gas/
* config/tc-riscv.c (riscv_frag_align_code): New local insn_alignment.
Early return if bytes less than or equal to insn_alignment.
* testsuite/gas/riscv/align-1.l: New.
* testsuite/gas/riscv/align-1.s: New.
* testsuite/gas/riscv/riscv.exp: Use run_dump_tests. Use run_list_test
for align-1.
This fixes some EH failures for the medany code model in the g++ testsuite.
The problem is that the assembler is computing some values in the eh_frame
section as constants, that instead should have had relocs to be resolved by
the linker. This happens in output_cfi_insn in the DW_CFA_advance_loc case
where it compares label frags and immediately simplifies if they are the
same. We can fix that by forcing a new frag after every instruction
that the linker can reduce in size. I've also added a testcase to verify
the fix. This was tested with binutils make check, and gcc/g++ make checks on
qemu for medlow and medany code models.
gas/
* config/tc-riscv.c (append_insn): Call frag_wane and frag_new at
end for linker optimizable relocs.
* testsuite/gas/riscv/eh-relocs.d: New.
* testsuite/gas/riscv/eh-relocs.s: New.
* testsuite/gas/riscv/riscv.exp: Run eh-relocs test.
The RISC-V privileged ISA changed the name of sptbr (Supervisor Page
Table Base Register) to satp (Supervisor Address Translation and
Protection) to reflect the fact it could be used for more than just
paging. This patch adds an alias, as they're the same register.
include/ChangeLog
2017-11-06 Palmer Dabbelt <palmer@dabbelt.com>
* opcode/riscv-opc.h (sptbr): Rename to satp.
(CSR_SPTBR): Rename to CSR_SATP.
(sptbr): Alias to CSR_SATP.
gas/ChangeLog
2017-11-06 Palmer Dabbelt <palmer@dabbelt.com>
* testsuite/gas/riscv/satp.d: New test.
testsuite/gas/riscv/satp.s: Likewise.
testsuite/gas/riscv/riscv.exp: Likewise.
config/tc-riscv.c (md_begin): Handle CSR aliases.
Systems without the C extension mandate 4-byte alignment for
instructions, so there is no reason to allow for 2-byte alignment. This
change avoids emitting lots of unimplemented instructions into object
files on non-C targets, which users keep reporting as a bug. While this
isn't actually a bug (as none of the offsets in object files are
relevant until RISC-V), it is ugly.
gas/ChangeLog
2017-10-23 Palmer Dabbelt <palmer@dabbelt.com>
* config/tc-riscv.c (riscv_frag_align_code): Align code by 4
bytes on non-RVC systems.
In the medany code model the compiler generates PCREL_HI20+PCREL_LO12
relocation pairs against local symbols because HI20+LO12 relocations
can't reach high addresses. We relax HI20+LO12 pairs to GPREL
relocations when possible, which is an important optimization for
Dhrystone. Without this commit we are unable to relax
PCREL_HI20+PCREL_LO12 pairs to GPREL when possible, causing a 10%
permormance hit on Dhrystone on Rocket.
Note that we'll now relax
la gp, __global_pointer$
to
mv gp, gp
which probably isn't what you want in your entry code. Users who want
gp-relative symbols to continue to resolve should add ".option norelax"
accordingly. Due to this, the assembler now pairs PCREL relocations
with RELAX relocations when they're expected to be relaxed just like
every other relaxable relocation.
bfd/ChangeLog
2017-10-19 Palmer Dabbelt <palmer@dabbelt.com>
* elfnn-riscv.c (riscv_pcgp_hi_reloc): New structure.
(riscv_pcgp_lo_reloc): Likewise.
(riscv_pcgp_relocs): Likewise.
(riscv_init_pcgp_relocs): New function.
(riscv_free_pcgp_relocs): Likewise.
(riscv_record_pcgp_hi_reloc): Likewise.
(riscv_record_pcgp_lo_reloc): Likewise.
(riscv_delete_pcgp_hi_reloc): Likewise.
(riscv_use_pcgp_hi_reloc): Likewise.
(riscv_record_pcgp_lo_reloc): Likewise.
(riscv_find_pcgp_lo_reloc): Likewise.
(riscv_delete_pcgp_lo_reloc): Likewise.
(_bfd_riscv_relax_pc): Likewise.
(_bfd_riscv_relax_section): Handle R_RISCV_PCREL_* relocations
via the new functions above.
gas/ChangeLog
2017-10-19 Palmer Dabbelt <palmer@dabbelt.com>
* config/tc-riscv.c (md_apply_fix): Mark
BFD_RELOC_RISCV_PCREL_HI20 as relaxable when relaxations are
enabled.
When linking the following code
.global _prog_start
_prog_start:
mv x1, x1
mv x2, x2
.align 2
rvc_boundry:
.option norvc
.align 3
mv x3, x3
we currently emit an invalid two-byte 0 instruction. The actual output
code looks like
0000000080000000 <_prog_start>:
80000000: 8086 mv ra,ra
80000002: 810a mv sp,sp
0000000080000004 <rvc_boundry>:
80000004: 0000 unimp
80000006: 0001 nop
80000008: 00018193 mv gp,gp
This ends up manifesting due to the two-byte compressed NOP that's
pessimisticly emitted by the ".align 2", which results in "rvc_boundry"
being 2-byte aligned. frag_align_code() then goes and outputs a 2-byte
NOP (which is invalid in no-RVC mode) to align the code back to a 4-byte
boundry, which can't be relaxed away by the linker as it's not part of
the R_RISCV_RELAX relocation.
The fix is to just always emit the worst case possible alignment into
the output as a single R_RISCV_RELAX, which the linker will then fix up.
With this patch I get the expected code generation
0000000080000000 <_prog_start>:
80000000: 8086 mv ra,ra
80000002: 810a mv sp,sp
0000000080000004 <rvc_boundry>:
80000004: 00000013 nop
80000008: 00018193 mv gp,gp
gas/ChangeLog
2017-09-07 Palmer Dabbelt <palmer@dabbelt.com>
* config/tc-riscv.c (riscv_frag_align_code): Emit the entire
alignment sequence inside R_RISCV_ALIGN.
The symbol address in .eh_frame may be adjusted in
_bfd_elf_discard_section_eh_frame, and the content of .eh_frame will be
adjusted in _bfd_elf_write_section_eh_frame. Therefore, we cannot insert
a relocation whose addend symbol is in .eh_frame. Othrewise, the value
may be adjusted twice.
bfd/ChangeLog
2017-06-26 Kuan-Lin Chen <rufus@andestech.com>
* elfnn-riscv.c (perform_relocation): Support the new
R_RISCV_32_PCREL relocation.
(riscv_elf_relocate_section): Likewise.
* elfxx-riscv.c (howto_table): Likewise.
(riscv_reloc_map): Likewise.
* bfd-in2.h (BFD_RELOC_RISCV_32_PCREL): New relocation.
* libbfd.h: Regenerate.
gas/ChangeLog
2017-06-26 Kuan-Lin Chen <rufus@andestech.com>
* config/tc-riscv.c (md_apply_fix) [BFD_RELOC_32]: Convert to a
R_RISCV_32_PCREL relocation.
include/ChangeLog
2017-06-26 Kuan-Lin Chen <rufus@andestech.com>
* elf/riscv.h (R_RISCV_32_PCREL): New.
Without this patch, passing "-march=rv64ic -march=rv64i" results in
you getting a "RV64IC" toolchain, which isn't expected.
gas/ChangeLog:
2017-03-30 Palmer Dabbelt <palmer@dabbelt.com>
* config/tc-riscv.c (riscv_clear_subsets): New function.
(riscv_add_subset): Call riscv_clear_subsets and riscv_set_rvc to
clear RVC when it's been previously set.
It looks like I missed the GAS help text when going through all the
documentation last time, so it printed some of the old-format (never
upstream) arguments. I fixed this, and when I went to check doc/ I
noticed it was missing the '-fpic'/'-fno-pic' options.
- They can accept 0 in imm field
2017-03-14 Kito Cheng <kito.cheng@gmail.com>
* riscv-opc.c (riscv_opcodes> <c.li>: Use the 'o' immediate encoding.
<c.andi>: Likewise.
<c.addiw> Likewise.
gas/ChangeLog:
2017-03-02 Kuan-Lin Chen <rufus@andestech.com>
* config/tc-riscv.c (md_apply_fix): Set fx_frag and
fx_next->fx_frag for CFA_advance_loc relocations.
Previously, some pseudoinstructions like "call" only accepted
symbolic addresses and rejected constant addresses with an
esoteric internal error. This patch enables them by deferring
application of constant relocations to md_apply_fix, rather than
eagerly applying them during instruction assembly.
gas/ChangeLog
2017-01-09 Andrew Waterman <andrew@sifive.com>
* config/tc-riscv.c (append_insn): Don't eagerly apply relocations
against constants.
(md_apply_fix): Mark relocations against constants as "done."
TLS relocs against constants previously segfaulted, and illegal
symbol subtractions were silently ignored.
The previous behavior was to segfault.
gas/ChangeLog
2017-01-09 Andrew Waterman <andrew@sifive.com>
* config/tc-riscv.c (md_apply_fix): Report TLS relocations against
constants. Report disallowed symbol subtractions.
gas * config/tc-riscv.c (riscv_set_arch): Whitelist the "q" ISA
extension.
(riscv_after_parse_args): Set FLOAT_ABI_QUAD when the Q ISA is
enabled and no other ABI is specified.
include * opcode/riscv-opc.h: Add support for the "q" ISA extension.
opcodes * riscv-opc.c (riscv-opcodes): Add support for the "q" ISA
extension.
* riscv-opcodes/all-opcodes: Likewise.
Previously, the alignment directives were not correctly supported
in the text section when current alignment was only 1 byte (i.e.,
when the address was odd). Since there are no 1-byte instructions
in RISC-V, this patch resolves the bug by writing a zero byte to
obtain 2-byte alignment, at which point a 2-byte NOP can be used
to obtain 4-byte alignment.
Resolves https://github.com/riscv/riscv-gnu-toolchain/issues/205
* config/tc-riscv.c (riscv_make_nops): Emit 2-byte NOPs.
(riscv_frag_align_code): Correct frag_align_code arg.
We've decided to standardize on two flags for RISC-V: "-march" sets the
target architecture (which determines which instructions can be
generated), and "-mabi" sets the target ABI. We needed to rework this
because the old flag set didn't support soft-float or single-float ABIs,
and didn't support an x32-style ABI on RISC-V.
Additionally, we've changed the behavior of the -march flag: it's now a
lot stricter and only parses things we can actually understand.
Additionally, it's now lowercase-only: the rationale is that while the
RISC-V ISA manual specifies that ISA strings are case-insensitive, in
Linux-land things are usually case-sensitive. Since this flag can be
used to determine library paths, we didn't want to bake some
case-insensitivity in there that would case trouble later.
This patch implements these two new flags and removes the old flags that
could conflict with these. There wasn't a RISC-V release before, so we
want to just support a clean flag set.
include/
* elf/riscv.h (EF_RISCV_SOFT_FLOAT): Don't define.
(EF_RISCV_FLOAT_ABI, EF_RISCV_FLOAT_ABI_SOFT): Define.
(EF_RISCV_FLOAT_ABI_SINGLE, EF_RISCV_FLOAT_ABI_DOUBLE): Define.
(EF_RISCV_FLOAT_ABI_QUAD): Define.
bfd/
* elfnn-riscv.c (_bfd_riscv_elf_merge_private_bfd_data): Use
EF_RISCV_FLOAT_ABI_SOFT instead of EF_RISCV_SOFT_FLOAT.
binutils/
* readelf.c (get_machine_flags): Use
EF_RISCV_FLOAT_ABI_{SOFT,SINGLE,DOBULE,QUAD) instead of
EF_RISCV_{SOFT,HARD}_FLOAT.
gas/
* config/tc-riscv.h (xlen): Delete.
* config/tc-riscv.c (xlen): Make static.
(abi_xlen): New variable.
(options): Replace OPTION_{M32,M64,MSOFT_FLOAT,MHARD_FLOAT,MRVC}
with OPTION_MABI.
(md_longopts): Likewise.
(md_parse_option): Likewise.
(riscv_elf_final_processing): Likewise.
* doc/as.texinfo (Target RISC-V options): Likewise.
* doc/c-riscv.texi (OPTIONS): Likewise.
* config/tc-riscv.c (float_mode): Removed.
(float_abi): New type, specifies the floating-point ABI.
(riscv_set_abi): New function.
(riscv_add_subset): Only allow lower-case ISA names and require
them to start with "rv".
(riscv_after_parse_args): Likewise.
opcodes/
* riscv-dis.c (riscv_disassemble_insn): Default to the ELF's
XLEN when none is provided.
Before this commit we didn't cleanly support CFI directives because the
internal offsets used to get relaxed which broke them. This patch
significantly reworks how we handle linker relaxations:
* DWARF is now properly supported
* There is a ".option norelax" to disable relaxations, for when users
write assembly that can't be relaxed (if it's to be later patched up,
for example).
* There is an additional _RELAX relocation that specifies when previous
relocations can be relaxed.
We're in the process of documenting the RISC-V ELF ABI, which will
include documentation of our relocations
https://github.com/riscv/riscv-elf-psabi-doc/blob/master/riscv-elf.md
but we expect that this relocation set will remain ABI compatible in the
future (ie, it's safe to release).
Thanks to Kuan-Lin Chen for figuring out how to correctly relax the
debug info!
include/
* elf/riscv.h: Add R_RISCV_TPREL_I through R_RISCV_SET32.
bfd/
* reloc.c (BFD_RELOC_RISCV_TPREL_I): New relocation.
(BFD_RELOC_RISCV_TPREL_S): Likewise.
(BFD_RELOC_RISCV_RELAX): Likewise.
(BFD_RELOC_RISCV_CFA): Likewise.
(BFD_RELOC_RISCV_SUB6): Likewise.
(BFD_RELOC_RISCV_SET8): Likewise.
(BFD_RELOC_RISCV_SET8): Likewise.
(BFD_RELOC_RISCV_SET16): Likewise.
(BFD_RELOC_RISCV_SET32): Likewise.
* elfnn-riscv.c (perform_relocation): Handle the new
relocations.
(_bfd_riscv_relax_tls_le): Likewise.
(_bfd_riscv_relax_align): Likewise.
(_bfd_riscv_relax_section): Likewise.
(howto_table): Likewise.
(riscv_reloc_map): Likewise.
(relax_func_t): New type.
(_bfd_riscv_relax_call): Add reserve_size argument, which
controls the maximal offset pessimism. Correct type of max_alignment.
(_bfd_riscv_relax_lui): Likewise.
(_bfd_riscv_relax_tls_le): Likewise.
(_bfd_riscv_relax_align): Likewise.
(_bfd_riscv_relax_section): Compute the required reserve size
when relocating and use it to when calling relax_func.
* bfd-in2.h: Regenerate.
* libbfd.h: Likewise.
gas/
* config/tc-riscv.c (riscv_set_options): Add relax.
(riscv_opts): Likewise.
(s_riscv_option): Add relax and norelax.
(riscv_apply_const_reloc): New function.
(append_insn): Move constant relocation handling to
riscv_apply_const_reloc.
(md_pcrel_from): Likewise.
(parse_relocation): Skip BFD_RELOC_UNUSED.
(md_pcrel_from): Handle BFD_RELOC_RISCV_SUB6,
BFD_RELOC_RISCV_RELAX, BFD_RELOC_RISCV_CFA.
(md_apply_fix): Likewise.
(riscv_pre_output_hook): New function.
* config/tc-riscv.h (md_pre_output_hook): Define.
(riscv_pre_output_hook): Declare.
(DWARF_CIE_DATA_ALIGNMENT): Always -4.
This is a mixed bag of format changes:
* Replacing constants with macros (0xffffffff with MINUS_ONE, for
example). There's one technically functional change in here (some
MINUS_ONEs are changed to 0), but it only changes the behavior of an
otherwise-unused field.
* Using 0 instead of 0x0 in the relocation table.
* There were some missing spaces before parens, the spaces have been
added.
* A handful of comments are now more descriptive.
* A bunch of whitespace-only changes, mostly alignment and brace
newlines.
bfd/
* elfnn-riscv.c: Formatting and comment fixes throughout.
* elfxx-riscv.c: Likewise.
(howto_table): Change the src_mask field from MINUS_ONE to 0 for
R_RISCV_TLS_DTPMOD32, R_RISCV_TLS_DTPMOD64, R_RISCV_TLS_DTPREL32,
R_RISCV_TLS_DTPREL64, R_RISCV_TLS_TPREL32, R_RISCV_TLS_TPREL64.
opcodes/
* riscv-opc.c: Formatting fixes.
gas/
* config/tc-riscv.c: Formatting and comment fixes throughout.
