[patch] Thumb-2 Instructio relaxation
Mon Aug 29 16:35:00 GMT 2005
The attached patch implements assembler relaxation for Thumb-2 instructions.
There are two different classes of relaxation performed:
- PC-relative branch, adr and ldr instructions.
- Other (absolute) immediate operands. The current implementation This
currently only knows how to handle literal constants, but I plan on teaching
it how to handle symbolic constants.
I've removed the disassembled insn address matching from thumb32.d because
it's a pain to keep consistent, and doesn't seem to provide any benefit. The
size if the insn is implicitly checked by checking the hex opcode bytes.
Tested with cross to arm-none-eabi.
2005-08-28 Paul Brook <email@example.com>
* config/tc-arm.c (arm_it): Add relax field.
(T16_32_TAB): Add addi, addis, add_pc, add_sp, dec_sp, inc_sp,
b, bcond, ldr_pc, ldr_pc2, ldr_sp, str_sp, subi, subis.
(do_t_add_sub, do_t_addr, do_t_branch, do_t_ldst,
do_t_mov_cmp): Allow relaxation.
(output_relax_insn): New function.
(put_thumb32_insn): New function.
(output_inst): Use new functions.
(md_assemble): Don't throw error on relaxable instructions.
(insns): Change "b" entry from TCE(...) to tCE(...).
(md_estimate_size_before_relax): Return 2.
(md_convert_frag, relax_immediate, relax_adr, relax_addsub,
relax_branch, arm_relax_frag): New functions.
(arm_force_relocation): Return 0 for Thumb-2 immediate operand
* config/tc-arm.h (md_convert_frag): Remove definition.
(arm_relax_frag): Add prototype.
* gas/arm/thumb2_relax.d: New test.
* gas/arm/thumb2_relax.s: New test.
* gas/arm/thumb32.d: Adjust expected results to include relaxation.
* gas/arm/thumb32.s: Tweak for better coverage of relaxable
instructions. Remove load/store tests.
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