Commit Graph

92 Commits

Author SHA1 Message Date
Peter Collingbourne 97aae40880 ARM/ELF: Better codegen for global variable addresses.
In PIC mode we were previously computing global variable addresses (or GOT
entry addresses) by adding the PC, the PC-relative GOT displacement and
the GOT-relative symbol/GOT entry displacement. Because the latter two
displacements are fixed, we ended up performing one more addition than
necessary.

This change causes us to compute addresses using a single PC-relative
displacement, resulting in a shorter code sequence. This reduces code size
by about 4% in a recent build of Chromium for Android.

As a result of this change we no longer need to compute the GOT base address
in the ARM backend, which allows us to remove the Global Base Reg pass and
SDAG lowering for the GOT.

We also now no longer use the GOT when addressing a symbol which is known
to be defined in the same linkage unit. Specifically, the symbol must have
either hidden visibility or a strong definition in the current module in
order to not use the the GOT.

This is a change from the previous behaviour where we would use the GOT to
address externally visible symbols defined in the same module. I think the
only cases where this could matter are cases involving symbol interposition,
but we don't really support that well anyway.

Differential Revision: http://reviews.llvm.org/D13650

llvm-svn: 251322
2015-10-26 18:23:16 +00:00
Alexander Kornienko f00654e31b Revert r240137 (Fixed/added namespace ending comments using clang-tidy. NFC)
Apparently, the style needs to be agreed upon first.

llvm-svn: 240390
2015-06-23 09:49:53 +00:00
Alexander Kornienko 70bc5f1398 Fixed/added namespace ending comments using clang-tidy. NFC
The patch is generated using this command:

tools/clang/tools/extra/clang-tidy/tool/run-clang-tidy.py -fix \
  -checks=-*,llvm-namespace-comment -header-filter='llvm/.*|clang/.*' \
  llvm/lib/


Thanks to Eugene Kosov for the original patch!

llvm-svn: 240137
2015-06-19 15:57:42 +00:00
Akira Hatanaka 4a61619ff5 [ARM] Pass a callback to FunctionPass constructors to enable skipping execution
on a per-function basis.

Previously some of the passes were conditionally added to ARM's pass pipeline
based on the target machine's subtarget. This patch makes changes to add those
passes unconditionally and execute them conditonally based on the predicate
functor passed to the pass constructors. This enables running different sets of
passes for different functions in the module.

rdar://problem/20542263

Differential Revision: http://reviews.llvm.org/D8717

llvm-svn: 239325
2015-06-08 18:50:43 +00:00
Ahmed Bougacha bf2b90e92d [ARM] Remove unused declaration. NFC.
GlobalMerge was moved to lib/CodeGen a while ago, and is no longer
called "ARMGlobalMerge".

llvm-svn: 229448
2015-02-16 22:30:08 +00:00
Chandler Carruth d8b3e9a420 [PM] Remove a bunch of stale TTI creation method declarations. I nuked
their definitions, but forgot to clean up all the declarations which are
in different files.

llvm-svn: 227698
2015-02-01 00:22:15 +00:00
Eric Christopher 79cc1e3ae7 Reinstate "Nuke the old JIT."
Approved by Jim Grosbach, Lang Hames, Rafael Espindola.

This reinstates commits r215111, 215115, 215116, 215117, 215136.

llvm-svn: 216982
2014-09-02 22:28:02 +00:00
Benjamin Kramer a7c40ef022 Canonicalize header guards into a common format.
Add header guards to files that were missing guards. Remove #endif comments
as they don't seem common in LLVM (we can easily add them back if we decide
they're useful)

Changes made by clang-tidy with minor tweaks.

llvm-svn: 215558
2014-08-13 16:26:38 +00:00
Eric Christopher b9fd9ed37e Temporarily Revert "Nuke the old JIT." as it's not quite ready to
be deleted. This will be reapplied as soon as possible and before
the 3.6 branch date at any rate.

Approved by Jim Grosbach, Lang Hames, Rafael Espindola.

This reverts commits r215111, 215115, 215116, 215117, 215136.

llvm-svn: 215154
2014-08-07 22:02:54 +00:00
Rafael Espindola f8b27c41e8 Nuke the old JIT.
I am sure we will be finding bits and pieces of dead code for years to
come, but this is a good start.

Thanks to Lang Hames for making MCJIT a good replacement!

llvm-svn: 215111
2014-08-07 14:21:18 +00:00
Tim Northover 037f26f212 Atomics: promote ARM's IR-based atomics pass to CodeGen.
Still only 32-bit ARM using it at this stage, but the promotion allows
direct testing via opt and is a reasonably self-contained patch on the
way to switching ARM64.

At this point, other targets should be able to make use of it without
too much difficulty if they want. (See ARM64 commit coming soon for an
example).

llvm-svn: 206485
2014-04-17 18:22:47 +00:00
Tim Northover c882eb0723 ARM: expand atomic ldrex/strex loops in IR
The previous situation where ATOMIC_LOAD_WHATEVER nodes were expanded
at MachineInstr emission time had grown to be extremely large and
involved, to account for the subtly different code needed for the
various flavours (8/16/32/64 bit, cmpxchg/add/minmax).

Moving this transformation into the IR clears up the code
substantially, and makes future optimisations much easier:

1. an atomicrmw followed by using the *new* value can be more
   efficient. As an IR pass, simple CSE could handle this
   efficiently.
2. Making use of cmpxchg success/failure orderings only has to be done
   in one (simpler) place.
3. The common "cmpxchg; did we store?" idiom can be exposed to
   optimisation.

I intend to gradually improve this situation within the ARM backend
and make sure there are no hidden issues before moving the code out
into CodeGen to be shared with (at least ARM64/AArch64, though I think
PPC & Mips could benefit too).

llvm-svn: 205525
2014-04-03 11:44:58 +00:00
Renato Golin d93295ea56 Remove duplicated DMB instructions
ARM specific optimiztion, finding places in ARM machine code where 2 dmbs
follow one another, and eliminating one of them.

Patch by Reinoud Elhorst.

llvm-svn: 205409
2014-04-02 09:03:43 +00:00
Craig Topper a9253267a9 Prune includes in ARM target.
llvm-svn: 204548
2014-03-22 23:51:00 +00:00
Silviu Baranga 82dd6ac3bc Adding an A15 specific optimization pass for interactions between S/D/Q registers. The pass handles all the required transformations pre-regalloc.
llvm-svn: 177169
2013-03-15 18:28:25 +00:00
Jim Grosbach 553eb75663 ARM: Fix a few copy-paste errors.
s/X86/ARM/

llvm-svn: 171789
2013-01-07 21:12:13 +00:00
Chandler Carruth 664e354de7 Switch TargetTransformInfo from an immutable analysis pass that requires
a TargetMachine to construct (and thus isn't always available), to an
analysis group that supports layered implementations much like
AliasAnalysis does. This is a pretty massive change, with a few parts
that I was unable to easily separate (sorry), so I'll walk through it.

The first step of this conversion was to make TargetTransformInfo an
analysis group, and to sink the nonce implementations in
ScalarTargetTransformInfo and VectorTargetTranformInfo into
a NoTargetTransformInfo pass. This allows other passes to add a hard
requirement on TTI, and assume they will always get at least on
implementation.

The TargetTransformInfo analysis group leverages the delegation chaining
trick that AliasAnalysis uses, where the base class for the analysis
group delegates to the previous analysis *pass*, allowing all but tho
NoFoo analysis passes to only implement the parts of the interfaces they
support. It also introduces a new trick where each pass in the group
retains a pointer to the top-most pass that has been initialized. This
allows passes to implement one API in terms of another API and benefit
when some other pass above them in the stack has more precise results
for the second API.

The second step of this conversion is to create a pass that implements
the TargetTransformInfo analysis using the target-independent
abstractions in the code generator. This replaces the
ScalarTargetTransformImpl and VectorTargetTransformImpl classes in
lib/Target with a single pass in lib/CodeGen called
BasicTargetTransformInfo. This class actually provides most of the TTI
functionality, basing it upon the TargetLowering abstraction and other
information in the target independent code generator.

The third step of the conversion adds support to all TargetMachines to
register custom analysis passes. This allows building those passes with
access to TargetLowering or other target-specific classes, and it also
allows each target to customize the set of analysis passes desired in
the pass manager. The baseline LLVMTargetMachine implements this
interface to add the BasicTTI pass to the pass manager, and all of the
tools that want to support target-aware TTI passes call this routine on
whatever target machine they end up with to add the appropriate passes.

The fourth step of the conversion created target-specific TTI analysis
passes for the X86 and ARM backends. These passes contain the custom
logic that was previously in their extensions of the
ScalarTargetTransformInfo and VectorTargetTransformInfo interfaces.
I separated them into their own file, as now all of the interface bits
are private and they just expose a function to create the pass itself.
Then I extended these target machines to set up a custom set of analysis
passes, first adding BasicTTI as a fallback, and then adding their
customized TTI implementations.

The fourth step required logic that was shared between the target
independent layer and the specific targets to move to a different
interface, as they no longer derive from each other. As a consequence,
a helper functions were added to TargetLowering representing the common
logic needed both in the target implementation and the codegen
implementation of the TTI pass. While technically this is the only
change that could have been committed separately, it would have been
a nightmare to extract.

The final step of the conversion was just to delete all the old
boilerplate. This got rid of the ScalarTargetTransformInfo and
VectorTargetTransformInfo classes, all of the support in all of the
targets for producing instances of them, and all of the support in the
tools for manually constructing a pass based around them.

Now that TTI is a relatively normal analysis group, two things become
straightforward. First, we can sink it into lib/Analysis which is a more
natural layer for it to live. Second, clients of this interface can
depend on it *always* being available which will simplify their code and
behavior. These (and other) simplifications will follow in subsequent
commits, this one is clearly big enough.

Finally, I'm very aware that much of the comments and documentation
needs to be updated. As soon as I had this working, and plausibly well
commented, I wanted to get it committed and in front of the build bots.
I'll be doing a few passes over documentation later if it sticks.

Commits to update DragonEgg and Clang will be made presently.

llvm-svn: 171681
2013-01-07 01:37:14 +00:00
Jush Lu 47172a064f [arm-fast-isel] Add support for ELF PIC.
This is a preliminary step towards ELF support; currently ARMFastISel hasn't
been used for ELF object files yet.

llvm-svn: 164759
2012-09-27 05:21:41 +00:00
Craig Topper 188ed9d56e Reorder includes to match coding standards. Fix an issue or two exposed by that.
llvm-svn: 152978
2012-03-17 07:33:42 +00:00
Jia Liu 608dc6e257 comment fix ARM.h
llvm-svn: 150904
2012-02-19 02:04:03 +00:00
Jia Liu b22310fda6 Emacs-tag and some comment fix for all ARM, CellSPU, Hexagon, MBlaze, MSP430, PPC, PTX, Sparc, X86, XCore.
llvm-svn: 150878
2012-02-18 12:03:15 +00:00
Jakob Stoklund Olesen bf64024a39 Delete NEONMoveFix, now unused.
llvm-svn: 140773
2011-09-29 02:56:45 +00:00
Bill Wendling a0d5f268a9 Move to ISelLowering.
llvm-svn: 140754
2011-09-29 01:13:55 +00:00
Bill Wendling 354ff9e348 This is the start of the new SjLj EH preparation pass, which will replace the
current IR-level pass.

The old SjLj EH pass has some problems, especially with the new EH model. Most
significantly, it violates some of the new restrictions the new model has. For
instance, the 'dispatch' table wants to jump to the landing pad, but we cannot
allow that because only an invoke's unwind edge can jump to a landing pad. This
requires us to mangle the code something awful. In addition, we need to keep the
now dead landingpad instructions around instead of CSE'ing them because the
DWARF emitter uses that information (they are dead because no control flow edge
will execute them - the control flow edge from an invoke's unwind is superceded
by the edge coming from the dispatch).

Basically, this pass belongs not at the IR level where SSA is king, but at the
code-gen level, where we have more flexibility.

llvm-svn: 140646
2011-09-27 22:14:12 +00:00
Evan Cheng f5bf19530b Code clean up.
llvm-svn: 135954
2011-07-25 20:18:48 +00:00
Evan Cheng ad5f485957 Sink ARM mc routines into MCTargetDesc.
llvm-svn: 135825
2011-07-23 00:00:19 +00:00
Evan Cheng bc153d49b7 Next round of MC refactoring. This patch factor MC table instantiations, MC
registeration and creation code into XXXMCDesc libraries.

llvm-svn: 135184
2011-07-14 20:59:42 +00:00
Evan Cheng c5e6d2f519 - Eliminate MCCodeEmitter's dependency on TargetMachine. It now uses MCInstrInfo
and MCSubtargetInfo.
- Added methods to update subtarget features (used when targets automatically
  detect subtarget features or switch modes).
- Teach X86Subtarget to update MCSubtargetInfo features bits since the
  MCSubtargetInfo layer can be shared with other modules.
- These fixes .code 16 / .code 32 support since mode switch is updated in
  MCSubtargetInfo so MC code emitter can do the right thing.

llvm-svn: 134884
2011-07-11 03:57:24 +00:00
Jim Grosbach 51897047da Add missing header.
llvm-svn: 133640
2011-06-22 20:40:30 +00:00
Jim Grosbach 2354f87a9d Move ARMMachObjectWriter to its own file.
Just tidy up a bit. No functional change.

llvm-svn: 133638
2011-06-22 20:14:52 +00:00
Evan Cheng 62c7b5bf76 Making use of VFP / NEON floating point multiply-accumulate / subtraction is
difficult on current ARM implementations for a few reasons.
1. Even though a single vmla has latency that is one cycle shorter than a pair
   of vmul + vadd, a RAW hazard during the first (4? on Cortex-a8) can cause
   additional pipeline stall. So it's frequently better to single codegen
   vmul + vadd.
2. A vmla folowed by a vmul, vmadd, or vsub causes the second fp instruction to
   stall for 4 cycles. We need to schedule them apart.
3. A vmla followed vmla is a special case. Obvious issuing back to back RAW
   vmla + vmla is very bad. But this isn't ideal either:
     vmul
     vadd
     vmla
   Instead, we want to expand the second vmla:
     vmla
     vmul
     vadd
   Even with the 4 cycle vmul stall, the second sequence is still 2 cycles
   faster.

Up to now, isel simply avoid codegen'ing fp vmla / vmls. This works well enough
but it isn't the optimial solution. This patch attempts to make it possible to
use vmla / vmls in cases where it is profitable.

A. Add missing isel predicates which cause vmla to be codegen'ed.
B. Make sure the fmul in (fadd (fmul)) has a single use. We don't want to
   compute a fmul and a fmla.
C. Add additional isel checks for vmla, avoid cases where vmla is feeding into
   fp instructions (except for the #3 exceptional case).
D. Add ARM hazard recognizer to model the vmla / vmls hazards.
E. Add a special pre-regalloc case to expand vmla / vmls when it's likely the
   vmla / vmls will trigger one of the special hazards.

Work in progress, only A+B are enabled.

llvm-svn: 120960
2010-12-05 22:04:16 +00:00
Jim Grosbach d0d1329fc8 Move the ARMAsmPrinter class defintiion into a header file.
llvm-svn: 120551
2010-12-01 03:45:07 +00:00
Chris Lattner de16ca8ecc rename LowerToMCInst -> LowerARMMachineInstrToMCInst.
llvm-svn: 119071
2010-11-14 21:00:02 +00:00
Chris Lattner c5afd12557 even more simplifications. ARM MCInstLowering is now just
a single function instead of a class.  It doesn't need the
complexity that X86 does.

llvm-svn: 119070
2010-11-14 20:58:38 +00:00
Jason W Kim b32124545b I added a new file ARMAsmBackend which stubs out in similar ways to
the eqv X86 class.
For now, I split the ELFARMAsmBackend from the DarwinARMAsmBackend
(also mimicking X86)

Tested against -r115126

llvm-svn: 115129
2010-09-30 02:17:26 +00:00
Jim Grosbach 1287f4f3b8 Add skeleton infrastructure for the ARMMCCodeEmitter class. Patch by Jason Kim!
llvm-svn: 114195
2010-09-17 18:46:17 +00:00
Jim Grosbach 91fbd8f86e Factor out basic enums and hleper functions from ARM.h for cleaner sharing
between the compiler back end and the MC libraries.

llvm-svn: 114007
2010-09-15 19:26:06 +00:00
Bob Wilson c597fd3b4a Convert some VTBL and VTBX instructions to use pseudo instructions prior to
register allocation.  Remove the NEONPreAllocPass, which is no longer needed.
Yeah!!

llvm-svn: 113818
2010-09-13 23:55:10 +00:00
Bill Wendling 2c64ba63a1 Add comments for what the condition code symbols mean.
llvm-svn: 111889
2010-08-24 01:11:30 +00:00
Johnny Chen 8e8f1c133a Cleaned up the for-disassembly-only entries in the arm instruction table so that
the memory barrier variants (other than 'SY' full system domain read and write)
are treated as one instruction with option operand.

llvm-svn: 110951
2010-08-12 20:46:17 +00:00
Anton Korobeynikov 19edda0323 Hook in GlobalMerge pass
llvm-svn: 109359
2010-07-24 21:52:08 +00:00
Evan Cheng c3525dc0fd Remove early IT block formation. It's not used.
llvm-svn: 107513
2010-07-02 21:07:09 +00:00
Bob Wilson 01ac8f9fc0 Remove the hidden "neon-reg-sequence" option. The reg sequences are working
now, so there's no need to disable them.

llvm-svn: 106155
2010-06-16 21:34:01 +00:00
Evan Cheng 47cd593023 Thumb2 IT blocks are fairly expensive. When there are multiple selects using
the same condition, it's important to make sure they are scheduled together
to avoid forming multiple IT blocks. I'm adding a pre-regalloc pass that forms
IT blocks early (by re-scheduling instructions and split basic blocks) to
attempt to fix this. This is not turned on by default since I am not sure this
is the right fix.

Another issue is llvm selects are modeled as two-address conditional moves.
This can be very bad when the copies before the conditional moves are not
coalesced away. Teach IT formation pass to move the copies above the IT block
(when legal) to avoid breaking the IT block.

llvm-svn: 105669
2010-06-09 01:46:50 +00:00
Evan Cheng d85631e700 Model CONCAT_VECTORS of two 64-bit values as a REG_SEQUENCE.
llvm-svn: 103104
2010-05-05 18:28:36 +00:00
Anton Korobeynikov 6e01726eae Remove late ARM codegen optimization pass committed by accident.
It is not ready for public yet.

llvm-svn: 100673
2010-04-07 18:23:27 +00:00
Anton Korobeynikov 0453de0133 Some initial version of global merger
llvm-svn: 100641
2010-04-07 18:19:07 +00:00
Chris Lattner f46359642f tidy some targets.
llvm-svn: 95146
2010-02-02 22:13:21 +00:00
Chris Lattner c83cfb9dfa remove dead code.
llvm-svn: 95134
2010-02-02 21:38:59 +00:00
Jim Grosbach 2c3a6c6589 Factor the stack alignment calculations out into a target independent pass.
No functionality change.

llvm-svn: 90336
2009-12-02 19:30:24 +00:00