/*
 * Copyright 2008 Nicolai Haehnle.
 * SPDX-License-Identifier: MIT
 */

#include "radeon_program.h"

#include <stdio.h>

#include "radeon_compiler.h"
#include "radeon_dataflow.h"


/**
 * Transform the given clause in the following way:
 *  1. Replace it with an empty clause
 *  2. For every instruction in the original clause, try the given
 *     transformations in order.
 *  3. If one of the transformations returns GL_TRUE, assume that it
 *     has emitted the appropriate instruction(s) into the new clause;
 *     otherwise, copy the instruction verbatim.
 *
 * \note The transformation is currently not recursive; in other words,
 * instructions emitted by transformations are not transformed.
 *
 * \note The transform is called 'local' because it can only look at
 * one instruction at a time.
 */
void rc_local_transform(
	struct radeon_compiler * c,
	void *user)
{
	struct radeon_program_transformation *transformations =
		(struct radeon_program_transformation*)user;
	struct rc_instruction * inst = c->Program.Instructions.Next;

	while(inst != &c->Program.Instructions) {
		struct rc_instruction * current = inst;
		int i;

		inst = inst->Next;

		for(i = 0; transformations[i].function; ++i) {
			struct radeon_program_transformation* t = transformations + i;

			if (t->function(c, current, t->userData))
				break;
		}
	}
}

unsigned int rc_find_free_temporary(struct radeon_compiler * c)
{
	/* Find the largest used temp index when called for the first time. */
	if (c->max_temp_index == -1) {
		for (struct rc_instruction * inst = c->Program.Instructions.Next;
			inst != &c->Program.Instructions; inst = inst->Next) {
			const struct rc_opcode_info * opcode =
				rc_get_opcode_info(inst->U.I.Opcode);
			if (opcode->HasDstReg &&
				inst->U.I.DstReg.File == RC_FILE_TEMPORARY &&
				inst->U.I.WriteALUResult == RC_ALURESULT_NONE &&
				inst->U.I.DstReg.Index > c->max_temp_index)
				c->max_temp_index = inst->U.I.DstReg.Index;
		}
	}

	c->max_temp_index++;
	if (c->max_temp_index > RC_REGISTER_MAX_INDEX) {
		rc_error(c, "Ran out of temporary registers\n");
		return 0;
	}
	return c->max_temp_index;
}


struct rc_instruction *rc_alloc_instruction(struct radeon_compiler * c)
{
	struct rc_instruction * inst = memory_pool_malloc(&c->Pool, sizeof(struct rc_instruction));

	memset(inst, 0, sizeof(struct rc_instruction));

	inst->U.I.Opcode = RC_OPCODE_ILLEGAL_OPCODE;
	inst->U.I.DstReg.WriteMask = RC_MASK_XYZW;
	inst->U.I.SrcReg[0].Swizzle = RC_SWIZZLE_XYZW;
	inst->U.I.SrcReg[1].Swizzle = RC_SWIZZLE_XYZW;
	inst->U.I.SrcReg[2].Swizzle = RC_SWIZZLE_XYZW;

	return inst;
}

void rc_insert_instruction(struct rc_instruction * after, struct rc_instruction * inst)
{
	inst->Prev = after;
	inst->Next = after->Next;

	inst->Prev->Next = inst;
	inst->Next->Prev = inst;
}

struct rc_instruction *rc_insert_new_instruction(struct radeon_compiler * c, struct rc_instruction * after)
{
	struct rc_instruction * inst = rc_alloc_instruction(c);

	rc_insert_instruction(after, inst);

	return inst;
}

void rc_remove_instruction(struct rc_instruction * inst)
{
	inst->Prev->Next = inst->Next;
	inst->Next->Prev = inst->Prev;
}

/**
 * Return the number of instructions in the program.
 */
unsigned int rc_recompute_ips(struct radeon_compiler * c)
{
	unsigned int ip = 0;
	struct rc_instruction * inst;

	for(inst = c->Program.Instructions.Next;
	    inst != &c->Program.Instructions;
	    inst = inst->Next) {
		inst->IP = ip++;
	}

	c->Program.Instructions.IP = 0xcafedead;

	return ip;
}