copies.
This patch extends the peephole optimization introduced in r190713 to produce
register-coalescer friendly copies when possible.
This extension taught the existing cross-bank copy optimization how to deal
with the instructions that generate cross-bank copies, i.e., insert_subreg,
extract_subreg, reg_sequence, and subreg_to_reg.
E.g.
b = insert_subreg e, A, sub0 <-- cross-bank copy
...
C = copy b.sub0 <-- cross-bank copy
Would produce the following code:
b = insert_subreg e, A, sub0 <-- cross-bank copy
...
C = copy A <-- same-bank copy
This patch also introduces a new helper class for that: ValueTracker.
This class implements the logic to look through the copy related instructions
and get the related source.
For now, the advanced rewriting is disabled by default as we are lacking the
semantic on target specific instructions to catch the motivating examples.
Related to <rdar://problem/12702965>.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@212100 91177308-0d34-0410-b5e6-96231b3b80d8
This reverts commit r205974, it turns out that this wasn't such a great idea
after all. Using DIVariable as return value is self-documenting and marginally
more type safe.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205979 91177308-0d34-0410-b5e6-96231b3b80d8
Makes iteration over implicit and explicit machine operands more
explicit (har har). Insipired by code review discussion for r205565.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205680 91177308-0d34-0410-b5e6-96231b3b80d8
Member functions defined within a class definition are implicitly
'inline' for linkage purposes. Compilers might slightly favor inlining
functions explicitly marked 'inline', but LLVM doesn't make a stylistic
habit of doing this generally.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@205679 91177308-0d34-0410-b5e6-96231b3b80d8
The old system was fairly convoluted:
* A temporary label was created.
* A single PROLOG_LABEL was created with it.
* A few MCCFIInstructions were created with the same label.
The semantics were that the cfi instructions were mapped to the PROLOG_LABEL
via the temporary label. The output position was that of the PROLOG_LABEL.
The temporary label itself was used only for doing the mapping.
The new CFI_INSTRUCTION has a 1:1 mapping to MCCFIInstructions and points to
one by holding an index into the CFI instructions of this function.
I did consider removing MMI.getFrameInstructions completelly and having
CFI_INSTRUCTION own a MCCFIInstruction, but MCCFIInstructions have non
trivial constructors and destructors and are somewhat big, so the this setup
is probably better.
The net result is that we don't create temporary labels that are never used.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@203204 91177308-0d34-0410-b5e6-96231b3b80d8
already lived there and it is where it belongs -- this is the in-memory
debug location representation.
This is just cleanup -- Modules can actually cope with this, but that
doesn't make it right. After chatting with folks that have out-of-tree
stuff, going ahead and moving the rest of the headers seems preferable.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@202960 91177308-0d34-0410-b5e6-96231b3b80d8
The greedy register allocator tries to split a live-range around each
instruction where it is used or defined to relax the constraints on the entire
live-range (this is a last chance split before falling back to spill).
The goal is to have a big live-range that is unconstrained (i.e., that can use
the largest legal register class) and several small local live-range that carry
the constraints implied by each instruction.
E.g.,
Let csti be the constraints on operation i.
V1=
op1 V1(cst1)
op2 V1(cst2)
V1 live-range is constrained on the intersection of cst1 and cst2.
tryInstructionSplit relaxes those constraints by aggressively splitting each
def/use point:
V1=
V2 = V1
V3 = V2
op1 V3(cst1)
V4 = V2
op2 V4(cst2)
Because of how the coalescer infrastructure works, each new variable (V3, V4)
that is alive at the same time as V1 (or its copy, here V2) interfere with V1.
Thus, we end up with an uncoalescable copy for each split point.
To make tryInstructionSplit less aggressive, we check if the split point
actually relaxes the constraints on the whole live-range. If it does not, we do
not insert it.
Indeed, it will not help the global allocation problem:
- V1 will have the same constraints.
- V1 will have the same interference + possibly the newly added split variable
VS.
- VS will produce an uncoalesceable copy if alive at the same time as V1.
<rdar://problem/15570057>
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@198369 91177308-0d34-0410-b5e6-96231b3b80d8
A DBG_VALUE is register-indirect iff the first operand is a register
_and_ the second operand is an immediate.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@190821 91177308-0d34-0410-b5e6-96231b3b80d8
If the frame pointer is omitted, and any stack changes occur in the inline
assembly, e.g.: "pusha", then any C local variable or C argument references
will be incorrect.
I pass no judgement on anyone who would do such a thing. ;)
rdar://13218191
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@175334 91177308-0d34-0410-b5e6-96231b3b80d8
When calling hasProperty() on an instruction inside a bundle, it should
always behave as if IgnoreBundle was passed, and just return properties
for the current instruction.
Only attempt to aggregate bundle properties whan asked about the bundle
header.
The assertion fires on existing ARM test cases without this fix.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@172082 91177308-0d34-0410-b5e6-96231b3b80d8
It is possible to build MI bundles that don't begin with a BUNDLE
header. Add support for such bundles, counting all instructions inside
the bundle.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171985 91177308-0d34-0410-b5e6-96231b3b80d8
The series of patches leading up to this one makes llc -O0 run 8% faster.
When deallocating a MachineFunction, there is no need to visit all
MachineInstr and MachineOperand objects to deallocate them. All their
memory come from a BumpPtrAllocator that is about to be purged, and they
have empty destructors anyway.
This only applies when deallocating the MachineFunction.
DeleteMachineInstr() should still be used to recycle MI memory during
the codegen passes.
Remove the LeakDetector support for MachineInstr. I've never seen it
used before, and now it definitely doesn't work. With this patch, leaked
MachineInstrs would be much less of a problem since all of their memory
will be reclaimed by ~MachineFunction().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171599 91177308-0d34-0410-b5e6-96231b3b80d8
Instead of an std::vector<MachineOperand>, use MachineOperand arrays
from an ArrayRecycler living in MachineFunction.
This has several advantages:
- MachineInstr now has a trivial destructor, making it possible to
delete them in batches when destroying MachineFunction. This will be
enabled in a later patch.
- Bypassing malloc() and free() can be faster, depending on the system
library.
- MachineInstr objects and their operands are allocated from the same
BumpPtrAllocator, so they will usually be next to each other in
memory, providing better locality of reference.
- Reduce MachineInstr footprint. A std::vector is 24 bytes, the new
operand array representation only uses 8+4+1 bytes in MachineInstr.
- Better control over operand array reallocations. In the old
representation, the use-def chains would be reordered whenever a
std::vector reached its capacity. The new implementation never changes
the use-def chain order.
Note that some decisions in the code generator depend on the use-def
chain orders, so this patch may cause different assembly to be produced
in a few cases.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171598 91177308-0d34-0410-b5e6-96231b3b80d8
into their new header subdirectory: include/llvm/IR. This matches the
directory structure of lib, and begins to correct a long standing point
of file layout clutter in LLVM.
There are still more header files to move here, but I wanted to handle
them in separate commits to make tracking what files make sense at each
layer easier.
The only really questionable files here are the target intrinsic
tablegen files. But that's a battle I'd rather not fight today.
I've updated both CMake and Makefile build systems (I think, and my
tests think, but I may have missed something).
I've also re-sorted the includes throughout the project. I'll be
committing updates to Clang, DragonEgg, and Polly momentarily.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@171366 91177308-0d34-0410-b5e6-96231b3b80d8
Instructions that are inserted in a basic block can still be decorated
with addOperand(MO).
Make the two-argument addOperand() function contain the actual
implementation. This function will now always have a valid MF reference
that it can use for memory allocation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170798 91177308-0d34-0410-b5e6-96231b3b80d8
This function is often used to decorate dangling instructions, so a
context reference is required to allocate memory for the operands.
Also add a corresponding MachineInstrBuilder method.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170797 91177308-0d34-0410-b5e6-96231b3b80d8
Just like for addMemOperand(), the function pointer provides a context
for allocating memory. This will make it possible to use a better memory
allocation strategy for the MI operand list, which is currently a slow
std::vector.
Most calls to addOperand() come from MachineInstrBuilder, so give that
class an MF reference as well. Code using BuildMI() won't need changing
at all since the MF reference is already required to allocate a
MachineInstr.
Future patches will fix code that calls MI::addOperand(Op) directly, as
well as code that uses the now deprecated MachineInstrBuilder(MI)
constructor.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170574 91177308-0d34-0410-b5e6-96231b3b80d8
The bundle flags are now maintained by the slightly higher-level
functions bundleWithPred() / bundleWithSucc() which enforce consistent
bundle flags between neighboring instructions.
See also MIBundleBuilder for an even higher-level approach to building
bundles.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170475 91177308-0d34-0410-b5e6-96231b3b80d8
The bundle_iterator::operator++ function now doesn't need to dig out the
basic block and check against end(). It can use the isBundledWithSucc()
flag to find the last bundled instruction safely.
Similarly, MachineInstr::isBundled() no longer needs to look at
iterators etc. It only has to look at flags.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170473 91177308-0d34-0410-b5e6-96231b3b80d8
The bundle-related MI flags need to be kept in sync with the neighboring
instructions. Don't allow the bulk flag-setting setFlags() function to
change them.
Also don't copy MI flags when cloning an instruction. The clone's bundle
flags will be set when it is explicitly inserted into a bundle.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170459 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@170384 91177308-0d34-0410-b5e6-96231b3b80d8
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().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169583 91177308-0d34-0410-b5e6-96231b3b80d8
A MachineInstr can only ever be constructed by CreateMachineInstr() and
CloneMachineInstr(), and those factories don't use the removed
constructors.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169395 91177308-0d34-0410-b5e6-96231b3b80d8
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.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@169133 91177308-0d34-0410-b5e6-96231b3b80d8
the MachineInstr MayLoad/MayLoad flags are based on the tablegen implementation.
For inline assembly, however, we need to compute these based on the constraints.
Revert r166929 as this is no longer needed, but leave the test case in place.
rdar://12033048 and PR13504
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The MachineOperand::TiedTo field was maintained, but not used.
This patch enables it in isRegTiedToDefOperand() and
isRegTiedToUseOperand() which are the actual functions use by the
register allocator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163153 91177308-0d34-0410-b5e6-96231b3b80d8
After much agonizing, use a full 4 bits of precious MachineOperand space
to encode this. This uses existing padding, and doesn't grow
MachineOperand beyond its current 32 bytes.
This allows tied defs among the first 15 operands on a normal
instruction, just like the current MCInstrDesc constraint encoding.
Inline assembly needs to be able to tie more than the first 15 operands,
and gets special treatment.
Tied uses can appear beyond 15 operands, as long as they are tied to a
def that's in range.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163151 91177308-0d34-0410-b5e6-96231b3b80d8
Manage tied operands entirely internally to MachineInstr. This makes it
possible to change the representation of tied operands, as I will do
shortly.
The constraint that tied uses and defs must be in the same order was too
restrictive.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@163021 91177308-0d34-0410-b5e6-96231b3b80d8
Ordered memory operations are more constrained than volatile loads and
stores because they must be ordered with respect to all other memory
operations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@162861 91177308-0d34-0410-b5e6-96231b3b80d8
