[arm] Thumb-2 merge

Mon Dec 11 22:45:00 GMT 2006

The attached patch merges ARM Thumb-2 support from sourcerygxx-4_1 branch to 
mainline.

Thumb-2 is a superset of the existing Thumb-1 instruction set that adds 32-bit 
instruction encodings. The end result has approximately the same 
functionality as ARM mode. For this reason gcc treats it as a third mode, 
rather than trying to extend Thumb mode.

The existing -mthumb option is used to select both Thumb-1 and Thumb-2, 
depending on the CPU/Architecture selected.

To facilitate using the same assembly for both ARM and Thumb-2 there is a 
new "Unified" assembly syntax.  However this is only supported by relatively 
new gas. gcc generates Unified syntax when generating Thumb-2 code, and the 
old legacy syntax when targeting ARM and Thumb-1.

- Conditional execution happens via an additional "If Then" instruction, which 
causes a subsequent block of instructions to be conditionally executed. We 
hide this from the compiler and pretend we have normal conditional execution. 
Then output IT insns into the assembly stream at the last minute.
- Some variants have integer division instructions.
- Tablejump instructions with compact offset encodings for switch statements.
- Slightly different constant and address offset ranges compared to ARM mode.
- A System model that allows use of C routines as interrupt handlers. However 
due to issues with early hardware revisions these need to be able to cope 
with a misaligned stack.
- Hardware exists that only implements Thumb-2 mode. This means armv7/Thumb-2 
libgcc must not contain ARM assembly.
- Coprocessor instructions (eg. VFP) are included in Thumb-2.

Tested on arm-linux-gnueabi and arm-none-eabi with an armv7 multilib, and 
checked that arm-elf/binutils2.15 still builds.

The merge was mostly straight forward, just a few new Thumb-1 patters that 
needed updating. All changes are within config/arm.

I'll apply this patch in a few of days if noone objects.

Paul

2006-12-06  Paul Brook  <paul@codesourcery.com>

	Merge from sourcerygxx-4_1.
	* config/arm/thumb2.md: New file.
	* config/arm/elf.h (JUMP_TABLES_IN_TEXT_SECTION): Return True for
	Thumb-2.
	* config/arm/coff.h (JUMP_TABLES_IN_TEXT_SECTION): Ditto.
	* config/arm/aout.h (ASM_OUTPUT_ADDR_VEC_ELT): Add !Thumb-2 assertion.
	(ASM_OUTPUT_ADDR_DIFF_ELT): Output Thumb-2 jump tables.
	* config/arm/aof.h (ASM_OUTPUT_ADDR_DIFF_ELT): Output Thumb-2 jump
	tables.
	(ASM_OUTPUT_ADDR_VEC_ELT): Add !Thumb-2 assertion.
	* config/arm/ieee754-df.S: Use macros for Thumb-2/Unified asm
	comptibility.
	* config/arm/ieee754-sf.S: Ditto.
	* config/arm/arm.c (thumb_base_register_rtx_p): Rename...
	(thumb1_base_register_rtx_p): ... to this.
	(thumb_index_register_rtx_p): Rename...
	(thumb1_index_register_rtx_p): ... to this.
	(thumb_output_function_prologue): Rename...
	(thumb1_output_function_prologue): ... to this.
	(thumb_legitimate_address_p): Rename...
	(thumb1_legitimate_address_p): ... to this.
	(thumb_rtx_costs): Rename...
	(thumb1_rtx_costs): ... to this.
	(thumb_compute_save_reg_mask): Rename...
	(thumb1_compute_save_reg_mask): ... to this.
	(thumb_final_prescan_insn): Rename...
	(thumb1_final_prescan_insn): ... to this.
	(thumb_expand_epilogue): Rename...
	(thumb1_expand_epilogue): ... to this.
	(arm_unwind_emit_stm): Rename...
	(arm_unwind_emit_sequence): ... to this.
	(thumb2_legitimate_index_p, thumb2_legitimate_address_p,
	thumb1_compute_save_reg_mask, arm_dwarf_handle_frame_unspec,
	thumb2_index_mul_operand, output_move_vfp, arm_shift_nmem,
	arm_save_coproc_regs, thumb_set_frame_pointer, arm_print_condition,
	thumb2_final_prescan_insn, thumb2_asm_output_opcode, arm_output_shift,
	thumb2_output_casesi): New functions.
	(TARGET_DWARF_HANDLE_FRAME_UNSPEC): Define.
	(FL_THUMB2, FL_NOTM, FL_DIV, FL_FOR_ARCH6T2, FL_FOR_ARCH7,
	FL_FOR_ARCH7A, FL_FOR_ARCH7R, FL_FOR_ARCH7M, ARM_LSL_NAME,
	THUMB2_WORK_REGS): Define.
	(arm_arch_notm, arm_arch_thumb2, arm_arch_hwdiv, arm_condexec_count,
	arm_condexec_mask, arm_condexec_masklen)): New variables.
	(all_architectures): Add armv6t2, armv7, armv7a, armv7r and armv7m.
	(arm_override_options): Check new CPU capabilities.
	Set new architecture flag variables.
	(arm_isr_value): Handle v7m interrupt functions.
	(user_return_insn): Return 0 for v7m interrupt functions.  Handle
	Thumb-2.
	(const_ok_for_arm): Handle Thumb-2 constants.
	(arm_gen_constant): Ditto.  Use movw when available.
	(arm_function_ok_for_sibcall): Return false for v7m interrupt
	functions.
	(legitimize_pic_address, arm_call_tls_get_addr): Handle Thumb-2.
	(thumb_find_work_register, arm_load_pic_register,
	legitimize_tls_address, arm_address_cost, load_multiple_sequence,
	emit_ldm_seq, emit_stm_seq, arm_select_cc_mode, get_jump_table_size,
	print_multi_reg, output_mov_long_double_fpa_from_arm,
	output_mov_long_double_arm_from_fpa, output_mov_double_fpa_from_arm,
	output_mov_double_fpa_from_arm, output_move_double,
	arm_compute_save_reg_mask, arm_compute_save_reg0_reg12_mask,
	output_return_instruction, arm_output_function_prologue,
	arm_output_epilogue, arm_get_frame_offsets, arm_regno_class,
	arm_output_mi_thunk, thumb_set_return_address): Ditto.
	(arm_expand_prologue): Handle Thumb-2.  Use arm_save_coproc_regs.
	(arm_coproc_mem_operand): Allow POST_INC/PRE_DEC.
	(arithmetic_instr, shift_op): Use arm_shift_nmem.
	(arm_print_operand): Use arm_print_condition.  Handle '(', ')', '.',
	'!' and 'L'.
	(arm_final_prescan_insn): Use extract_constrain_insn_cached.
	(thumb_expand_prologue): Use thumb_set_frame_pointer.
	(arm_file_start): Output directive for unified syntax.
	(arm_unwind_emit_set): Handle stack alignment instruction.
	* config/arm/lib1funcs.asm: Remove default for __ARM_ARCH__.
	Add v6t2, v7, v7a, v7r and v7m.
	(RETLDM): Add Thumb-2 code.
	(do_it, shift1, do_push, do_pop, COND, THUMB_SYNTAX): New macros.
	* config/arm/arm.h (TARGET_CPU_CPP_BUILTINS): Define __thumb2__.
	(TARGET_THUMB1, TARGET_32BIT, TARGET_THUMB2, TARGET_DSP_MULTIPLY,
	TARGET_INT_SIMD, TARGET_UNIFIED_ASM, ARM_FT_STACKALIGN, IS_STACKALIGN,
	THUMB2_TRAMPOLINE_TEMPLATE, TRAMPOLINE_ADJUST_ADDRESS,
	ASM_OUTPUT_OPCODE, THUMB2_GO_IF_LEGITIMATE_ADDRESS,
	THUMB2_LEGITIMIZE_ADDRESS, CASE_VECTOR_PC_RELATIVE,
	CASE_VECTOR_SHORTEN_MODE, ADDR_VEC_ALIGN, ASM_OUTPUT_CASE_END,
	ADJUST_INSN_LENGTH): Define.
	(TARGET_REALLY_IWMMXT, TARGET_IWMMXT_ABI, CONDITIONAL_REGISTER_USAGE,
	STATIC_CHAIN_REGNUM, HARD_REGNO_NREGS, INDEX_REG_CLASS,
	BASE_REG_CLASS, MODE_BASE_REG_CLASS, SMALL_REGISTER_CLASSES,
	PREFERRED_RELOAD_CLASS, SECONDARY_OUTPUT_RELOAD_CLASS,
	SECONDARY_INPUT_RELOAD_CLASS, LIBCALL_VALUE, FUNCTION_VALUE_REGNO_P,
	TRAMPOLINE_SIZE, INITIALIZE_TRAMPOLINE, HAVE_PRE_INCREMENT,
	HAVE_POST_DECREMENT, HAVE_PRE_DECREMENT, HAVE_PRE_MODIFY_DISP,
	HAVE_POST_MODIFY_DISP, HAVE_PRE_MODIFY_REG, HAVE_POST_MODIFY_REG,
	REGNO_MODE_OK_FOR_BASE_P, LEGITIMATE_CONSTANT_P,
	REG_MODE_OK_FOR_BASE_P, REG_OK_FOR_INDEX_P, GO_IF_LEGITIMATE_ADDRESS,
	LEGITIMIZE_ADDRESS, THUMB2_LEGITIMIZE_ADDRESS,
	GO_IF_MODE_DEPENDENT_ADDRESS, MEMORY_MOVE_COST, BRANCH_COST,
	ASM_APP_OFF, ASM_OUTPUT_CASE_LABEL, ARM_DECLARE_FUNCTION_NAME,
	FINAL_PRESCAN_INSN, PRINT_OPERAND_PUNCT_VALID_P,
	PRINT_OPERAND_ADDRESS): Adjust for Thumb-2.
	(arm_arch_notm, arm_arch_thumb2, arm_arch_hwdiv): New declarations.
	* config/arm/arm-cores.def: Add arm1156t2-s, cortex-a8, cortex-r4 and
	cortex-m3.
	* config/arm/arm-tune.md: Regenerate.
	* config/arm/arm-protos.h: Update prototypes.
	* config/arm/vfp.md: Enable patterns for Thumb-2.
	(arm_movsi_vfp): Add movw alternative.  Use output_move_vfp.
	(arm_movdi_vfp, movsf_vfp, movdf_vfp): Use output_move_vfp.
	(thumb2_movsi_vfp, thumb2_movdi_vfp, thumb2_movsf_vfp,
	thumb2_movdf_vfp, thumb2_movsfcc_vfp, thumb2_movdfcc_vfp): New.
	* config/arm/libunwind.S: Add Thumb-2 code.
	* config/arm/constraints.md: Update include Thumb-2.
	* config/arm/ieee754-sf.S: Add Thumb-2/Unified asm support.
	* config/arm/ieee754-df.S: Ditto.
	* config/arm/bpabi.S: Ditto.
	* config/arm/t-arm (MD_INCLUDES): Add thumb2.md.
	* config/arm/predicates.md (low_register_operand,
	low_reg_or_int_operand, thumb_16bit_operator): New.
	(thumb_cmp_operand, thumb_cmpneg_operand): Rename...
	(thumb1_cmp_operand, thumb1_cmpneg_operand): ... to this.
	* config/arm/t-arm-elf: Add armv7 multilib.
	* config/arm/arm.md: Update patterns for Thumb-2 and Unified asm.
	Include thumb2.md.
	(UNSPEC_STACK_ALIGN, ce_count): New.
	(arm_incscc, arm_decscc, arm_umaxsi3, arm_uminsi3,
	arm_zero_extendsidi2, arm_zero_extendqidi2): New
	insns/expanders.
	* config/arm/fpa.md: Update patterns for Thumb-2 and Unified asm.
	(thumb2_movsf_fpa, thumb2_movdf_fpa, thumb2_movxf_fpa,
	thumb2_movsfcc_fpa, thumb2_movdfcc_fpa): New insns.
	* config/arm/cirrus.md: Update patterns for Thumb-2 and Unified asm.
	(cirrus_thumb2_movdi, cirrus_thumb2_movsi_insn,
	thumb2_cirrus_movsf_hard_insn, thumb2_cirrus_movdf_hard_insn): New
	insns.
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