015-11-06 01:08:35 +00:00
Andrew Kaylor 29cd576554 [WinEH] Clone funclets with multiple parents
Windows EH funclets need to always return to a single parent funclet.  However, it is possible for earlier optimizations to combine funclets (probably based on one funclet having an unreachable terminator) in such a way that this condition is violated.

These changes add code to the WinEHPrepare pass to detect situations where a funclet has multiple parents and clone such funclets, fixing up the unwind and catch return edges so that each copy of the funclet returns to the correct parent funclet.

Differential Revision: http://reviews.llvm.org/D13274?id=39098

llvm-svn: 252249
2015-11-06 00:20:50 +00:00
Peter Collingbourne d4bff30370 DI: Reverse direction of subprogram -> function edge.
Previously, subprograms contained a metadata reference to the function they
described. Because most clients need to get or set a subprogram for a given
function rather than the other way around, this created unneeded inefficiency.

For example, many passes needed to call the function llvm::makeSubprogramMap()
to build a mapping from functions to subprograms, and the IR linker needed to
fix up function references in a way that caused quadratic complexity in the IR
linking phase of LTO.

This change reverses the direction of the edge by storing the subprogram as
function-level metadata and removing DISubprogram's function field.

Since this is an IR change, a bitcode upgrade has been provided.

Fixes PR23367. An upgrade script for textual IR for out-of-tree clients is
attached to the PR.

Differential Revision: http://reviews.llvm.org/D14265

llvm-svn: 252219
2015-11-05 22:03:56 +00:00
Reid Kleckner 6ddae31045 [WinEH] Fix funclet prologues with stack realignment
We already had a test for this for 32-bit SEH catchpads, but those don't
actually create funclets. We had a bug that only appeared in funclet
prologues, where we would establish EBP and ESI as our FP and BP, and
then downstream prologue code would overwrite them.

While I was at it, I fixed Win64+funclets+stackrealign. This issue
doesn't come up as often there due to the ABI requring 16 byte stack
alignment, but now we can rest easy that AVX and WinEH will work well
together =P.

llvm-svn: 252210
2015-11-05 21:09:49 +00:00
Sanjay Patel 387e66e79f replace MachineCombinerPattern namespace and enum with enum class; NFCI
Also, remove an enum hack where enum values were used as indexes into an array.

We may want to make this a real class to allow pattern-based queries/customization (D13417).

llvm-svn: 252196
2015-11-05 19:34:57 +00:00
Eugene Zelenko ffec81ca00 Fix some Clang-tidy modernize warnings, other minor fixes.
Fixed warnings are: modernize-use-override, modernize-use-nullptr and modernize-redundant-void-arg.

Differential revision: http://reviews.llvm.org/D14312

llvm-svn: 252087
2015-11-04 22:32:32 +00:00
Cong Hou 23a3bf0147 Add new interfaces to MBB for manipulating successors with probabilities instead of weights. NFC.
This is part-1 of the patch that replaces all edge weights in MBB by
probabilities, which only adds new interfaces. No functional changes.

Differential revision: http://reviews.llvm.org/D13908

llvm-svn: 252083
2015-11-04 21:37:58 +00:00
Igor Laevsky 35fe692025 [StatepointLowering] Remove distinction between call and invoke safepoints
There is no point in having invoke safepoints handled differently than the
call safepoints. All relevant decisions could be made by looking at whether
or not gc.result and gc.relocate lay in a same basic block. This change will
 allow to lower call safepoints with relocates and results in a different 
basic blocks. See test case for example.

Differential Revision: http://reviews.llvm.org/D14158

llvm-svn: 252028
2015-11-04 01:16:10 +00:00
Peter Collingbourne 94d778697a CodeGen, Target: Move Mach-O-specific symbol name logic to Mach-O lowering.
A profile of an LTO link of Chrome revealed that we were spending some
~30-50% of execution time in the function Constant::getRelocationInfo(),
which is called from TargetLoweringObjectFile::getKindForGlobal() and in turn
from TargetMachine::getNameWithPrefix().

It turns out that we only need the result of getKindForGlobal() when
targeting Mach-O, so this change moves the relevant part of the logic to
TargetLoweringObjectFileMachO.

NFCI.

Differential Revision: http://reviews.llvm.org/D14168

llvm-svn: 252014
2015-11-03 23:40:03 +00:00
Simon Pilgrim 191ac7c679 [SelectionDAG] Use existing constant nodes instead of recreating them. NFC.
llvm-svn: 251990
2015-11-03 22:21:38 +00:00
Rafael Espindola 43e2e251ea Delete dead code.
llvm-svn: 251960
2015-11-03 18:55:58 +00:00
Igor Laevsky f637b4a52e [CodegenPrepare] Do not rematerialize gc.relocates across different basic blocks
Differential Revision: http://reviews.llvm.org/D14258

llvm-svn: 251957
2015-11-03 18:37:40 +00:00
Michael Kuperstein 73dc85293f [X86] Generate .cfi_adjust_cfa_offset correctly when pushing arguments
When push instructions are being used to pass function arguments on
the stack, and either EH or debugging are enabled, we need to generate
.cfi_adjust_cfa_offset directives appropriately. For (synch) EH, it is
enough for the CFA offset to be correct at every call site, while
for debugging we want to be correct after every push.

Darwin does not support this well, so don't use pushes whenever it
would be required.

Differential Revision: http://reviews.llvm.org/D13767

llvm-svn: 251904
2015-11-03 08:17:25 +00:00
Matthias Braun 6f4ed269b9 RegisterPressure: Improve assert message
llvm-svn: 251885
2015-11-03 01:53:36 +00:00
Matthias Braun 11859b5c8f RegisterPressure: Slightly nicer pressure diff dumping
llvm-svn: 251884
2015-11-03 01:53:33 +00:00
Matthias Braun 93563e7032 ScheduleDAGInstrs: Remove IsPostRA flag; NFC
ScheduleDAGInstrs doesn't behave differently before or after register
allocation. It was only used in a method of MachineSchedulerBase which
behaved differently in MachineScheduler/PostMachineScheduler. Change
this to let MachineScheduler/PostMachineScheduler just pass in a
parameter to that function.

The order of the LiveIntervals* and bool RemoveKillFlags paramters have
been switched to make out-of-tree code fail instead of unintentionally
passing a value intended for the IsPostRA flag to the (previously
following and default initialized) RemoveKillFlags.

Differential Revision: http://reviews.llvm.org/D14245

llvm-svn: 251883
2015-11-03 01:53:29 +00:00
Sanjay Patel 0ed9aeaa5f [CGP] widen switch condition and case constants to target's register width (2nd try)
This is a redo of r251849 except the tests have been split into arch-specific folders
to hopefully make the bots happy.

This is a follow-up from the discussion in D12965. The block-at-a-time limitation of
SelectionDAG also came up in D13297.

Without the InstCombine change from D12965, I don't expect this patch to make any
difference in the real world because InstCombine does not shrink cases like this in
visitSwitchInst(). But we need to have this CGP safety harness in place before
proceeding with any shrinkage in D12965, so we won't generate extra extends for compares.

I've opted for IR regression tests in the patch because that seems like a clearer way to
test the transform, but PowerPC CodeGen for an i16 widening test is shown below. x86
will need more work to solve: https://llvm.org/bugs/show_bug.cgi?id=22473

Before:
BB#0:
  mr 4, 3
  extsh. 3, 4
  ble 0, .LBB0_5
 BB#1:
  cmpwi  3, 99
  bgt    0, .LBB0_9
 BB#2:
  rlwinm 4, 4, 0, 16, 31      <--- 32-bit mask/extend
  li 3, 0
  cmplwi         4, 1
  beqlr 0
 BB#3:
  cmplwi         4, 10
  bne    0, .LBB0_12
 BB#4:
  li 3, 1
  blr
.LBB0_5:
  rlwinm 3, 4, 0, 16, 31      <--- 32-bit mask/extend
  cmplwi         3, 65436
  beq    0, .LBB0_13
 BB#6:
  cmplwi         3, 65526
  beq    0, .LBB0_15
 BB#7:
  cmplwi         3, 65535
  bne    0, .LBB0_12
 BB#8:
  li 3, 4
  blr
.LBB0_9:
  rlwinm 3, 4, 0, 16, 31      <--- 32-bit mask/extend
  cmplwi         3, 100
  beq    0, .LBB0_14
...

After:
BB#0:
  rlwinm 4, 3, 0, 16, 31      <--- mask/extend to 32-bit and then use that for comparisons
  cmpwi  4, 999
  ble 0, .LBB0_5
 BB#1:
  lis 3, 0
  ori 3, 3, 65525
  cmpw   4, 3
  bgt    0, .LBB0_9
 BB#2:
  cmplwi         4, 1000
  beq    0, .LBB0_14
 BB#3:
  cmplwi         4, 65436
  bne    0, .LBB0_13
 BB#4:
  li 3, 6
  blr
.LBB0_5:
  li 3, 0
  cmplwi         4, 1
  beqlr 0
 BB#6:
  cmplwi         4, 10
  beq    0, .LBB0_12
 BB#7:
  cmplwi         4, 100
  bne    0, .LBB0_13
 BB#8:
  li 3, 2
  blr
.LBB0_9:
  cmplwi         4, 65526
  beq    0, .LBB0_15
 BB#10:
  cmplwi         4, 65535
  bne    0, .LBB0_13
...


Differential Revision: http://reviews.llvm.org/D13532

llvm-svn: 251857
2015-11-02 23:22:49 +00:00
Sanjay Patel dfc825eb36 revert r251849; need to move tests to arch-specific folders
llvm-svn: 251851
2015-11-02 23:05:20 +00:00
Sanjay Patel b90a078de9 [CGP] widen switch condition and case constants to target's register width
This is a follow-up from the discussion in D12965. The block-at-a-time limitation of 
SelectionDAG also came up in D13297.

Without the InstCombine change from D12965, I don't expect this patch to make any 
difference in the real world because InstCombine does not shrink cases like this in
visitSwitchInst(). But we need to have this CGP safety harness in place before
proceeding with any shrinkage in D12965, so we won't generate extra extends for compares.

I've opted for IR regression tests in the patch because that seems like a clearer way to
test the transform, but PowerPC CodeGen for an i16 widening test is shown below. x86
will need more work to solve: https://llvm.org/bugs/show_bug.cgi?id=22473

Before:
BB#0:
  mr 4, 3
  extsh. 3, 4
  ble 0, .LBB0_5
 BB#1: 
  cmpwi	 3, 99
  bgt	 0, .LBB0_9
 BB#2:            
  rlwinm 4, 4, 0, 16, 31      <--- 32-bit mask/extend
  li 3, 0
  cmplwi	 4, 1
  beqlr 0
 BB#3:            
  cmplwi	 4, 10
  bne	 0, .LBB0_12
 BB#4:                      
  li 3, 1
  blr
.LBB0_5:                             
  rlwinm 3, 4, 0, 16, 31      <--- 32-bit mask/extend
  cmplwi	 3, 65436
  beq	 0, .LBB0_13
 BB#6:                            
  cmplwi	 3, 65526
  beq	 0, .LBB0_15
 BB#7:                       
  cmplwi	 3, 65535
  bne	 0, .LBB0_12
 BB#8:                       
  li 3, 4
  blr
.LBB0_9:                       
  rlwinm 3, 4, 0, 16, 31      <--- 32-bit mask/extend
  cmplwi	 3, 100
  beq	 0, .LBB0_14
...

After:
BB#0:        
  rlwinm 4, 3, 0, 16, 31      <--- mask/extend to 32-bit and then use that for comparisons
  cmpwi	 4, 999
  ble 0, .LBB0_5
 BB#1:          
  lis 3, 0
  ori 3, 3, 65525
  cmpw	 4, 3
  bgt	 0, .LBB0_9
 BB#2:         
  cmplwi	 4, 1000
  beq	 0, .LBB0_14
 BB#3:    
  cmplwi	 4, 65436
  bne	 0, .LBB0_13
 BB#4:       
  li 3, 6
  blr
.LBB0_5:   
  li 3, 0
  cmplwi	 4, 1
  beqlr 0
 BB#6: 
  cmplwi	 4, 10
  beq	 0, .LBB0_12
 BB#7:             
  cmplwi	 4, 100
  bne	 0, .LBB0_13
 BB#8:             
  li 3, 2
  blr
.LBB0_9:       
  cmplwi	 4, 65526
  beq	 0, .LBB0_15
 BB#10:      
  cmplwi	 4, 65535
  bne	 0, .LBB0_13
...


Differential Revision: http://reviews.llvm.org/D13532

llvm-svn: 251849
2015-11-02 22:46:24 +00:00
Cong Hou b90b9e0531 In MachineBlockPlacement, filter cold blocks off the loop chain when profile data is available.
In the current BB placement algorithm, a loop chain always contains all loop blocks. This has a drawback that cold blocks in the loop may be inserted on a hot function path, hence increasing branch cost and also reducing icache locality.

Consider a simple example shown below:

A
|
B⇆C
|
D

When B->C is quite cold, the best BB-layout should be A,B,D,C. But the current implementation produces A,C,B,D.

This patch filters those cold blocks off from the loop chain by comparing the ratio:

LoopBBFreq / LoopFreq

to 20%: if it is less than 20%, we don't include this BB to the loop chain. Here LoopFreq is the frequency of the loop when we reduce the loop into a single node. In general we have more cold blocks when the loop has few iterations. And vice versa.


Differential revision: http://reviews.llvm.org/D11662

llvm-svn: 251833
2015-11-02 21:24:00 +00:00
James Y Knight 646c4032e7 Fix two issues in MergeConsecutiveStores:
1) PR25154. This is basically a repeat of PR18102, which was fixed in
r200201, and broken again by r234430. The latter changed which of the
store nodes was merged into from the first to the last. Thus, we now
also need to prefer merging a later store at a given address into the
target node, instead of an earlier one.

2) While investigating that, I also realized I'd introduced a bug in
r236850. There, I removed a check for alignment -- not realizing that
nothing except the alignment check was ensuring that none of the stores
were overlapping! This is a really bogus way to ensure there's no
aliased stores.

A better solution to both of these issues is likely to always use the
code added in the 'if (UseAA)' branches which rearrange the chain based
on a more principled analysis. I'll look into whether that can be used
always, but in the interest of getting things back to working, I think a
minimal change makes sense.

llvm-svn: 251816
2015-11-02 18:48:08 +00:00
Jonas Paulsson 72640f1c9f [MachineVerifier] Analyze MachineMemOperands for mem-to-mem moves.
Since the verifier will give false reports if it incorrectly thinks MI is
loading or storing using an FI, it is necessary to scan memoperands and
find out how the FI is used in the instruction. This should be relatively
rare.

Needed to make CodeGen/SystemZ/spill-01.ll pass, which now runs with this flag.

Reviewed by Quentin Colombet.

llvm-svn: 251620
2015-10-29 08:28:35 +00:00
Matthias Braun f2f194455f Revert "ScheduleDAGInstrs: Remove IsPostRA flag"
It broke 3 arm testcases.

This reverts commit r251608.

llvm-svn: 251615
2015-10-29 05:06:41 +00:00
Matthias Braun dc7580aa88 MachineScheduler: Fix typo in debug message
Maybe I just missed the humor there ;-)

llvm-svn: 251609
2015-10-29 03:57:28 +00:00
Matthias Braun 7ffadd0087 ScheduleDAGInstrs: Remove IsPostRA flag
This was a layering violation in ScheduleDAGInstrs (and
MachineSchedulerBase) they both shouldn't know directly whether they are
used by the PostMachineScheduler or the MachineScheduler.

llvm-svn: 251608
2015-10-29 03:57:24 +00:00
Matthias Braun b0c437bc76 MachineScheduler: Use ranged for and slightly simplify the code
llvm-svn: 251607
2015-10-29 03:57:17 +00:00
Tim Northover 2d4d161519 ARM: support .watchos_version_min and .tvos_version_min.
These MachO file directives are used by linkers and other tools to provide
compatibility information, much like the existing .ios_version_min and
.macosx_version_min.

llvm-svn: 251569
2015-10-28 22:36:05 +00:00
Sanjoy Das 1d1929aace [ValueTracking] Use !range metadata more aggressively in KnownBits
Summary:
Teach `computeKnownBitsFromRangeMetadata` to use `!range` metadata more
aggressively.

Reviewers: majnemer, nlewycky, jingyue

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14100

llvm-svn: 251487
2015-10-28 03:20:15 +00:00
Sanjoy Das 4ff3cf6d92 [SelectionDAG] Don't inspect !range metadata for extended loads
Summary:
Don't call `computeKnownBitsFromRangeMetadata` for extended loads --
this can cause a mismatch between the width of the !range metadata and
the width of the APInt's accumulating `KnownZero` (and `KnownOne` in the
future).  This isn't a problem now, but will be after a future change.

Note: this can be made more aggressive in the future.

Reviewers: nlewycky

Subscribers: llvm-commits

Differential Revision: http://reviews.llvm.org/D14107

llvm-svn: 251486
2015-10-28 03:20:10 +00:00
James Y Knight 14eedd189b Make the SelectionDAG graph printer use SDNode::PersistentId labels.
r248010 changed the -debug output to use short ids, but did not
similarly modify the graph printer. Change to be consistent, for ease of
cross-reference.

llvm-svn: 251465
2015-10-27 23:09:03 +00:00
Sanjay Patel bbd4c79c8f Use the 'arcp' fast-math-flag when combining repeated FP divisors
This is a usage of the IR-level fast-math-flags now that they are propagated to SDNodes. 
This was originally part of D8900.

Removing the global 'enable-unsafe-fp-math' checks will require auto-upgrade and 
possibly other changes.

Differential Revision: http://reviews.llvm.org/D9708

llvm-svn: 251450
2015-10-27 20:27:25 +00:00