and xor. The 32-bit move immediates can be hoisted out of loops by machine
LICM but the isel hacks were preventing them.
Instead, let peephole optimization pass recognize registers that are defined by
immediates and the ARM target hook will fold the immediates in.
Other changes include 1) do not fold and / xor into cmp to isel TST / TEQ
instructions if there are multiple uses. This happens when the 'and' is live
out, machine sink would have sinked the computation and that ends up pessimizing
code. The peephole pass would recognize situations where the 'and' can be
toggled to define CPSR and eliminate the comparison anyway.
2) Move peephole pass to after machine LICM, sink, and CSE to avoid blocking
important optimizations.
rdar://8663787, rdar://8241368
llvm-svn: 119548
operand list instead of the operand list redundantly declared on the alias
or instruction.
With this change, we finally remove the ins/outs list on the alias. Before:
def : InstAlias<(outs GR16:$dst), (ins GR8 :$src),
"movsx $src, $dst",
(MOVSX16rr8W GR16:$dst, GR8:$src)>;
After:
def : InstAlias<"movsx $src, $dst",
(MOVSX16rr8W GR16:$dst, GR8:$src)>;
This also makes the alias mechanism more general and powerful, which will
be exploited in subsequent patches.
llvm-svn: 118329
filling them in one at a time. Previously this iterated over the
asmoperands, which left the problem of "holes". The new approach
simplifies things.
llvm-svn: 118104
aliases installed and working. They now work when the
matched pattern and the result instruction have exactly
the same operand list.
This is now enough for us to define proper aliases for
movzx and movsx, implementing rdar://8017633 and PR7459.
Note that we do not accept instructions like:
movzx 0(%rsp), %rsi
GAS accepts this instruction, but it doesn't make any
sense because we don't know the size of the memory
operand. It could be 8/16/32 bits.
llvm-svn: 117901
CodeGenInstruction::FlattenAsmStringVariants method. Use it
to simplify the code in AsmWriterInst, which now no longer
needs to worry about variants.
llvm-svn: 117886
operand values. This is useful for operands which require additional trickery
to encode into the instruction. For example, the ARM shifted immediate and
shifted register operands.
llvm-svn: 116353
try to match them by name first. If there is no by-name match, fall back to
assuming they are in order (this was the previous behavior).
llvm-svn: 116211
need the Compare flag after all.
--- Reverse-merging r109901 into '.':
U include/llvm/Target/TargetInstrDesc.h
U include/llvm/Target/Target.td
U utils/TableGen/InstrInfoEmitter.cpp
U utils/TableGen/CodeGenInstruction.cpp
U utils/TableGen/CodeGenInstruction.h
llvm-svn: 110424
later to identify and possibly remove superfluous compare instructions -- those
that are testing for and setting a status flag that should already be set.
llvm-svn: 109901
from two places in CodeGenDAGPatterns.cpp, and
use it in DAGISelMatcherGen.cpp instead of using
an incorrect predicate that happened to get lucky
on our current targets.
llvm-svn: 99726
for representing constraint info semantically instead of
as a c expression that will be blatted out to the .inc
file. Fix X86RecognizableInstr to use this instead of
parsing C code :).
llvm-svn: 95753
bunch of associated comments, because it doesn't have anything to do
with DAGs or scheduling. This is another step in decoupling MachineInstr
emitting from scheduling.
llvm-svn: 85517
set, these flags indicate the instructions source / def operands have special
register allocation requirement that are not captured in their register classes.
Post-allocation passes (e.g. post-alloc scheduler) should not change their
allocations. e.g. ARM::LDRD require the two definitions to be allocated
even / odd register pair.
llvm-svn: 83196
instruction to execute. This can be used for transformations (like two-address
conversion) to remat an instruction instead of generating a "move"
instruction. The idea is to decrease the live ranges and register pressure and
all that jazz.
llvm-svn: 51660
x86 backend where instructions were not marked maystore/mayload, and perf issues where
instructions were not marked neverHasSideEffects. It would be really nice if we could
write patterns for copy instructions.
I have audited all the x86 instructions down to MOVDQAmr. The flags on others and on
other targets are probably not right in all cases, but no clients currently use this
info that are enabled by default.
llvm-svn: 45829
InOperandList. This gives one piece of important information: # of results
produced by an instruction.
An example of the change:
def ADD32rr : I<0x01, MRMDestReg, (ops GR32:$dst, GR32:$src1, GR32:$src2),
"add{l} {$src2, $dst|$dst, $src2}",
[(set GR32:$dst, (add GR32:$src1, GR32:$src2))]>;
=>
def ADD32rr : I<0x01, MRMDestReg, (outs GR32:$dst), (ins GR32:$src1, GR32:$src2),
"add{l} {$src2, $dst|$dst, $src2}",
[(set GR32:$dst, (add GR32:$src1, GR32:$src2))]>;
llvm-svn: 40033
instruction flag, and use the flag along with a virtual member function
hook for targets to override if there are instructions that are only
trivially rematerializable with specific operands (i.e. constant pool
loads).
llvm-svn: 37728
with a general target hook to identify rematerializable instructions. Some
instructions are only rematerializable with specific operands, such as loads
from constant pools, while others are always rematerializable. This hook
allows both to be identified as being rematerializable with the same
mechanism.
llvm-svn: 37644
Evan Cheng