if users don't specific -mattr, the default target-feature come
from IR attribute.
Reviewers: lenary, asb
Reviewed By: lenary, asb
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70837
Only PPC seems to be using it, and only checks some simple cases and
doesn't distinguish between FP. Just switch to using LLT to simplify
use from GlobalISel.
When the "disable-tail-calls" attribute was added, checks were added for
it in various backends. Now this code has proliferated, and it is
something the target is responsible for checking. Move that
responsibility back to the ISels (fast, global, and SD).
There's no major functionality change, except for targets that never
implemented this check.
This LLVM attribute was originally added in
d9699bc7bd (2015).
Reviewers: echristo, MaskRay
Differential Revision: https://reviews.llvm.org/D72118
This has two main effects:
- Optimizes debug info size by saving 221.86 MB of obj file size in a
Windows optimized+debug build of 'all'. This is 3.03% of 7,332.7MB of
object file size.
- Incremental step towards decoupling target intrinsics.
The enums are still compact, so adding and removing a single
target-specific intrinsic will trigger a rebuild of all of LLVM.
Assigning distinct target id spaces is potential future work.
Part of PR34259
Reviewers: efriedma, echristo, MaskRay
Reviewed By: echristo, MaskRay
Differential Revision: https://reviews.llvm.org/D71320
Summary:
Forcing Local Exec TLS requires the use of copy relocations. Copy
relocations need special handling in the runtime linker when being used
against TLS symbols, which is present in glibc, but not in FreeBSD nor
musl, and so cannot be relied upon. Moreover, copy relocations are a
hack that embed the size of an object in the ABI when it otherwise
wouldn't be, and break protected symbols (which are expected to be DSO
local), whilst also wasting space, thus they should be avoided whenever
possible. As discussed in D70398, RISC-V should move away from forcing
Local Exec, and instead use Initial Exec like other targets, with
possible linker relaxation to follow. The RISC-V GCC maintainers also
intend to adopt this more-conventional behaviour (see
https://github.com/riscv/riscv-elf-psabi-doc/issues/122).
Reviewers: asb, MaskRay
Reviewed By: MaskRay
Subscribers: emaste, krytarowski, hiraditya, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, lenary, s.egerton, pzheng, sameer.abuasal, apazos, llvm-commits, bsdjhb
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D70649
Summary: The hook should work for any RISC-V register. Non-allocatable registers
do not need to be reserved, for the remaining the hook will only succeed
if you pass clang the -ffixed-xX flag. This builds upon D67185, which
currently only allows reserving GPRs.
Reviewers: asb, lenary
Reviewed By: lenary
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69130
Summary:
Until this commit, these have lowered to a call to abort().
`llvm.trap()` now lowers to `unimp`, which should trap on all systems.
`llvm.debugtrap()` now lowers to `ebreak`, which is exactly what this
instruction is for.
Reviewers: asb, luismarques
Reviewed By: asb
Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, pzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D69390
Complete fp16 support by ensuring that load extension / truncate store
operations are properly expanded.
Reviewers: asb, lenary
Reviewed By: lenary
Differential Revision: https://reviews.llvm.org/D69246
This adds support for reserving GPRs such that the compiler will not
choose a register for register allocation. The implementation follows
the same design as for AArch64; each reserved register becomes a target
feature and used for getting the reserved registers for a given
MachineFunction. The backend checks that it does not need to write to
any reserved register; if it does a relevant error is generated.
Differential Revision: https://reviews.llvm.org/D67185
LLVM may annotate the function with fastcc if there has only one caller
and there're no other caller out of the module and the function is not
naked or contain variable arguments.
The fastcc functions could pass the arguments by the caller saved registers.
Differential Revision: https://reviews.llvm.org/D68559
llvm-svn: 374857
The new names for FPRs ensure that the Register values within the same class are
enumerated consecutively (the order is determined by the `LessRecordRegister`
function object). Where there were tables mapping between 32- and 64-bit FPRs
(and vice versa) this patch replaces them with Register arithmetic. The
enumeration order between different register classes is expected to continue to
be arbitrary, although it does impact the conversion from the (overloaded) asm
FPR names to Register values, and therefore might require updates to the target
if the sorting algorithm is changed. Static asserts were added to ensure that
changes to the ordering that would impact the current implementation are
detected.
Differential Revision: https://reviews.llvm.org/D67423
llvm-svn: 373096
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: nemanjai, javed.absar, hiraditya, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, s.egerton, pzheng, ychen, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67267
llvm-svn: 371212
Summary:
This is patch is part of a series to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet
Subscribers: jyknight, sdardis, nemanjai, javed.absar, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, PkmX, jocewei, jsji, s.egerton, pzheng, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D67229
llvm-svn: 371200
Summary:
This patch renames functions that takes or returns alignment as log2, this patch will help with the transition to llvm::Align.
The renaming makes it explicit that we deal with log(alignment) instead of a power of two alignment.
A few renames uncovered dubious assignments:
- `MirParser`/`MirPrinter` was expecting powers of two but `MachineFunction` and `MachineBasicBlock` were using deal with log2(align). This patch fixes it and updates the documentation.
- `MachineBlockPlacement` exposes two flags (`align-all-blocks` and `align-all-nofallthru-blocks`) supposedly interpreted as power of two alignments, internally these values are interpreted as log2(align). This patch updates the documentation,
- `MachineFunctionexposes` exposes `align-all-functions` also interpreted as power of two alignment, internally this value is interpreted as log2(align). This patch updates the documentation,
Reviewers: lattner, thegameg, courbet
Subscribers: dschuff, arsenm, jyknight, dylanmckay, sdardis, nemanjai, jvesely, nhaehnle, javed.absar, hiraditya, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, atanasyan, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, Jim, s.egerton, llvm-commits, courbet
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65945
llvm-svn: 371045
The patch fixed the issue that RV64 didn't clear the upper bits
when return complex floating value with lp64 ABI.
float _Complex
complex_add(float _Complex a, float _Complex b)
{
return a + b;
}
RealResult = zero_extend(RealA + RealB)
ImageResult = ImageA + ImageB
Return (RealResult | (ImageResult << 32))
The patch introduces shouldExtendTypeInLibCall target hook to suppress
the AssertZext generation when lowering floating LibCall.
Thanks to Eli's comments from the Bugzilla
https://bugs.llvm.org/show_bug.cgi?id=42820
Differential Revision: https://reviews.llvm.org/D65497
llvm-svn: 370275
Only in public interfaces that have not yet been converted should there remain
registers with unsigned type.
Differential Revision: https://reviews.llvm.org/D66252
llvm-svn: 369114
This allows arguments with the constraint A to be lowered to input nodes
for RISC-V, which implies a memory address stored in a register.
This patch adds the minimal amount of code required to get operands with
the right constraints to compile.
https://reviews.llvm.org/D54296
llvm-svn: 369095
Summary:
Ana Pazos reported a bug where we were not checking that an APInt would
fit into 64-bits before calling `getSExtValue()`. This caused asserts when
compiling large constants, such as i128s, as happens when compiling compiler-rt.
This patch adds a testcase and makes the callback less error-prone.
Reviewers: apazos, asb, luismarques
Reviewed By: luismarques
Subscribers: hiraditya, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66081
llvm-svn: 368572
Summary:
Clang will replace references to registers using ABI names in inline
assembly constraints with references to architecture names, but other
frontends do not. LLVM uses the regular assembly parser to parse inline asm,
so inline assembly strings can contain references to registers using their
ABI names.
This patch adds support for parsing constraints using either the ABI name or
the architectural register name. This means we do not need to implement the
ABI name replacement code in every single frontend, especially those like
Rust which are a very thin shim on top of LLVM IR's inline asm, and that
constraints can more closely match the assembly strings they refer to.
Reviewers: asb, simoncook
Reviewed By: simoncook
Subscribers: hiraditya, rbar, johnrusso, JDevlieghere, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65947
llvm-svn: 368303
Summary:
This is patch is part of a serie to introduce an Alignment type.
See this thread for context: http://lists.llvm.org/pipermail/llvm-dev/2019-July/133851.html
See this patch for the introduction of the type: https://reviews.llvm.org/D64790
Reviewers: courbet, jfb, jakehehrlich
Reviewed By: jfb
Subscribers: wuzish, jholewinski, arsenm, dschuff, nemanjai, jvesely, nhaehnle, javed.absar, sbc100, jgravelle-google, hiraditya, aheejin, kbarton, asb, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, dexonsmith, PkmX, jocewei, jsji, s.egerton, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D65514
llvm-svn: 367828
Summary:
This adds the 'f' inline assembly constraint, as supported by GCC. An
'f'-constrained operand is passed in a floating point register. Exactly
which kind of floating-point register (32-bit or 64-bit) is decided
based on the operand type and the available standard extensions (-f and
-d, respectively).
This patch adds support in both the clang frontend, and LLVM itself.
Reviewers: asb, lewis-revill
Reviewed By: asb
Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, cfe-commits, llvm-commits
Tags: #clang, #llvm
Differential Revision: https://reviews.llvm.org/D65500
llvm-svn: 367403
This adds the required extension to RISC-V's getRegForInlineAsmConstraint
in order to be able to correctly distringuish between the 32 and 64-bit
floating point registers when the generic fX name appears in inlineasm
clobber contraints. It also adds a check to validate that callee saved
floating point registers are only saved in this case when a hard-float
ABI is selected.
Differential Revision: https://reviews.llvm.org/D64751
llvm-svn: 367397
Summary:
There was an error being thrown from isDesirableToCommuteWithShift in
some tests. This was tracked down to the method being called before
legalisation, with an extended value type, not a machine value type.
In the case I diagnosed, the error was only hit with an instruction sequence
involving `i24`s in the add and shift. `i24` is not a Machine ValueType, it is
instead an Extended ValueType which was causing the issue.
I have added a test to cover this case, and fixed the error in the callback.
Reviewers: asb, luismarques
Reviewed By: asb
Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D64425
llvm-svn: 365511
Defines RISCV registers for getExceptionPointerRegister() and
getExceptionSelectorRegister().
Differential Revision: https://reviews.llvm.org/D63411
Patch by Edward Jones.
Modified by Alex Bradbury to add CHECK lines to exception-pointer-register.ll.
llvm-svn: 365301
On RISC-V, the `cycle` CSR holds a 64-bit count of the number of clock
cycles executed by the core, from an arbitrary point in the past. This
matches the intended semantics of `@llvm.readcyclecounter()`, which we
currently leave to the default lowering (to the constant 0).
With this patch, we will now correctly lower this intrinsic to the
intended semantics, using the user-space instruction `rdcycle`. On
64-bit targets, we can directly lower to this instruction.
On 32-bit targets, we need to do more, as `rdcycle` only returns the low
32-bits of the `cycle` CSR. In this case, we perform a custom lowering,
based on the PowerPC lowering, using `rdcycleh` to obtain the high
32-bits of the `cycle` CSR. This custom lowering inserts a new basic
block which detects overflow in the high 32-bits of the `cycle` CSR
during reading (because multiple instructions are required to read). The
emitted assembly matches the suggested assembly in the RISC-V
specification.
Differential Revision: https://reviews.llvm.org/D64125
llvm-svn: 365201
This patch adds lowering for global TLS addresses for the TLS models of
InitialExec, GlobalDynamic, LocalExec and LocalDynamic.
LocalExec support required using a 4-operand add instruction, which uses
the fourth operand to express a relocation on the symbol. The necessary
fixup is emitted when the instruction is emitted.
Differential Revision: https://reviews.llvm.org/D55305
llvm-svn: 363771
Summary:
DAGCombine will normally turn a `(shl (add x, c1), c2)` into `(add (shl x, c2), c1 << c2)`, where `c1` and `c2` are constants. This can be prevented by a callback in TargetLowering.
On RISC-V, materialising the constant `c1 << c2` can be more expensive than materialising `c1`, because materialising the former may take more instructions, and may use a register, where materialising the latter would not.
This patch implements the hook in RISCVTargetLowering to prevent this transform, in the cases where:
- `c1` fits into the immediate field in an `addi` instruction.
- `c1` takes fewer instructions to materialise than `c1 << c2`.
In future, DAGCombine could do the check to see whether `c1` fits into an add immediate, which might simplify more targets hooks than just RISC-V.
Reviewers: asb, luismarques, efriedma
Reviewed By: asb
Subscribers: xbolva00, lebedev.ri, craig.topper, lewis-revill, Jim, hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62857
llvm-svn: 363736
This patch adds support for generating calls through the procedure
linkage table where required for a given ExternalSymbol or GlobalAddress
callee.
Differential Revision: https://reviews.llvm.org/D55304
llvm-svn: 363686
This patch allows lowering of PIC addresses by using PC-relative
addressing for DSO-local symbols and accessing the address through the
global offset table for non-DSO-local symbols.
Differential Revision: https://reviews.llvm.org/D55303
llvm-svn: 363058
This validates and lowers arguments to inline asm nodes which have the
constraints I, J & K, with the following semantics (equivalent to GCC):
I: Any 12-bit signed immediate.
J: Immediate integer zero only.
K: Any 5-bit unsigned immediate.
Differential Revision: https://reviews.llvm.org/D54093
llvm-svn: 363054
Summary:
This allows some integer bitwise operations to instead be performed by
hardware fp instructions. This is correct because the RISC-V spec
requires the F and D extensions to use the IEEE-754 standard
representation, and fp register loads and stores to be bit-preserving.
This is tested against the soft-float ABI, but with hardware float
extensions enabled, so that the tests also ensure the optimisation also
fires in this case.
Reviewers: asb, luismarques
Reviewed By: asb
Subscribers: hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, jrtc27, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D62900
llvm-svn: 362790
When not optimizing for minimum size (-Oz) we custom lower wide shifts
(SHL_PARTS, SRA_PARTS, SRL_PARTS) instead of expanding to a libcall.
Differential Revision: https://reviews.llvm.org/D59477
llvm-svn: 358498
This patch replaces the addition of VK_RISCV_CALL in RISCVMCCodeEmitter by
creating the RISCVMCExpr when tail/call are parsed, or in the codegen case
when the callee symbols are created.
This required adding a new CallSymbol operand to allow only adding
VK_RISCV_CALL to tail/call instructions.
This patch will allow further expansion of parsing and codegen to easily
include PLT symbols which must generate the R_RISCV_CALL_PLT relocation.
Differential Revision: https://reviews.llvm.org/D55560
Patch by Lewis Revill.
llvm-svn: 357396
This patch adds an implementation of a PC-relative addressing sequence to be
used when -mcmodel=medium is specified. With absolute addressing, a 'medium'
codemodel may cause addresses to be out of range. This is because while
'medium' implies a 2 GiB addressing range, this 2 GiB can be at any offset as
opposed to 'small', which implies the first 2 GiB only.
Note that LLVM/Clang currently specifies code models differently to GCC, where
small and medium imply the same functionality as GCC's medlow and medany
respectively.
Differential Revision: https://reviews.llvm.org/D54143
Patch by Lewis Revill.
llvm-svn: 357393
Adds a `seto` pattern expansion. Without it the lowerings of `fcmp one` and
`fcmp ord` would be inefficient due to an unoptimized double negation.
Differential Revision: https://reviews.llvm.org/D59699
llvm-svn: 357378
This patch adds support for the RISC-V hard float ABIs, building on top of
rL355771, which added basic target-abi parsing and MC layer support. It also
builds on some re-organisations and expansion of the upstream ABI and calling
convention tests which were recently committed directly upstream.
A number of aspects of the RISC-V float hard float ABIs require frontend
support (e.g. flattening of structs and passing int+fp for fp+fp structs in a
pair of registers), and will be addressed in a Clang patch.
As can be seen from the tests, it would be worthwhile extending
RISCVMergeBaseOffsets to handle constant pool as well as global accesses.
Differential Revision: https://reviews.llvm.org/D59357
llvm-svn: 357352
The SplitF64 node is used on RV32D to convert an f64 directly to a pair of i32
(necessary as bitcasting to i64 isn't legal). When performed on a ConstantFP,
this will result in a FP load from the constant pool followed by a store to
the stack and two integer loads from the stack (necessary as there is no way
to directly move between f64 FPRs and i32 GPRs on RV32D). It's always cheaper
to just materialise integers for the lo and hi parts of the FP constant, so do
that instead.
llvm-svn: 357341
The RISC-V ISA defines RV32E as an alternative "base" instruction set
encoding, that differs from RV32I by having only 16 rather than 32 registers.
This patch adds basic definitions for RV32E as well as MC layer support
(assembling, disassembling) and tests. The only supported ABI on RV32E is
ILP32E.
Add a new RISCVFeatures::validate() helper to RISCVUtils which can be called
from codegen or MC layer libraries to validate the combination of TargetTriple
and FeatureBitSet. Other targets have similar checks (e.g. erroring if SPE is
enabled on PPC64 or oddspreg + o32 ABI on Mips), but they either duplicate the
checks (Mips), or fail to check for both codegen and MC codepaths (PPC).
Codegen for the ILP32E ABI support and RV32E codegen are left for a future
patch/patches.
Differential Revision: https://reviews.llvm.org/D59470
llvm-svn: 356744
This patch optimizes the emission of a sequence of SELECTs with the same
condition, avoiding the insertion of unnecessary control flow. Such a sequence
often occurs when a SELECT of values wider than XLEN is legalized into two
SELECTs with legal types. We have identified several use cases where the
SELECTs could be interleaved with other instructions. Therefore, we extend the
sequence to include non-SELECT instructions if we are able to detect that the
non-SELECT instructions do not impact the optimization.
This patch supersedes https://reviews.llvm.org/D59096, which attempted to
address this issue by introducing a new SelectionDAG node. Hat tip to Eli
Friedman for his feedback on how to best handle this issue.
Differential Revision: https://reviews.llvm.org/D59355
Patch by Luís Marques.
llvm-svn: 356741
This patch adds proper handling of -target-abi, as accepted by llvm-mc and
llc. Lowering (codegen) for the hard-float ABIs will follow in a subsequent
patch. However, this patch does add MC layer support for the hard float and
RVE ABIs (emission of the appropriate ELF flags
https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md#-file-header).
ABI parsing must be shared between codegen and the MC layer, so we add
computeTargetABI to RISCVUtils. A warning will be printed if an invalid or
unrecognized ABI is given.
Differential Revision: https://reviews.llvm.org/D59023
llvm-svn: 355771
This patch:
* Adds necessary RV64D codegen patterns
* Modifies CC_RISCV so it will properly handle f64 types (with soft float ABI)
Note that in general there is no reason to try to select fcvt.w[u].d rather than fcvt.l[u].d for i32 conversions because fptosi/fptoui produce poison if the input won't fit into the target type.
Differential Revision: https://reviews.llvm.org/D53237
llvm-svn: 352833
This requires a little extra work due tothe fact i32 is not a legal type. When
call lowering happens post-legalisation (e.g. when an intrinsic was inserted
during legalisation). A bitcast from f32 to i32 can't be introduced. This is
similar to the challenges with RV32D. To handle this, we introduce
target-specific DAG nodes that perform bitcast+anyext for f32->i64 and
trunc+bitcast for i64->f32.
Differential Revision: https://reviews.llvm.org/D53235
llvm-svn: 352807
DAGCombiner::visitBITCAST will perform:
fold (bitconvert (fneg x)) -> (xor (bitconvert x), signbit)
fold (bitconvert (fabs x)) -> (and (bitconvert x), (not signbit))
As shown in double-bitmanip-dagcombines.ll, this can be advantageous. But
RV32FD doesn't use bitcast directly (as i64 isn't a legal type), and instead
uses RISCVISD::SplitF64. This patch adds an equivalent DAG combine for
SplitF64.
llvm-svn: 352247
Follow the same custom legalisation strategy as used in D57085 for
variable-length shifts (see that patch summary for more discussion). Although
we may lose out on some late-stage DAG combines, I think this custom
legalisation strategy is ultimately easier to reason about.
There are some codegen changes in rv64m-exhaustive-w-insts.ll but they are all
neutral in terms of the number of instructions.
Differential Revision: https://reviews.llvm.org/D57096
llvm-svn: 352171
The previous DAG combiner-based approach had an issue with infinite loops
between the target-dependent and target-independent combiner logic (see
PR40333). Although this was worked around in rL351806, the combiner-based
approach is still potentially brittle and can fail to select the 32-bit shift
variant when profitable to do so, as demonstrated in the pr40333.ll test case.
This patch instead introduces target-specific SelectionDAG nodes for
SHLW/SRLW/SRAW and custom-lowers variable i32 shifts to them. pr40333.ll is a
good example of how this approach can improve codegen.
This adds DAG combine that does SimplifyDemandedBits on the operands (only
lower 32-bits of first operand and lower 5 bits of second operand are read).
This seems better than implementing SimplifyDemandedBitsForTargetNode as there
is no guarantee that would be called (and it's not for e.g. the anyext return
test cases). Also implements ComputeNumSignBitsForTargetNode.
There are codegen changes in atomic-rmw.ll and atomic-cmpxchg.ll but the new
instruction sequences are semantically equivalent.
Differential Revision: https://reviews.llvm.org/D57085
llvm-svn: 352169
Avoid the infinite loop caused by the target DAG combine converting ANYEXT to
SIGNEXT and the target-independent DAG combine logic converting back to
ANYEXT. Do this by not adding the new node to the worklist.
Committing directly as this definitely doesn't make the problem any worse, and
I intend to follow-up with a patch that avoids this custom combiner logic
altogether and just lowers the i32 operations to a target-specific
SelectionDAG node. This should be easier to reason about and improve codegen
quality in some cases (though may miss out on some later DAG combines).
llvm-svn: 351806
This broke the RISCV build, and even with that fixed, one of the RISCV
tests behaves surprisingly differently with asserts than without,
leaving there no clear test pattern to use. Generally it seems bad for
hte IR to differ substantially due to asserts (as in, an alloca is used
with asserts that isn't needed without!) and nothing I did simply would
fix it so I'm reverting back to green.
This also required reverting the RISCV build fix in r351782.
llvm-svn: 351796
to reflect the new license.
We understand that people may be surprised that we're moving the header
entirely to discuss the new license. We checked this carefully with the
Foundation's lawyer and we believe this is the correct approach.
Essentially, all code in the project is now made available by the LLVM
project under our new license, so you will see that the license headers
include that license only. Some of our contributors have contributed
code under our old license, and accordingly, we have retained a copy of
our old license notice in the top-level files in each project and
repository.
llvm-svn: 351636
In order to support codegen RV64A, this patch:
* Introduces masked atomics intrinsics for atomicrmw operations and cmpxchg
that use the i64 type. These are ultimately lowered to masked operations
using lr.w/sc.w, but we need to use these alternate intrinsics for RV64
because i32 is not legal
* Modifies RISCVExpandPseudoInsts.cpp to handle PseudoAtomicLoadNand64 and
PseudoCmpXchg64
* Modifies the AtomicExpandPass hooks in RISCVTargetLowering to sext/trunc as
needed for RV64 and to select the i64 intrinsic IDs when necessary
* Adds appropriate patterns to RISCVInstrInfoA.td
* Updates test/CodeGen/RISCV/atomic-*.ll to show RV64A support
This ends up being a fairly mechanical change, as the logic for RV32A is
effectively reused.
Differential Revision: https://reviews.llvm.org/D53233
llvm-svn: 351422
As discussed on llvm-dev
<http://lists.llvm.org/pipermail/llvm-dev/2018-December/128497.html>, we have
to be careful when trying to select the *w RV64M instructions. i32 is not a
legal type for RV64 in the RISC-V backend, so operations have been promoted by
the time they reach instruction selection. Information about whether the
operation was originally a 32-bit operations has been lost, and it's easy to
write incorrect patterns.
Similarly to the variable 32-bit shifts, a DAG combine on ANY_EXTEND will
produce a SIGN_EXTEND if this is likely to result in sdiv/udiv/urem being
selected (and so save instructions to sext/zext the input operands).
Differential Revision: https://reviews.llvm.org/D53230
llvm-svn: 350993
This restores support for selecting the SLLW/SRLW/SRAW instructions, which was
removed in rL348067 as the previous patterns made some unsafe assumptions.
Also see the related llvm-dev discussion
<http://lists.llvm.org/pipermail/llvm-dev/2018-December/128497.html>
Ultimately I didn't introduce a custom SelectionDAG node, but instead added a
DAG combine that inserts an AssertZext i5 on the shift amount for an i32
variable-length shift and also added an ANY_EXTEND DAG-combine which will
instead produce a SIGN_EXTEND for an i32 variable-length shift, increasing the
opportunity to safely select SLLW/SRLW/SRAW.
There are obviously different ways of addressing this (a number discussed in
the llvm-dev thread), so I'd welcome further feedback and comments.
Note that there are now some cases in
test/CodeGen/RISCV/rv64i-exhaustive-w-insts.ll where sraw/srlw/sllw is
selected even though sra/srl/sll could be used without any extra instructions.
Given both are semantically equivalent, there doesn't seem a good reason to
prefer one vs the other. Given that would require more logic to still select
sra/srl/sll in those cases, I've left it preferring the *w variants.
Differential Revision: https://reviews.llvm.org/D56264
llvm-svn: 350992
Adds support for the various RISC-V FMA instructions (fmadd, fmsub, fnmsub, fnmadd).
The criteria for choosing whether a fused add or subtract is used, as well as
whether the product is negated or not, is whether some of the arguments to the
llvm.fma.* intrinsic are negated or not. In the tests, extraneous fadd
instructions were added to avoid the negation being performed using a xor
trick, which prevented the proper FMA forms from being selected and thus
tested.
The FMA instruction patterns might seem incorrect (e.g., fnmadd: -rs1 * rs2 -
rs3), but they should be correct. The misleading names were inherited from
MIPS, where the negation happens after computing the sum.
The llvm.fmuladd.* intrinsics still do not generate RISC-V FMA instructions,
as that depends on TargetLowering::isFMAFasterthanFMulAndFAdd.
Some comments in the test files about what type of instructions are there
tested were updated, to better reflect the current content of those test
files.
Differential Revision: https://reviews.llvm.org/D54205
Patch by Luís Marques.
llvm-svn: 349023
DAGTypeLegalizer::PromoteSetCCOperands currently prefers to zero-extend
operands when it is able to do so. For some targets this is more expensive
than a sign-extension, which is also a valid choice. Introduce the
isSExtCheaperThanZExt hook and use it in the new SExtOrZExtPromotedInteger
helper. On RISC-V, we prefer sign-extension for FromTy == MVT::i32 and ToTy ==
MVT::i64, as it can be performed using a single instruction.
Differential Revision: https://reviews.llvm.org/D52978
llvm-svn: 347977
Utilise a similar ('late') lowering strategy to D47882. The changes to
AtomicExpandPass allow this strategy to be utilised by other targets which
implement shouldExpandAtomicCmpXchgInIR.
All cmpxchg are lowered as 'strong' currently and failure ordering is ignored.
This is conservative but correct.
Differential Revision: https://reviews.llvm.org/D48131
llvm-svn: 347914
Mark the FREM SelectionDAG node as Expand, which is necessary in order to
support the frem IR instruction on RISC-V. This is expanded into a library
call. Adds the corresponding test. Previously, this would have triggered an
assertion at instruction selection time.
Differential Revision: https://reviews.llvm.org/D54159
Patch by Luís Marques.
llvm-svn: 346958
A number of intrinsics, such as llvm.sin.f32, would result in a failure to
select. This patch adds expansions for the relevant selection DAG nodes, as
well as exhaustive testing for all f32 and f64 intrinsics.
The codegen for FMA remains a TODO item, pending support for the various
RISC-V FMA instruction variants.
The llvm.minimum.f32.* and llvm.maximum.* tests are commented-out, pending
upstream support for target-independent expansion, as discussed in
http://lists.llvm.org/pipermail/llvm-dev/2018-November/127408.html.
Differential Revision: https://reviews.llvm.org/D54034
Patch by Luís Marques.
llvm-svn: 346034
lowerGlobalAddress, lowerBlockAddress, and insertIndirectBranch contain
overzealous checks for is64Bit. These functions are all safe as-implemented
for RV64.
llvm-svn: 343781
f32 values passed on the stack would previously cause an assertion in
unpackFromMemLoc.. This would only trigger in the presence of the F extension
making f32 a legal type. Otherwise the f32 would be legalized.
This patch fixes that by keeping LocVT=f32 when a float is passed on the
stack. It also adds test coverage for this case, and tests that also
demonstrate lw/sw/flw/fsw will be selected when most profitable. i.e. there is
no unnecessary i32<->f32 conversion in registers.
llvm-svn: 343756
r343712 performed this optimisation during instruction selection. As Eli
Friedman pointed out in post-commit review, implementing this as a DAGCombine
might allow opportunities for further optimisations.
llvm-svn: 343741
There was some duplicated logic for using the LocInfo of a CCValAssign in
order to convert from the ValVT to LocVT or vice versa. Resolve this by
factoring out convertLocVTFromValVT from unpackFromRegLoc. Also rename
packIntoRegLoc to the more appropriate convertValVTToLocVT and call these
helper functions consistently.
llvm-svn: 343737
Introduce a new RISCVExpandPseudoInsts pass to expand atomic
pseudo-instructions after register allocation. This is necessary in order to
ensure that register spills aren't introduced between LL and SC, thus breaking
the forward progress guarantee for the operation. AArch64 does something
similar for CmpXchg (though only at O0), and Mips is moving towards this
approach (see D31287). See also [this mailing list
post](http://lists.llvm.org/pipermail/llvm-dev/2016-May/099490.html) from
James Knight, which summarises the issues with lowering to ll/sc in IR or
pre-RA.
See the [accompanying RFC
thread](http://lists.llvm.org/pipermail/llvm-dev/2018-June/123993.html) for an
overview of the lowering strategy.
Differential Revision: https://reviews.llvm.org/D47882
llvm-svn: 342534
This function is not virtual, it is private and it is not called anywhere. No
regression is introduced by removing it.
I think we can safely remove it.
Differential Revision: https://reviews.llvm.org/D50836
llvm-svn: 340024
- Save/restore only registers that are used.
This includes Callee saved registers and Caller saved registers
(arguments and temporaries) for integer and FP registers.
- If there is a call in the interrupt handler, save/restore all
Caller saved registers (arguments and temporaries) and all FP registers.
- Emit special return instructions depending on "interrupt"
attribute type.
Based on initial patch by Zhaoshi Zheng.
Reviewers: asb
Reviewed By: asb
Subscribers: rkruppe, the_o, MartinMosbeck, brucehoult, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, rogfer01, llvm-commits
Differential Revision: https://reviews.llvm.org/D48411
llvm-svn: 338047
Fences are inserted according to table A.6 in the current draft of version 2.3
of the RISC-V Instruction Set Manual, which incorporates the memory model
changes and definitions contributed by the RISC-V Memory Consistency Model
task group.
Instruction selection failures will now occur for 8/16/32-bit atomicrmw and
cmpxchg operations when targeting RV32IA until lowering for these operations
is added in a follow-on patch.
Differential Revision: https://reviews.llvm.org/D47589
llvm-svn: 334591
This patch adds lowering for atomic fences and relies on AtomicExpandPass to
lower atomic loads/stores, atomic rmw, and cmpxchg to __atomic_* libcalls.
test/CodeGen/RISCV/atomic-* are modelled on the exhaustive
test/CodeGen/PPC/atomics-regression.ll, and will prove more useful once RV32A
codegen support is introduced.
Fence mappings are taken from table A.6 in the current draft of version 2.3 of
the RISC-V Instruction Set Manual, which incorporates the memory model changes
and definitions contributed by the RISC-V Memory Consistency Model task group.
Differential Revision: https://reviews.llvm.org/D47587
llvm-svn: 334590
Summary:
They've been deprecated in favor of UADDO/ADDCARRY or USUBO/SUBCARRY for a while.
Target that uses these opcodes are changed in order to ensure their behavior doesn't change.
Reviewers: efriedma, craig.topper, dblaikie, bkramer
Subscribers: jholewinski, arsenm, jyknight, sdardis, nemanjai, nhaehnle, kbarton, fedor.sergeev, asb, rbar, johnrusso, simoncook, jordy.potman.lists, apazos, sabuasal, niosHD, jrtc27, zzheng, edward-jones, mgrang, atanasyan, llvm-commits
Differential Revision: https://reviews.llvm.org/D47422
llvm-svn: 333748
Summary:
When lowering global address, lower the base as a TargetGlobal first then
create an SDNode for the offset separately and chain it to the address calculation
This optimization will create a DAG where the base address of a global access will
be reused between different access. The offset can later be folded into the immediate
part of the memory access instruction.
With this optimization we generate:
lui a0, %hi(s)
addi a0, a0, %lo(s) ; shared base address.
addi a1, zero, 20 ; 2 instructions per access.
sw a1, 44(a0)
addi a1, zero, 10
sw a1, 8(a0)
addi a1, zero, 30
sw a1, 80(a0)
Instead of:
lui a0, %hi(s+44) ; 3 instructions per access.
addi a1, zero, 20
sw a1, %lo(s+44)(a0)
lui a0, %hi(s+8)
addi a1, zero, 10
sw a1, %lo(s+8)(a0)
lui a0, %hi(s+80)
addi a1, zero, 30
sw a1, %lo(s+80)(a0)
Which will save one instruction per access.
Reviewers: asb, apazos
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, mgrang, apazos, asb, llvm-commits
Differential Revision: https://reviews.llvm.org/D46989
llvm-svn: 332641
The DEBUG() macro is very generic so it might clash with other projects.
The renaming was done as follows:
- git grep -l 'DEBUG' | xargs sed -i 's/\bDEBUG\s\?(/LLVM_DEBUG(/g'
- git diff -U0 master | ../clang/tools/clang-format/clang-format-diff.py -i -p1 -style LLVM
- Manual change to APInt
- Manually chage DOCS as regex doesn't match it.
In the transition period the DEBUG() macro is still present and aliased
to the LLVM_DEBUG() one.
Differential Revision: https://reviews.llvm.org/D43624
llvm-svn: 332240
I'm unable to construct a representative test case that demonstrates the
advantage, but it seems sensible to report accurate target-specific
information regardless.
llvm-svn: 330938
This has no impact on codegen for the current RISC-V unit tests or my small
benchmark set and very minor changes in a few programs in the GCC torture
suite. Based on this, I haven't been able to produce a representative test
program that demonstrates a benefit from isLegalAddressingMode. I'm committing
the patch anyway, on the basis that presenting accurate information to the
target-independent code is preferable to relying on incorrect generic
assumptions.
llvm-svn: 330932
To do this:
1. Change GlobalAddress SDNode to TargetGlobalAddress to avoid legalizer
split the symbol.
2. Change ExternalSymbol SDNode to TargetExternalSymbol to avoid legalizer
split the symbol.
3. Let PseudoCALL match direct call with target operand TargetGlobalAddress
and TargetExternalSymbol.
Differential Revision: https://reviews.llvm.org/D44885
llvm-svn: 330827
Summary:
Specifying assert message with an || operator makes the compiler interpret it
as a bool. Changed it to &&.
Reviewers: asb, apazos
Reviewed By: asb
Subscribers: rbar, johnrusso, simoncook, jordy.potman.lists, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, llvm-commits
Differential Revision: https://reviews.llvm.org/D45660
llvm-svn: 330148
Summary:
According RISC-V ELF psABI specification, base RV32 and RV64 ISAs only
allow 32-bit instruction alignment, but instruction allow to be aligned
to 16-bit boundaries for C-extension.
So we just align to 4 bytes and 2 bytes for C-extension is enough.
Reviewers: asb, apazos
Differential Revision: https://reviews.llvm.org/D45560
Patch by Kito Cheng.
llvm-svn: 329899
Also add double-prevoius-failure.ll which captures a test case that at one
point triggered a compiler crash, while developing calling convention support
for f64 on RV32D with soft-float ABI.
llvm-svn: 329877
fadd.d is required in order to force floating point registers to be used in
test code, as parameters are passed in integer registers in the soft float
ABI.
Much of this patch is concerned with support for passing f64 on RV32D with a
soft-float ABI. Similar to Mips, introduce pseudoinstructions to build an f64
out of a pair of i32 and to split an f64 to a pair of i32. BUILD_PAIR and
EXTRACT_ELEMENT can't be used, as a BITCAST to i64 would be necessary, but i64
is not a legal type.
llvm-svn: 329871
Zakk Chen