bearch_sparc.c

/*
 * Copyright (C) 1995-2010 University of Karlsruhe.  All right reserved.
 *
 * This file is part of libFirm.
 *
 * This file may be distributed and/or modified under the terms of the
 * GNU General Public License version 2 as published by the Free Software
 * Foundation and appearing in the file LICENSE.GPL included in the
 * packaging of this file.
 *
 * Licensees holding valid libFirm Professional Edition licenses may use
 * this file in accordance with the libFirm Commercial License.
 * Agreement provided with the Software.
 *
 * This file is provided AS IS with NO WARRANTY OF ANY KIND, INCLUDING THE
 * WARRANTY OF DESIGN, MERCHANTABILITY AND FITNESS FOR A PARTICULAR
 * PURPOSE.
 */

/**
 * @file
 * @brief    The main sparc backend driver file.
 * @author   Hannes Rapp, Matthias Braun
 * @version  $Id$
 */
#include "config.h"

#include "lc_opts.h"
#include "lc_opts_enum.h"

#include "irgwalk.h"
#include "irprog.h"
#include "irprintf.h"
#include "ircons.h"
#include "irgmod.h"
#include "irgopt.h"
#include "iroptimize.h"
#include "irtools.h"
#include "irdump.h"
#include "lowering.h"
#include "lower_dw.h"

#include "bitset.h"
#include "debug.h"
#include "array_t.h"
#include "error.h"
#include "util.h"

#include "../bearch.h"
#include "../benode.h"
#include "../belower.h"
#include "../besched.h"
#include "be.h"
#include "../bemachine.h"
#include "../bemodule.h"
#include "../beirg.h"
#include "../bespillslots.h"
#include "../begnuas.h"
#include "../belistsched.h"
#include "../beflags.h"

#include "bearch_sparc_t.h"

#include "sparc_new_nodes.h"
#include "gen_sparc_regalloc_if.h"
#include "sparc_transform.h"
#include "sparc_emitter.h"

DEBUG_ONLY(static firm_dbg_module_t *dbg = NULL;)

static arch_irn_class_t sparc_classify(const ir_node *node)
{
	(void) node;
	return arch_irn_class_none;
}

static ir_entity *sparc_get_frame_entity(const ir_node *node)
{
	if (is_sparc_FrameAddr(node)) {
		const sparc_attr_t *attr = get_sparc_attr_const(node);
		return attr->immediate_value_entity;
	}

	if (sparc_has_load_store_attr(node)) {
		const sparc_load_store_attr_t *load_store_attr
			= get_sparc_load_store_attr_const(node);
		if (load_store_attr->is_frame_entity) {
			return load_store_attr->base.immediate_value_entity;
		}
	}

	return NULL;
}

/**
 * This function is called by the generic backend to correct offsets for
 * nodes accessing the stack.
 */
static void sparc_set_frame_offset(ir_node *node, int offset)
{
	sparc_attr_t *attr = get_sparc_attr(node);
	attr->immediate_value += offset;

	/* must be a FrameAddr or a load/store node with frame_entity */
	assert(is_sparc_FrameAddr(node) ||
			get_sparc_load_store_attr_const(node)->is_frame_entity);
}

static int sparc_get_sp_bias(const ir_node *node)
{
	if (is_sparc_Save(node)) {
		const sparc_attr_t *attr = get_sparc_attr_const(node);
		if (get_irn_arity(node) == 3)
			panic("no support for _reg variant yet");

		/* Note we do not report the change of the SPARC_MIN_STACKSIZE
		 * size, since we have additional magic in the emitter which
		 * calculates that! */
		assert(attr->immediate_value <= -SPARC_MIN_STACKSIZE);
		return attr->immediate_value + SPARC_MIN_STACKSIZE;
	} else if (is_sparc_RestoreZero(node)) {
		return SP_BIAS_RESET;
	}
	return 0;
}

/* fill register allocator interface */

const arch_irn_ops_t sparc_irn_ops = {
	sparc_classify,
	sparc_get_frame_entity,
	sparc_set_frame_offset,
	sparc_get_sp_bias,
	NULL,    /* get_inverse             */
	NULL,    /* get_op_estimated_cost   */
	NULL,    /* possible_memory_operand */
	NULL,    /* perform_memory_operand  */
};

/**
 * Transforms the standard firm graph into
 * a SPARC firm graph
 */
static void sparc_prepare_graph(ir_graph *irg)
{
	sparc_transform_graph(irg);
}

static bool sparc_modifies_flags(const ir_node *node)
{
	return arch_irn_get_flags(node) & sparc_arch_irn_flag_modifies_flags;
}

static bool sparc_modifies_fp_flags(const ir_node *node)
{
	return arch_irn_get_flags(node) & sparc_arch_irn_flag_modifies_fp_flags;
}

static void sparc_before_ra(ir_graph *irg)
{
	/* fixup flags register */
	be_sched_fix_flags(irg, &sparc_reg_classes[CLASS_sparc_flags_class],
	                   NULL, sparc_modifies_flags);
	be_sched_fix_flags(irg, &sparc_reg_classes[CLASS_sparc_fpflags_class],
	                   NULL, sparc_modifies_fp_flags);
}

/**
 * transform reload node => load
 */
static void transform_Reload(ir_node *node)
{
	ir_node   *block  = get_nodes_block(node);
	dbg_info  *dbgi   = get_irn_dbg_info(node);
	ir_node   *ptr    = get_irn_n(node, n_be_Spill_frame);
	ir_node   *mem    = get_irn_n(node, n_be_Reload_mem);
	ir_mode   *mode   = get_irn_mode(node);
	ir_entity *entity = be_get_frame_entity(node);
	const arch_register_t *reg;
	ir_node   *proj;
	ir_node   *load;

	ir_node  *sched_point = sched_prev(node);

	load = new_bd_sparc_Ld_imm(dbgi, block, ptr, mem, mode, entity, 0, true);
	sched_add_after(sched_point, load);
	sched_remove(node);

	proj = new_rd_Proj(dbgi, load, mode, pn_sparc_Ld_res);

	reg = arch_get_irn_register(node);
	arch_set_irn_register(proj, reg);

	exchange(node, proj);
}

/**
 * transform spill node => store
 */
static void transform_Spill(ir_node *node)
{
	ir_node   *block  = get_nodes_block(node);
	dbg_info  *dbgi   = get_irn_dbg_info(node);
	ir_node   *ptr    = get_irn_n(node, n_be_Spill_frame);
	ir_graph  *irg    = get_irn_irg(node);
	ir_node   *mem    = get_irg_no_mem(irg);
	ir_node   *val    = get_irn_n(node, n_be_Spill_val);
	ir_mode   *mode   = get_irn_mode(val);
	ir_entity *entity = be_get_frame_entity(node);
	ir_node   *sched_point;
	ir_node   *store;

	sched_point = sched_prev(node);
	store = new_bd_sparc_St_imm(dbgi, block, val, ptr, mem, mode, entity, 0, true);
	sched_remove(node);
	sched_add_after(sched_point, store);

	exchange(node, store);
}

/**
 * walker to transform be_Spill and be_Reload nodes
 */
static void sparc_after_ra_walker(ir_node *block, void *data)
{
	ir_node *node, *prev;
	(void) data;

	for (node = sched_last(block); !sched_is_begin(node); node = prev) {
		prev = sched_prev(node);

		if (be_is_Reload(node)) {
			transform_Reload(node);
		} else if (be_is_Spill(node)) {
			transform_Spill(node);
		}
	}
}

static void sparc_collect_frame_entity_nodes(ir_node *node, void *data)
{
	be_fec_env_t  *env = (be_fec_env_t*)data;
	const ir_mode *mode;
	int            align;
	ir_entity     *entity;
	const sparc_load_store_attr_t *attr;

	if (be_is_Reload(node) && be_get_frame_entity(node) == NULL) {
		mode  = get_irn_mode(node);
		align = get_mode_size_bytes(mode);
		be_node_needs_frame_entity(env, node, mode, align);
		return;
	}

	if (!is_sparc_Ld(node) && !is_sparc_Ldf(node))
		return;

	attr   = get_sparc_load_store_attr_const(node);
	entity = attr->base.immediate_value_entity;
	mode   = attr->load_store_mode;
	if (entity != NULL)
		return;
	if (!attr->is_frame_entity)
		return;
	if (arch_irn_get_flags(node) & sparc_arch_irn_flag_needs_64bit_spillslot)
		mode = mode_Lu;
	align  = get_mode_size_bytes(mode);
	be_node_needs_frame_entity(env, node, mode, align);
}

static void sparc_set_frame_entity(ir_node *node, ir_entity *entity)
{
	if (is_be_node(node)) {
		be_node_set_frame_entity(node, entity);
	} else {
		/* we only say be_node_needs_frame_entity on nodes with load_store
		 * attributes, so this should be fine */
		sparc_load_store_attr_t *attr = get_sparc_load_store_attr(node);
		assert(attr->is_frame_entity);
		assert(attr->base.immediate_value_entity == NULL);
		attr->base.immediate_value_entity = entity;
	}
}

static void sparc_after_ra(ir_graph *irg)
{
	be_stack_layout_t *stack_layout = be_get_irg_stack_layout(irg);
	bool               at_begin     = stack_layout->sp_relative ? true : false;
	be_fec_env_t      *fec_env      = be_new_frame_entity_coalescer(irg);

	irg_walk_graph(irg, NULL, sparc_collect_frame_entity_nodes, fec_env);
	be_assign_entities(fec_env, sparc_set_frame_entity, at_begin);
	be_free_frame_entity_coalescer(fec_env);

	irg_block_walk_graph(irg, NULL, sparc_after_ra_walker, NULL);

	sparc_introduce_prolog_epilog(irg);
}

static void sparc_init_graph(ir_graph *irg)
{
	(void) irg;
}

extern const arch_isa_if_t sparc_isa_if;
static sparc_isa_t sparc_isa_template = {
	{
		&sparc_isa_if,                      /* isa interface implementation */
		N_SPARC_REGISTERS,
		sparc_registers,
		N_SPARC_CLASSES,
		sparc_reg_classes,
		&sparc_registers[REG_SP],           /* stack pointer register */
		&sparc_registers[REG_FRAME_POINTER],/* base pointer register */
		&sparc_reg_classes[CLASS_sparc_gp], /* link pointer register class */
		3,                                  /* power of two stack alignment
		                                       for calls */
		NULL,                               /* main environment */
		7,                                  /* costs for a spill instruction */
		5,                                  /* costs for a reload instruction */
		true,                               /* custom abi handling */
	},
	NULL,     /* constants */
};

/**
 * rewrite unsigned->float conversion.
 * Sparc has no instruction for this so instead we do the following:
 *
 *   int    signed_x = unsigned_value_x;
 *   double res      = signed_x;
 *   if (signed_x < 0)
 *       res += 4294967296. ;
 *   return (float) res;
 */
static void rewrite_unsigned_float_Conv(ir_node *node)
{
	ir_graph *irg         = get_irn_irg(node);
	dbg_info *dbgi        = get_irn_dbg_info(node);
	ir_node  *lower_block = get_nodes_block(node);

	part_block(node);

	{
		ir_node   *block       = get_nodes_block(node);
		ir_node   *unsigned_x  = get_Conv_op(node);
		ir_mode   *mode_u      = get_irn_mode(unsigned_x);
		ir_mode   *mode_s      = find_signed_mode(mode_u);
		ir_mode   *mode_d      = mode_D;
		ir_node   *signed_x    = new_rd_Conv(dbgi, block, unsigned_x, mode_s);
		ir_node   *res         = new_rd_Conv(dbgi, block, signed_x, mode_d);
		ir_node   *zero        = new_r_Const(irg, get_mode_null(mode_s));
		ir_node   *cmp         = new_rd_Cmp(dbgi, block, signed_x, zero,
		                                    ir_relation_less);
		ir_node   *cond        = new_rd_Cond(dbgi, block, cmp);
		ir_node   *proj_true   = new_r_Proj(cond, mode_X, pn_Cond_true);
		ir_node   *proj_false  = new_r_Proj(cond, mode_X, pn_Cond_false);
		ir_node   *in_true[1]  = { proj_true };
		ir_node   *in_false[1] = { proj_false };
		ir_node   *true_block  = new_r_Block(irg, ARRAY_SIZE(in_true), in_true);
		ir_node   *false_block = new_r_Block(irg, ARRAY_SIZE(in_false),in_false);
		ir_node   *true_jmp    = new_r_Jmp(true_block);
		ir_node   *false_jmp   = new_r_Jmp(false_block);
		ir_tarval *correction  = new_tarval_from_double(4294967296., mode_d);
		ir_node   *c_const     = new_r_Const(irg, correction);
		ir_node   *fadd        = new_rd_Add(dbgi, true_block, res, c_const,
		                                   mode_d);

		ir_node  *lower_in[2] = { true_jmp, false_jmp };
		ir_node  *phi_in[2]   = { fadd, res };
		ir_mode  *dest_mode   = get_irn_mode(node);
		ir_node  *phi;
		ir_node  *res_conv;

		set_irn_in(lower_block, ARRAY_SIZE(lower_in), lower_in);
		phi = new_r_Phi(lower_block, ARRAY_SIZE(phi_in), phi_in, mode_d);
		assert(get_Block_phis(lower_block) == NULL);
		set_Block_phis(lower_block, phi);
		set_Phi_next(phi, NULL);

		res_conv = new_rd_Conv(dbgi, lower_block, phi, dest_mode);

		exchange(node, res_conv);
	}
}

static int sparc_rewrite_Conv(ir_node *node, void *ctx)
{
	ir_mode *to_mode   = get_irn_mode(node);
	ir_node *op        = get_Conv_op(node);
	ir_mode *from_mode = get_irn_mode(op);
	(void) ctx;

	if (mode_is_float(to_mode) && mode_is_int(from_mode)
			&& get_mode_size_bits(from_mode) == 32
			&& !mode_is_signed(from_mode)) {
		rewrite_unsigned_float_Conv(node);
		return 1;
	}

	return 0;
}

static void sparc_handle_intrinsics(void)
{
	ir_type *tp, *int_tp, *uint_tp;
	i_record records[8];
	size_t n_records = 0;

	runtime_rt rt_iMod, rt_uMod;

#define ID(x) new_id_from_chars(x, sizeof(x)-1)

	int_tp  = new_type_primitive(mode_Is);
	uint_tp = new_type_primitive(mode_Iu);

	/* we need to rewrite some forms of int->float conversions */
	{
		i_instr_record *map_Conv = &records[n_records++].i_instr;

		map_Conv->kind     = INTRINSIC_INSTR;
		map_Conv->op       = op_Conv;
		map_Conv->i_mapper = sparc_rewrite_Conv;
	}
	/* SPARC has no signed mod instruction ... */
	{
		i_instr_record *map_Mod = &records[n_records++].i_instr;

		tp = new_type_method(2, 1);
		set_method_param_type(tp, 0, int_tp);
		set_method_param_type(tp, 1, int_tp);
		set_method_res_type(tp, 0, int_tp);

		rt_iMod.ent             = new_entity(get_glob_type(), ID(".rem"), tp);
		set_entity_ld_ident(rt_iMod.ent, ID(".rem"));
		rt_iMod.mode            = mode_T;
		rt_iMod.res_mode        = mode_Is;
		rt_iMod.mem_proj_nr     = pn_Mod_M;
		rt_iMod.regular_proj_nr = pn_Mod_X_regular;
		rt_iMod.exc_proj_nr     = pn_Mod_X_except;
		rt_iMod.res_proj_nr     = pn_Mod_res;

		set_entity_visibility(rt_iMod.ent, ir_visibility_external);

		map_Mod->kind     = INTRINSIC_INSTR;
		map_Mod->op       = op_Mod;
		map_Mod->i_mapper = (i_mapper_func)i_mapper_RuntimeCall;
		map_Mod->ctx      = &rt_iMod;
	}
	/* ... nor an unsigned mod. */
	{
		i_instr_record *map_Mod = &records[n_records++].i_instr;

		tp = new_type_method(2, 1);
		set_method_param_type(tp, 0, uint_tp);
		set_method_param_type(tp, 1, uint_tp);
		set_method_res_type(tp, 0, uint_tp);

		rt_uMod.ent             = new_entity(get_glob_type(), ID(".urem"), tp);
		set_entity_ld_ident(rt_uMod.ent, ID(".urem"));
		rt_uMod.mode            = mode_T;
		rt_uMod.res_mode        = mode_Iu;
		rt_uMod.mem_proj_nr     = pn_Mod_M;
		rt_uMod.regular_proj_nr = pn_Mod_X_regular;
		rt_uMod.exc_proj_nr     = pn_Mod_X_except;
		rt_uMod.res_proj_nr     = pn_Mod_res;

		set_entity_visibility(rt_uMod.ent, ir_visibility_external);

		map_Mod->kind     = INTRINSIC_INSTR;
		map_Mod->op       = op_Mod;
		map_Mod->i_mapper = (i_mapper_func)i_mapper_RuntimeCall;
		map_Mod->ctx      = &rt_uMod;
	}

	assert(n_records < ARRAY_SIZE(records));
	lower_intrinsics(records, n_records, /*part_block_used=*/ true);
}

/**
 * Initializes the backend ISA
 */
static arch_env_t *sparc_init(FILE *outfile)
{
	sparc_isa_t *isa = XMALLOC(sparc_isa_t);
	*isa = sparc_isa_template;
	isa->constants = pmap_create();

	be_emit_init(outfile);

	sparc_register_init();
	sparc_create_opcodes(&sparc_irn_ops);
	sparc_handle_intrinsics();

	return &isa->base;
}

/**
 * Closes the output file and frees the ISA structure.
 */
static void sparc_done(void *self)
{
	sparc_isa_t *isa = (sparc_isa_t*)self;

	/* emit now all global declarations */
	be_gas_emit_decls(isa->base.main_env);

	pmap_destroy(isa->constants);
	be_emit_exit();
	free(isa);
}


/**
 * Get the register class which shall be used to store a value of a given mode.
 * @param self The this pointer.
 * @param mode The mode in question.
 * @return A register class which can hold values of the given mode.
 */
static const arch_register_class_t *sparc_get_reg_class_for_mode(const ir_mode *mode)
{
	if (mode_is_float(mode))
		return &sparc_reg_classes[CLASS_sparc_fp];
	else
		return &sparc_reg_classes[CLASS_sparc_gp];
}

/**
 * Returns the necessary byte alignment for storing a register of given class.
 */
static int sparc_get_reg_class_alignment(const arch_register_class_t *cls)
{
	ir_mode *mode = arch_register_class_mode(cls);
	return get_mode_size_bytes(mode);
}

static ir_node *sparc_create_set(ir_node *cond)
{
	return ir_create_cond_set(cond, mode_Iu);
}

static void sparc_lower_for_target(void)
{
	size_t i, n_irgs = get_irp_n_irgs();
	lower_mode_b_config_t lower_mode_b_config = {
		mode_Iu,
		sparc_create_set,
		0,
	};
	lower_params_t params = {
		4,                                     /* def_ptr_alignment */
		LF_COMPOUND_RETURN | LF_RETURN_HIDDEN, /* flags */
		ADD_HIDDEN_ALWAYS_IN_FRONT,            /* hidden_params */
		NULL,                                  /* find pointer type */
		NULL,                                  /* ret_compound_in_regs */
	};
	lower_calls_with_compounds(&params);

	sparc_lower_64bit();

	for (i = 0; i < n_irgs; ++i) {
		ir_graph *irg = get_irp_irg(i);
		ir_lower_mode_b(irg, &lower_mode_b_config);
		lower_switch(irg, 4, 256, false);
	}
}

static int sparc_is_mux_allowed(ir_node *sel, ir_node *mux_false,
                                ir_node *mux_true)
{
	ir_graph *irg  = get_irn_irg(sel);
	ir_mode  *mode = get_irn_mode(mux_true);

	if (get_irg_phase_state(irg) == phase_low)
		return false;

	if (!mode_is_int(mode) && !mode_is_reference(mode) && mode != mode_b)
		return false;
	if (is_Const(mux_true) && is_Const_one(mux_true) &&
			is_Const(mux_false) && is_Const_null(mux_false))
		return true;
	return false;
}

/**
 * Returns the libFirm configuration parameter for this backend.
 */
static const backend_params *sparc_get_backend_params(void)
{
	static const ir_settings_arch_dep_t arch_dep = {
		1,     /* also_use_subs */
		1,     /* maximum_shifts */
		31,    /* highest_shift_amount */
		NULL,  /* evaluate_cost_func */
		1,     /* allow mulhs */
		1,     /* allow mulhu */
		32,    /* max_bits_for_mulh */
	};
	static backend_params p = {
		0,     /* no inline assembly */
		0,     /* no support for RotL nodes */
		1,     /* big endian */
		&arch_dep,              /* will be set later */
		sparc_is_mux_allowed,   /* parameter for if conversion */
		32,    /* machine size */
		NULL,  /* float arithmetic mode */
		128,   /* size of long double */
		0,     /* no trampoline support: size 0 */
		0,     /* no trampoline support: align 0 */
		NULL,  /* no trampoline support: no trampoline builder */
		4      /* alignment of stack parameter: typically 4 (32bit) or 8 (64bit) */
	};
	return &p;
}

static ir_graph **sparc_get_backend_irg_list(const void *self,
                                             ir_graph ***irgs)
{
	(void) self;
	(void) irgs;
	return NULL;
}

static asm_constraint_flags_t sparc_parse_asm_constraint(const char **c)
{
	(void) c;
	return ASM_CONSTRAINT_FLAG_INVALID;
}

static int sparc_is_valid_clobber(const char *clobber)
{
	(void) clobber;
	return 0;
}

const arch_isa_if_t sparc_isa_if = {
	sparc_init,
	sparc_lower_for_target,
	sparc_done,
	NULL,                /* handle intrinsics */
	sparc_get_reg_class_for_mode,
	NULL,
	sparc_get_reg_class_alignment,
	sparc_get_backend_params,
	sparc_get_backend_irg_list,
	NULL,                    /* mark remat */
	sparc_parse_asm_constraint,
	sparc_is_valid_clobber,

	sparc_init_graph,
	NULL, /* get_pic_base */
	NULL, /* before_abi */
	sparc_prepare_graph,
	sparc_before_ra,
	sparc_after_ra,
	sparc_finish,
	sparc_emit_routine,
	NULL, /* register_saved_by */
};

BE_REGISTER_MODULE_CONSTRUCTOR(be_init_arch_sparc)
void be_init_arch_sparc(void)
{
	be_register_isa_if("sparc", &sparc_isa_if);
	FIRM_DBG_REGISTER(dbg, "firm.be.sparc.cg");
	sparc_init_transform();
	sparc_init_emitter();
}