Implementing this via ComputeMaskedBits has two advantages:
+ It actually works. DAGISel doesn't deal with the chains properly
in the previous pattern-based solution, so they never trigger.
+ The information can be used in other DAG combines, as well as the
trivial "get rid of truncs". For example if the trunc is in a
different basic block.
rdar://problem/16227836
llvm-svn: 205540
The previous situation where ATOMIC_LOAD_WHATEVER nodes were expanded
at MachineInstr emission time had grown to be extremely large and
involved, to account for the subtly different code needed for the
various flavours (8/16/32/64 bit, cmpxchg/add/minmax).
Moving this transformation into the IR clears up the code
substantially, and makes future optimisations much easier:
1. an atomicrmw followed by using the *new* value can be more
efficient. As an IR pass, simple CSE could handle this
efficiently.
2. Making use of cmpxchg success/failure orderings only has to be done
in one (simpler) place.
3. The common "cmpxchg; did we store?" idiom can be exposed to
optimisation.
I intend to gradually improve this situation within the ARM backend
and make sure there are no hidden issues before moving the code out
into CodeGen to be shared with (at least ARM64/AArch64, though I think
PPC & Mips could benefit too).
llvm-svn: 205525
The Cyclone CPU is similar to swift for most LLVM purposes, but does have two
preferred instructions for zeroing a VFP register. This teaches LLVM about
them.
llvm-svn: 205309
We've already got versions without the barriers, so this just adds IR-level
support for generating the new v8 ones.
rdar://problem/16227836
llvm-svn: 204813
ATOMIC_STORE operations always get here as a lowered ATOMIC_SWAP, so there's no
need for any code to handle them specially.
There should be no functionality change so no tests.
llvm-svn: 203567
Summary:
This commit gives an address mode to the PLD instruction. We
were getting an assertion failure in the frame lowering code
because we had code that was doing a pld of a stack allocated
address. The frame lowering was checking the address mode and
then asserting because pld had none defined.
This commit fixes pld for arm mode. There was a previous fix for
thumb mode in a separate commit. The commit for thumb mode
added a test in a separate file because it would otherwise fail
for arm. This commit moves the thumb test back into the prefetch.ll
file and adds the corresponding arm test.
Differential Revision: http://llvm-reviews.chandlerc.com/D2622
llvm-svn: 200248
With constant-sharing, litpool loads consume 4 + N*2 bytes of code, but
movw/movt pairs consume 8*N. This means litpools are better than movw/movt even
with just one use. Other materialisation strategies can still be better though,
so the logic is a little odd.
llvm-svn: 199891
Fix MLA defs to use register class GPRnopc.
Add encoding tests for multiply instructions.
(Alias for MUL/SMLAL/UMLAL added by r199026.)
Patch by Zhaoshi.
llvm-svn: 199491
The implicit immediate 0 forms are assembly aliases, not distinct instruction
encodings. Fix the initial implementation introduced in r198914 to an alias to
avoid two separate instruction definitions for the same encoding.
An InstAlias is insufficient in this case as the necessary due to the need to
add a new additional operand for the implicit zero. By using the AsmPsuedoInst,
fall back to the C++ code to transform the instruction to the equivalent
_POST_IMM form, inserting the additional implicit immediate 0.
llvm-svn: 199032
The disassembler would no longer be able to disambiguage between the two
variants (explicit immediate #0 vs implicit, omitted #0) for the ldrt, strt,
ldrbt, strbt mnemonics as both versions indicated the disassembler routine.
llvm-svn: 198944
The GNU assembler has an extension that allows for the elision of the paired
register (dt2) for the LDRD and STRD mnemonics. Add support for this in the
assembly parser. Canonicalise the usage during the instruction parsing from
the specified version.
llvm-svn: 198915
The ARM ARM indicates the mnemonics as follows:
ldrbt{<c>}{<q>} <Rt>, [<Rn>], {, #+/-<imm>}
ldrt{<c>}{<q>} <Rt>, [<Rn>] {, #+/-<imm>}
strbt{<c>}{<q>} <Rt>, [<Rn>] {, #<imm>}
strt{<c>}{<q>} <Rt>, [<Rn>] {, #+/-<imm>}
This improves the parser to deal with the implicit immediate 0 for the mnemonics
as per the specification.
Thanks to Joerg Sonnenberger for the tests!
llvm-svn: 198914
The ARM backend has been using most of the MachO related subtarget
checks almost interchangeably, and since the only target it's had to
run on has been IOS (which is all three of MachO, Darwin and IOS) it's
worked out OK so far.
But we'd like to support embedded targets under the "*-*-none-macho"
triple, which means everything starts falling apart and inconsistent
behaviours emerge.
This patch should pick a reasonably sensible set of behaviours for the
new triple (and any others that come along, with luck). Some choices
were debatable (notably FP == r7 or r11), but we can revisit those
later when deficiencies become apparent.
llvm-svn: 198617
The bkpt mnemonic has an implicit immediate constant of 0 unless otherwise
specified. Add an instruction alias for the unvalued breakpoint mnemonic to
treat it as a 0. This improves compatibility with GNU AS.
Signed-off-by: Saleem Abdulrasool <compnerd@compnerd.org>
llvm-svn: 197913
These are used by MachO only at the moment, and (much like the existing
MOVW/MOVT set) work around the fact that the labels used in the actual
instructions often contain PC-dependent components, which means that repeatedly
materialising the same global can't be CSEed.
With small modifications, it could be adapted to how ELF finds the address of
_GLOBAL_OFFSET_TABLE_, which would give similar benefits in PIC mode there.
llvm-svn: 196090
These are handled almost identically to static mode (and ELF's global address
materialisation), except that a symbol may have "$non_lazy_ptr" appended. This
can be handled by passing appropriate flags along with the instruction instead
of using entirely separate pseudo-instructions.
llvm-svn: 195655
There is no sane way for an LEApcrel (= single ADR) instruction to generate a
global address on any ARM target I know of. Fortunately, no-one was trying to
any more, but there were vestigial patterns.
llvm-svn: 195644
Adds a subtarget feature for the CRC instructions (optional in v8-A) to the ARM (32-bit) backend.
Differential Revision: http://llvm-reviews.chandlerc.com/D2036
llvm-svn: 193599
This prevents us from silently accepting invalid instructions on (for example)
Cortex-M4 with just single-precision VFP support.
No tests for the extra Pat Requires because they're essentially assertions: the
affected code should have been lowered to libcalls before ISel.
rdar://problem/15302004
llvm-svn: 193354
The hint instructions ("nop", "yield", etc) are mostly Thumb2-only, but have
been ported across to the v6M architecture. Fortunately, v6M seems to sit
nicely between v6 (thumb-1 only) and v6T2, so we can add a feature for it
fairly easily.
rdar://problem/15144406
llvm-svn: 192097
This function-attribute modifies the callee-saved register list and function
epilogue (specifically the return instruction) so that a routine is suitable
for use as an interrupt-handler of the specified type without disrupting
user-mode applications.
rdar://problem/14207019
llvm-svn: 191766
The 'Deprecated' class allows you to specify a SubtargetFeature that the
instruction is deprecated on.
The 'ComplexDeprecationPredicate' class allows you to define a custom
predicate that is called to check for deprecation.
For example:
ComplexDeprecationPredicate<"MCR">
would mean you would have to define the following function:
bool getMCRDeprecationInfo(MCInst &MI, MCSubtargetInfo &STI,
std::string &Info)
Which returns 'false' for not deprecated, and 'true' for deprecated
and store the warning message in 'Info'.
The MCTargetAsmParser constructor was chaned to take an extra argument of
the MCInstrInfo class, so out-of-tree targets will need to be changed.
llvm-svn: 190598
These were pretty straightforward instructions, with some assembly support
required for HLT.
The ARM assembler is keen to split the instruction mnemonic into a
(non-existent) 'H' instruction with the LT condition code. An exception for
HLT is needed.
HLT follows the same rules as BKPT when in IT blocks, so the special BKPT
hadling code has been adapted to handle HLT also.
Regression tests added including diagnostic tests for out of range immediates
and illegal condition codes, as well as negative tests for pre-ARMv8.
llvm-svn: 190053
Fix a few things in one swoop.
# Add some negative tests.
# Fix some formatting issues.
# Add some missing IsThumb / ARMv8
# Fix some outs / ins mistakes.
llvm-svn: 189490
I'd forgotten that "Requires" blocks override rather than add to the
constraints, so my pseudo-instruction was being selected in Thumb mode leading
to nonsense instructions.
rdar://problem/14817358
llvm-svn: 189096
Back in the mists of time (2008), it seems TableGen couldn't handle the
patterns necessary to match ARM's CMOV node that we convert select operations
to, so we wrote a lot of fairly hairy C++ to do it for us.
TableGen can deal with it now: there were a few minor differences to CodeGen
(see tests), but nothing obviously worse that I could see, so we should
probably address anything that *does* come up in a localised manner.
llvm-svn: 188995
According to the ARM specification, "mov" is a valid mnemonic for all Thumb2 MOV encodings.
To achieve this, the patch adds one instruction alias with a special range condition to avoid collision with the Thumb1 MOV.
llvm-svn: 188901
After Ulrich's r180677 (thanks!) TableGen is intelligent enough to
handle tied constraints involving complex operands properly, so
virtually all of the ARM custom converters are now unnecessary.
llvm-svn: 186810
A "pkhtb x, x, y asr #num" uses the lower 16 bits of "y asr #num" and packs them
in the bottom half of "x". An arithmetic and logic shift are only equivalent in
this context if the shift amount is 16. We would be shifting in ones into the
bottom 16bits instead of zeros if "y" is negative.
radar://14338767
llvm-svn: 185712
1. it should accept only 4-byte aligned addresses
2. the maximum offset should be 1020
3. it should be encoded with the offset scaled by two bits
llvm-svn: 185528
The mapping between SRS pseudo-instructions and SRS native instructions was incorrect, the correct mapping is:
srsfa -> srsib
srsea -> srsia
srsfd -> srsdb
srsed -> srsda
This fixes <rdar://problem/14214734>.
llvm-svn: 185155
Unfortunately this addresses two issues (by the time I'd disentangled the logic
it wasn't worth putting it back to half-broken):
+ Coprocessor instructions should all be predicable in Thumb mode.
+ BKPT should never be predicable.
llvm-svn: 184965
The cdp2 instruction should have the same restrictions as cdp on the
co-processor registers.
VFP instructions on v8/AArch32 share the same encoding space as cdp2.
llvm-svn: 184445
Handle the case when the disassembler table can't tell
the difference between some encodings of QADD and CPS.
Add some necessary safe guards in CPS decoding as well.
llvm-svn: 183610
"hint" space for Thumb actually overlaps the encoding space of the CPS
instruction. In actuality, hints can be defined as CPS instructions where imod
and M bits are all nil.
Handle decoding of permitted nop-compatible hints (i.e. nop, yield, wfi, wfe,
sev) in DecodeT2CPSInstruction.
This commit adds a proper diagnostic message for Imm0_4 and updates all tests.
Patch by Mihail Popa <Mihail.Popa@arm.com>.
llvm-svn: 180617
The reference manual defines only 5 permitted values for the immediate field of the "hint" instruction:
1. nop (imm == 0)
2. yield (imm == 1)
3. wfe (imm == 2)
4. wfi (imm == 3)
5. sev (imm == 4)
Therefore, restrict the permitted values for the "hint" instruction to 0 through 4.
Patch by Mihail Popa <Mihail.Popa@arm.com>
llvm-svn: 179707
According to the ARM reference manual, constant offsets are mandatory for pre-indexed addressing modes.
The MC disassembler was not obeying this when the offset is 0.
It was producing instructions like: str r0, [r1]!.
Correct syntax is: str r0, [r1, #0]!.
This change modifies the dumping of operands so that the offset is always printed, regardless of its value, when pre-indexed addressing mode is used.
Patch by Mihail Popa <Mihail.Popa@arm.com>
llvm-svn: 179398
These instructions aren't universally available, but depend on a specific
extension to the normal ARM architecture (rather than, say, v6/v7/...) so a new
feature is appropriate.
This also enables the feature by default on A-class cores which usually have
these extensions, to avoid breaking existing code and act as a sensible
default.
llvm-svn: 179171
Reapply r177968:
After commit 178074 we can now have undefined scheduler variants.
Move the CortexA9 resources into the CortexA9 SchedModel namespace. Define
resource mappings under the CortexA9 SchedModel. Define resources and mappings
for the SwiftModel.
Incooperate Andrew's feedback.
llvm-svn: 178460
This reverts commit r177968. It is causing failures in a local build bot.
"fatal error: error in backend: Expected a variant SchedClass"
Original commit message:
Move the CortexA9 resources into the CortexA9 SchedModel namespace. Define
resource mappings under the CortexA9 SchedModel. Define resources and mappings
for the SwiftModel.
llvm-svn: 178028
Move the CortexA9 resources into the CortexA9 SchedModel namespace. Define
resource mappings under the CortexA9 SchedModel. Define resources and mappings
for the SwiftModel.
llvm-svn: 177968
This patch replaces the hard coded GPR pair [R0, R1] of
Intrinsic:arm_ldrexd and [R2, R3] of Intrinsic:arm_strexd with
even/odd GPRPair reg class.
Similar to the lowering of atomic_64 operation.
llvm-svn: 168207
registers. Previously, the register we being marked as implicitly defined, but
not killed. In some cases this would cause the register scavenger to spill a
dead register.
Also, use an empty register mask to simplify the logic and to reduce the memory
footprint.
rdar://12592448
llvm-svn: 167499
into a sbc with a positive number, the immediate should be complemented, not
negated. Also added a missing pattern for ARM codegen.
rdar://12559385
llvm-svn: 166613
This patch corrects the definition of umlal/smlal instructions and adds support
for matching them to the ARM dag combiner.
Bug 12213
Patch by Yin Ma!
llvm-svn: 163136
This wasn't the right way to enforce ordering of atomics.
We are already setting the isVolatile bit on memory operands of atomic
operations which is good enough to enforce the correct ordering.
llvm-svn: 162732
It is not safe to use normal LDR instructions because they may be
reordered by the scheduler. The ATOMIC_LDR pseudos have a mayStore flag
that prevents reordering.
Atomic loads are also prevented from participating in rematerialization
and load folding.
llvm-svn: 162713
It's not clear that they should be marked as such, but tbb formation
fails if t2LEApcrelJT is hoisted of of a loop.
This doesn't change the flags on these instructions,
UnmodeledSideEffects was already inferred from the missing pattern.
llvm-svn: 162603
It is not my plan to duplicate the entire ARM instruction set with
predicated versions. We need a way of representing predicated
instructions in SSA form without requiring a separate opcode.
Then the pseudo-instructions can go away.
llvm-svn: 162061
The ARM select instructions are just predicated moves. If the select is
the only use of an operand, the instruction defining the operand can be
predicated instead, saving one instruction and decreasing register
pressure.
This implementation can turn AND/ORR/EOR instructions into their
corresponding ANDCC/ORRCC/EORCC variants. Ideally, we should be able to
predicate any instruction, but we don't yet support predicated
instructions in SSA form.
llvm-svn: 161994
When predicating this instruction:
Rd = ADD Rn, Rm
We need an extra operand to represent the value given to Rd when the
predicate is false:
Rd = ADDCC Rfalse, Rn, Rm, pred
The Rd and Rfalse operands are different registers while in SSA form.
Rfalse is tied to Rd to make sure they get the same register during
register allocation.
Previously, Rd and Rn were tied, but that is not required.
Compare to MOVCC:
Rd = MOVCC Rfalse, Rtrue, pred
llvm-svn: 161955
This patch corrects the definition of umlal/smlal instructions and adds support
for matching them to the ARM dag combiner.
Bug 12213
Patch by Yin Ma!
llvm-svn: 161581
Function argument registers are added to the call SDNode, but
InstrEmitter now knows how to make those operands implicit, and the call
instruction doesn't have to be variadic.
Explicit register operands should only be those that are encoded in the
instruction, implicit register operands are for extra dependencies like
call argument and return values.
llvm-svn: 160188
There are patterns to handle immediates when they fit in the immediate field.
e.g. %sub = add i32 %x, -123
=> sub r0, r0, #123
Add patterns to catch immediates that do not fit but should be materialized
with a single movw instruction rather than movw + movt pair.
e.g. %sub = add i32 %x, -65535
=> movw r1, #65535
sub r0, r0, r1
rdar://11726136
llvm-svn: 159057
As an example of how the custom DiagnosticType can be used to provide
better operand-mismatch diagnostics, add a custom diagnostic for
the imm0_15 operand class used for several system instructions.
Update the tests to expect the improved diagnostic.
rdar://8987109
llvm-svn: 159051
boolean flag to an enum: { Fast, Standard, Strict } (default = Standard).
This option controls the creation by optimizations of fused FP ops that store
intermediate results in higher precision than IEEE allows (E.g. FMAs). The
behavior of this option is intended to match the behaviour specified by a
soon-to-be-introduced frontend flag: '-ffuse-fp-ops'.
Fast mode - allows formation of fused FP ops whenever they're profitable.
Standard mode - allow fusion only for 'blessed' FP ops. At present the only
blessed op is the fmuladd intrinsic. In the future more blessed ops may be
added.
Strict mode - allow fusion only if/when it can be proven that the excess
precision won't effect the result.
Note: This option only controls formation of fused ops by the optimizers. Fused
operations that are explicitly requested (e.g. FMA via the llvm.fma.* intrinsic)
will always be honored, regardless of the value of this option.
Internally TargetOptions::AllowExcessFPPrecision has been replaced by
TargetOptions::AllowFPOpFusion.
llvm-svn: 158956
This patch adds DAG combines to form FMAs from pairs of FADD + FMUL or
FSUB + FMUL. The combines are performed when:
(a) Either
AllowExcessFPPrecision option (-enable-excess-fp-precision for llc)
OR
UnsafeFPMath option (-enable-unsafe-fp-math)
are set, and
(b) TargetLoweringInfo::isFMAFasterThanMulAndAdd(VT) is true for the type of
the FADD/FSUB, and
(c) The FMUL only has one user (the FADD/FSUB).
If your target has fast FMA instructions you can make use of these combines by
overriding TargetLoweringInfo::isFMAFasterThanMulAndAdd(VT) to return true for
types supported by your FMA instruction, and adding patterns to match ISD::FMA
to your FMA instructions.
llvm-svn: 158757
The NOP, WFE, WFI, SEV and YIELD instructions are all hints w/
a different immediate value in bits [7,0]. Define a generic HINT
instruction and refactor NOP, WFI, WFI, SEV and YIELD to be
assembly aliases of that.
rdar://11600518
llvm-svn: 158674
We turned off the CMN instruction because it had semantics which we weren't
getting correct. If we are comparing with an immediate, then it's okay to use
the CMN instruction.
<rdar://problem/7569620>
llvm-svn: 158302
We handle struct byval by inserting a pseudo op, which will be expanded to a
loop at ExpandISelPseudos.
A separate patch for clang will be submitted to enable struct byval.
rdar://9877866
llvm-svn: 157793
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
llvm-svn: 155499
predicates.
Also remove NEON2 since it's not really useful and it is confusing. If
NEON + VFP4 implies NEON2 but NEON2 doesn't imply NEON + VFP4, what does it
really mean?
rdar://10139676
llvm-svn: 154480
1. The new instruction itinerary entries are not properly described.
2. The asm parser can't handle vfms and vfnms.
3. There were no assembler, disassembler test cases.
4. HasNEON2 has the wrong assembler predicate.
rdar://10139676
llvm-svn: 154456
After register masks were introdruced to represent the call clobbers, it
is no longer necessary to have duplicate instruction for iOS.
llvm-svn: 154209
We had special instructions for iOS because r9 is call-clobbered, but
that is represented dynamically by the register mask operands now, so
there is no need for the pseudo-instructions.
llvm-svn: 154144
A MOVCCr instruction can be commuted by inverting the condition. This
can help reduce register pressure and remove unnecessary copies in some
cases.
<rdar://problem/11182914>
llvm-svn: 154033
In this update:
- I assumed neon2 does not imply vfpv4, but neon and vfpv4 imply neon2.
- I kept setting .fpu=neon-vfpv4 code attribute because that is what the
assembler understands.
Patch by Ana Pazos <apazos@codeaurora.org>
llvm-svn: 152036
the processor keeps a return addresses stack (RAS) which stores the address
and the instruction execution state of the instruction after a function-call
type branch instruction.
Calling a "noreturn" function with normal call instructions (e.g. bl) can
corrupt RAS and causes 100% return misprediction so LLVM should use a
unconditional branch instead. i.e.
mov lr, pc
b _foo
The "mov lr, pc" is issued in order to get proper backtrace.
rdar://8979299
llvm-svn: 151623
