[3/4, committed] Opcodes and assembler support for Nios II R2

[Sandra Loosemore <sandra at codesourcery dot com>]

This patch adds the new opcodes, assembler, and disassembler support
for Nios II R2.  This is a pretty gigantic patch, but there isn't a
good way to split it up into pieces.  As a brief roadmap:

The new file include/opcode/nios2r2.h has defines for all the new
instruction formats, fields, and opcodes.  The names are Altera's,
taken from the R2 processor documentation.

The R2 instruction syntax is in the new nios2_r2_opcodes array in
opcodes/nios2-opc.c.  Note that, unlike on some other targets that
support compressed instruction encodings, on Nios II the new 16-bit
CDX instructions are always explicitly designated, and the assembler
doesn't attempt to choose the best encoding automatically based on
command-line flags.  So, the assembly and disassembly implementation
generally still follows the same outline as for the existing R1 code,
driven by a descriptor string for each instruction that uses a letter
to describe the form and encoding of each argument.  There are a whole
pile of new argument descriptor letters (documented in
include/opcode/nios2.h), which require both assembler
(gas/config/tc-nios2.c) and disassembler (opcodes/nios2-dis.c)
support.  Likewise the assembler/disassembler are both extended to
know about the new R2 instruction formats for the argument letters
already used for the R1 instruction subset.

There are some other random bits like support for swapping in the
right instruction tables for the mach variant, mappings for the new R2
fields that are defined as enumerations, branch relaxation support,
handling for the new alignment and padding behavior, etc.

The R2 assembler test cases will be posted as a separate patch.

-Sandra

2015-07-01  Sandra Loosemore  <sandra@codesourcery.com>
	    Cesar Philippidis  <cesar@codesourcery.com>

	gas/
	* config/tc-nios2.c (nios2_min_align): New.
	(nop): Replace with....
	(nop_r1, nop_r2, nop_r2_cdx, nop32, nop16): New.
	(nios2_align): Handle alignment on 2-byte boundaries when CDX
	instructions may be present.
	(s_nios2_align): Adjust reference to nop.
	(CDXBRANCH, IS_CDXBRANCH): New.
	(CDX_UBRANCH_SUBTYPE, CDX_CBRANCH_SUBTYPE): New.
	(nios2_relax_subtype_size): Handle 2-byte CDX branches.
	(nios2_relax_frag): Likewise.
	(md_convert_frag): Handle R2 encodings.
	(nios2_check_overflow): Check that low-order bits are zero
	before applying rightshift from howto.
	(nios2_check_overflow): Correct negative overflow calculation.
	(nios2_diagnose_overflow): Handle signed_immed12_overflow.  Issue
	generic overflow messages for miscellaneous instruction formats.
	(md_apply_fix): Recognize new R2 relocations.  For pc_relative
	relocations, store fixup in *valP.
	(nios2_reglist_mask, nios2_reglist_dir): New.
	(nios2_parse_reglist): New.
	(nios2_parse_base_register): New.
	(nios2_assemble_expression): Handle constant expressions designated
	by BFD_RELOC_NONE.
	(nios2_assemble_reg3): New.
	(nios2_assemble_arg_c): Handle R2 instruction formats.
	(nios2_assemble_arg_d): Likewise.
	(nios2_assemble_arg_s): Likewise.
	(nios2_assemble_arg_t): Likewise.
	(nios2_assemble_arg_D): New.
	(nios2_assemble_arg_S): New.
	(nios2_assemble_arg_T): New.
	(nios2_assemble_arg_i): Handle R2 instruction formats.
	(nios2_assemble_arg_I): New.
	(nios2_assemble_arg_u): Handle R2 instruction formats.
	(nios2_assemble_arg_U): New.
	(nios2_assemble_arg_V): New.
	(nios2_assemble_arg_W): New.
	(nios2_assemble_arg_X): New.
	(nios2_assemble_arg_Y): New.
	(nios2_assemble_arg_o): Handle R2 instruction formats.
	(nios2_assemble_arg_O): New.
	(nios2_assemble_arg_P): New.
	(nios2_assemble_arg_j): Handle R2 instruction formats.
	(nios2_assemble_arg_k): New.
	(nios2_assemble_arg_l): Handle R2 instruction formats.
	(nios2_assemble_arg_m): Likewise.
	(nios2_assemble_arg_M): New.
	(nios2_assemble_arg_N): New.
	(nios2_assemble_arg_e): New.
	(nios2_assemble_arg_f): New.
	(nios2_assemble_arg_g): New.
	(nios2_assemble_arg_h): New.
	(nios2_assemble_arg_R): New.
	(nios2_assemble_arg_B): New.
	(nios2_assemble_args): Handle new argument letters.
	(nios2_consume_arg): Likewise.
	(nios2_translate_pseudo_insn): Avoid dereferencing null pointer
	in error message.
	(nios2_ps_insn_info_structs): Add nop.n.
	(output_ubranch): Handle CDX branches.
	(output_cbranch): Likewise.
	(output_call): Handle R2 encodings.
	(output_movia): Likewise.
	(md_begin): Initialize nios2_min_align.
	(md_assemble): Align to nios2_min_align.  Adjust nios2_min_align
	if a 16-bit instruction is seen.
	(nios2_cons_align): Use appropriate nop pattern.

	include/opcode/
	* nios2.h (enum iw_format_type): Add R2 formats.
	(enum overflow_type): Add signed_immed12_overflow and
	enumeration_overflow for R2.
	(struct nios2_opcode): Document new argument letters for R2.
	(REG_3BIT, REG_LDWM, REG_POP): Define.
	(includes): Include nios2r2.h.
	(nios2_r2_opcodes, nios2_num_r2_opcodes): Declare.
	(nios2_r2_asi_n_mappings, nios2_num_r2_asi_n_mappings): Declare.
	(nios2_r2_shi_n_mappings, nios2_num_r2_shi_n_mappings): Declare.
	(nios2_r2_andi_n_mappings, nios2_num_r2_andi_n_mappings): Declare.
	(nios2_r2_reg3_mappings, nios2_num_r2_reg3_mappings): Declare.
	(nios2_r2_reg_range_mappings, nios2_num_r2_reg_range_mappings):
	Declare.
	* nios2r2.h: New file.

	opcodes/
	* nios2-dis.c (nios2_extract_opcode): New.
	(nios2_disassembler_state): New.
	(nios2_find_opcode_hash): Use mach parameter to select correct
	disassembler state.
	(nios2_print_insn_arg): Extend to support new R2 argument letters
	and formats.
	(print_insn_nios2): Check for 16-bit instruction at end of memory.
	* nios2-opc.c (nios2_builtin_regs): Add R2 register attributes.
	(NIOS2_NUM_OPCODES): Rename to...
	(NIOS2_NUM_R1_OPCODES): This.
	(nios2_r2_opcodes): New.
	(NIOS2_NUM_R2_OPCODES): New.
	(nios2_num_r2_opcodes): New.
	(nios2_r2_asi_n_mappings, nios2_num_r2_asi_n_mappings): New.
	(nios2_r2_shi_n_mappings, nios2_num_r2_shi_n_mappings): New.
	(nios2_r2_andi_n_mappings, nios2_num_r2_andi_n_mappings): New.
	(nios2_r2_reg3_mappings, nios2_num_r2_reg3_mappings): New.
	(nios2_r2_reg_range_mappings, nios2_num_r2_reg_range_mappings):	New.

Attachment: binutils-nios2r2-3.patch.gz
Description: GNU Zip compressed data