arm_transform.c

/*
 * Copyright (C) 1995-2008 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 codegenerator (transform FIRM into arm FIRM)
 * @author  Oliver Richter, Tobias Gneist, Michael Beck
 * @version $Id$
 */
#include "config.h"

#include "irnode_t.h"
#include "irgraph_t.h"
#include "irmode_t.h"
#include "irgmod.h"
#include "iredges.h"
#include "irvrfy.h"
#include "ircons.h"
#include "irprintf.h"
#include "dbginfo.h"
#include "iropt_t.h"
#include "debug.h"
#include "error.h"

#include "../benode_t.h"
#include "../beirg_t.h"
#include "../beutil.h"
#include "../betranshlp.h"
#include "bearch_arm_t.h"

#include "arm_nodes_attr.h"
#include "archop.h"
#include "arm_transform.h"
#include "arm_optimize.h"
#include "arm_new_nodes.h"
#include "arm_map_regs.h"

#include "gen_arm_regalloc_if.h"

#include <limits.h>


/** hold the current code generator during transformation */
static arm_code_gen_t *env_cg;

extern ir_op *get_op_Mulh(void);


/****************************************************************************************************
 *                  _        _                        __                           _   _
 *                 | |      | |                      / _|                         | | (_)
 *  _ __   ___   __| | ___  | |_ _ __ __ _ _ __  ___| |_ ___  _ __ _ __ ___   __ _| |_ _  ___  _ __
 * | '_ \ / _ \ / _` |/ _ \ | __| '__/ _` | '_ \/ __|  _/ _ \| '__| '_ ` _ \ / _` | __| |/ _ \| '_ \
 * | | | | (_) | (_| |  __/ | |_| | | (_| | | | \__ \ || (_) | |  | | | | | | (_| | |_| | (_) | | | |
 * |_| |_|\___/ \__,_|\___|  \__|_|  \__,_|_| |_|___/_| \___/|_|  |_| |_| |_|\__,_|\__|_|\___/|_| |_|
 *
 ****************************************************************************************************/

static inline int mode_needs_gp_reg(ir_mode *mode) {
	return mode_is_int(mode) || mode_is_reference(mode);
}

/**
 * Creates a arm_Const node.
 */
static ir_node *create_mov_node(dbg_info *dbg, ir_node *block, long value) {
	ir_mode *mode  = mode_Iu;
	ir_node *res;

	if (mode_needs_gp_reg(mode))
		mode = mode_Iu;
	res = new_bd_arm_Mov_i(dbg, block, mode, value);
	be_dep_on_frame(res);
	return res;
}

/**
 * Creates a arm_Const_Neg node.
 */
static ir_node *create_mvn_node(dbg_info *dbg, ir_node *block, long value) {
	ir_mode *mode = mode_Iu;
	ir_node *res;

	if (mode_needs_gp_reg(mode))
		mode = mode_Iu;
	res = new_bd_arm_Mvn_i(dbg, block, mode, value);
	be_dep_on_frame(res);
	return res;
}

#define NEW_BINOP_NODE(opname, env, op1, op2) new_bd_arm_##opname(env->dbg, current_ir_graph, env->block, op1, op2, env->mode)

/**
 * Creates a possible DAG for an constant.
 */
static ir_node *create_const_graph_value(dbg_info *dbg, ir_node *block, unsigned int value) {
	ir_node *result;
	arm_vals v, vn;
	int cnt;
	ir_mode *mode = mode_Iu;

	arm_gen_vals_from_word(value, &v);
	arm_gen_vals_from_word(~value, &vn);

	if (vn.ops < v.ops) {
		/* remove bits */
		result = create_mvn_node(dbg, block, arm_encode_imm_w_shift(vn.shifts[0], vn.values[0]));

		for (cnt = 1; cnt < vn.ops; ++cnt) {
			long value = arm_encode_imm_w_shift(vn.shifts[cnt], vn.values[cnt]);
			ir_node *bic_i_node = new_bd_arm_Bic_i(dbg, block, result, mode, value);
			result = bic_i_node;
		}
	}
	else {
		/* add bits */
		result = create_mov_node(dbg, block, arm_encode_imm_w_shift(v.shifts[0], v.values[0]));

		for (cnt = 1; cnt < v.ops; ++cnt) {
			long value = arm_encode_imm_w_shift(v.shifts[cnt], v.values[cnt]);
			ir_node *orr_i_node = new_bd_arm_Or_i(dbg, block, result, mode, value);
			result = orr_i_node;
		}
	}
	return result;
}

/**
 * Create a DAG constructing a given Const.
 *
 * @param irn  a Firm const
 */
static ir_node *create_const_graph(ir_node *irn, ir_node *block) {
	tarval  *tv = get_Const_tarval(irn);
	ir_mode *mode = get_tarval_mode(tv);
	int     value;

	if (mode_is_reference(mode)) {
		/* ARM is 32bit, so we can safely convert a reference tarval into Iu */
		assert(get_mode_size_bits(mode) == get_mode_size_bits(mode_Iu));
		tv = tarval_convert_to(tv, mode_Iu);
	}
	value = get_tarval_long(tv);
	return create_const_graph_value(get_irn_dbg_info(irn), block, value);
}

/**
 * Create an And that will mask all upper bits
 */
static ir_node *gen_zero_extension(dbg_info *dbg, ir_node *block, ir_node *op, int result_bits) {
	unsigned mask_bits = (1 << result_bits) - 1;
	ir_node *mask_node = create_const_graph_value(dbg, block, mask_bits);
	return new_bd_arm_And(dbg, block, op, mask_node, mode_Iu, ARM_SHF_NONE, 0);
}

/**
 * Generate code for a sign extension.
 */
static ir_node *gen_sign_extension(dbg_info *dbg, ir_node *block, ir_node *op, int result_bits) {
	int shift_width = 32 - result_bits;
	ir_node *shift_const_node = create_const_graph_value(dbg, block, shift_width);
	ir_node *lshift_node = new_bd_arm_Shl(dbg, block, op, shift_const_node, mode_Iu);
	ir_node *rshift_node = new_bd_arm_Shrs(dbg, block, lshift_node, shift_const_node, mode_Iu);
	return rshift_node;
}

/**
 * Transforms a Conv node.
 *
 * @return The created ia32 Conv node
 */
static ir_node *gen_Conv(ir_node *node) {
	ir_node  *block    = be_transform_node(get_nodes_block(node));
	ir_node  *op       = get_Conv_op(node);
	ir_node  *new_op   = be_transform_node(op);
	ir_mode  *src_mode = get_irn_mode(op);
	ir_mode  *dst_mode = get_irn_mode(node);
	dbg_info *dbg      = get_irn_dbg_info(node);

	if (src_mode == dst_mode)
		return new_op;

	if (mode_is_float(src_mode) || mode_is_float(dst_mode)) {
		env_cg->have_fp_insn = 1;

		if (USE_FPA(env_cg->isa)) {
			if (mode_is_float(src_mode)) {
				if (mode_is_float(dst_mode)) {
					/* from float to float */
					return new_bd_arm_fpaMvf(dbg, block, new_op, dst_mode);
				}
				else {
					/* from float to int */
					return new_bd_arm_fpaFix(dbg, block, new_op, dst_mode);
				}
			}
			else {
				/* from int to float */
				return new_bd_arm_fpaFlt(dbg, block, new_op, dst_mode);
			}
		}
		else if (USE_VFP(env_cg->isa)) {
			panic("VFP not supported yet");
			return NULL;
		}
		else {
			panic("Softfloat not supported yet");
			return NULL;
		}
	}
	else { /* complete in gp registers */
		int src_bits = get_mode_size_bits(src_mode);
		int dst_bits = get_mode_size_bits(dst_mode);
		int min_bits;
		ir_mode *min_mode;

		if (is_Load(skip_Proj(op))) {
			if (src_bits == dst_bits) {
				/* kill unneccessary conv */
				return new_op;
			}
			/* after a load, the bit size is already converted */
			src_bits = 32;
		}

		if (src_bits == dst_bits) {
			/* kill unneccessary conv */
			return new_op;
		} else if (dst_bits <= 32 && src_bits <= 32) {
			if (src_bits < dst_bits) {
				min_bits = src_bits;
				min_mode = src_mode;
			} else {
				min_bits = dst_bits;
				min_mode = dst_mode;
			}
			if (mode_is_signed(min_mode)) {
				return gen_sign_extension(dbg, block, new_op, min_bits);
			} else {
				return gen_zero_extension(dbg, block, new_op, min_bits);
			}
		} else {
			panic("Cannot handle Conv %+F->%+F with %d->%d bits", src_mode, dst_mode,
				src_bits, dst_bits);
			return NULL;
		}
	}
}

/**
 * Return true if an operand is a shifter operand
 */
static int is_shifter_operand(ir_node *n, arm_shift_modifier *pmod) {
	arm_shift_modifier mod = ARM_SHF_NONE;

	if (is_arm_Mov(n))
		mod = get_arm_shift_modifier(n);

	*pmod = mod;
	if (mod != ARM_SHF_NONE) {
		long v = get_arm_imm_value(n);
		if (v < 32)
			return (int)v;
	}
	return 0;
}

/**
 * Creates an ARM Add.
 *
 * @return the created arm Add node
 */
static ir_node *gen_Add(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op1     = get_Add_left(node);
	ir_node  *new_op1 = be_transform_node(op1);
	ir_node  *op2     = get_Add_right(node);
	ir_node  *new_op2 = be_transform_node(op2);
	ir_mode  *mode    = get_irn_mode(node);
	ir_node  *new_op3;
	int v;
	arm_shift_modifier mod;
	dbg_info *dbg = get_irn_dbg_info(node);

	if (mode_is_float(mode)) {
		env_cg->have_fp_insn = 1;
		if (USE_FPA(env_cg->isa)) {
			if (is_arm_fpaMvf_i(new_op1))
				return new_bd_arm_fpaAdf_i(dbg, block, new_op2, mode, get_arm_imm_value(new_op1));
			if (is_arm_fpaMvf_i(new_op2))
				return new_bd_arm_fpaAdf_i(dbg, block, new_op1, mode, get_arm_imm_value(new_op2));
			return new_bd_arm_fpaAdf(dbg, block, new_op1, new_op2, mode);
		} else if (USE_VFP(env_cg->isa)) {
			assert(mode != mode_E && "IEEE Extended FP not supported");
			panic("VFP not supported yet");
			return NULL;
		}
		else {
			panic("Softfloat not supported yet");
			return NULL;
		}
	} else {
		assert(mode_is_data(mode));
		mode = mode_Iu;

		if (is_arm_Mov_i(new_op1))
			return new_bd_arm_Add_i(dbg, block, new_op2, mode, get_arm_imm_value(new_op1));
		if (is_arm_Mov_i(new_op2))
			return new_bd_arm_Add_i(dbg, block, new_op1, mode, get_arm_imm_value(new_op2));

		/* check for MLA */
		if (is_arm_Mul(new_op1) && get_irn_n_edges(op1) == 1) {
			new_op3 = new_op2;
			new_op2 = get_irn_n(new_op1, 1);
			new_op1 = get_irn_n(new_op1, 0);

			return new_bd_arm_Mla(dbg, block, new_op1, new_op2, new_op3, mode);
		}
		if (is_arm_Mul(new_op2) && get_irn_n_edges(op2) == 1) {
			new_op3 = new_op1;
			new_op1 = get_irn_n(new_op2, 0);
			new_op2 = get_irn_n(new_op2, 1);

			return new_bd_arm_Mla(dbg, block, new_op1, new_op2, new_op3, mode);
		}

		/* is the first a shifter */
		v = is_shifter_operand(new_op1, &mod);
		if (v) {
			new_op1 = get_irn_n(new_op1, 0);
			return new_bd_arm_Add(dbg, block, new_op2, new_op1, mode, mod, v);
		}
		/* is the second a shifter */
		v = is_shifter_operand(new_op2, &mod);
		if (v) {
			new_op2 = get_irn_n(new_op2, 0);
			return new_bd_arm_Add(dbg, block, new_op1, new_op2, mode, mod, v);
		}

		/* normal ADD */
		return new_bd_arm_Add(dbg, block, new_op1, new_op2, mode, ARM_SHF_NONE, 0);
	}
}

/**
 * Creates an ARM Mul.
 *
 * @return the created arm Mul node
 */
static ir_node *gen_Mul(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op1     = get_Mul_left(node);
	ir_node  *new_op1 = be_transform_node(op1);
	ir_node  *op2     = get_Mul_right(node);
	ir_node  *new_op2 = be_transform_node(op2);
	ir_mode  *mode    = get_irn_mode(node);
	dbg_info *dbg     = get_irn_dbg_info(node);

	if (mode_is_float(mode)) {
		env_cg->have_fp_insn = 1;
		if (USE_FPA(env_cg->isa)) {
			if (is_arm_Mov_i(new_op1))
				return new_bd_arm_fpaMuf_i(dbg, block, new_op2, mode, get_arm_imm_value(new_op1));
			if (is_arm_Mov_i(new_op2))
				return new_bd_arm_fpaMuf_i(dbg, block, new_op1, mode, get_arm_imm_value(new_op2));
			return new_bd_arm_fpaMuf(dbg, block, new_op1, new_op2, mode);
		}
		else if (USE_VFP(env_cg->isa)) {
			assert(mode != mode_E && "IEEE Extended FP not supported");
			panic("VFP not supported yet");
			return NULL;
		}
		else {
			panic("Softfloat not supported yet");
			return NULL;
		}
	}
	assert(mode_is_data(mode));
	mode = mode_Iu;
	return new_bd_arm_Mul(dbg, block, new_op1, new_op2, mode);
}

/**
 * Creates an ARM floating point Div.
 *
 * @param env   The transformation environment
 * @return the created arm fDiv node
 */
static ir_node *gen_Quot(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op1     = get_Quot_left(node);
	ir_node  *new_op1 = be_transform_node(op1);
	ir_node  *op2     = get_Quot_right(node);
	ir_node  *new_op2 = be_transform_node(op2);
	ir_mode  *mode    = get_irn_mode(node);
	dbg_info *dbg     = get_irn_dbg_info(node);

	assert(mode != mode_E && "IEEE Extended FP not supported");

	env_cg->have_fp_insn = 1;
	if (USE_FPA(env_cg->isa)) {
		if (is_arm_Mov_i(new_op1))
			return new_bd_arm_fpaRdf_i(dbg, block, new_op2, mode, get_arm_imm_value(new_op1));
		if (is_arm_Mov_i(new_op2))
			return new_bd_arm_fpaDvf_i(dbg, block, new_op1, mode, get_arm_imm_value(new_op2));
		return new_bd_arm_fpaDvf(dbg, block, new_op1, new_op2, mode);
	} else if (USE_VFP(env_cg->isa)) {
		assert(mode != mode_E && "IEEE Extended FP not supported");
		panic("VFP not supported yet");
	}
	else {
		panic("Softfloat not supported yet");
		return NULL;
	}
}

#define GEN_INT_OP(op) \
	ir_node  *block   = be_transform_node(get_nodes_block(node)); \
	ir_node  *op1     = get_ ## op ## _left(node); \
	ir_node  *new_op1 = be_transform_node(op1); \
	ir_node  *op2     = get_ ## op ## _right(node); \
	ir_node  *new_op2 = be_transform_node(op2); \
	ir_mode  *mode    = mode_Iu; \
	dbg_info *dbg     = get_irn_dbg_info(node); \
	int      v; \
	arm_shift_modifier mod; \
 \
	if (is_arm_Mov_i(new_op1)) \
		return new_bd_arm_ ## op ## _i(dbg, block, new_op2, mode, get_arm_imm_value(new_op1)); \
	if (is_arm_Mov_i(new_op2)) \
		return new_bd_arm_ ## op ## _i(dbg, block, new_op1, mode, get_arm_imm_value(new_op2)); \
	/* is the first a shifter */ \
	v = is_shifter_operand(new_op1, &mod); \
	if (v) { \
		new_op1 = get_irn_n(new_op1, 0); \
		return new_bd_arm_ ## op(dbg, block, new_op2, new_op1, mode, mod, v); \
	} \
	/* is the second a shifter */ \
	v = is_shifter_operand(new_op2, &mod); \
	if (v) { \
		new_op2 = get_irn_n(new_op2, 0); \
		return new_bd_arm_ ## op(dbg, block, new_op1, new_op2, mode, mod, v); \
	} \
	/* Normal op */ \
	return new_bd_arm_ ## op(dbg, block, new_op1, new_op2, mode, ARM_SHF_NONE, 0) \

/**
 * Creates an ARM And.
 *
 * @return the created arm And node
 */
static ir_node *gen_And(ir_node *node) {
	GEN_INT_OP(And);
}

/**
 * Creates an ARM Orr.
 *
 * @param env   The transformation environment
 * @return the created arm Or node
 */
static ir_node *gen_Or(ir_node *node) {
	GEN_INT_OP(Or);
}

/**
 * Creates an ARM Eor.
 *
 * @return the created arm Eor node
 */
static ir_node *gen_Eor(ir_node *node) {
	GEN_INT_OP(Eor);
}

/**
 * Creates an ARM Sub.
 *
 * @return the created arm Sub node
 */
static ir_node *gen_Sub(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op1     = get_Sub_left(node);
	ir_node  *new_op1 = be_transform_node(op1);
	ir_node  *op2     = get_Sub_right(node);
	ir_node  *new_op2 = be_transform_node(op2);
	ir_mode  *mode    = get_irn_mode(node);
	dbg_info *dbg     = get_irn_dbg_info(node);
	int      v;
	arm_shift_modifier mod;

	if (mode_is_float(mode)) {
		env_cg->have_fp_insn = 1;
		if (USE_FPA(env_cg->isa)) {
			if (is_arm_Mov_i(new_op1))
				return new_bd_arm_fpaRsf_i(dbg, block, new_op2, mode, get_arm_imm_value(new_op1));
			if (is_arm_Mov_i(new_op2))
				return new_bd_arm_fpaSuf_i(dbg, block, new_op1, mode, get_arm_imm_value(new_op2));
			return new_bd_arm_fpaSuf(dbg, block, new_op1, new_op2, mode);
		} else if (USE_VFP(env_cg->isa)) {
			assert(mode != mode_E && "IEEE Extended FP not supported");
			panic("VFP not supported yet");
			return NULL;
		}
		else {
			panic("Softfloat not supported yet");
			return NULL;
		}
	}
	else {
		assert(mode_is_data(mode) && "unknown mode for Sub");
		mode = mode_Iu;

		if (is_arm_Mov_i(new_op1))
			return new_bd_arm_Rsb_i(dbg, block, new_op2, mode, get_arm_imm_value(new_op1));
		if (is_arm_Mov_i(new_op2))
			return new_bd_arm_Sub_i(dbg, block, new_op1, mode, get_arm_imm_value(new_op2));

		/* is the first a shifter */
		v = is_shifter_operand(new_op1, &mod);
		if (v) {
			new_op1 = get_irn_n(new_op1, 0);
			return new_bd_arm_Rsb(dbg, block, new_op2, new_op1, mode, mod, v);
		}
		/* is the second a shifter */
		v = is_shifter_operand(new_op2, &mod);
		if (v) {
			new_op2 = get_irn_n(new_op2, 0);
			return new_bd_arm_Sub(dbg, block, new_op1, new_op2, mode, mod, v);
		}
		/* normal sub */
		return new_bd_arm_Sub(dbg, block, new_op1, new_op2, mode, ARM_SHF_NONE, 0);
	}
}

/**
 * Creates an ARM Shl.
 *
 * @return the created ARM Shl node
 */
static ir_node *gen_Shl(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op1     = get_Shl_left(node);
	ir_node  *new_op1 = be_transform_node(op1);
	ir_node  *op2     = get_Shl_right(node);
	ir_node  *new_op2 = be_transform_node(op2);
	ir_mode  *mode    = mode_Iu;
	dbg_info *dbg     = get_irn_dbg_info(node);

	if (is_arm_Mov_i(new_op2)) {
		return new_bd_arm_Mov(dbg, block, new_op1, mode, ARM_SHF_LSL, get_arm_imm_value(new_op2));
	}
	return new_bd_arm_Shl(dbg, block, new_op1, new_op2, mode);
}

/**
 * Creates an ARM Shr.
 *
 * @return the created ARM Shr node
 */
static ir_node *gen_Shr(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op1     = get_Shr_left(node);
	ir_node  *new_op1 = be_transform_node(op1);
	ir_node  *op2     = get_Shr_right(node);
	ir_node  *new_op2 = be_transform_node(op2);
	ir_mode  *mode    = mode_Iu;
	dbg_info *dbg     = get_irn_dbg_info(node);

	if (is_arm_Mov_i(new_op2)) {
		return new_bd_arm_Mov(dbg, block, new_op1, mode, ARM_SHF_LSR, get_arm_imm_value(new_op2));
	}
	return new_bd_arm_Shr(dbg, block, new_op1, new_op2, mode);
}

/**
 * Creates an ARM Shrs.
 *
 * @return the created ARM Shrs node
 */
static ir_node *gen_Shrs(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op1     = get_Shrs_left(node);
	ir_node  *new_op1 = be_transform_node(op1);
	ir_node  *op2     = get_Shrs_right(node);
	ir_node  *new_op2 = be_transform_node(op2);
	ir_mode  *mode    = mode_Iu;
	dbg_info *dbg     = get_irn_dbg_info(node);

	if (is_arm_Mov_i(new_op2)) {
		return new_bd_arm_Mov(dbg, block, new_op1, mode, ARM_SHF_ASR, get_arm_imm_value(new_op2));
	}
	return new_bd_arm_Shrs(dbg, block, new_op1, new_op2, mode);
}

/**
 * Creates an ARM Ror.
 *
 * @return the created ARM Ror node
 */
static ir_node *gen_Ror(ir_node *node, ir_node *op1, ir_node *op2) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *new_op1 = be_transform_node(op1);
	ir_node  *new_op2 = be_transform_node(op2);
	ir_mode  *mode    = mode_Iu;
	dbg_info *dbg     = get_irn_dbg_info(node);

	if (is_arm_Mov_i(new_op2)) {
		return new_bd_arm_Mov(dbg, block, new_op1, mode, ARM_SHF_ROR, get_arm_imm_value(new_op2));
	}
	return new_bd_arm_Ror(dbg, block, new_op1, new_op2, mode);
}

/**
 * Creates an ARM Rol.
 *
 * @return the created ARM Rol node
 *
 * Note: there is no Rol on arm, we have to use Ror
 */
static ir_node *gen_Rol(ir_node *node, ir_node *op1, ir_node *op2) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *new_op1 = be_transform_node(op1);
	ir_mode  *mode    = mode_Iu;
	dbg_info *dbg     = get_irn_dbg_info(node);
	ir_node  *new_op2 = be_transform_node(op2);

	new_op2 = new_bd_arm_Rsb_i(dbg, block, new_op2, mode, 32);
	return new_bd_arm_Ror(dbg, block, new_op1, new_op2, mode);
}

/**
 * Creates an ARM ROR from a Firm Rotl.
 *
 * @return the created ARM Ror node
 */
static ir_node *gen_Rotl(ir_node *node) {
	ir_node *rotate = NULL;
	ir_node *op1    = get_Rotl_left(node);
	ir_node *op2    = get_Rotl_right(node);

	/* Firm has only RotL, so we are looking for a right (op2)
	   operand "-e+mode_size_bits" (it's an already modified "mode_size_bits-e",
	   that means we can create a RotR. */

	if (is_Add(op2)) {
		ir_node *right = get_Add_right(op2);
		if (is_Const(right)) {
			tarval  *tv   = get_Const_tarval(right);
			ir_mode *mode = get_irn_mode(node);
			long     bits = get_mode_size_bits(mode);
			ir_node *left = get_Add_left(op2);

			if (is_Minus(left) &&
			    tarval_is_long(tv)          &&
			    get_tarval_long(tv) == bits &&
			    bits                == 32)
				rotate = gen_Ror(node, op1, get_Minus_op(left));
		}
	} else if (is_Sub(op2)) {
		ir_node *left = get_Sub_left(op2);
		if (is_Const(left)) {
			tarval  *tv   = get_Const_tarval(left);
			ir_mode *mode = get_irn_mode(node);
			long     bits = get_mode_size_bits(mode);
			ir_node *right = get_Sub_right(op2);

			if (tarval_is_long(tv)          &&
			    get_tarval_long(tv) == bits &&
			    bits                == 32)
				rotate = gen_Ror(node, op1, right);
		}
	} else if (is_Const(op2)) {
			tarval  *tv   = get_Const_tarval(op2);
			ir_mode *mode = get_irn_mode(node);
			long     bits = get_mode_size_bits(mode);

			if (tarval_is_long(tv) && bits == 32) {
				ir_node  *block   = be_transform_node(get_nodes_block(node));
				ir_node  *new_op1 = be_transform_node(op1);
				ir_mode  *mode    = mode_Iu;
				dbg_info *dbg     = get_irn_dbg_info(node);

				bits = (bits - get_tarval_long(tv)) & 31;
				rotate = new_bd_arm_Mov(dbg, block, new_op1, mode, ARM_SHF_ROR, bits);
			}
	}

	if (rotate == NULL) {
		rotate = gen_Rol(node, op1, op2);
	}

	return rotate;
}

/**
 * Transforms a Not node.
 *
 * @return the created ARM Not node
 */
static ir_node *gen_Not(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op      = get_Not_op(node);
	ir_node  *new_op  = be_transform_node(op);
	dbg_info *dbg     = get_irn_dbg_info(node);
	ir_mode  *mode    = mode_Iu;
	arm_shift_modifier mod = ARM_SHF_NONE;
	int      v        = is_shifter_operand(new_op, &mod);

	if (v) {
		new_op = get_irn_n(new_op, 0);
	}
	return new_bd_arm_Mvn(dbg, block, new_op, mode, mod, v);
}

/**
 * Transforms an Abs node.
 *
 * @param env   The transformation environment
 * @return the created ARM Abs node
 */
static ir_node *gen_Abs(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op      = get_Abs_op(node);
	ir_node  *new_op  = be_transform_node(op);
	dbg_info *dbg     = get_irn_dbg_info(node);
	ir_mode  *mode    = get_irn_mode(node);

	if (mode_is_float(mode)) {
		env_cg->have_fp_insn = 1;
		if (USE_FPA(env_cg->isa))
			return new_bd_arm_fpaAbs(dbg, block, new_op, mode);
		else if (USE_VFP(env_cg->isa)) {
			assert(mode != mode_E && "IEEE Extended FP not supported");
			panic("VFP not supported yet");
		}
		else {
			panic("Softfloat not supported yet");
		}
	}
	assert(mode_is_data(mode));
	mode = mode_Iu;
	return new_bd_arm_Abs(dbg, block, new_op, mode);
}

/**
 * Transforms a Minus node.
 *
 * @return the created ARM Minus node
 */
static ir_node *gen_Minus(ir_node *node) {
	ir_node  *block   = be_transform_node(get_nodes_block(node));
	ir_node  *op      = get_Minus_op(node);
	ir_node  *new_op  = be_transform_node(op);
	dbg_info *dbg     = get_irn_dbg_info(node);
	ir_mode  *mode    = get_irn_mode(node);

	if (mode_is_float(mode)) {
		env_cg->have_fp_insn = 1;
		if (USE_FPA(env_cg->isa))
			return new_bd_arm_fpaMvf(dbg, block, op, mode);
		else if (USE_VFP(env_cg->isa)) {
			assert(mode != mode_E && "IEEE Extended FP not supported");
			panic("VFP not supported yet");
		}
		else {
			panic("Softfloat not supported yet");
		}
	}
	assert(mode_is_data(mode));
	mode = mode_Iu;
	return new_bd_arm_Rsb_i(dbg, block, new_op, mode, 0);
}

/**
 * Transforms a Load.
 *
 * @return the created ARM Load node
 */
static ir_node *gen_Load(ir_node *node) {
	ir_node  *block    = be_transform_node(get_nodes_block(node));
	ir_node  *ptr      = get_Load_ptr(node);
	ir_node  *new_ptr  = be_transform_node(ptr);
	ir_node  *mem      = get_Load_mem(node);
	ir_node  *new_mem  = be_transform_node(mem);
	ir_mode  *mode     = get_Load_mode(node);
	dbg_info *dbg      = get_irn_dbg_info(node);
	ir_node  *new_load = NULL;

	if (mode_is_float(mode)) {
		env_cg->have_fp_insn = 1;
		if (USE_FPA(env_cg->isa))
			new_load = new_bd_arm_fpaLdf(dbg, block, new_ptr, new_mem, mode);
		else if (USE_VFP(env_cg->isa)) {
			assert(mode != mode_E && "IEEE Extended FP not supported");
			panic("VFP not supported yet");
		}
		else {
			panic("Softfloat not supported yet");
		}
	}
	else {
		assert(mode_is_data(mode) && "unsupported mode for Load");

		if (mode_is_signed(mode)) {
			/* sign extended loads */
			switch (get_mode_size_bits(mode)) {
			case 8:
				new_load = new_bd_arm_Loadbs(dbg, block, new_ptr, new_mem);
				break;
			case 16:
				new_load = new_bd_arm_Loadhs(dbg, block, new_ptr, new_mem);
				break;
			case 32:
				new_load = new_bd_arm_Load(dbg, block, new_ptr, new_mem);
				break;
			default:
				panic("mode size not supported");
			}
		} else {
			/* zero extended loads */
			switch (get_mode_size_bits(mode)) {
			case 8:
				new_load = new_bd_arm_Loadb(dbg, block, new_ptr, new_mem);
				break;
			case 16:
				new_load = new_bd_arm_Loadh(dbg, block, new_ptr, new_mem);
				break;
			case 32:
				new_load = new_bd_arm_Load(dbg, block, new_ptr, new_mem);
				break;
			default:
				panic("mode size not supported");
			}
		}
	}
	set_irn_pinned(new_load, get_irn_pinned(node));

	/* check for special case: the loaded value might not be used */
	if (be_get_Proj_for_pn(node, pn_Load_res) == NULL) {
		ir_graph *irg = current_ir_graph;

		/* add a result proj and a Keep to produce a pseudo use */
		ir_node *proj = new_r_Proj(irg, block, new_load, mode_Iu, pn_arm_Load_res);
		be_new_Keep(arch_get_irn_reg_class_out(proj), irg, block, 1, &proj);
	}

	return new_load;
}

/**
 * Transforms a Store.
 *
 * @return the created ARM Store node
 */
static ir_node *gen_Store(ir_node *node) {
	ir_node  *block    = be_transform_node(get_nodes_block(node));
	ir_node  *ptr      = get_Store_ptr(node);
	ir_node  *new_ptr  = be_transform_node(ptr);
	ir_node  *mem      = get_Store_mem(node);
	ir_node  *new_mem  = be_transform_node(mem);
	ir_node  *val      = get_Store_value(node);
	ir_node  *new_val  = be_transform_node(val);
	ir_mode  *mode     = get_irn_mode(val);
	dbg_info *dbg      = get_irn_dbg_info(node);
	ir_node *new_store = NULL;