Commit Graph

18985 Commits

Author SHA1 Message Date
Quentin Colombet
3df507cbfa [RAGreedy] Add an experimental deferred spilling feature.
The idea of deferred spilling is to delay the insertion of spill code until the
very end of the allocation. A "candidate" to spill variable might not required
to be spilled because of other evictions that happened after this decision was
taken. The spirit is similar to the optimistic coloring strategy implemented in
Preston and Briggs graph coloring algorithm.

For now, this feature is highly experimental. Although correct, it would require
much more modification to properly model the effect of spilling.

Anyway, this early patch helps prototyping this feature.

Note: The test case cannot unfortunately be reduced and is probably fragile.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242585 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 23:04:06 +00:00
Alex Lorenz
310bd3c747 MIR Parser: Allow the dollar characters in all of the identifier tokens.
This commit modifies the machine instruction lexer so that it now accepts the
'$' characters in identifier tokens.

This change makes the syntax for unquoted global value tokens consistent with
the syntax for the global idenfitier tokens in the LLVM's assembly language.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242584 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 22:48:04 +00:00
Matthias Braun
63f73d7b80 Use llvm_unreachable() instead of report_fatal_error() if the machine model is incomplete
This error is for developers only so it makes sense to abort and get a
backtrace.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242551 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 17:50:11 +00:00
John Brawn
591adee23b Make global aliases have symbol size equal to their type
This is mainly for the benefit of GlobalMerge, so that an alias into a
MergedGlobals variable has the same size as the original non-merged
variable.

Differential Revision: http://reviews.llvm.org/D10837


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242520 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 12:12:03 +00:00
Matt Arsenault
ac69d5205b Only do fmul (fadd x, x), c combine if the fadd only has one use
This was increasing the instruction count if the fadd has multiple uses.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242498 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 01:14:35 +00:00
Alex Lorenz
2744189c46 MIR Serialization: Serialize the frame setup machine instruction flag.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242491 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-17 00:24:15 +00:00
Alex Lorenz
ed2032f17a MIR Serialization: Serialize the frame index machine operands.
Reviewers: Duncan P. N. Exon Smith


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242487 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 23:37:45 +00:00
Matthias Braun
9e4654db1a Fix __builtin_setjmp in combination with sjlj exception handling.
llvm.eh.sjlj.setjmp was used as part of the SjLj exception handling
style but is also used in clang to implement __builtin_setjmp.  The ARM
backend needs to output additional dispatch tables for the SjLj
exception handling style, these tables however can't be emitted if
llvm.eh.sjlj.setjmp is simply used for __builtin_setjmp and no actual
landing pad blocks exist.

To solve this issue a new llvm.eh.sjlj.setup_dispatch intrinsic is
introduced which is used instead of llvm.eh.sjlj.setjmp in the SjLj
exception handling lowering, so we can differentiate between the case
where we actually need to setup a dispatch table and the case where we
just need the __builtin_setjmp semantic.

Differential Revision: http://reviews.llvm.org/D9313

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242481 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 22:34:16 +00:00
Matthias Braun
0219a272ec LiveInterval: Document and enforce rules about empty subranges.
Empty subranges are not allowed in a LiveInterval and must be removed
instead: Check this in the verifiers, put a reminder for this in the
comment of the shrinkToUses variant for a single lane and make it
automatic for the shrinkToUses variant for a LiveInterval.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242431 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 18:55:35 +00:00
Matthias Braun
ac40c926aa Do not duplicate method name in comment, remove duplicate comment
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242430 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 18:55:32 +00:00
Cong Hou
204b59072d Rename LoopInfo::Analyze() to LoopInfo::analyze() and turn its parameter type to const&.
The benefit of turning the parameter of LoopInfo::analyze() to const& is that it now can accept a rvalue.

http://reviews.llvm.org/D11250



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242426 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 18:23:57 +00:00
James Molloy
acd275a629 [Codegen] Add intrinsics 'absdiff' and corresponding SDNodes for absolute difference operation
This adds new intrinsics "*absdiff" for absolute difference ops to facilitate efficient code generation for "sum of absolute differences" operation.
The patch also contains the introduction of corresponding SDNodes and basic legalization support.Sanity of the generated code is tested on X86.

This is 1st of the three patches.

Patch by Shahid Asghar-ahmad!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242409 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 15:22:46 +00:00
Mehdi Amini
9c5961b7ba Move most user of TargetMachine::getDataLayout to the Module one
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

This patch is quite boring overall, except for some uglyness in
ASMPrinter which has a getDataLayout function but has some clients
that use it without a Module (llmv-dsymutil, llvm-dwarfdump), so
some methods are taking a DataLayout as parameter.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11090

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242386 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 06:11:10 +00:00
Mehdi Amini
a5574d611a Remove DataLayout from TargetLoweringObjectFile, redirect to Module
Summary:
This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits, jholewinski

Differential Revision: http://reviews.llvm.org/D11079

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242385 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 06:04:17 +00:00
Mehdi Amini
24e2a7c43f Redirect pointerSize query to the TargetMachine in ASMPrinter
Summary:
Because llvm-dsymutil is using ASMPrinter without any MachineFunction
of Module available.

This change is part of a series of commits dedicated to have a single
DataLayout during compilation by using always the one owned by the
module.

Reviewers: echristo

Subscribers: yaron.keren, rafael, llvm-commits

Differential Revision: http://reviews.llvm.org/D11078

From: Mehdi Amini <mehdi.amini@apple.com>

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242384 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-16 05:59:25 +00:00
Alex Lorenz
a2e819fb09 MIR Serialization: Serialize the jump table index operands.
Reviewers: Duncan P. N. Exon Smith


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242358 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 23:38:35 +00:00
Alex Lorenz
81bef8c7a7 MIR Serialization: Serialize the jump table info.
The jump table info is serialized using a YAML mapping that contains its kind
and a YAML sequence of jump table entries. A jump table entry is a YAML mapping
that has an ID and an inline YAML sequence of machine basic block references.

The testcase 'CodeGen/MIR/X86/jump-table-info.mir' doesn't have any instructions
because one of them contains a jump table index operand. The jump table index
operands will be serialized in a follow up patch, and the appropriate
instructions will be added to this testcase.

Reviewers: Duncan P. N. Exon Smith


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242357 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 23:31:07 +00:00
Cong Hou
8770f7af5f Create a wrapper pass for BranchProbabilityInfo.
This new wrapper pass is useful when we want to do branch probability analysis conditionally (e.g. only in PGO mode) but don't want to add one more pass dependence.

http://reviews.llvm.org/D11241



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242349 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 22:48:29 +00:00
Matthias Braun
2aa5727755 TargetRegisterInfo: Provide a way to check assigned registers in getRegAllocationHints()
Pass a const reference to LiveRegMatrix to getRegAllocationHints()
because some targets can prodive better hints if they can test whether a
physreg has been used for register allocation yet.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242340 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 22:16:00 +00:00
Alex Lorenz
71da3635d9 MIR Serialization: Serialize references from the stack objects to named allocas.
This commit serializes the references to the named LLVM alloca instructions from
the stack objects in the machine frame info. This commit adds a field 'Name' to
the struct 'yaml::MachineStackObject'. This new field is used to store the name
of the alloca instruction when the alloca is present and when it has a name.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242339 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 22:14:49 +00:00
Paul Robinson
641735d426 Add a "debugger tuning" concept that allows us to fine-tune how we
emit debug info, according to the preferences of the different
debuggers used on various targets.
Darwin and FreeBSD default to tuning for LLDB; PS4 defaults to tuning for
the SCE (Sony Computer Entertainment) debugger.  All others default to GDB.

Differential Revision: http://reviews.llvm.org/D8506


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242338 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 22:04:54 +00:00
Cong Hou
2fa118d257 Rename doFunction() in BFI to calculate() and change its parameters from pointers to references.
http://reviews.llvm.org/D11196



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242322 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 19:58:26 +00:00
Bruno Cardoso Lopes
162c547bf6 Revert "Refactor optimizeUncoalescable logic"
Likely broke compilation on ARM:

http://lab.llvm.org:8011/builders/clang-native-arm-lnt/builds/13054

This reverts commit 0b7824464fbe3d3f386e2d4aef6a431422709e53.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242311 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 18:10:46 +00:00
Bruno Cardoso Lopes
ae1ebf6cf7 Revert "Look through PHIs to find additional register sources"
Likely broke compilation on ARM:

http://lab.llvm.org:8011/builders/clang-native-arm-lnt/builds/13054

This reverts commit 131ce4a838c081516cbfed039fc986b33e3979d6.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242310 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 18:10:35 +00:00
Cong Hou
15afc3140e Test commit.
This is a test commit (one blank line deleted).



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242308 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 17:58:15 +00:00
Adrian Prantl
bd584159e1 Debug Info: Add basic support for external types references.
This is a necessary prerequisite for bootstrapping the emission
of debug info inside modules.

- Adds a FlagExternalTypeRef to DICompositeType.
  External types must have a unique identifier.
- External type references are emitted using a forward declaration
  with a DW_AT_signature([DW_FORM_ref_sig8]) based on the UID.

http://reviews.llvm.org/D9612

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242302 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 17:01:41 +00:00
Bruno Cardoso Lopes
b11d8102cf Look through PHIs to find additional register sources
- Teaches the ValueTracker in the PeepholeOptimizer to look through PHI
instructions.
- Add findNextSourceAndRewritePHI method to lookup into multiple sources
returnted by the ValueTracker and rewrite PHIs with new sources.

With these changes we can find more register sources and rewrite more
copies to allow coaslescing of bitcast instructions. Hence, we eliminate
unnecessary VR64 <-> GR64 copies in x86, but it could be extended to
other archs by marking "isBitcast" on target specific instructions. The
x86 example follows:

A:
  psllq %mm1, %mm0
  movd  %mm0, %r9
  jmp C

B:
  por %mm1, %mm0
  movd  %mm0, %r9
  jmp C

C:
  movd  %r9, %mm0
  pshufw  $238, %mm0, %mm0

Becomes:

A:
  psllq %mm1, %mm0
  jmp C

B:
  por %mm1, %mm0
  jmp C

C:
  pshufw  $238, %mm0, %mm0

Differential Revision: http://reviews.llvm.org/D11197

rdar://problem/20404526

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242295 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 15:35:23 +00:00
Bruno Cardoso Lopes
7c72a2254c Refactor optimizeUncoalescable logic
- Create a new CopyRewriter for Uncoalescable copy-like instructions
- Change the ValueTracker to return a ValueTrackerResult

This makes optimizeUncoalescable looks more like optimizeCoalescable and
use the CopyRewritter infrastructure.

This is also the preparation for looking up into PHI nodes in the
ValueTracker.

Differential Revision: http://reviews.llvm.org/D11195

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242294 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 15:35:09 +00:00
Alexey Bataev
a018099669 [SDAG] Optimize unordered comparison in soft-float mode (patch by Anton Nadolskiy)
Current implementation handles unordered comparison poorly in soft-float mode. 
Consider (a ULE b) which is a <= b. It is lowered to (ledf2(a, b) <= 0 || unorddf2(a, b) != 0) (in general). We can do better job by lowering it to (__gtdf2(a, b) <= 0). 
Such replacement is true for other CMP's (ult, ugt, uge). In general, we just call same function as for ordered case but negate comparison against zero.
Differential Revision: http://reviews.llvm.org/D10804


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242280 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 08:39:35 +00:00
Hal Finkel
b2a353c753 [MachineCombiner] Work with itineraries
MachineCombiner predicated its use of scheduling-based metrics on
hasInstrSchedModel(), but useful conclusions can be drawn from pipeline
itineraries as well. Almost all of the logic (except for resource tracking in
preservesResourceLen) can be used if we have an itinerary, so enable it in that
case as well.

This will be used by the PowerPC backend in an upcoming commit.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242277 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 08:22:23 +00:00
Pete Cooper
5f34535ced Use enum instead of unsigned. NFC.
The unsigned opcode argument here was the result of BinaryOperator->getOpcode().
That returns a BinaryOps enum which is more accurate than passing around an
unsigned.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242265 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 01:31:26 +00:00
Pete Cooper
babb387919 Use cast<> instead of dyn_cast to remove llvm_unreachable. NFC.
This code was checking if we are an ICmpInst or FCmpInst then throwing
unreachable if we are neither.  We must be one or the other, so use a
cast on the FCmpInst case to ensure that we are that case.  Then we can
avoid having an unreachable but still catch an error if we ever had another
subclass of CmpInst.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242264 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 01:31:23 +00:00
Pete Cooper
483db5542f Use another foreach loop. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242263 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 01:31:20 +00:00
Pete Cooper
b1de2ea603 Use getAnyExtOrTrunc helper instead of manually doing ext/trunc check. NFC.
The code here was doing exactly what is already in getAnyExtOrTrunc().
Just use that method instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242261 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 00:43:57 +00:00
Pete Cooper
40e41e1c58 Use getZExtOrTrunc helper instead of manually doing zext/trunc check. NFC.
The code here was doing exactly what is already in getZExtOrTrunc().
Just use that method instead.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242260 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 00:43:54 +00:00
Pete Cooper
74d5c14956 Use getStoreSize() instead of getStoreSizeInBits()/8. NFC.
The calls here were both to getStoreSizeInBits() which multiplies by 8.
We then immediately divided by 8.  Calling getStoreSize() returns the
values we need without the extra arithmetic.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242254 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-15 00:07:55 +00:00
Pete Cooper
8c63486145 Use more foreach loops in SelectionDAG. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242249 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 23:43:29 +00:00
Pete Cooper
ba77f37392 Add allnodes() iterator range to SelectionDAG. NFC.
SelectionDAG already had begin/end methods for iterating over all
the nodes, but didn't define an iterator_range for us in foreach
loops.

This adds such a method and uses it in some of the eligible places
throughout the backends.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242212 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 22:10:54 +00:00
Pete Cooper
f1c70f9279 Constify parameters in SelectionDAG methods. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242210 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 21:54:52 +00:00
Pete Cooper
ec664779b3 Remove unnecessary .getNode() in SelectionDAG. NFC.
The simplify_type specialisation allows us to cast directly from
SDValue to an SDNode* subclass so we don't need to pass a SDNode*
to cast<>.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242209 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 21:54:48 +00:00
Pete Cooper
6e6119a92e Use more foreach loops in SelectionDAG. NFC
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242208 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 21:54:45 +00:00
Alex Lorenz
6e50c921d0 MIR Serialization: Serialize the machine basic block live in registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242204 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 21:24:41 +00:00
Alex Lorenz
7ebf4b21c7 MIR Printer: move the function 'printReg'. NFC.
This commit moves the function 'printReg' towards the start of the file so that
it can be used by the conversion methods in MIRPrinter and not just the printing
methods in MIPrinter.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242203 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 21:18:25 +00:00
Keno Fischer
890c16626f [CodeGen] Force emission of personality directive if explicitly specified
Summary:
Before this change, personality directives were not emitted
if there was no invoke left in the function (of course until
recently this also meant that we couldn't know what
the personality actually was). This patch forces personality directives
to still be emitted, unless it is known to be a noop in the absence of
invokes, or the user explicitly specified `nounwind` (and not
`uwtable`) on the function.

Reviewers: majnemer, rnk

Subscribers: rnk, llvm-commits

Differential Revision: http://reviews.llvm.org/D10884

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242185 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 19:22:51 +00:00
Matthias Braun
2addf067a2 MachineRegisterInfo: Remove UsedPhysReg infrastructure
We have a detailed def/use lists for every physical register in
MachineRegisterInfo anyway, so there is little use in maintaining an
additional bitset of which ones are used.

Removing it frees us from extra book keeping. This simplifies
VirtRegMap.

Differential Revision: http://reviews.llvm.org/D10911

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242173 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 17:52:07 +00:00
Matthias Braun
65a4053af8 RAGreedy: Keep track of allocated PhysRegs internally
Do not use MachineRegisterInfo::setPhysRegUsed()/isPhysRegUsed()
anymore. This bitset changes function-global state and is set by the
VirtRegRewriter anyway.
Simply use a bitvector private to RAGreedy.

Differential Revision: http://reviews.llvm.org/D10910

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242169 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 17:38:17 +00:00
Matthias Braun
a36268215f PrologEpilogInserter: Rewrite API to determine callee save regsiters.
This changes TargetFrameLowering::processFunctionBeforeCalleeSavedScan():

- Rename the function to determineCalleeSaves()
- Pass a bitset of callee saved registers by reference, thus avoiding
  the function-global PhysRegUsed bitset in MachineRegisterInfo.
- Without PhysRegUsed the implementation is fine tuned to not save
  physcial registers which are only read but never modified.

Related to rdar://21539507

Differential Revision: http://reviews.llvm.org/D10909

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242165 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 17:17:13 +00:00
Matthias Braun
21910d8bd5 Revert "LegalizeDAG: Fix and improve FCOPYSIGN/FABS legalization"
Accidental commit, needs review first.

This reverts commit r242107.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242108 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 02:09:57 +00:00
Matthias Braun
2a46e4c020 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

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242107 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 02:08:26 +00:00
Alex Lorenz
dee03ee0f9 MIR Serialization: Serialize the variable sized stack objects.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@242095 91177308-0d34-0410-b5e6-96231b3b80d8
2015-07-14 00:26:26 +00:00