TableGen creates new register classes and sub-register indices based on
the sub-register structure present in the register bank. So far, it has
been doing that on a per-register basis, but that is not very efficient.
This patch teaches TableGen to compute topological signatures for
registers, and use that to reduce the amount of redundant computation.
Registers get the same TopoSig if they have identical sub-register
structure.
TopoSigs are not currently exposed outside TableGen.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156761 91177308-0d34-0410-b5e6-96231b3b80d8
Don't compute the SuperRegs list until the sub-register graph is
completely finished. This guarantees that the list of super-registers is
properly topologically ordered, and has no duplicates.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156629 91177308-0d34-0410-b5e6-96231b3b80d8
The sub-registers explicitly listed in SubRegs in the .td files form a
tree. In a complicated register bank, it is possible to have
sub-register relationships across sub-trees. For example, the ARM NEON
double vector Q0_Q1 is a tree:
Q0_Q1 = [Q0, Q1], Q0 = [D0, D1], Q1 = [D2, D3]
But we also define the DPair register D1_D2 = [D1, D2] which is fully
contained in Q0_Q1.
This patch teaches TableGen to find such sub-register relationships, and
assign sub-register indices to them. In the example, TableGen will
create a dsub_1_dsub_2 sub-register index, and add D1_D2 as a
sub-register of Q0_Q1.
This will eventually enable the coalescer to handle copies of skewed
sub-registers.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156587 91177308-0d34-0410-b5e6-96231b3b80d8
The .td files specify a tree of sub-registers. Store that tree as
ExplicitSubRegs lists in CodeGenRegister instead of extracting it from
the Record when needed.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156555 91177308-0d34-0410-b5e6-96231b3b80d8
This mapping is for internal use by TableGen. It will not be exposed in
the generated files.
Unfortunately, the mapping is not completely well-defined. The X86 xmm
registers appear with multiple sub-register indices in the ymm
registers. This is because of the odd idempotent sub_sd and sub_ss
sub-register indices. I hope to be able to eliminate them entirely, so
we can require the sub-registers to form a tree.
For now, just place the canonical sub_xmm index in the mapping, and
ignore the idempotents.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156519 91177308-0d34-0410-b5e6-96231b3b80d8
Previously, if an instruction definition was missing the mnemonic,
the next line would just assert(). Issue a real diagnostic instead.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156263 91177308-0d34-0410-b5e6-96231b3b80d8
This is still a topological ordering such that every register class gets
a smaller enum value than its sub-classes.
Placing the smaller spill sizes first makes a difference for the
super-register class bit masks. When looking for a super-register class,
we usually want the smallest possible kind of super-register. That is
now available as the first bit set in the bit mask.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156222 91177308-0d34-0410-b5e6-96231b3b80d8
This manually enumerated list of super-register classes has been
superceeded by the automatically computed super-register class masks
available through SuperRegClassIterator.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156151 91177308-0d34-0410-b5e6-96231b3b80d8
This is a pointer into one of the tables used by
getMatchingSuperRegClass(). It makes it possible to use a shared
implementation of that function.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156121 91177308-0d34-0410-b5e6-96231b3b80d8
The RC->getSubClassMask() pointer now points to a sequence of register
class bit masks. The first bit mask is the normal sub-class mask. The
following masks are super-reg class masks used by
getMatchingSuperRegClass().
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156120 91177308-0d34-0410-b5e6-96231b3b80d8
Many register classes only have a few super-registers, so it is not
necessary to keep individual bit masks for all possible sub-register
indices.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156083 91177308-0d34-0410-b5e6-96231b3b80d8
Some targets have no sub-registers at all. Use the TargetRegisterInfo
versions of composeSubRegIndices(), getSubClassWithSubReg(), and
getMatchingSuperRegClass() for those targets.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@156075 91177308-0d34-0410-b5e6-96231b3b80d8
When an instruction match is found, but the subtarget features it
requires are not available (missing floating point unit, or thumb vs arm
mode, for example), issue a diagnostic that identifies what the feature
mismatch is.
rdar://11257547
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155499 91177308-0d34-0410-b5e6-96231b3b80d8
Assembly matchers for instructions with a two-operand form. ARM is full
of these, for example:
add {Rd}, Rn, Rm // Rd is optional and is the same as Rn if omitted.
The property TwoOperandAliasConstraint on the instruction definition controls
when, and if, an alias will be formed. No explicit InstAlias definitions
are required.
rdar://11255754
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155172 91177308-0d34-0410-b5e6-96231b3b80d8
There's almost always a small number of instruction operands, so
use a SmallVector and save on heap allocations.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@155143 91177308-0d34-0410-b5e6-96231b3b80d8
Handle mixing allocatable and unallocatable register gracefully.
Simplify the pruning of register unit sets.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@154474 91177308-0d34-0410-b5e6-96231b3b80d8