/*
 * Copyright 2009 Nicolai Hähnle <nhaehnle@gmail.com>
 *
 * Permission is hereby granted, free of charge, to any person obtaining a
 * copy of this software and associated documentation files (the "Software"),
 * to deal in the Software without restriction, including without limitation
 * on the rights to use, copy, modify, merge, publish, distribute, sub
 * license, and/or sell copies of the Software, and to permit persons to whom
 * the Software is furnished to do so, subject to the following conditions:
 *
 * The above copyright notice and this permission notice (including the next
 * paragraph) shall be included in all copies or substantial portions of the
 * Software.
 *
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
 * FITNESS FOR A PARTICULAR PURPOSE AND NON-INFRINGEMENT. IN NO EVENT SHALL
 * THE AUTHOR(S) AND/OR THEIR SUPPLIERS BE LIABLE FOR ANY CLAIM,
 * DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR
 * OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE
 * USE OR OTHER DEALINGS IN THE SOFTWARE. */

#include "radeon_compiler.h"

#include "shader/prog_parameter.h"
#include "shader/prog_print.h"
#include "shader/prog_statevars.h"

#include "radeon_nqssadce.h"
#include "radeon_program_alu.h"
#include "r300_fragprog.h"
#include "r300_fragprog_swizzle.h"
#include "r500_fragprog.h"


static void nqssadce_init(struct nqssadce_state* s)
{
	s->Outputs[FRAG_RESULT_COLOR].Sourced = WRITEMASK_XYZW;
	s->Outputs[FRAG_RESULT_DEPTH].Sourced = WRITEMASK_W;
}

/**
 * Transform the program to support fragment.position.
 *
 * Introduce a small fragment at the start of the program that will be
 * the only code that directly reads the FRAG_ATTRIB_WPOS input.
 * All other code pieces that reference that input will be rewritten
 * to read from a newly allocated temporary.
 *
 */
static void insert_WPOS_trailer(struct r300_fragment_program_compiler *compiler)
{
	GLuint InputsRead = compiler->program->InputsRead;

	if (!(InputsRead & FRAG_BIT_WPOS)) {
		compiler->code->wpos_attr = FRAG_ATTRIB_MAX;
		return;
	}

	static gl_state_index tokens[STATE_LENGTH] = {
		STATE_INTERNAL, STATE_R300_WINDOW_DIMENSION, 0, 0, 0
	};
	struct prog_instruction *fpi;
	GLuint window_index;
	int i = 0;

	for (i = FRAG_ATTRIB_TEX0; i <= FRAG_ATTRIB_TEX7; ++i)
	{
		if (!(InputsRead & (1 << i))) {
			InputsRead &= ~(1 << FRAG_ATTRIB_WPOS);
			InputsRead |= 1 << i;
			compiler->program->InputsRead = InputsRead;
			compiler->code->wpos_attr = i;
			break;
		}
	}

	GLuint tempregi = _mesa_find_free_register(compiler->program, PROGRAM_TEMPORARY);

	_mesa_insert_instructions(compiler->program, 0, 3);
	fpi = compiler->program->Instructions;
	i = 0;

	/* perspective divide */
	fpi[i].Opcode = OPCODE_RCP;

	fpi[i].DstReg.File = PROGRAM_TEMPORARY;
	fpi[i].DstReg.Index = tempregi;
	fpi[i].DstReg.WriteMask = WRITEMASK_W;
	fpi[i].DstReg.CondMask = COND_TR;

	fpi[i].SrcReg[0].File = PROGRAM_INPUT;
	fpi[i].SrcReg[0].Index = compiler->code->wpos_attr;
	fpi[i].SrcReg[0].Swizzle = SWIZZLE_WWWW;
	i++;

	fpi[i].Opcode = OPCODE_MUL;

	fpi[i].DstReg.File = PROGRAM_TEMPORARY;
	fpi[i].DstReg.Index = tempregi;
	fpi[i].DstReg.WriteMask = WRITEMASK_XYZ;
	fpi[i].DstReg.CondMask = COND_TR;

	fpi[i].SrcReg[0].File = PROGRAM_INPUT;
	fpi[i].SrcReg[0].Index = compiler->code->wpos_attr;
	fpi[i].SrcReg[0].Swizzle = SWIZZLE_XYZW;

	fpi[i].SrcReg[1].File = PROGRAM_TEMPORARY;
	fpi[i].SrcReg[1].Index = tempregi;
	fpi[i].SrcReg[1].Swizzle = SWIZZLE_WWWW;
	i++;

	/* viewport transformation */
	window_index = _mesa_add_state_reference(compiler->program->Parameters, tokens);

	fpi[i].Opcode = OPCODE_MAD;

	fpi[i].DstReg.File = PROGRAM_TEMPORARY;
	fpi[i].DstReg.Index = tempregi;
	fpi[i].DstReg.WriteMask = WRITEMASK_XYZ;
	fpi[i].DstReg.CondMask = COND_TR;

	fpi[i].SrcReg[0].File = PROGRAM_TEMPORARY;
	fpi[i].SrcReg[0].Index = tempregi;
	fpi[i].SrcReg[0].Swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_ZERO);

	fpi[i].SrcReg[1].File = PROGRAM_STATE_VAR;
	fpi[i].SrcReg[1].Index = window_index;
	fpi[i].SrcReg[1].Swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_ZERO);

	fpi[i].SrcReg[2].File = PROGRAM_STATE_VAR;
	fpi[i].SrcReg[2].Index = window_index;
	fpi[i].SrcReg[2].Swizzle = MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_Y, SWIZZLE_Z, SWIZZLE_ZERO);
	i++;

	for (; i < compiler->program->NumInstructions; ++i) {
		int reg;
		for (reg = 0; reg < 3; reg++) {
			if (fpi[i].SrcReg[reg].File == PROGRAM_INPUT &&
			    fpi[i].SrcReg[reg].Index == FRAG_ATTRIB_WPOS) {
				fpi[i].SrcReg[reg].File = PROGRAM_TEMPORARY;
				fpi[i].SrcReg[reg].Index = tempregi;
			}
		}
	}
}


/**
 * Rewrite fragment.fogcoord to use a texture coordinate slot.
 * Note that fogcoord is forced into an X001 pattern, and this enforcement
 * is done here.
 *
 * See also the counterpart rewriting for vertex programs.
 */
static void rewriteFog(struct r300_fragment_program_compiler *compiler)
{
	struct rX00_fragment_program_code *code = compiler->code;
	GLuint InputsRead = compiler->program->InputsRead;
	int i;

	if (!(InputsRead & FRAG_BIT_FOGC)) {
		code->fog_attr = FRAG_ATTRIB_MAX;
		return;
	}

	for (i = FRAG_ATTRIB_TEX0; i <= FRAG_ATTRIB_TEX7; ++i)
	{
		if (!(InputsRead & (1 << i))) {
			InputsRead &= ~(1 << FRAG_ATTRIB_FOGC);
			InputsRead |= 1 << i;
			compiler->program->InputsRead = InputsRead;
			code->fog_attr = i;
			break;
		}
	}

	{
		struct prog_instruction *inst;

		inst = compiler->program->Instructions;
		while (inst->Opcode != OPCODE_END) {
			const int src_regs = _mesa_num_inst_src_regs(inst->Opcode);
			for (i = 0; i < src_regs; ++i) {
				if (inst->SrcReg[i].File == PROGRAM_INPUT && inst->SrcReg[i].Index == FRAG_ATTRIB_FOGC) {
					inst->SrcReg[i].Index = code->fog_attr;
					inst->SrcReg[i].Swizzle = combine_swizzles(
						MAKE_SWIZZLE4(SWIZZLE_X, SWIZZLE_ZERO, SWIZZLE_ZERO, SWIZZLE_ONE),
						inst->SrcReg[i].Swizzle);
				}
			}
			++inst;
		}
	}
}


static void rewrite_depth_out(struct gl_program *prog)
{
	struct prog_instruction *inst;

	for (inst = prog->Instructions; inst->Opcode != OPCODE_END; ++inst) {
		if (inst->DstReg.File != PROGRAM_OUTPUT || inst->DstReg.Index != FRAG_RESULT_DEPTH)
			continue;

		if (inst->DstReg.WriteMask & WRITEMASK_Z) {
			inst->DstReg.WriteMask = WRITEMASK_W;
		} else {
			inst->DstReg.WriteMask = 0;
			continue;
		}

		switch (inst->Opcode) {
			case OPCODE_FRC:
			case OPCODE_MOV:
				inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
				break;
			case OPCODE_ADD:
			case OPCODE_MAX:
			case OPCODE_MIN:
			case OPCODE_MUL:
				inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
				inst->SrcReg[1] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[1]);
				break;
			case OPCODE_CMP:
			case OPCODE_MAD:
				inst->SrcReg[0] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[0]);
				inst->SrcReg[1] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[1]);
				inst->SrcReg[2] = lmul_swizzle(SWIZZLE_ZZZZ, inst->SrcReg[2]);
				break;
			default:
				// Scalar instructions needn't be reswizzled
				break;
		}
	}
}

GLboolean r3xx_compile_fragment_program(struct r300_fragment_program_compiler* c)
{
	GLboolean success = GL_FALSE;

	if (c->Base.Debug) {
		fflush(stdout);
		_mesa_printf("Fragment Program: Initial program:\n");
		_mesa_print_program(c->program);
		fflush(stdout);
	}

	insert_WPOS_trailer(c);

	rewriteFog(c);

	rewrite_depth_out(c->program);

	if (c->is_r500) {
		struct radeon_program_transformation transformations[] = {
			{ &r500_transform_TEX, c },
			{ &radeonTransformALU, 0 },
			{ &radeonTransformDeriv, 0 },
			{ &radeonTransformTrigScale, 0 }
		};
		radeonLocalTransform(c->program, 4, transformations);
	} else {
		struct radeon_program_transformation transformations[] = {
			{ &r300_transform_TEX, c },
			{ &radeonTransformALU, 0 },
			{ &radeonTransformTrigSimple, 0 }
		};
		radeonLocalTransform(c->program, 3, transformations);
	}

	if (c->Base.Debug) {
		_mesa_printf("Fragment Program: After native rewrite:\n");
		_mesa_print_program(c->program);
		fflush(stdout);
	}

	if (c->is_r500) {
		struct radeon_nqssadce_descr nqssadce = {
			.Init = &nqssadce_init,
			.IsNativeSwizzle = &r500FPIsNativeSwizzle,
			.BuildSwizzle = &r500FPBuildSwizzle
		};
		radeonNqssaDce(c->program, &nqssadce, 0);
	} else {
		struct radeon_nqssadce_descr nqssadce = {
			.Init = &nqssadce_init,
			.IsNativeSwizzle = &r300FPIsNativeSwizzle,
			.BuildSwizzle = &r300FPBuildSwizzle
		};
		radeonNqssaDce(c->program, &nqssadce, 0);
	}

	if (c->Base.Debug) {
		_mesa_printf("Compiler: after NqSSA-DCE:\n");
		_mesa_print_program(c->program);
		fflush(stdout);
	}

	rc_mesa_to_rc_program(&c->Base, c->program);

	if (c->is_r500) {
		success = r500BuildFragmentProgramHwCode(c);
	} else {
		success = r300BuildFragmentProgramHwCode(c);
	}

	if (!success || c->Base.Debug) {
		if (c->is_r500) {
			r500FragmentProgramDump(c->code);
		} else {
			r300FragmentProgramDump(c->code);
		}
	}

	return success;
}