+/*
+ * Copyright (C) 1995-2007 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 Lowering of high level constructs.
+ * @author Michael Beck
+ * @version $Id$
+ */
+#ifndef FIRM_LOWERING_H
+#define FIRM_LOWERING_H
+
+/**
+ * A type telling where to add hidden parameters.
+ */
+typedef enum add_hidden_params {
+ ADD_HIDDEN_ALWAYS_IN_FRONT = 0, /**< always add hidden parameters in front (default). */
+ ADD_HIDDEN_ALWAYS_LAST = 1, /**< always add hidden parameters last, did not work for variadic functions. */
+ ADD_HIDDEN_SMART = 2 /**< add hidden parameters last for non-variadic and first for variadic functions. */
+} add_hidden;
+
+/**
+ * Additional flags for the lowering.
+ */
+enum lowering_flags {
+ LF_NONE = 0, /**< no additional flags */
+ LF_COMPOUND_PARAM = 1, /**< lower calls with compound parameters */
+ LF_COMPOUND_RETURN = 2, /**< lower calls with compound returns */
+ LF_RETURN_HIDDEN = 4, /**< return the hidden address instead of void */
+ LF_SMALL_CMP_IN_REGS = 8 /**< return small compound values in registers */
+};
+
+/** Maximum number of registers that can be used to return compound values. */
+#define MAX_REGISTER_RET_VAL 2
+
+/**
+ * A struct containing all control parameters for
+ * lower_compound_ret_calls().
+ */
+typedef struct {
+ int def_ptr_alignment; /**< Default alignment for data pointer. */
+ unsigned flags; /**< A bitmask of enum lowering_flags. */
+ add_hidden hidden_params; /**< Where to add hidden parameters. */
+
+ /**
+ * A function returning a pointer type for a given type.
+ * If this pointer is NULL, a new pointer type is always created.
+ */
+ ir_type *(*find_pointer_type)(ir_type *e_type, ir_mode *mode, int alignment);
+
+ /**
+ * If the LF_SMALL_CMP_IN_REGS flag is set, this function will be called
+ * to decide, whether a compound value should be returned in registers.
+ * This function must return the number of used registers and fill in the modes
+ * of the registers to use. Up to MAX_REGISTER_RET_VAL registers can be used.
+ */
+ int (*ret_compound_in_regs)(ir_type *compound_tp, ir_mode **modes);
+} lower_params_t;
+
+/**
+ * Lower calls with compound parameter and return types.
+ * This function does the following transformations:
+ *
+ * If LF_COMPOUND_PARAM is set:
+ *
+ * - Copy compound parameters to a new location on the callers
+ * stack and transmit the address of this new location
+ *
+ * If LF_COMPOUND_RETURN is set:
+ *
+ * - Adds a new (hidden) pointer parameter for
+ * any return compound type. The return type is replaced by void
+ * or if LOWERING_FLAGS_RETURN_HIDDEN is set by the address.
+ *
+ * - Use of the hidden parameters in the function code.
+ *
+ * - Change all calls to functions with compound return
+ * by providing space for the hidden parameter on the callers
+ * stack.
+ *
+ * - Replace a possible block copy after the function call.
+ *
+ * General:
+ *
+ * - Changes the types of methods and calls to the lowered ones
+ *
+ * - lower all method types of existing entities
+ *
+ * In pseudo-code, the following transformation is done:
+ *
+ @code
+ struct x ret = func(a, b);
+ @endcode
+ *
+ * is translated into
+ @code
+ struct x ret;
+ func(&ret, a, b);
+ @endcode
+ *
+ * If the function returns only one possible result, the copy-on-return
+ * optimization is done, ie.
+ @code
+ struct x func(a) {
+ struct x ret;
+ ret.a = a;
+ return ret;
+ }
+ @endcode
+ *
+ * is transformed into
+ *
+ @code
+ void func(struct x *ret, a) {
+ ret->a = a;
+ }
+ @endcode
+ *
+ * @param params A structure containing the control parameter for this
+ * transformation.
+ *
+ * During the transformation, pointer types must be created or reused.
+ * The caller can provide params->find_pointer_type for this task to
+ * reduce the number of created pointer types.
+ * If params->find_pointer_type is NULL, new pointer types
+ * are always created automatically.
+ */
+void lower_calls_with_compounds(const lower_params_t *params);
+
+/**
+ * A callback type for creating an intrinsic entity for a given opcode.
+ *
+ * @param method the method type of the emulation function entity
+ * @param op the emulated ir_op
+ * @param imode the input mode of the emulated opcode
+ * @param omode the output mode of the emulated opcode
+ * @param context the context parameter
+ */
+typedef ir_entity *(create_intrinsic_fkt)(ir_type *method, const ir_op *op,
+ const ir_mode *imode, const ir_mode *omode,
+ void *context);
+
+/**
+ * The lowering parameter description.
+ */
+typedef struct _lwrdw_param_t {
+ int enable; /**< if true lowering is enabled */
+ int little_endian; /**< if true should be lowered for little endian, else big endian */
+ ir_mode *high_signed; /**< the double word signed mode to be lowered, typically Ls */
+ ir_mode *high_unsigned; /**< the double word unsigned mode to be lowered, typically Lu */
+ ir_mode *low_signed; /**< the word signed mode to be used, typically Is */
+ ir_mode *low_unsigned; /**< the word unsigned mode to be used, typically Iu */
+
+ /** callback that creates the intrinsic entity */
+ create_intrinsic_fkt *create_intrinsic;
+ void *ctx; /**< context parameter for the creator function */
+} lwrdw_param_t;
+
+/**
+ * Lower all double word operations.
+ */
+void lower_dw_ops(const lwrdw_param_t *param);
+
+/**
+ * Default implementation. Context is unused.
+ */
+ir_entity *def_create_intrinsic_fkt(ir_type *method, const ir_op *op,
+ const ir_mode *imode, const ir_mode *omode,
+ void *context);
+
+/**
+ * Replaces SymConsts by a real constant if possible.
+ * Replace Sel nodes by address computation. Also resolves array access.
+ * Handle Bitfields by added And/Or calculations.
+ *
+ * @Note: There is NO lowering ob objects oriented types. This is highly compiler
+ * and ABI specific and should be placed directly in the compiler.
+ */
+void lower_highlevel(void);
+
+/**
+ * An intrinsic mapper function.
+ *
+ * @param node the IR-node that will be mapped
+ * @param ctx a context
+ *
+ * @return non-zero if the call was mapped
+ */
+typedef int (*i_mapper_func)(ir_node *node, void *ctx);
+
+enum ikind {
+ INTRINSIC_CALL = 0, /**< the record represents an intrinsic call */
+ INTRINSIC_INSTR /**< the record represents an intrinsic instruction */
+};
+
+/**
+ * An intrinsic call record.
+ */
+typedef struct _i_call_record {
+ enum ikind kind; /**< must be INTRINSIC_CALL */
+ ir_entity *i_ent; /**< the entity representing an intrinsic call */
+ i_mapper_func i_mapper; /**< the mapper function to call */
+ void *ctx; /**< mapper context */
+ void *link; /**< used in the construction algorithm, must be NULL */
+} i_call_record;
+
+/**
+ * An intrinsic instruction record.
+ */
+typedef struct _i_instr_record {
+ enum ikind kind; /**< must be INTRINSIC_INSTR */
+ ir_op *op; /**< the opcode that must be mapped. */
+ i_mapper_func i_mapper; /**< the mapper function to call */
+ void *ctx; /**< mapper context */
+ void *link; /**< used in the construction algorithm, must be NULL */
+} i_instr_record;
+
+/**
+ * An intrinsic record.
+ */
+typedef union _i_record {
+ i_call_record i_call;
+ i_instr_record i_instr;
+} i_record;
+
+/**
+ * Go through all graphs and map calls to intrinsic functions and instructions.
+ *
+ * Every call or instruction is reported to its mapper function,
+ * which is responsible for rebuilding the graph.
+ *
+ * current_ir_graph is always set.
+ *
+ * @param list an array of intrinsic map records
+ * @param length the length of the array
+ *
+ * @return number of found intrinsics.
+ */
+unsigned lower_intrinsics(i_record *list, int length);
+
+/**
+ * A mapper for the integer absolute value: inttype abs(inttype v).
+ * Replaces the call by a Abs node.
+ *
+ * @return always 1
+ */
+int i_mapper_Abs(ir_node *call, void *ctx);
+
+/**
+ * A mapper for the alloca() function: pointer alloca(inttype size)
+ * Replaces the call by a Alloca(stack_alloc) node.
+ *
+ * @return always 1
+ */
+int i_mapper_Alloca(ir_node *call, void *ctx);
+
+/**
+ * A runtime routine description.
+ */
+typedef struct _runtime_rt {
+ ir_entity *ent; /**< The entity representing the runtime routine. */
+ ir_mode *mode; /**< The operation mode of the mapped instruction. */
+ ir_mode *res_mode; /**< The result mode of the mapped instruction or NULL. */
+ long mem_proj_nr; /**< if >= 0, create a memory ProjM() */
+ long regular_proj_nr; /**< if >= 0, create a regular ProjX() */
+ long exc_proj_nr; /**< if >= 0, create a exception ProjX() */
+ long exc_mem_proj_nr; /**< if >= 0, create a exception memory ProjM() */
+ long res_proj_nr; /**< if >= 0, first result projection number */
+} runtime_rt;
+
+/**
+ * A mapper for mapping unsupported instructions to runtime calls.
+ * Maps a op(arg_0, ..., arg_n) into a call to a runtime function
+ * rt(arg_0, ..., arg_n).
+ *
+ * The mapping is only done, if the modes of all arguments matches the
+ * modes of rt's argument.
+ * Further, if op has a memory input, the generated Call uses it, else
+ * it gets a NoMem.
+ * The pinned state of the Call will be set to the pinned state of op.
+ *
+ * Note that i_mapper_RuntimeCall() must be used with a i_instr_record.
+ *
+ * @return 1 if an op was mapped, 0 else
+ *
+ * Some examples:
+ *
+ * - Maps signed Div nodes to calls to rt_Div():
+ @code
+ runtime_rt rt_Div = {
+ ent("int rt_Div(int, int)"),
+ mode_T,
+ mode_Is,
+ pn_Div_M,
+ pn_Div_X_regular,
+ pn_Div_X_except,
+ pn_Div_M,
+ pn_Div_res
+ };
+ i_instr_record map_Div = {
+ INTRINSIC_INSTR,
+ op_Div,
+ i_mapper_RuntimeCall,
+ &rt_Div,
+ NULL
+ };
+ @endcode
+ *
+ * - Maps ConvD(F) to calls to rt_Float2Div():
+ @code
+ runtime_rt rt_Float2Double = {
+ ent("double rt_Float2Div(float)"),
+ get_type_mode("double"),
+ NULL,
+ -1,
+ -1,
+ -1,
+ -1,
+ -1
+ };
+ i_instr_record map_Float2Double = {
+ INTRINSIC_INSTR,
+ op_Conv,
+ i_mapper_RuntimeCall,
+ &rt_Float2Double,
+ NULL
+ };
+ @endcode
+ */
+int i_mapper_RuntimeCall(ir_node *node, runtime_rt *rt);
+
+#endif /* FIRM_LOWERING_H */