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diff --git a/src/gallium/drivers/llvmpipe/lp_bld_interp.c b/src/gallium/drivers/llvmpipe/lp_bld_interp.c
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+/**************************************************************************
+ *
+ * Copyright 2009 VMware, Inc.
+ * Copyright 2007-2008 Tungsten Graphics, Inc., Cedar Park, Texas.
+ * All Rights Reserved.
+ *
+ * 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 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 TUNGSTEN GRAPHICS AND/OR ITS 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.
+ *
+ **************************************************************************/
+
+/**
+ * @file
+ * Position and shader input interpolation.
+ *
+ * @author Jose Fonseca <[email protected]>
+ */
+
+#include "pipe/p_shader_tokens.h"
+#include "util/u_debug.h"
+#include "util/u_memory.h"
+#include "util/u_math.h"
+#include "tgsi/tgsi_parse.h"
+#include "gallivm/lp_bld_debug.h"
+#include "gallivm/lp_bld_const.h"
+#include "gallivm/lp_bld_arit.h"
+#include "gallivm/lp_bld_swizzle.h"
+#include "lp_bld_interp.h"
+
+
+/*
+ * The shader JIT function operates on blocks of quads.
+ * Each block has 2x2 quads and each quad has 2x2 pixels.
+ *
+ * We iterate over the quads in order 0, 1, 2, 3:
+ *
+ * #################
+ * # | # | #
+ * #---0---#---1---#
+ * # | # | #
+ * #################
+ * # | # | #
+ * #---2---#---3---#
+ * # | # | #
+ * #################
+ *
+ * Within each quad, we have four pixels which are represented in SOA
+ * order:
+ *
+ * #########
+ * # 0 | 1 #
+ * #---+---#
+ * # 2 | 3 #
+ * #########
+ *
+ * So the green channel (for example) of the four pixels is stored in
+ * a single vector register: {g0, g1, g2, g3}.
+ */
+
+
+static void
+attrib_name(LLVMValueRef val, unsigned attrib, unsigned chan, const char *suffix)
+{
+ if(attrib == 0)
+ lp_build_name(val, "pos.%c%s", "xyzw"[chan], suffix);
+ else
+ lp_build_name(val, "input%u.%c%s", attrib - 1, "xyzw"[chan], suffix);
+}
+
+
+/**
+ * Initialize the bld->a0, dadx, dady fields. This involves fetching
+ * those values from the arrays which are passed into the JIT function.
+ */
+static void
+coeffs_init(struct lp_build_interp_soa_context *bld,
+ LLVMValueRef a0_ptr,
+ LLVMValueRef dadx_ptr,
+ LLVMValueRef dady_ptr)
+{
+ LLVMBuilderRef builder = bld->base.builder;
+ unsigned attrib;
+ unsigned chan;
+
+ for(attrib = 0; attrib < bld->num_attribs; ++attrib) {
+ const unsigned mask = bld->mask[attrib];
+ const unsigned interp = bld->interp[attrib];
+ for(chan = 0; chan < NUM_CHANNELS; ++chan) {
+ if(mask & (1 << chan)) {
+ LLVMValueRef index = LLVMConstInt(LLVMInt32Type(), attrib*NUM_CHANNELS + chan, 0);
+ LLVMValueRef a0 = NULL;
+ LLVMValueRef dadx = NULL;
+ LLVMValueRef dady = NULL;
+
+ switch( interp ) {
+ case TGSI_INTERPOLATE_PERSPECTIVE:
+ /* fall-through */
+
+ case TGSI_INTERPOLATE_LINEAR:
+ dadx = LLVMBuildLoad(builder, LLVMBuildGEP(builder, dadx_ptr, &index, 1, ""), "");
+ dady = LLVMBuildLoad(builder, LLVMBuildGEP(builder, dady_ptr, &index, 1, ""), "");
+ dadx = lp_build_broadcast_scalar(&bld->base, dadx);
+ dady = lp_build_broadcast_scalar(&bld->base, dady);
+ attrib_name(dadx, attrib, chan, ".dadx");
+ attrib_name(dady, attrib, chan, ".dady");
+ /* fall-through */
+
+ case TGSI_INTERPOLATE_CONSTANT:
+ a0 = LLVMBuildLoad(builder, LLVMBuildGEP(builder, a0_ptr, &index, 1, ""), "");
+ a0 = lp_build_broadcast_scalar(&bld->base, a0);
+ attrib_name(a0, attrib, chan, ".a0");
+ break;
+
+ default:
+ assert(0);
+ break;
+ }
+
+ bld->a0 [attrib][chan] = a0;
+ bld->dadx[attrib][chan] = dadx;
+ bld->dady[attrib][chan] = dady;
+ }
+ }
+ }
+}
+
+
+/**
+ * Emit LLVM code to compute the fragment shader input attribute values.
+ * For example, for a color input, we'll compute red, green, blue and alpha
+ * values for the four pixels in a quad.
+ * Recall that we're operating on 4-element vectors so each arithmetic
+ * operation is operating on the four pixels in a quad.
+ */
+static void
+attribs_init(struct lp_build_interp_soa_context *bld)
+{
+ LLVMValueRef x = bld->pos[0];
+ LLVMValueRef y = bld->pos[1];
+ LLVMValueRef oow = NULL;
+ unsigned attrib;
+ unsigned chan;
+
+ for(attrib = 0; attrib < bld->num_attribs; ++attrib) {
+ const unsigned mask = bld->mask[attrib];
+ const unsigned interp = bld->interp[attrib];
+ for(chan = 0; chan < NUM_CHANNELS; ++chan) {
+ if(mask & (1 << chan)) {
+ LLVMValueRef a0 = bld->a0 [attrib][chan];
+ LLVMValueRef dadx = bld->dadx[attrib][chan];
+ LLVMValueRef dady = bld->dady[attrib][chan];
+ LLVMValueRef res;
+
+ res = a0;
+
+ if (interp != TGSI_INTERPOLATE_CONSTANT) {
+ /* res = res + x * dadx */
+ res = lp_build_add(&bld->base, res, lp_build_mul(&bld->base, x, dadx));
+ /* res = res + y * dady */
+ res = lp_build_add(&bld->base, res, lp_build_mul(&bld->base, y, dady));
+ }
+
+ /* Keep the value of the attribute before perspective divide
+ * for faster updates.
+ */
+ bld->attribs_pre[attrib][chan] = res;
+
+ if (interp == TGSI_INTERPOLATE_PERSPECTIVE) {
+ LLVMValueRef w = bld->pos[3];
+ assert(attrib != 0);
+ if(!oow)
+ oow = lp_build_rcp(&bld->base, w);
+ res = lp_build_mul(&bld->base, res, oow);
+ }
+
+ attrib_name(res, attrib, chan, "");
+
+ bld->attribs[attrib][chan] = res;
+ }
+ }
+ }
+}
+
+
+/**
+ * Increment the shader input attribute values.
+ * This is called when we move from one quad to the next.
+ */
+static void
+attribs_update(struct lp_build_interp_soa_context *bld, int quad_index)
+{
+ LLVMValueRef oow = NULL;
+ unsigned attrib;
+ unsigned chan;
+
+ assert(quad_index < 4);
+
+ for(attrib = 0; attrib < bld->num_attribs; ++attrib) {
+ const unsigned mask = bld->mask[attrib];
+ const unsigned interp = bld->interp[attrib];
+
+ if (interp != TGSI_INTERPOLATE_CONSTANT) {
+ for(chan = 0; chan < NUM_CHANNELS; ++chan) {
+ if(mask & (1 << chan)) {
+ LLVMValueRef dadx = bld->dadx[attrib][chan];
+ LLVMValueRef dady = bld->dady[attrib][chan];
+ LLVMValueRef res;
+
+ res = bld->attribs_pre[attrib][chan];
+
+ if (quad_index == 1 || quad_index == 3) {
+ /* top-right or bottom-right quad */
+ /* build res = res + dadx + dadx */
+ res = lp_build_add(&bld->base, res, dadx);
+ res = lp_build_add(&bld->base, res, dadx);
+ }
+
+ if (quad_index == 2 || quad_index == 3) {
+ /* bottom-left or bottom-right quad */
+ /* build res = res + dady + dady */
+ res = lp_build_add(&bld->base, res, dady);
+ res = lp_build_add(&bld->base, res, dady);
+ }
+
+ if (interp == TGSI_INTERPOLATE_PERSPECTIVE) {
+ LLVMValueRef w = bld->pos[3];
+ assert(attrib != 0);
+ if(!oow)
+ oow = lp_build_rcp(&bld->base, w);
+ res = lp_build_mul(&bld->base, res, oow);
+ }
+
+ attrib_name(res, attrib, chan, "");
+
+ bld->attribs[attrib][chan] = res;
+ }
+ }
+ }
+ }
+}
+
+
+/**
+ * Generate the position vectors.
+ *
+ * Parameter x0, y0 are the integer values with the quad upper left coordinates.
+ */
+static void
+pos_init(struct lp_build_interp_soa_context *bld,
+ LLVMValueRef x0,
+ LLVMValueRef y0)
+{
+ lp_build_name(x0, "pos.x");
+ lp_build_name(y0, "pos.y");
+
+ bld->attribs[0][0] = x0;
+ bld->attribs[0][1] = y0;
+}
+
+
+/**
+ * Update quad position values when moving to the next quad.
+ */
+static void
+pos_update(struct lp_build_interp_soa_context *bld, int quad_index)
+{
+ LLVMValueRef x = bld->attribs[0][0];
+ LLVMValueRef y = bld->attribs[0][1];
+ const int xstep = 2, ystep = 2;
+
+ if (quad_index == 1 || quad_index == 3) {
+ /* top-right or bottom-right quad in block */
+ /* build x += xstep */
+ x = lp_build_add(&bld->base, x,
+ lp_build_const_vec(bld->base.type, xstep));
+ }
+
+ if (quad_index == 2) {
+ /* bottom-left quad in block */
+ /* build y += ystep */
+ y = lp_build_add(&bld->base, y,
+ lp_build_const_vec(bld->base.type, ystep));
+ /* build x -= xstep */
+ x = lp_build_sub(&bld->base, x,
+ lp_build_const_vec(bld->base.type, xstep));
+ }
+
+ lp_build_name(x, "pos.x");
+ lp_build_name(y, "pos.y");
+
+ bld->attribs[0][0] = x;
+ bld->attribs[0][1] = y;
+}
+
+
+/**
+ * Initialize fragment shader input attribute info.
+ */
+void
+lp_build_interp_soa_init(struct lp_build_interp_soa_context *bld,
+ const struct tgsi_token *tokens,
+ boolean flatshade,
+ LLVMBuilderRef builder,
+ struct lp_type type,
+ LLVMValueRef a0_ptr,
+ LLVMValueRef dadx_ptr,
+ LLVMValueRef dady_ptr,
+ LLVMValueRef x0,
+ LLVMValueRef y0)
+{
+ struct tgsi_parse_context parse;
+ struct tgsi_full_declaration *decl;
+
+ memset(bld, 0, sizeof *bld);
+
+ lp_build_context_init(&bld->base, builder, type);
+
+ /* For convenience */
+ bld->pos = bld->attribs[0];
+ bld->inputs = (const LLVMValueRef (*)[NUM_CHANNELS]) bld->attribs[1];
+
+ /* Position */
+ bld->num_attribs = 1;
+ bld->mask[0] = TGSI_WRITEMASK_ZW;
+ bld->interp[0] = TGSI_INTERPOLATE_LINEAR;
+
+ /* Inputs */
+ tgsi_parse_init( &parse, tokens );
+ while( !tgsi_parse_end_of_tokens( &parse ) ) {
+ tgsi_parse_token( &parse );
+
+ switch( parse.FullToken.Token.Type ) {
+ case TGSI_TOKEN_TYPE_DECLARATION:
+ decl = &parse.FullToken.FullDeclaration;
+ if( decl->Declaration.File == TGSI_FILE_INPUT ) {
+ unsigned first, last, mask;
+ unsigned attrib;
+
+ first = decl->Range.First;
+ last = decl->Range.Last;
+ mask = decl->Declaration.UsageMask;
+
+ for( attrib = first; attrib <= last; ++attrib ) {
+ bld->mask[1 + attrib] = mask;
+
+ /* XXX: have mesa set INTERP_CONSTANT in the fragment
+ * shader.
+ */
+ if (decl->Semantic.Name == TGSI_SEMANTIC_COLOR &&
+ flatshade)
+ bld->interp[1 + attrib] = TGSI_INTERPOLATE_CONSTANT;
+ else
+ bld->interp[1 + attrib] = decl->Declaration.Interpolate;
+ }
+
+ bld->num_attribs = MAX2(bld->num_attribs, 1 + last + 1);
+ }
+ break;
+
+ case TGSI_TOKEN_TYPE_INSTRUCTION:
+ case TGSI_TOKEN_TYPE_IMMEDIATE:
+ case TGSI_TOKEN_TYPE_PROPERTY:
+ break;
+
+ default:
+ assert( 0 );
+ }
+ }
+ tgsi_parse_free( &parse );
+
+ coeffs_init(bld, a0_ptr, dadx_ptr, dady_ptr);
+
+ pos_init(bld, x0, y0);
+
+ attribs_init(bld);
+}
+
+
+/**
+ * Advance the position and inputs to the given quad within the block.
+ */
+void
+lp_build_interp_soa_update(struct lp_build_interp_soa_context *bld,
+ int quad_index)
+{
+ assert(quad_index < 4);
+
+ pos_update(bld, quad_index);
+
+ attribs_update(bld, quad_index);
+}