Summary:
Previously, we would erroneously turn %pcrel_lo(label), where label has
a %pcrel_hi against a weak symbol, into %pcrel_lo(label + offset), as
evaluatePCRelLo would believe the target independent logic was going to
fold it. Moreover, even if that were fixed, shouldForceRelocation lacks
an MCAsmLayout and thus cannot evaluate the %pcrel_hi fixup to a value
and check the symbol, so we would then erroneously constant-fold the
%pcrel_lo whilst leaving the %pcrel_hi intact. After D72197, this same
sequence also occurs for symbols with global binding, which is triggered
in real-world code.
Instead, as discussed in D71978, we introduce a new FKF_IsTarget flag to
avoid these kinds of issues. All the resolution logic happens in one
place, with no coordination required between RISCAsmBackend and
RISCVMCExpr to ensure they implement the same logic twice. Although the
implementation of %pcrel_hi can be left as target independent, we make
it target dependent to ensure that they are handled identically to
%pcrel_lo, otherwise we risk one of them being constant folded but the
other being preserved. This also allows us to properly support fixup
pairs where the instructions are in different fragments.
Reviewers: asb, lenary, efriedma
Reviewed By: efriedma
Subscribers: arichardson, hiraditya, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, MaskRay, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, s.egerton, pzheng, sameer.abuasal, apazos, luismarques, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D73211
Summary:
Now that llvm-objdump allows target-specific options, we match the
`no-aliases` and `numeric` options for RISC-V, as supported by GNU objdump.
This is done by overriding the variables used for the command-line options, so
that the command-line options are still supported.
This patch updates all tests using `llvm-objdump -riscv-no-aliases` to use
`llvm-objdump -M no-aliases`.
Reviewers: luismarques, asb
Reviewed By: luismarques, asb
Subscribers: pzheng, 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, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D66139
llvm-svn: 371534
The canonical GNU form of JALR resembles a load/store instruction rather
than placing the immediate offset as a separate argument, so match this
behaviour. Also add parser-only aliases for the three-operand form, and
add other shorter aliases also emitted by GNU tools.
Differential Revision: https://reviews.llvm.org/D55277
Patch by James Clarke.
llvm-svn: 366179
Summary:
Useful for jumps, such as `j .`.
I am not sure who should review this. Do not hesitate to change the reviewers if needed.
Reviewers: asb, jrtc27, lenary
Reviewed By: lenary
Subscribers: MaskRay, lenary, hiraditya, rbar, johnrusso, simoncook, apazos, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, psnobl, benna, Jim, llvm-commits
Tags: #llvm
Differential Revision: https://reviews.llvm.org/D63669
Patch by John LLVM (JohnLLVM)
llvm-svn: 365881
This patch allows immediates (and CSR alias immediates) which start with
a tilde token or an exclaim (!) token to be parsed as intended.
Differential Revision: https://reviews.llvm.org/D57320
llvm-svn: 363783
Since the parser attempts to parse an operand as a register with
parentheses before parsing it as an immediate, immediates in
parentheses should not be parsed by parseRegister. However in the case
where the immediate does not start with an identifier, the LParen is not
unlexed and so the RParen causes an unexpected token error.
This patch adds the missing UnLex, and modifies the existing UnLex to
not use a buffered token, as it should always be unlexing an LParen.
Differential Revision: https://reviews.llvm.org/D57319
llvm-svn: 363782
Summary:
Floating-point CSRs should be accessible even when F extension is not enabled.
But pseudo instructions that access floating point CSRs still require the F extension.
GNU tools already implement this behavior. RISC-V spec is pending update to reflect
this behavior and to extend it to pseudo instructions that access floating point CSRs.
Reviewers: asb
Reviewed By: asb
Subscribers: asb, rbar, johnrusso, simoncook, sabuasal, niosHD, kito-cheng, shiva0217, zzheng, edward-jones, rogfer01, MartinMosbeck, brucehoult, the_o, rkruppe, PkmX, jocewei, llvm-commits
Differential Revision: https://reviews.llvm.org/D58932
llvm-svn: 355753
This further improves compatibility with GNU as, allowing input such as the
following to be assembled:
.equ CONST, 0x123456
li a0, CONST
addi a0, a0, %lo(CONST)
.equ CONST, 1
slli a0, a0, CONST
Note that we don't have perfect compatibility with gas, as it will avoid
emitting a relocation in this case:
addi a0, a0, %lo(CONST2)
.equ CONST2, 0x123456
Thanks to Shiva Chen for suggesting a better way to approach this during review.
Differential Revision: https://reviews.llvm.org/D52298
llvm-svn: 350831
This patch adds support for UNIMP in both 32- and 16-bit forms. The 32-bit
form can be seen as a variant of the ECALL/EBREAK/etc. family of instructions.
The 16-bit form is just all zeroes, which isn't a valid RISC-V instruction,
but still follows the 16-bit instruction form (i.e. bits 0-1 != 11).
Until recently unimp was undocumented and supported just by binutils, which
printed unimp for either the 16 or 32-bit form. Both forms are now documented
<https://github.com/riscv/riscv-asm-manual/pull/20> and binutils now supports
c.unimp <https://sourceware.org/ml/binutils-cvs/2018-11/msg00179.html>.
Differential Revision: https://reviews.llvm.org/D54316
Patch by Luís Marques.
llvm-svn: 347988
Examples such as `jal a3`, `j a3` and `jal a3, a3` are accepted by gas
but rejected by LLVM MC. This patch rectifies this. I introduce
RISCVAsmParser::parseJALOffset to ensure that symbol names that coincide with
register names can safely be parsed. This is made a somewhat fiddly due to the
single-operand alias form (see the comment in parseJALOffset for more info).
Differential Revision: https://reviews.llvm.org/D52029
llvm-svn: 342629
addi a0, a0, foo and lw a0, foo(a0) and similar are now rejected. An explicit
%lo and %pcrel_lo modifier is required. This matches gas behaviour.
llvm-svn: 342487
Reject bare symbols and accept only %pcrel_hi(sym) for auipc and %hi(sym) for
lui. Also test valid operand modifiers in rv32i-valid.s.
Note this is slightly stricter than gas, which will accept either %pcrel_hi or
%hi for both lui and auipc.
Differential Revision: https://reviews.llvm.org/D51731
llvm-svn: 342486
Standardise on check lines:
* CHECK-ASM
* CHECK-OBJ
* CHECK-ASM-AND-OBJ
This allows for the addition of tests involving symbol operands, which will
not result in identical instructions in both assembly and disassembled object
output.
This commit doesn't exploit this reworking to increase test coverage of symbol
operands - that will come in a future patch.
llvm-svn: 341546
The instruction makes use of a previously ignored field in the fence
instruction. It is introduced in the version 2.3 draft of the RISC-V
specification after much work by the Memory Model Task Group.
As clarified here <https://github.com/riscv/riscv-isa-manual/issues/186>,
the fence.tso assembler mnemonic does not have operands.
llvm-svn: 334278
This patch switches the default for -riscv-no-aliases to false
and updates all affected MC and CodeGen tests. As recommended in
D41071, MC tests use the canonical instructions and the CodeGen
tests use the aliases.
Additionally, for the f and d instructions with rounding mode,
the tests for the aliased versions are moved and tightened such
that they can actually detect if alias emission is enabled.
(see D40902 for context)
Differential Revision: https://reviews.llvm.org/D41225
Patch by Mario Werner.
llvm-svn: 320797
%lo(), %hi(), and %pcrel_hi() are supported and test cases have been added to
ensure the appropriate fixups and relocations are generated. I've added an
instruction format field which is used in RISCVMCCodeEmitter to, for
instance, tell whether it should emit a lo12_i fixup or a lo12_s fixup
(RISC-V has two 12-bit immediate encodings depending on the instruction
type).
Differential Revision: https://reviews.llvm.org/D23568
llvm-svn: 314389
This Disassembly support allows for 'round-trip' testing, and rv32i-valid.s
has been updated appropriately.
Differential Revision: https://reviews.llvm.org/D23567
llvm-svn: 313486
This patch supports all RV32I instructions as described in the RISC-V manual.
A future patch will add support for pseudoinstructions and other instruction
expansions (e.g. 0-arg fence -> fence iorw, iorw).
Differential Revision: https://reviews.llvm.org/D23566
llvm-svn: 313485
With the addition of RISCVInstPrinter, it is now possible to test the basic
operation of the RISCV MC layer.
Differential Revision: https://reviews.llvm.org/D23564
llvm-svn: 310917
James Clarke