diff options
Diffstat (limited to 'mesalib/src/mesa/program')
-rw-r--r-- | mesalib/src/mesa/program/register_allocate.c | 916 |
1 files changed, 458 insertions, 458 deletions
diff --git a/mesalib/src/mesa/program/register_allocate.c b/mesalib/src/mesa/program/register_allocate.c index f984e2f14..8992b91b6 100644 --- a/mesalib/src/mesa/program/register_allocate.c +++ b/mesalib/src/mesa/program/register_allocate.c @@ -1,458 +1,458 @@ -/* - * Copyright © 2010 Intel Corporation - * - * 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, sublicense, - * 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 NONINFRINGEMENT. IN NO EVENT SHALL - * THE AUTHORS OR COPYRIGHT HOLDERS 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. - * - * Authors: - * Eric Anholt <eric@anholt.net> - * - */ - -/** @file register_allocate.c - * - * Graph-coloring register allocator. - */ - -#include <talloc.h> - -#include "main/imports.h" -#include "main/macros.h" -#include "main/mtypes.h" -#include "register_allocate.h" - -struct ra_reg { - GLboolean *conflicts; - unsigned int *conflict_list; - unsigned int conflict_list_size; - unsigned int num_conflicts; -}; - -struct ra_regs { - struct ra_reg *regs; - unsigned int count; - - struct ra_class **classes; - unsigned int class_count; -}; - -struct ra_class { - GLboolean *regs; - - /** - * p_B in Runeson/Nyström paper. - * - * This is "how many regs are in the set." - */ - unsigned int p; - - /** - * q_B,C in Runeson/Nyström paper. - */ - unsigned int *q; -}; - -struct ra_node { - GLboolean *adjacency; - unsigned int *adjacency_list; - unsigned int class; - unsigned int adjacency_count; - unsigned int reg; - GLboolean in_stack; - float spill_cost; -}; - -struct ra_graph { - struct ra_regs *regs; - /** - * the variables that need register allocation. - */ - struct ra_node *nodes; - unsigned int count; /**< count of nodes. */ - - unsigned int *stack; - unsigned int stack_count; -}; - -struct ra_regs * -ra_alloc_reg_set(unsigned int count) -{ - unsigned int i; - struct ra_regs *regs; - - regs = talloc_zero(NULL, struct ra_regs); - regs->count = count; - regs->regs = talloc_zero_array(regs, struct ra_reg, count); - - for (i = 0; i < count; i++) { - regs->regs[i].conflicts = talloc_zero_array(regs->regs, GLboolean, count); - regs->regs[i].conflicts[i] = GL_TRUE; - - regs->regs[i].conflict_list = talloc_array(regs->regs, unsigned int, 4); - regs->regs[i].conflict_list_size = 4; - regs->regs[i].conflict_list[0] = i; - regs->regs[i].num_conflicts = 1; - } - - return regs; -} - -static void -ra_add_conflict_list(struct ra_regs *regs, unsigned int r1, unsigned int r2) -{ - struct ra_reg *reg1 = ®s->regs[r1]; - - if (reg1->conflict_list_size == reg1->num_conflicts) { - reg1->conflict_list_size *= 2; - reg1->conflict_list = talloc_realloc(regs, - reg1->conflict_list, - unsigned int, - reg1->conflict_list_size); - } - reg1->conflict_list[reg1->num_conflicts++] = r2; - reg1->conflicts[r2] = GL_TRUE; -} - -void -ra_add_reg_conflict(struct ra_regs *regs, unsigned int r1, unsigned int r2) -{ - if (!regs->regs[r1].conflicts[r2]) { - ra_add_conflict_list(regs, r1, r2); - ra_add_conflict_list(regs, r2, r1); - } -} - -unsigned int -ra_alloc_reg_class(struct ra_regs *regs) -{ - struct ra_class *class; - - regs->classes = talloc_realloc(regs, regs->classes, - struct ra_class *, - regs->class_count + 1); - - class = talloc_zero(regs, struct ra_class); - regs->classes[regs->class_count] = class; - - class->regs = talloc_zero_array(class, GLboolean, regs->count); - - return regs->class_count++; -} - -void -ra_class_add_reg(struct ra_regs *regs, unsigned int c, unsigned int r) -{ - struct ra_class *class = regs->classes[c]; - - class->regs[r] = GL_TRUE; - class->p++; -} - -/** - * Must be called after all conflicts and register classes have been - * set up and before the register set is used for allocation. - */ -void -ra_set_finalize(struct ra_regs *regs) -{ - unsigned int b, c; - - for (b = 0; b < regs->class_count; b++) { - regs->classes[b]->q = talloc_array(regs, unsigned int, regs->class_count); - } - - /* Compute, for each class B and C, how many regs of B an - * allocation to C could conflict with. - */ - for (b = 0; b < regs->class_count; b++) { - for (c = 0; c < regs->class_count; c++) { - unsigned int rc; - int max_conflicts = 0; - - for (rc = 0; rc < regs->count; rc++) { - int conflicts = 0; - int i; - - if (!regs->classes[c]->regs[rc]) - continue; - - for (i = 0; i < regs->regs[rc].num_conflicts; i++) { - unsigned int rb = regs->regs[rc].conflict_list[i]; - if (regs->classes[b]->regs[rb]) - conflicts++; - } - max_conflicts = MAX2(max_conflicts, conflicts); - } - regs->classes[b]->q[c] = max_conflicts; - } - } -} - -static void -ra_add_node_adjacency(struct ra_graph *g, unsigned int n1, unsigned int n2) -{ - g->nodes[n1].adjacency[n2] = GL_TRUE; - g->nodes[n1].adjacency_list[g->nodes[n1].adjacency_count] = n2; - g->nodes[n1].adjacency_count++; -} - -struct ra_graph * -ra_alloc_interference_graph(struct ra_regs *regs, unsigned int count) -{ - struct ra_graph *g; - unsigned int i; - - g = talloc_zero(regs, struct ra_graph); - g->regs = regs; - g->nodes = talloc_zero_array(g, struct ra_node, count); - g->count = count; - - g->stack = talloc_zero_array(g, unsigned int, count); - - for (i = 0; i < count; i++) { - g->nodes[i].adjacency = talloc_zero_array(g, GLboolean, count); - g->nodes[i].adjacency_list = talloc_array(g, unsigned int, count); - g->nodes[i].adjacency_count = 0; - ra_add_node_adjacency(g, i, i); - g->nodes[i].reg = ~0; - } - - return g; -} - -void -ra_set_node_class(struct ra_graph *g, - unsigned int n, unsigned int class) -{ - g->nodes[n].class = class; -} - -void -ra_add_node_interference(struct ra_graph *g, - unsigned int n1, unsigned int n2) -{ - if (!g->nodes[n1].adjacency[n2]) { - ra_add_node_adjacency(g, n1, n2); - ra_add_node_adjacency(g, n2, n1); - } -} - -static GLboolean pq_test(struct ra_graph *g, unsigned int n) -{ - unsigned int j; - unsigned int q = 0; - int n_class = g->nodes[n].class; - - for (j = 0; j < g->nodes[n].adjacency_count; j++) { - unsigned int n2 = g->nodes[n].adjacency_list[j]; - unsigned int n2_class = g->nodes[n2].class; - - if (n != n2 && !g->nodes[n2].in_stack) { - q += g->regs->classes[n_class]->q[n2_class]; - } - } - - return q < g->regs->classes[n_class]->p; -} - -/** - * Simplifies the interference graph by pushing all - * trivially-colorable nodes into a stack of nodes to be colored, - * removing them from the graph, and rinsing and repeating. - * - * Returns GL_TRUE if all nodes were removed from the graph. GL_FALSE - * means that either spilling will be required, or optimistic coloring - * should be applied. - */ -GLboolean -ra_simplify(struct ra_graph *g) -{ - GLboolean progress = GL_TRUE; - int i; - - while (progress) { - progress = GL_FALSE; - - for (i = g->count - 1; i >= 0; i--) { - if (g->nodes[i].in_stack) - continue; - - if (pq_test(g, i)) { - g->stack[g->stack_count] = i; - g->stack_count++; - g->nodes[i].in_stack = GL_TRUE; - progress = GL_TRUE; - } - } - } - - for (i = 0; i < g->count; i++) { - if (!g->nodes[i].in_stack) - return GL_FALSE; - } - - return GL_TRUE; -} - -/** - * Pops nodes from the stack back into the graph, coloring them with - * registers as they go. - * - * If all nodes were trivially colorable, then this must succeed. If - * not (optimistic coloring), then it may return GL_FALSE; - */ -GLboolean -ra_select(struct ra_graph *g) -{ - int i; - - while (g->stack_count != 0) { - unsigned int r; - int n = g->stack[g->stack_count - 1]; - struct ra_class *c = g->regs->classes[g->nodes[n].class]; - - /* Find the lowest-numbered reg which is not used by a member - * of the graph adjacent to us. - */ - for (r = 0; r < g->regs->count; r++) { - if (!c->regs[r]) - continue; - - /* Check if any of our neighbors conflict with this register choice. */ - for (i = 0; i < g->nodes[n].adjacency_count; i++) { - unsigned int n2 = g->nodes[n].adjacency_list[i]; - - if (!g->nodes[n2].in_stack && - g->regs->regs[r].conflicts[g->nodes[n2].reg]) { - break; - } - } - if (i == g->nodes[n].adjacency_count) - break; - } - if (r == g->regs->count) - return GL_FALSE; - - g->nodes[n].reg = r; - g->nodes[n].in_stack = GL_FALSE; - g->stack_count--; - } - - return GL_TRUE; -} - -/** - * Optimistic register coloring: Just push the remaining nodes - * on the stack. They'll be colored first in ra_select(), and - * if they succeed then the locally-colorable nodes are still - * locally-colorable and the rest of the register allocation - * will succeed. - */ -void -ra_optimistic_color(struct ra_graph *g) -{ - unsigned int i; - - for (i = 0; i < g->count; i++) { - if (g->nodes[i].in_stack) - continue; - - g->stack[g->stack_count] = i; - g->stack_count++; - g->nodes[i].in_stack = GL_TRUE; - } -} - -GLboolean -ra_allocate_no_spills(struct ra_graph *g) -{ - if (!ra_simplify(g)) { - ra_optimistic_color(g); - } - return ra_select(g); -} - -unsigned int -ra_get_node_reg(struct ra_graph *g, unsigned int n) -{ - return g->nodes[n].reg; -} - -static float -ra_get_spill_benefit(struct ra_graph *g, unsigned int n) -{ - int j; - float benefit = 0; - int n_class = g->nodes[n].class; - - /* Define the benefit of eliminating an interference between n, n2 - * through spilling as q(C, B) / p(C). This is similar to the - * "count number of edges" approach of traditional graph coloring, - * but takes classes into account. - */ - for (j = 0; j < g->nodes[n].adjacency_count; j++) { - unsigned int n2 = g->nodes[n].adjacency_list[j]; - if (n != n2) { - unsigned int n2_class = g->nodes[n2].class; - benefit += ((float)g->regs->classes[n_class]->q[n2_class] / - g->regs->classes[n_class]->p); - } - } - - return benefit; -} - -/** - * Returns a node number to be spilled according to the cost/benefit using - * the pq test, or -1 if there are no spillable nodes. - */ -int -ra_get_best_spill_node(struct ra_graph *g) -{ - unsigned int best_node = -1; - unsigned int best_benefit = 0.0; - unsigned int n; - - for (n = 0; n < g->count; n++) { - float cost = g->nodes[n].spill_cost; - float benefit; - - if (cost <= 0.0) - continue; - - benefit = ra_get_spill_benefit(g, n); - - if (benefit / cost > best_benefit) { - best_benefit = benefit / cost; - best_node = n; - } - } - - return best_node; -} - -/** - * Only nodes with a spill cost set (cost != 0.0) will be considered - * for register spilling. - */ -void -ra_set_node_spill_cost(struct ra_graph *g, unsigned int n, float cost) -{ - g->nodes[n].spill_cost = cost; -} +/*
+ * Copyright © 2010 Intel Corporation
+ *
+ * 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, sublicense,
+ * 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 NONINFRINGEMENT. IN NO EVENT SHALL
+ * THE AUTHORS OR COPYRIGHT HOLDERS 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.
+ *
+ * Authors:
+ * Eric Anholt <eric@anholt.net>
+ *
+ */
+
+/** @file register_allocate.c
+ *
+ * Graph-coloring register allocator.
+ */
+
+#include <talloc.h>
+
+#include "main/imports.h"
+#include "main/macros.h"
+#include "main/mtypes.h"
+#include "register_allocate.h"
+
+struct ra_reg {
+ GLboolean *conflicts;
+ unsigned int *conflict_list;
+ unsigned int conflict_list_size;
+ unsigned int num_conflicts;
+};
+
+struct ra_regs {
+ struct ra_reg *regs;
+ unsigned int count;
+
+ struct ra_class **classes;
+ unsigned int class_count;
+};
+
+struct ra_class {
+ GLboolean *regs;
+
+ /**
+ * p_B in Runeson/Nyström paper.
+ *
+ * This is "how many regs are in the set."
+ */
+ unsigned int p;
+
+ /**
+ * q_B,C in Runeson/Nyström paper.
+ */
+ unsigned int *q;
+};
+
+struct ra_node {
+ GLboolean *adjacency;
+ unsigned int *adjacency_list;
+ unsigned int class;
+ unsigned int adjacency_count;
+ unsigned int reg;
+ GLboolean in_stack;
+ float spill_cost;
+};
+
+struct ra_graph {
+ struct ra_regs *regs;
+ /**
+ * the variables that need register allocation.
+ */
+ struct ra_node *nodes;
+ unsigned int count; /**< count of nodes. */
+
+ unsigned int *stack;
+ unsigned int stack_count;
+};
+
+struct ra_regs *
+ra_alloc_reg_set(unsigned int count)
+{
+ unsigned int i;
+ struct ra_regs *regs;
+
+ regs = talloc_zero(NULL, struct ra_regs);
+ regs->count = count;
+ regs->regs = talloc_zero_array(regs, struct ra_reg, count);
+
+ for (i = 0; i < count; i++) {
+ regs->regs[i].conflicts = talloc_zero_array(regs->regs, GLboolean, count);
+ regs->regs[i].conflicts[i] = GL_TRUE;
+
+ regs->regs[i].conflict_list = talloc_array(regs->regs, unsigned int, 4);
+ regs->regs[i].conflict_list_size = 4;
+ regs->regs[i].conflict_list[0] = i;
+ regs->regs[i].num_conflicts = 1;
+ }
+
+ return regs;
+}
+
+static void
+ra_add_conflict_list(struct ra_regs *regs, unsigned int r1, unsigned int r2)
+{
+ struct ra_reg *reg1 = ®s->regs[r1];
+
+ if (reg1->conflict_list_size == reg1->num_conflicts) {
+ reg1->conflict_list_size *= 2;
+ reg1->conflict_list = talloc_realloc(regs->regs,
+ reg1->conflict_list,
+ unsigned int,
+ reg1->conflict_list_size);
+ }
+ reg1->conflict_list[reg1->num_conflicts++] = r2;
+ reg1->conflicts[r2] = GL_TRUE;
+}
+
+void
+ra_add_reg_conflict(struct ra_regs *regs, unsigned int r1, unsigned int r2)
+{
+ if (!regs->regs[r1].conflicts[r2]) {
+ ra_add_conflict_list(regs, r1, r2);
+ ra_add_conflict_list(regs, r2, r1);
+ }
+}
+
+unsigned int
+ra_alloc_reg_class(struct ra_regs *regs)
+{
+ struct ra_class *class;
+
+ regs->classes = talloc_realloc(regs->regs, regs->classes,
+ struct ra_class *,
+ regs->class_count + 1);
+
+ class = talloc_zero(regs, struct ra_class);
+ regs->classes[regs->class_count] = class;
+
+ class->regs = talloc_zero_array(class, GLboolean, regs->count);
+
+ return regs->class_count++;
+}
+
+void
+ra_class_add_reg(struct ra_regs *regs, unsigned int c, unsigned int r)
+{
+ struct ra_class *class = regs->classes[c];
+
+ class->regs[r] = GL_TRUE;
+ class->p++;
+}
+
+/**
+ * Must be called after all conflicts and register classes have been
+ * set up and before the register set is used for allocation.
+ */
+void
+ra_set_finalize(struct ra_regs *regs)
+{
+ unsigned int b, c;
+
+ for (b = 0; b < regs->class_count; b++) {
+ regs->classes[b]->q = talloc_array(regs, unsigned int, regs->class_count);
+ }
+
+ /* Compute, for each class B and C, how many regs of B an
+ * allocation to C could conflict with.
+ */
+ for (b = 0; b < regs->class_count; b++) {
+ for (c = 0; c < regs->class_count; c++) {
+ unsigned int rc;
+ int max_conflicts = 0;
+
+ for (rc = 0; rc < regs->count; rc++) {
+ int conflicts = 0;
+ int i;
+
+ if (!regs->classes[c]->regs[rc])
+ continue;
+
+ for (i = 0; i < regs->regs[rc].num_conflicts; i++) {
+ unsigned int rb = regs->regs[rc].conflict_list[i];
+ if (regs->classes[b]->regs[rb])
+ conflicts++;
+ }
+ max_conflicts = MAX2(max_conflicts, conflicts);
+ }
+ regs->classes[b]->q[c] = max_conflicts;
+ }
+ }
+}
+
+static void
+ra_add_node_adjacency(struct ra_graph *g, unsigned int n1, unsigned int n2)
+{
+ g->nodes[n1].adjacency[n2] = GL_TRUE;
+ g->nodes[n1].adjacency_list[g->nodes[n1].adjacency_count] = n2;
+ g->nodes[n1].adjacency_count++;
+}
+
+struct ra_graph *
+ra_alloc_interference_graph(struct ra_regs *regs, unsigned int count)
+{
+ struct ra_graph *g;
+ unsigned int i;
+
+ g = talloc_zero(regs, struct ra_graph);
+ g->regs = regs;
+ g->nodes = talloc_zero_array(g, struct ra_node, count);
+ g->count = count;
+
+ g->stack = talloc_zero_array(g, unsigned int, count);
+
+ for (i = 0; i < count; i++) {
+ g->nodes[i].adjacency = talloc_zero_array(g, GLboolean, count);
+ g->nodes[i].adjacency_list = talloc_array(g, unsigned int, count);
+ g->nodes[i].adjacency_count = 0;
+ ra_add_node_adjacency(g, i, i);
+ g->nodes[i].reg = ~0;
+ }
+
+ return g;
+}
+
+void
+ra_set_node_class(struct ra_graph *g,
+ unsigned int n, unsigned int class)
+{
+ g->nodes[n].class = class;
+}
+
+void
+ra_add_node_interference(struct ra_graph *g,
+ unsigned int n1, unsigned int n2)
+{
+ if (!g->nodes[n1].adjacency[n2]) {
+ ra_add_node_adjacency(g, n1, n2);
+ ra_add_node_adjacency(g, n2, n1);
+ }
+}
+
+static GLboolean pq_test(struct ra_graph *g, unsigned int n)
+{
+ unsigned int j;
+ unsigned int q = 0;
+ int n_class = g->nodes[n].class;
+
+ for (j = 0; j < g->nodes[n].adjacency_count; j++) {
+ unsigned int n2 = g->nodes[n].adjacency_list[j];
+ unsigned int n2_class = g->nodes[n2].class;
+
+ if (n != n2 && !g->nodes[n2].in_stack) {
+ q += g->regs->classes[n_class]->q[n2_class];
+ }
+ }
+
+ return q < g->regs->classes[n_class]->p;
+}
+
+/**
+ * Simplifies the interference graph by pushing all
+ * trivially-colorable nodes into a stack of nodes to be colored,
+ * removing them from the graph, and rinsing and repeating.
+ *
+ * Returns GL_TRUE if all nodes were removed from the graph. GL_FALSE
+ * means that either spilling will be required, or optimistic coloring
+ * should be applied.
+ */
+GLboolean
+ra_simplify(struct ra_graph *g)
+{
+ GLboolean progress = GL_TRUE;
+ int i;
+
+ while (progress) {
+ progress = GL_FALSE;
+
+ for (i = g->count - 1; i >= 0; i--) {
+ if (g->nodes[i].in_stack)
+ continue;
+
+ if (pq_test(g, i)) {
+ g->stack[g->stack_count] = i;
+ g->stack_count++;
+ g->nodes[i].in_stack = GL_TRUE;
+ progress = GL_TRUE;
+ }
+ }
+ }
+
+ for (i = 0; i < g->count; i++) {
+ if (!g->nodes[i].in_stack)
+ return GL_FALSE;
+ }
+
+ return GL_TRUE;
+}
+
+/**
+ * Pops nodes from the stack back into the graph, coloring them with
+ * registers as they go.
+ *
+ * If all nodes were trivially colorable, then this must succeed. If
+ * not (optimistic coloring), then it may return GL_FALSE;
+ */
+GLboolean
+ra_select(struct ra_graph *g)
+{
+ int i;
+
+ while (g->stack_count != 0) {
+ unsigned int r;
+ int n = g->stack[g->stack_count - 1];
+ struct ra_class *c = g->regs->classes[g->nodes[n].class];
+
+ /* Find the lowest-numbered reg which is not used by a member
+ * of the graph adjacent to us.
+ */
+ for (r = 0; r < g->regs->count; r++) {
+ if (!c->regs[r])
+ continue;
+
+ /* Check if any of our neighbors conflict with this register choice. */
+ for (i = 0; i < g->nodes[n].adjacency_count; i++) {
+ unsigned int n2 = g->nodes[n].adjacency_list[i];
+
+ if (!g->nodes[n2].in_stack &&
+ g->regs->regs[r].conflicts[g->nodes[n2].reg]) {
+ break;
+ }
+ }
+ if (i == g->nodes[n].adjacency_count)
+ break;
+ }
+ if (r == g->regs->count)
+ return GL_FALSE;
+
+ g->nodes[n].reg = r;
+ g->nodes[n].in_stack = GL_FALSE;
+ g->stack_count--;
+ }
+
+ return GL_TRUE;
+}
+
+/**
+ * Optimistic register coloring: Just push the remaining nodes
+ * on the stack. They'll be colored first in ra_select(), and
+ * if they succeed then the locally-colorable nodes are still
+ * locally-colorable and the rest of the register allocation
+ * will succeed.
+ */
+void
+ra_optimistic_color(struct ra_graph *g)
+{
+ unsigned int i;
+
+ for (i = 0; i < g->count; i++) {
+ if (g->nodes[i].in_stack)
+ continue;
+
+ g->stack[g->stack_count] = i;
+ g->stack_count++;
+ g->nodes[i].in_stack = GL_TRUE;
+ }
+}
+
+GLboolean
+ra_allocate_no_spills(struct ra_graph *g)
+{
+ if (!ra_simplify(g)) {
+ ra_optimistic_color(g);
+ }
+ return ra_select(g);
+}
+
+unsigned int
+ra_get_node_reg(struct ra_graph *g, unsigned int n)
+{
+ return g->nodes[n].reg;
+}
+
+static float
+ra_get_spill_benefit(struct ra_graph *g, unsigned int n)
+{
+ int j;
+ float benefit = 0;
+ int n_class = g->nodes[n].class;
+
+ /* Define the benefit of eliminating an interference between n, n2
+ * through spilling as q(C, B) / p(C). This is similar to the
+ * "count number of edges" approach of traditional graph coloring,
+ * but takes classes into account.
+ */
+ for (j = 0; j < g->nodes[n].adjacency_count; j++) {
+ unsigned int n2 = g->nodes[n].adjacency_list[j];
+ if (n != n2) {
+ unsigned int n2_class = g->nodes[n2].class;
+ benefit += ((float)g->regs->classes[n_class]->q[n2_class] /
+ g->regs->classes[n_class]->p);
+ }
+ }
+
+ return benefit;
+}
+
+/**
+ * Returns a node number to be spilled according to the cost/benefit using
+ * the pq test, or -1 if there are no spillable nodes.
+ */
+int
+ra_get_best_spill_node(struct ra_graph *g)
+{
+ unsigned int best_node = -1;
+ unsigned int best_benefit = 0.0;
+ unsigned int n;
+
+ for (n = 0; n < g->count; n++) {
+ float cost = g->nodes[n].spill_cost;
+ float benefit;
+
+ if (cost <= 0.0)
+ continue;
+
+ benefit = ra_get_spill_benefit(g, n);
+
+ if (benefit / cost > best_benefit) {
+ best_benefit = benefit / cost;
+ best_node = n;
+ }
+ }
+
+ return best_node;
+}
+
+/**
+ * Only nodes with a spill cost set (cost != 0.0) will be considered
+ * for register spilling.
+ */
+void
+ra_set_node_spill_cost(struct ra_graph *g, unsigned int n, float cost)
+{
+ g->nodes[n].spill_cost = cost;
+}
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