The CGEN support code in opcodes accesses instruction contents using a
couple of functions defined in cgen-opc.c: cgen_get_insn_value and
cgen_put_insn_value. These functions use the "instruction endianness"
in the CPU description to order the read/written bytes.
The process of writing an instruction to the object file is:
a) cgen_put_insn_value ;; Writes out the opcodes.
b) ARCH_cgen_insert_operand
insert_normal
insert_1
cgen_put_insn_value ;; Writes out the bytes of the
;; operand.
Likewise, the process of reading an instruction from the object file
is:
a) cgen_get_insn_value ;; Reads the opcodes.
b) ARCH_cgen_extract_operand
extract_normal
extract_1
cgen_get_insn_value ;; Reads in the bytes of the
;; operand.
As can be seen above, cgen_{get,put}_insn_value are used to both
process the instruction opcodes (the constant fields conforming the
base instruction) and also the values of the instruction operands,
such as immediates.
This is problematic for architectures in which the endianness of
instructions is different to the endianness of data. An example is
BPF, where instructions are always encoded big-endian but the data may
be either big or little.
This patch changes the cgen_{get,put}_insn_value functions in order to
get an extra argument with the endianness to use, and adapts the
existin callers to these functions in order to provide cd->endian or
cd->insn_endian, whatever appropriate. Callers like extract_1 and
insert_1 pass cd->endian (since they are reading/writing operand
values) while callers reading/writing the base instruction pass
cd->insn_endian instead.
A few little adjustments have been needed in some existing CGEN based
ports:
* The BPF assembler uses cgen_put_insn_value. It has been adapted to
pass the new endian argument.
* The mep port has code in mep.opc that uses cgen_{get,put}_insn_value.
It has been adapted to pass the new endianargument. Ditto for a
call in the assembler.
Tested with --enable-targets=all.
Regested in all supported targets.
No regressions.
include/ChangeLog:
2020-06-04 Jose E. Marchesi <jose.marchesi@oracle.com>
* opcode/cgen.h: Get an `endian' argument in both
cgen_get_insn_value and cgen_put_insn_value.
opcodes/ChangeLog:
2020-06-04 Jose E. Marchesi <jose.marchesi@oracle.com>
* cgen-opc.c (cgen_get_insn_value): Get an `endian' argument.
(cgen_put_insn_value): Likewise.
(cgen_lookup_insn): Pass endianness to cgen_{get,put}_insn_value.
* cgen-dis.in (print_insn): Likewise.
* cgen-ibld.in (insert_1): Likewise.
(insert_1): Likewise.
(insert_insn_normal): Likewise.
(extract_1): Likewise.
* bpf-dis.c: Regenerate.
* bpf-ibld.c: Likewise.
* bpf-ibld.c: Likewise.
* cgen-dis.in: Likewise.
* cgen-ibld.in: Likewise.
* cgen-opc.c: Likewise.
* epiphany-dis.c: Likewise.
* epiphany-ibld.c: Likewise.
* fr30-dis.c: Likewise.
* fr30-ibld.c: Likewise.
* frv-dis.c: Likewise.
* frv-ibld.c: Likewise.
* ip2k-dis.c: Likewise.
* ip2k-ibld.c: Likewise.
* iq2000-dis.c: Likewise.
* iq2000-ibld.c: Likewise.
* lm32-dis.c: Likewise.
* lm32-ibld.c: Likewise.
* m32c-dis.c: Likewise.
* m32c-ibld.c: Likewise.
* m32r-dis.c: Likewise.
* m32r-ibld.c: Likewise.
* mep-dis.c: Likewise.
* mep-ibld.c: Likewise.
* mt-dis.c: Likewise.
* mt-ibld.c: Likewise.
* or1k-dis.c: Likewise.
* or1k-ibld.c: Likewise.
* xc16x-dis.c: Likewise.
* xc16x-ibld.c: Likewise.
* xstormy16-dis.c: Likewise.
* xstormy16-ibld.c: Likewise.
gas/ChangeLog:
2020-06-04 Jose E. Marchesi <jose.marchesi@oracle.com>
* cgen.c (gas_cgen_finish_insn): Pass the endianness to
cgen_put_insn_value.
(gas_cgen_md_apply_fix): Likewise.
(gas_cgen_md_apply_fix): Likewise.
* config/tc-bpf.c (md_apply_fix): Pass data endianness to
cgen_put_insn_value.
* config/tc-mep.c (mep_check_ivc2_scheduling): Pass endianness to
cgen_put_insn_value.
cpu/ChangeLog:
2020-06-02 Jose E. Marchesi <jose.marchesi@oracle.com>
* mep.opc (print_slot_insn): Pass the insn endianness to
cgen_get_insn_value.
More nonsense fixing "bugs" with left shifts of signed values. Yes,
the C standard does say this is undefined (and right shifts of signed
values are implementation defined BTW) but in practice there is no
problem with current machines. 1's complement is a thing of the past.
cpu/
* m32c.cpu (f-src32-rn-unprefixed-QI): Shift before inverting.
(f-src32-rn-prefixed-QI, f-dst32-rn-unprefixed-QI): Likewise.
(f-dst32-rn-prefixed-QI): Likewise.
(f-dsp-32-s32): Mask before shifting left.
(f-dsp-48-u32, f-dsp-48-s32): Likewise.
(f-bitbase32-16-s11-unprefixed): Multiply signed field rather than
shifting left.
(f-bitbase32-24-s11-prefixed, f-bitbase32-24-s19-prefixed): Likewise.
(h-gr-SI): Mask before shifting.
opcodes/
* m32c-ibld.c: Regenerate.
There are probably a lot more of these still here.
cpu/
* m32c.cpu (f-dsp-8-u16, f-dsp-8-s16): Rearrange to mask any sign
bits before shifting rather than masking after shifting.
(f-dsp-16-u16, f-dsp-16-s16, f-dsp-32-u16, f-dsp-32-s16): Likewise.
(f-dsp-40-u16, f-dsp-40-s16, f-dsp-48-u16, f-dsp-48-s16): Likewise.
(f-dsp-64-u16, f-dsp-8-s24): Likewise.
(f-bitbase32-16-s19-unprefixed): Avoid signed left shift.
opcodes/
* m32c-ibld.c: Regenerate.
The calculation of the shift amount, used to insert fields into the
instruction buffer, is not correct when the following conditions are all
true:
- CGEN_INT_INSN_P is defined, and true.
- CGEN_INSN_LSB0_P is true
- Total instruction length is greater than the length of a single
instruction word (the instruction is made of multiple words)
- The word offset is non-zero (the field is outside the first word)
When the above conditions are all true, the calculated shift fails to
take account of the total instruction length.
After this commit the calculation of the shift amount is split into two
parts, first we calculate the shift required to get to BIT0 of the word
in which the field lives, then we calculate the shift required to place
the field within the instruction word.
The change in this commit only effects the CGEN_INT_INSN_P defined true
case, but changes the code for both CGEN_INSN_LSB0_P true, and false.
In the case of CGEN_INSN_LSB0_P being false, the code used to say:
shift = total_length - (word_offset + start + length);
Now it says:
shift_to_word = total_length - (word_offset + word_length);
shift_within_word = word_length - start - length;
shift = shift_to_word + shift_within_word;
From which we can see that in all cases the computed shift value should
be unchanged.
In the case of CGEN_INSN_LSB0_P being true, the code used to say:
shift = (word_offset + start + 1) - length;
Now it says:
shift_to_word = total_length - (word_offset + word_length);
shift_within_word = start + 1 - length;
shift = shift_to_word + shift_within_word;
In the case where 'total_length == word_length' AND 'word_offset ==
0' (which indicates an instruction of a single word), we see that the
computed shift value will be unchanged. However, when the total_length
and word_length are different, and the word_offset is non-zero then the
computed shift value will be different (and correct).
opcodes/ChangeLog:
* cgen-ibld.in (insert_normal): Rework calculation of shift.
* epiphany-ibld.c: Regenerate.
* fr30-ibld.c: Regenerate.
* frv-ibld.c: Regenerate.
* ip2k-ibld.c: Regenerate.
* iq2000-ibld.c: Regenerate.
* lm32-ibld.c: Regenerate.
* m32c-ibld.c: Regenerate.
* m32r-ibld.c: Regenerate.
* mep-ibld.c: Regenerate.
* mt-ibld.c: Regenerate.
* or1k-ibld.c: Regenerate.
* xc16x-ibld.c: Regenerate.
* xstormy16-ibld.c: Regenerate.
2005-07-14 Jim Blandy <jimb@redhat.com>
* configure.in: Add cases for Renesas m32c.
* configure: Regenerated.
bfd/ChangeLog:
2005-07-14 Jim Blandy <jimb@redhat.com>
Add support for m32c-*-elf (Renesas m32c and m16c).
* Makefile.am (ALL_MACHINES): Add cpu-m32c.lo.
(ALL_MACHINES_CFILES): Add cpu-m32c.c.
(BFD32_BACKENDS): Add elf32-m32c.lo.
(BFD32_BACKENDS_CFILES): Add elf32-m32c.c.
(cpu-m32c.lo, elf32-m32c.lo): New rules, generated by 'make dep-am'.
* Makefile.in: Regenerated.
* archures.c (bfd_arch_m32c, bfd_mach_m16c, bfd_mach_m32c): New
arch and mach codes.
(bfd_m32c_arch): New arch info object.
(bfd_archures_list): List bfd_m32c_arch.
* bfd-in2.h: Regenerated.
* config.bfd: Add case for the m32c.
* configure.in: Add case for the m32c.
* configure: Regenerated.
* cpu-m32c.c, elf32-m32c.c: New files.
* libbfd.h: Regenerated.
* targets.c (bfd_elf32_m32c_vec): Declare.
(_bfd_target_vector): List bfd_elf32_m32c_vec.
binutils/ChangeLog:
2005-07-14 Jim Blandy <jimb@redhat.com>
* readelf.c: #include "elf/m32c.h"
(guess_is_rela, dump_relocations, get_machine_name): Add cases for
EM_M32C.
* Makefile.am (readelf.o): Update dependencies.
* Makefile.in: Regenerated.
cpu/ChangeLog:
2005-07-14 Jim Blandy <jimb@redhat.com>
* m32c.cpu, m32c.opc: Machine description for the Renesas M32C.
gas/ChangeLog:
2005-07-14 Jim Blandy <jimb@redhat.com>
Add support for the Renesas M32C.
* Makefile.am (CPU_TYPES): List m32c.
(TARGET_CPU_CFILES): List config/tc-m32c.c.
(TARGET_CPU_HFILES): List config/tc-m32c.h.
* configure.in: Add case for m32c.
* configure.tgt: Add cases for m32c and m32c-*-elf.
* configure: Regenerated.
* config/tc-m32c.c, config/tc-m32c.h: New files.
* doc/Makefile.am (CPU_DOCS): Add c-m32c.texi.
* doc/Makefile.in: Regenerated.
* doc/all.texi: Set M32C.
* doc/as.texinfo: Add text for the M32C-specific options and line
comment characters, and refer to c-m32c.texi.
* doc/c-m32c.texi: New file.
include/ChangeLog:
2005-07-14 Jim Blandy <jimb@redhat.com>
* dis-asm.h (print_insn_m32c): New declaration.
include/elf/ChangeLog:
2005-07-14 Jim Blandy <jimb@redhat.com>
Add support for Renesas M32C and M16C.
* common.h (EM_M32C): New machine number.
* m32c.h: New file.
ld/ChangeLog:
2005-07-14 Jim Blandy <jimb@redhat.com>
Add support for the Renesas M32C and M16C.
* Makefile.am (ALL_EMULATIONS): Add eelf32m32c.o.
(eelf32m32c.c): New target.
* Makefile.in: Regenerated.
* configure.tgt: Add case for m32c-*-elf.
* emulparams/elf32m32c.sh: New file.
opcodes/ChangeLog:
2005-07-14 Jim Blandy <jimb@redhat.com>
Add support for the Renesas M32C and M16C.
* m32c-asm.c, m32c-desc.c, m32c-dis.c, m32c-ibld.c, m32c-opc.c: New.
* m32c-desc.h, m32c-opc.h: New.
* Makefile.am (HFILES): List m32c-desc.h and m32c-opc.h.
(CFILES): List m32c-asm.c, m32c-desc.c, m32c-dis.c, m32c-ibld.c,
m32c-opc.c.
(ALL_MACHINES): List m32c-asm.lo, m32c-desc.lo, m32c-dis.lo,
m32c-ibld.lo, m32c-opc.lo.
(CLEANFILES): List stamp-m32c.
(M32C_DEPS): List stamp-m32c, if CGEN_MAINT.
(CGEN_CPUS): Add m32c.
(m32c-asm.c, m32c-desc.c, m32c-dis.c, m32c-ibld.c, m32c-opc.c)
(m32c-desc.h, m32c-opc.h): Depend on M32C_DEPS.
(m32c_opc_h): New variable.
(stamp-m32c, m32c-asm.lo, m32c-desc.lo, m32c-dis.lo, m32c-ibld.lo)
(m32c-opc.lo): New rules.
* Makefile.in: Regenerated.
* configure.in: Add case for bfd_m32c_arch.
* configure: Regenerated.
* disassemble.c (ARCH_m32c): New.
[ARCH_m32c]: #include "m32c-desc.h".
(disassembler) [ARCH_m32c]: Add case for bfd_arch_m32c.
(disassemble_init_for_target) [ARCH_m32c]: Same.
* cgen-ops.h, cgen-types.h: New files.
* Makefile.am (HFILES): List them.
* Makefile.in: Regenerated.
Jose E. Marchesi
Alan Modra
Andrew Burgess
H.J. Lu
DJ Delorie
Doug Evans
Nick Clifton
Jim Blandy