replace use of uninitialized variable size in reset_literal_pool

See merge request !15

Fix jmp-shortening on x86 when target within instruction.

See merge request !12

* lightening/x86.c (jit_try_shorten): If the address is within the
  last instruction, don't shorten.  If the intstruction is a jump, we
  could elide it entirely in some cases, but we don't know if the user
  captured the PC before calling jit_patch_here.  Better to leave this
  to the user.

Thanks to Helmut Eller for the bug report and test case in
#17.

Spill whole words to stack, even for uint8_t args

Closes #15

See merge request !11

* lightening/lightening.c (abi_gpr_to_mem): Write whole words when
  spilling GPRs to the stack.  Always correct given that all Lightening
  operations that write GPRs write the whole register, and the current
  ABI targets allow writing the extra words.  Closes #15.

Literal pools have word-alignment, not u64-alignment

See merge request !10

Prevents useless over-alignment for ARM.

* lightening/lightening.c (struct jit_literal_pool_entry): Value is a
  uintptr_t.
  (emit_uintptr): New helper.
  (emit_abs_reloc): Use new helper.
  (patch_pending_literal): Value is a uintptr_t.
  (emit_literal_pool): Adapt to literal entry being uintptr_t.

Allow jit_begin_data to declare max data size

See merge request !9

* lightening.h:
* lightening/lightening.c (jit_begin_data): Add max data size
  parameter.  If nonzero, can allow the JIT to avoid prematurely
  emitting a constant pool.
  (jit_end_data): Allow pending literals.
* tests/jmp_table.c (run_test): Use new API.

Add support for emitting inline data and table switches

See merge request !6

* lightening.h:
* lightening/lightening.c (jit_begin_data, jit_end_data)
  (jit_emit_u8, jit_emit_u16, jit_emit_u32, jit_emit_u64): Add new raw
  data-emitting primitives, bracketed by begin/end so that we can flush
  constant pools first, if needed.
* lightening/lightening.c (struct jit_state): Add new emitting_data
  flag.
  (jit_begin, jit_reset, jit_end): Handle the new flag.
  (emit_abs_reloc): Move here, from x86.c.
* lightening/x86.c (emit_abs_reloc): Remove.
  (jit_try_shorten): Don't shorten if loc == start; could be raw data.
* tests/jmp_table.c: New test.

Ensure tail caller and callee in jmpi test have compatible ABI

See merge request !8

* tests/jmpi.c: Emit the tail callee using the JIT, to ensure that it
  saves and restores registers in the same way as the caller.  Fixes
  #16.

Fix patch_veneer on aarch64

See merge request !7

* lightening/aarch64.c (patch_veneer): Fix absolutely bogus patch_veneer
  implementation.

Dale Smith authored Jun 20, 2020 and civodul committed Jun 20, 2020

This is a followup to 1bb909a4.  It
reproduces the bug that 1bb909a4

 fixes
on ARMv7.

* tests/movi.c: New file.
Co-authored-by: Ludovic Courtès <ludo@gnu.org>

* tests/Makefile (CC_IA32, CC_AARCH64, CC_ARMv7): Remove 'glibc' from
the 'guix environment' command line since it's redundant with
'gcc-toolchain'.

This allows users to run "make TARGETS=armv7", for instance.

* tests/Makefile (TARGETS): Make it overridable.

Andrew Gierth authored Jun 19, 2020 and civodul committed Jun 20, 2020

* lightening/arm-cpu.c (encode_thumb_immediate): Fix return value in
third case.
Signed-off-by: Ludovic Courtès <ludo@gnu.org>

* lightening/lightening.c (jit_patch_there): Conditionally define
  flags.

Fix zeroing of literal pool entries

See merge request !5

* lightening/lightening.c (reset_literal_pool): Zero before setting size
  to 0.  Thanks to Dale Smith for pointing this out!

Fix undefined behavior in ARMv7 assembler

See merge request !4

* lightening/arm-cpu.c (rotate_left): Fix the case of rotating by zero,
  which produced undefined behavior.  Many thanks to Andrew
  Gierth (andrew at tao11 riddles org uk) for the debugging and the
  fix.

Fix armv7 with the ARM instruction set

Closes #12

See merge request !3

With this, Guile builds and runs in both ARM and Thumb mode.

Closes: #12

It is unlikely for any ARM code to be close enough to not have needed
a veneer, but it is possible, especially if running in a program with
another JIT library.

Thanks to the previous commit, the jump targets should all be correct.

This will allow supporting ARM code on armv7 without having to change
any users of Lightening.

This will allow supporting jumping to ARM (as opposed to Thumb) code.

* lightening/x86.c (reset_abi_arg_iterator): Reserve 32 stack bytes on
  64-bit Windows systems, in accordance with ABI.  Thanks a million to
  Charles Stanhope for the patch and to Mike Gran for testing!