libX11 libXinerama mesa git update 1 Feb 2011

1 files changed, 455 insertions, 458 deletions

diff --git a/mesalib/src/mesa/program/register_allocate.c b/mesalib/src/mesa/program/register_allocate.c
index 8992b91b6..95a9bde40 100644
--- a/mesalib/src/mesa/program/register_allocate.c
+++ b/mesalib/src/mesa/program/register_allocate.c
@@ -1,458 +1,455 @@
-/*

- * 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 = &regs->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;

-}

+/*
+ * 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 <ralloc.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 = rzalloc(NULL, struct ra_regs);
+   regs->count = count;
+   regs->regs = rzalloc_array(regs, struct ra_reg, count);
+
+   for (i = 0; i < count; i++) {
+      regs->regs[i].conflicts = rzalloc_array(regs->regs, GLboolean, count);
+      regs->regs[i].conflicts[i] = GL_TRUE;
+
+      regs->regs[i].conflict_list = ralloc_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 = &regs->regs[r1];
+
+   if (reg1->conflict_list_size == reg1->num_conflicts) {
+      reg1->conflict_list_size *= 2;
+      reg1->conflict_list = reralloc(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 = reralloc(regs->regs, regs->classes, struct ra_class *,
+			    regs->class_count + 1);
+
+   class = rzalloc(regs, struct ra_class);
+   regs->classes[regs->class_count] = class;
+
+   class->regs = rzalloc_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 = ralloc_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 = rzalloc(regs, struct ra_graph);
+   g->regs = regs;
+   g->nodes = rzalloc_array(g, struct ra_node, count);
+   g->count = count;
+
+   g->stack = rzalloc_array(g, unsigned int, count);
+
+   for (i = 0; i < count; i++) {
+      g->nodes[i].adjacency = rzalloc_array(g, GLboolean, count);
+      g->nodes[i].adjacency_list = ralloc_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;
+}