The normal insert() function takes an MBB::iterator position, and
inserts a stand-alone MachineInstr as before.
The insert() function that takes an MBB::instr_iterator position can
insert instructions inside a bundle, and will now update the bundle
flags correctly when that happens.
When the insert position is between two bundles, it is unclear whether
the instruction should be appended to the previous bundle, prepended to
the next bundle, or stand on its own. The MBB::insert() function doesn't
bundle the instruction in that case, use the MIBundleBuilder class for
that.
llvm-svn: 170437
Most code is oblivious to bundles and uses the MBB::iterator which only
visits whole bundles. MBB::erase() operates on whole bundles at a time
as before.
MBB::remove() now refuses to remove bundled instructions. It is not safe
to remove all instructions in a bundle without deleting them since there
is no way of returning pointers to all the removed instructions.
MBB::remove_instr() and MBB::erase_instr() will now update bundle flags
correctly, lifting individual instructions out of bundles while leaving
the remaining bundle intact.
The MachineInstr convenience functions are updated so
eraseFromParent() erases a whole bundle as before
eraseFromBundle() erases a single instruction, leaving the rest of its bundle.
removeFromParent() refuses to operate on bundled instructions, and
removeFromBundle() lifts a single instruction out of its bundle.
These functions will no longer accidentally split or coalesce bundles -
bundle flags are updated to preserve the existing bundling, and explicit
bundleWith* / unbundleFrom* functions should be used to change the
instruction bundling.
This API update is still a work in progress. I am going to update APIs
first so they maintain bundle flags automatically when possible. Then
I'll add stricter verification of the bundle flags.
llvm-svn: 170384
Accordingly, add helper funtions getSimpleValueType (in parallel to
getValueType) in SDValue, SDNode, and TargetLowering.
This is the first, in a series of patches.
This is the second attempt. In the first attempt (r169837), a few
getSimpleVT() were hoisted too far, detected by bootstrap failures.
llvm-svn: 170104
Also add an MIBundleBuilder constructor that takes an existing bundle.
Together these functions make it possible to add instructions to
existing bundles.
llvm-svn: 170063
Accordingly, add helper funtions getSimpleValueType (in parallel to
getValueType) in SDValue, SDNode, and TargetLowering.
This is the first, in a series of patches.
llvm-svn: 169837
This shouldn't affect codegen for -O0 compiles as tail call markers are not
emitted in unoptimized compiles. Testing with the external/internal nightly
test suite reveals no change in compile time performance. Testing with -O1,
-O2 and -O3 with fast-isel enabled did not cause any compile-time or
execution-time failures. All tests were performed on my x86 machine.
I'll monitor our arm testers to ensure no regressions occur there.
In an upcoming clang patch I will be marking the objc_autoreleaseReturnValue
and objc_retainAutoreleaseReturnValue as tail calls unconditionally. While
it's theoretically true that this is just an optimization, it's an
optimization that we very much want to happen even at -O0, or else ARC
applications become substantially harder to debug.
Part of rdar://12553082
llvm-svn: 169796
This is still a work in progress. The purpose is to make bundling and
unbundling operations explicit, and to catch errors where bundles are
broken or created inadvertently.
The old IsInsideBundle flag is replaced by two MI flags: BundledPred
which has the same meaning as IsInsideBundle, and BundledSucc which is
set on instructions that are bundled with a successor. Having two flags
provdes redundancy to detect when a bundle is inadvertently torn by a
splice() or insert(), and it makes it possible to write bundle iterators
that don't need to peek at adjacent instructions.
The new flags can't be manipulated directly (once setIsInsideBundle is
gone). Instead there are MI functions to make and break bundle bonds.
The setIsInsideBundle function will be removed in a future commit. It
should be replaced by bundleWithPred().
llvm-svn: 169583
This is much simpler to reason about, more efficient, and
fixes some corner cases involving implicit super-register defs.
Fixed rdar://12797931.
llvm-svn: 169425
A MachineInstr can only ever be constructed by CreateMachineInstr() and
CloneMachineInstr(), and those factories don't use the removed
constructors.
llvm-svn: 169395
- fixed ordering of calls to doFinalization to be the reverse of the pass run order due to potential dependencies
- fixed machine module info to operate in the doInitialization/doFinalization model, also fixes some FIXMEs
reviewed by Evan Cheng <evan.cheng@apple.com>
llvm-svn: 169391
the alignment is clamped to TargetFrameLowering.getStackAlignment if the target
does not support stack realignment or the option "realign-stack" is off.
This will cause miscompile if the address is treated as aligned and add is
replaced with or in DAGCombine.
Added a bool StackRealignable to TargetFrameLowering to check whether stack
realignment is implemented for the target. Also added a bool RealignOption
to MachineFrameInfo to check whether the option "realign-stack" is on.
rdar://12713765
llvm-svn: 169197
Now that there can be multiple hint registers from targets, it doesn't
make sense to have a function that returns 'the' preferred register.
llvm-svn: 169190
Targets can provide multiple hints now, so getRegAllocPref() doesn't
make sense any longer because it only returns one preferred register.
Replace it with getSimpleHint() in the remaining heuristics. This
function only
llvm-svn: 169188
Virtual registers with a known preferred register are prioritized by
RAGreedy. This function makes the condition explicit without depending
on getRegAllocPref().
llvm-svn: 169179
AKA: Recompile *ALL* the source code!
This one went much better. No manual edits here. I spot-checked for
silliness and grep-checked for really broken edits and everything seemed
good. It all still compiles. Yell if you see something that looks goofy.
llvm-svn: 169133
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. =]
llvm-svn: 169131
The original patch removed a bunch of code that the SjLjEHPrepare pass placed
into the entry block if all of the landing pads were removed during the
CodeGenPrepare class. The more natural way of doing things is to run the CGP
*before* we run the SjLjEHPrepare pass.
Make it so!
llvm-svn: 169044
No functional change, just moved header files.
Targets can inject custom passes between register allocation and
rewriting. This makes it possible to tweak the register allocation
before rewriting, using the full global interference checking available
from LiveRegMatrix.
llvm-svn: 168806
This is a simple, cheap infrastructure for analyzing the shape of a
DAG. It recognizes uniform DAGs that take the shape of bottom-up
subtrees, such as the included matrix multiplication example. This is
useful for heuristics that balance register pressure with ILP. Two
canonical expressions of the heuristic are implemented in scheduling
modes: -misched-ilpmin and -misched-ilpmax.
llvm-svn: 168773
positive.
In this particular case, R6 was being spilled by the register scavenger when it
was in fact dead. The isUsed function reported R6 as used because the R6_R7
alias was reserved (due to the fact that we've reserved R7 as the FP). The
solution is to only check if the original register (i.e., R6) isReserved and
not the aliases. The aliases are only checked to make sure they're available.
The test case is derived from one of the nightly tester benchmarks and is rather
intractable and difficult to reproduce, so I haven't included it.
rdar://12592448
llvm-svn: 168054
This infrastructure is generally useful for any target that wants to
strongly prefer two instructions to be adjacent after scheduling.
A following checkin will add target-specific hooks with unit
tests. Then this feature will be enabled by default with misched.
llvm-svn: 167742
This adds support for weak DAG edges to the general scheduling
infrastructure in preparation for MachineScheduler support for
heuristics based on weak edges.
llvm-svn: 167738
misched is disabled by default. With -enable-misched, these heuristics
balance the schedule to simultaneously avoid saturating processor
resources, expose ILP, and minimize register pressure. I've been
analyzing the performance of these heuristics on everything in the
llvm test suite in addition to a few other benchmarks. I would like
each heuristic check to be verified by a unit test, but I'm still
trying to figure out the best way to do that. The heuristics are still
in considerable flux, but as they are refined we should be rigorous
about unit testing the improvements.
llvm-svn: 167527
Expose the processor resources defined by the machine model to the
scheduler and other clients through the TargetSchedule interface.
Normalize each resource count with respect to other kinds of
resources. This allows scheduling heuristics to balance resources
against other kinds of resources and latency.
llvm-svn: 167444
