Instead of holding a mask, hold two value: the start index and the
length of the mapping. This is a more compact representation, although
less powerful. That being said, arbitrary masks would not have worked
for the generic so do not allow them in the first place.
llvm-svn: 267025
Although repairing definitions is not mandatory for correctness (only
phis would be impacted because of the RPO traversal), not repairing
might go against the cost model. Therefore, just repair when it is
possible.
llvm-svn: 266025
When assigning the register banks of an instruction, it is best to know
all the constraints of the input to have a good idea of how this will
impact the cost of the whole function.
llvm-svn: 265812
Do not give that much importance to the current register bank of an
operand. This is likely just a side effect of the current execution and
it is properly wise to prefer a register bank that can be extracted from
the information available statically (like encoding constraints and
type).
llvm-svn: 265810
Add verbose information when checking if the current and the desired
register banks match.
Detail what happens when we assign a register bank.
llvm-svn: 265804
specific type.
This will be used to find the default mapping of the instruction.
Also, this information is recorded, instead of computed, because it is
expensive from a type to know which register bank maps it.
Indeed, we need to iterate through all the register classes of all the
register banks to find the one that maps the given type.
llvm-svn: 265736
from a register.
On top of duplicating the logic, it was buggy! It would assert on
physical registers, since MachineRegisterInfo does not have any
information regarding register classes/banks for them.
llvm-svn: 265727
The pass walk through the machine function and assign the register banks
using the default mapping. In other words, there is no attempt to reduce
cross register copies.
llvm-svn: 265707
the mapping of an instruction on register bank.
For most instructions, it is possible to guess the mapping of the
instruciton by using the encoding constraints.
It remains instructions without encoding constraints.
For copy-like instructions, we try to propagate the information we get
from the other operands. Otherwise, the target has to give this
information.
llvm-svn: 265703
helper class.
The default constructor creates invalid (isValid() == false) instances
and may be used to communicate that a mapping was not found.
llvm-svn: 265699
getInstrMapping.
This implementation requires that the target implemented
getRegBankFromRegClass.
Indeed, the implementation uses the register classes for the encoding
constraints for the instructions to deduce the mapping of a value.
llvm-svn: 265624
This will be used by the register bank select pass to assign register banks
for generic virtual registers.
This was originally committed as r265573 but broke at least one windows bot.
The problem with the windows bot was that it was using a copy constructor for
the InstructionMappings class and could not synthesize it. Actually, the fact
that this class is not copy constructable is expected and the compiler should
use the move assignment constructor. Marking the problematic assignment
explicitly as using the move constructor has its own problems.
Indeed, with recent clang we get a warning that we may prevent the elision of
the copy by the compiler. A proper fix for both compilers would be to change the
API of getPossibleInstrMapping to take a InstructionMappings as input/output
parameter. This does not feel natural and since GISel is not used on windows
yet, I chose to workaround the problem by not compiling the problematic code on
windows.
llvm-svn: 265604
instruction on a register bank. This will be used by the register bank select
pass to assign register banks for generic virtual registers." and the follow-on
commits while I find out a way to fix the win7 bot:
http://lab.llvm.org:8011/builders/sanitizer-windows/builds/19882
This reverts commit r265578, r265581, r265584, and r265585.
llvm-svn: 265587
helper class.
The default constructor creates invalid (isValid() == false) instances
and may be used to communicate that a mapping was not found.
llvm-svn: 265581
The method checks that the value is fully defined accross the different partial
mappings and that the partial mappings are compatible between each other.
llvm-svn: 265556
As part of the TRI argument of addRegBankCoverage we already have access to
the TargetRegisterClass through the ID of that register class.
Therefore, there is no point in needing a TargetRegisterClass instance,
the ID is enough to get to it.
llvm-svn: 265487
Change the default constructor to create invalid object.
The target will have to properly initialize the register banks before
using them.
llvm-svn: 265460
Eric Liu