svn merge ^/branches/released .

1 files changed, 517 insertions, 455 deletions

diff --git a/mesalib/src/mesa/program/register_allocate.c b/mesalib/src/mesa/program/register_allocate.c
index 95a9bde40..e78db24a4 100644
--- a/mesalib/src/mesa/program/register_allocate.c
+++ b/mesalib/src/mesa/program/register_allocate.c
@@ -1,455 +1,517 @@
-/*
- * 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;
-}
+/*

+ * 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.

+ *

+ * The basic idea of graph coloring is to make a node in a graph for

+ * every thing that needs a register (color) number assigned, and make

+ * edges in the graph between nodes that interfere (can't be allocated

+ * to the same register at the same time).

+ *

+ * During the "simplify" process, any any node with fewer edges than

+ * there are registers means that that edge can get assigned a

+ * register regardless of what its neighbors choose, so that node is

+ * pushed on a stack and removed (with its edges) from the graph.

+ * That likely causes other nodes to become trivially colorable as well.

+ *

+ * Then during the "select" process, nodes are popped off of that

+ * stack, their edges restored, and assigned a color different from

+ * their neighbors.  Because they were pushed on the stack only when

+ * they were trivially colorable, any color chosen won't interfere

+ * with the registers to be popped later.

+ *

+ * The downside to most graph coloring is that real hardware often has

+ * limitations, like registers that need to be allocated to a node in

+ * pairs, or aligned on some boundary.  This implementation follows

+ * the paper "Retargetable Graph-Coloring Register Allocation for

+ * Irregular Architectures" by Johan Runeson and Sven-Olof Nyström.

+ *

+ * In this system, there are register classes each containing various

+ * registers, and registers may interfere with other registers.  For

+ * example, one might have a class of base registers, and a class of

+ * aligned register pairs that would each interfere with their pair of

+ * the base registers.  Each node has a register class it needs to be

+ * assigned to.  Define p(B) to be the size of register class B, and

+ * q(B,C) to be the number of registers in B that the worst choice

+ * register in C could conflict with.  Then, this system replaces the

+ * basic graph coloring test of "fewer edges from this node than there

+ * are registers" with "For this node of class B, the sum of q(B,C)

+ * for each neighbor node of class C is less than pB".

+ *

+ * A nice feature of the pq test is that q(B,C) can be computed once

+ * up front and stored in a 2-dimensional array, so that the cost of

+ * coloring a node is constant with the number of registers.  We do

+ * this during ra_set_finalize().

+ */

+

+#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) (indexed by C, B is this register class) in

+    * Runeson/Nyström paper.  This is "how many registers of B could

+    * the worst choice register from C conflict with".

+    */

+   unsigned int *q;

+};

+

+struct ra_node {

+   /** @{

+    *

+    * List of which nodes this node interferes with.  This should be

+    * symmetric with the other node.

+    */

+   GLboolean *adjacency;

+   unsigned int *adjacency_list;

+   unsigned int adjacency_count;

+   /** @} */

+

+   unsigned int class;

+

+   /* Register, if assigned, or ~0. */

+   unsigned int reg;

+

+   /**

+    * Set when the node is in the trivially colorable stack.  When

+    * set, the adjacency to this node is ignored, to implement the

+    * "remove the edge from the graph" in simplification without

+    * having to actually modify the adjacency_list.

+    */

+   GLboolean in_stack;

+

+   /* For an implementation that needs register spilling, this is the

+    * approximate cost of spilling this node.

+    */

+   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;

+}