Commit Graph

200 Commits

Author SHA1 Message Date
Silviu Baranga
fd79485dfa Allow generation of vmla.f32 instructions when targeting Cortex-A15. The patch also adds the VFP4 feature to Cortex-A15 and fixes the DontUseFusedMAC predicate so that we can still generate vmla.f32 instructions on non-darwin targets with VFP4.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@187349 91177308-0d34-0410-b5e6-96231b3b80d8
2013-07-29 09:25:50 +00:00
Bill Wendling
f9fd58a44b Access the TargetLoweringInfo from the TargetMachine object instead of caching it. The TLI may change between functions. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184352 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 21:07:11 +00:00
Bill Wendling
ea44281d5d Access the TargetLoweringInfo from the TargetMachine object instead of caching it. The TLI may change between functions. No functionality change.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@184349 91177308-0d34-0410-b5e6-96231b3b80d8
2013-06-19 20:51:24 +00:00
Rafael Espindola
4a971705bc Remove the MachineMove class.
It was just a less powerful and more confusing version of
MCCFIInstruction. A side effect is that, since MCCFIInstruction uses
dwarf register numbers, calls to getDwarfRegNum are pushed out, which
should allow further simplifications.

I left the MachineModuleInfo::addFrameMove interface unchanged since
this patch was already fairly big.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@181680 91177308-0d34-0410-b5e6-96231b3b80d8
2013-05-13 01:16:13 +00:00
Silviu Baranga
a210db781f Enabling the generation of dependency breakers for partial updates on Cortex-A15. Also fixing a small bug in getting the update clearence for VLD1LNd32.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@178134 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-27 12:38:44 +00:00
Renato Golin
3382a84074 Avoid NEON SP-FP unless unsafe-math or Darwin
NEON is not IEEE 754 compliant, so we should avoid lowering single-precision
floating point operations with NEON unless unsafe-math is turned on. The
equivalent VFP instructions are IEEE 754 compliant, but in some cores they're
much slower, so some archs/OSs might still request it to be on by default,
such as Swift and Darwin.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177651 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-21 18:47:47 +00:00
Silviu Baranga
bcbf3fddef Adding an A15 specific optimization pass for interactions between S/D/Q registers. The pass handles all the required transformations pre-regalloc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@177169 91177308-0d34-0410-b5e6-96231b3b80d8
2013-03-15 18:28:25 +00:00
Jim Grosbach
54f2187eac ARM: Fix a few copy-paste errors.
s/X86/ARM/

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171789 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 21:12:13 +00:00
Chandler Carruth
aeef83c6af 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.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171681 91177308-0d34-0410-b5e6-96231b3b80d8
2013-01-07 01:37:14 +00:00
Chandler Carruth
d04a8d4b33 Use the new script to sort the includes of every file under lib.
Sooooo many of these had incorrect or strange main module includes.
I have manually inspected all of these, and fixed the main module
include to be the nearest plausible thing I could find. If you own or
care about any of these source files, I encourage you to take some time
and check that these edits were sensible. I can't have broken anything
(I strictly added headers, and reordered them, never removed), but they
may not be the headers you'd really like to identify as containing the
API being implemented.

Many forward declarations and missing includes were added to a header
files to allow them to parse cleanly when included first. The main
module rule does in fact have its merits. =]

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169131 91177308-0d34-0410-b5e6-96231b3b80d8
2012-12-03 16:50:05 +00:00
Rafael Espindola
0d91c0b519 Remove TargetELFWriterInfo.
All the credit goes to Jan Voung for noticing it was dead!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166902 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-28 21:34:43 +00:00
Nadav Rotem
2704834661 Implement a basic VectorTargetTransformInfo interface to be used by the loop and bb vectorizers for modeling the cost of instructions.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166593 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-24 17:22:41 +00:00
Nadav Rotem
cbd9a19b5d Reapply the TargerTransformInfo changes, minus the changes to LSR and Lowerinvoke.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166248 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-18 23:22:48 +00:00
Bob Wilson
3b9a911efc Temporarily revert the TargetTransform changes.
The TargetTransform changes are breaking LTO bootstraps of clang.  I am
working with Nadav to figure out the problem, but I am reverting it for now
to get our buildbots working.

This reverts svn commits: 165665 165669 165670 165786 165787 165997
and I have also reverted clang svn 165741

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@166168 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-18 05:43:52 +00:00
Nadav Rotem
e3d0e86919 Add a new interface to allow IR-level passes to access codegen-specific information.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165665 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-10 22:04:55 +00:00
Micah Villmow
3574eca1b0 Move TargetData to DataLayout.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@165402 91177308-0d34-0410-b5e6-96231b3b80d8
2012-10-08 16:38:25 +00:00
Jush Lu
8f50647662 [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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@164759 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-27 05:21:41 +00:00
Silviu Baranga
616471d4bf This patch introduces A15 as a target in LLVM.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163803 91177308-0d34-0410-b5e6-96231b3b80d8
2012-09-13 15:05:10 +00:00
Bob Wilson
3fb99a7368 Consistently use AnalysisID types in TargetPassConfig.
This makes it possible to just use a zero value to represent "no pass", so
the phony NoPassID global variable is no longer needed.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159568 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-02 19:48:37 +00:00
Bob Wilson
564fbf6aff Add all codegen passes to the PassManager via TargetPassConfig.
This is a preliminary step toward having TargetPassConfig be able to
start and stop the compilation at specified passes for unit testing
and debugging.  No functionality change.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@159567 91177308-0d34-0410-b5e6-96231b3b80d8
2012-07-02 19:48:31 +00:00
Bill Wendling
7c4ce30ea6 Change the PassManager from a reference to a pointer.
The TargetPassManager's default constructor wants to initialize the PassManager
to 'null'. But it's illegal to bind a null reference to a null l-value. Make the
ivar a pointer instead.
PR12468


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155902 91177308-0d34-0410-b5e6-96231b3b80d8
2012-05-01 08:27:43 +00:00
Jim Grosbach
d4f020a3af Tidy up. 80 columns.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154226 91177308-0d34-0410-b5e6-96231b3b80d8
2012-04-06 23:43:50 +00:00
Jakob Stoklund Olesen
dc909bf46b Preserve implicit defs in ARMLoadStoreOptimizer.
When a number of sub-register VLRDS instructions are combined into a
VLDM, preserve any super-register implicit defs. This is required to
keep the register scavenger and machine code verifier happy.

Enable machine code verification after ARMLoadStoreOptimizer.
ARM/2012-01-26-CopyPropKills.ll was failing because of this.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@153610 91177308-0d34-0410-b5e6-96231b3b80d8
2012-03-28 22:50:56 +00:00
Andrew Trick
1dd8c8560d Codegen pass definition cleanup. No functionality.
Moving toward a uniform style of pass definition to allow easier target configuration.
Globally declare Pass ID.
Globally declare pass initializer.
Use INITIALIZE_PASS consistently.
Add a call to the initializer from CodeGen.cpp.
Remove redundant "createPass" functions and "getPassName" methods.

While cleaning up declarations, cleaned up comments (sorry for large diff).

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@150100 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-08 21:23:13 +00:00
Andrew Trick
061efcfb3e TargetPassConfig: confine the MC configuration to TargetMachine.
Passes prior to instructon selection are now split into separate configurable stages.
Header dependencies are simplified.
The bulk of this diff is simply removal of the silly DisableVerify flags.

Sorry for the target header churn. Attempting to stabilize them.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149754 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-04 02:56:59 +00:00
Andrew Trick
843ee2e6a4 Added TargetPassConfig. The first little step toward configuring codegen passes.
Allows command line overrides to be centralized in LLVMTargetMachine.cpp.
LLVMTargetMachine can intercept common passes and give precedence to command line overrides.
Allows adding "internal" target configuration options without touching TargetOptions.
Encapsulates the PassManager.
Provides a good point to initialize all CodeGen passes so that Pass ID's can be used in APIs.
Allows modifying the target configuration hooks without rebuilding the world.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@149672 91177308-0d34-0410-b5e6-96231b3b80d8
2012-02-03 05:12:41 +00:00
David Blaikie
2d24e2a396 Unweaken vtables as per http://llvm.org/docs/CodingStandards.html#ll_virtual_anch
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146960 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-20 02:50:00 +00:00
Evan Cheng
ddfd1377d2 - Add MachineInstrBundle.h and MachineInstrBundle.cpp. This includes a function
to finalize MI bundles (i.e. add BUNDLE instruction and computing register def
  and use lists of the BUNDLE instruction) and a pass to unpack bundles.
- Teach more of MachineBasic and MachineInstr methods to be bundle aware.
- Switch Thumb2 IT block to MI bundles and delete the hazard recognizer hack to
  prevent IT blocks from being broken apart.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@146542 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-14 02:11:42 +00:00
Nick Lewycky
8a8d479214 Move global variables in TargetMachine into new TargetOptions class. As an API
change, now you need a TargetOptions object to create a TargetMachine. Clang
patch to follow.

One small functionality change in PTX. PTX had commented out the machine
verifier parts in their copy of printAndVerify. That now calls the version in
LLVMTargetMachine. Users of PTX who need verification disabled should rely on
not passing the command-line flag to enable it.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@145714 91177308-0d34-0410-b5e6-96231b3b80d8
2011-12-02 22:16:29 +00:00
Evan Cheng
b95fc31aa2 Sink codegen optimization level into MCCodeGenInfo along side relocation model
and code model. This eliminates the need to pass OptLevel flag all over the
place and makes it possible for any codegen pass to use this information.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@144788 91177308-0d34-0410-b5e6-96231b3b80d8
2011-11-16 08:38:26 +00:00
Devang Patel
827454e6e2 svn mv Target/ARM/ARMGlobalMerge.cpp Transforms/Scalar/GlobalMerge.cpp
There is no reason to have simple IR level pass in lib/Target.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@142200 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-17 17:17:43 +00:00
Lang Hames
bb5b3f3359 Add a natural stack alignment field to TargetData, and prevent InstCombine from
promoting allocas to preferred alignments that exceed the natural
alignment. This avoids some potentially expensive dynamic stack realignments.

The natural stack alignment is set in target data strings via the "S<size>"
option. Size is in bits and must be a multiple of 8. The natural stack alignment
defaults to "unspecified" (represented by a zero value), and the "unspecified"
value does not prevent any alignment promotions. Target maintainers that care
about avoiding promotions should explicitly add the "S<size>" option to their
target data strings.



git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@141599 91177308-0d34-0410-b5e6-96231b3b80d8
2011-10-10 23:42:08 +00:00
Jakob Stoklund Olesen
8bb3d3cb30 Use ExecutionDepsFix instead of NEONMoveFix.
This enables NEON domain tracking across basic blocks, but should
otherwise do the same thing.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140772 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-29 02:48:41 +00:00
Bill Wendling
3511cedf36 Move to ISelLowering.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140754 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-29 01:13:55 +00:00
Bill Wendling
39689c8154 Ahem...actually *add* the ARMSjLjLowering pass to the pass manager.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140718 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-28 20:29:28 +00:00
Bill Wendling
0481d29d49 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.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@140646 91177308-0d34-0410-b5e6-96231b3b80d8
2011-09-27 22:14:12 +00:00
Evan Cheng
77eaaf0a0c Hide -global-merge option.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138540 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-25 01:22:49 +00:00
Evan Cheng
b8cfe4ff41 Add a command line option to disable global merge pass.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138536 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-25 01:00:36 +00:00
Evan Cheng
0f660260e6 Remove a out-of-place comment.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138534 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-25 00:54:42 +00:00
Evan Cheng
3e74d6fdd2 Move TargetRegistry and TargetSelect from Target to Support where they belong.
These are strictly utilities for registering targets and components.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@138450 91177308-0d34-0410-b5e6-96231b3b80d8
2011-08-24 18:08:43 +00:00
Evan Cheng
be74029f44 Sink ARM mc routines into MCTargetDesc.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135825 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-23 00:00:19 +00:00
Evan Cheng
34ad6db8b9 - Move CodeModel from a TargetMachine global option to MCCodeGenInfo.
- Introduce JITDefault code model. This tells targets to set different default
  code model for JIT. This eliminates the ugly hack in TargetMachine where
  code model is changed after construction.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135580 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-20 07:51:56 +00:00
Evan Cheng
439661395f Introduce MCCodeGenInfo, which keeps information that can affect codegen
(including compilation, assembly). Move relocation model Reloc::Model from
TargetMachine to MCCodeGenInfo so it's accessible even without TargetMachine.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135468 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-19 06:37:02 +00:00
Evan Cheng
1abf2cb59b Rename createAsmInfo to createMCAsmInfo and move registration code to MCTargetDesc to prepare for next round of changes.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@135219 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-14 23:50:31 +00:00
Evan Cheng
ebdeeab812 Eliminate asm parser's dependency on TargetMachine:
- Each target asm parser now creates its own MCSubtatgetInfo (if needed).
- Changed AssemblerPredicate to take subtarget features which tablegen uses
  to generate asm matcher subtarget feature queries. e.g.
  "ModeThumb,FeatureThumb2" is translated to
  "(Bits & ModeThumb) != 0 && (Bits & FeatureThumb2) != 0".


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134678 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-08 01:53:10 +00:00
Evan Cheng
94ca42ff04 Factor ARM triple parsing out of ARMSubtarget. Another step towards making ARM subtarget info available to MC.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134569 91177308-0d34-0410-b5e6-96231b3b80d8
2011-07-07 00:08:19 +00:00
Evan Cheng
276365dd4b Fix the ridiculous SubtargetFeatures API where it implicitly expects CPU name to
be the first encoded as the first feature. It then uses the CPU name to look up
features / scheduling itineray even though clients know full well the CPU name
being used to query these properties.

The fix is to just have the clients explictly pass the CPU name!


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@134127 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-30 01:53:36 +00:00
Evan Cheng
df214fa517 Remove TargetOptions.h dependency from ARMSubtarget.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@133738 91177308-0d34-0410-b5e6-96231b3b80d8
2011-06-23 18:15:17 +00:00
Daniel Dunbar
912225e185 ADT/Triple: Move a variety of clients to using isOSDarwin() and isOSWindows()
predicates.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129816 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-19 21:14:45 +00:00
Bob Wilson
84c5eed15b This patch combines several changes from Evan Cheng for rdar://8659675.
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.

Enable these fp vmlx codegen changes for Cortex-A9.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@129775 91177308-0d34-0410-b5e6-96231b3b80d8
2011-04-19 18:11:57 +00:00