[Mesa-dev] [PATCH] glsl_to_tgsi: allocate and enlarge arrays for temporaries on demand

[Marek Olšák]

From: Marek Olšák <marek.olsak at amd.com>

This fixes crashes if the number of temporaries is greater than 4096.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=66184
Cc: 10.2 10.3 mesa-stable at lists.freedesktop.org
---
 src/mesa/state_tracker/st_glsl_to_tgsi.cpp | 45 ++++++++++++++++++------------
 1 file changed, 27 insertions(+), 18 deletions(-)

diff --git a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
index 84bdc4f..9beecf8 100644
--- a/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
+++ b/src/mesa/state_tracker/st_glsl_to_tgsi.cpp
@@ -75,14 +75,6 @@ extern "C" {
                            (1 << PROGRAM_UNIFORM))
 
 /**
- * Maximum number of temporary registers.
- *
- * It is too big for stack allocated arrays -- it will cause stack overflow on
- * Windows and likely Mac OS X.
- */
-#define MAX_TEMPS         4096
-
-/**
  * Maximum number of arrays
  */
 #define MAX_ARRAYS        256
@@ -3301,14 +3293,10 @@ get_src_arg_mask(st_dst_reg dst, st_src_reg src)
 void
 glsl_to_tgsi_visitor::simplify_cmp(void)
 {
-   unsigned *tempWrites;
+   int tempWritesSize = 0;
+   unsigned *tempWrites = NULL;
    unsigned outputWrites[MAX_PROGRAM_OUTPUTS];
 
-   tempWrites = new unsigned[MAX_TEMPS];
-   if (!tempWrites) {
-      return;
-   }
-   memset(tempWrites, 0, sizeof(unsigned) * MAX_TEMPS);
    memset(outputWrites, 0, sizeof(outputWrites));
 
    foreach_in_list(glsl_to_tgsi_instruction, inst, &this->instructions) {
@@ -3330,7 +3318,16 @@ glsl_to_tgsi_visitor::simplify_cmp(void)
          prevWriteMask = outputWrites[inst->dst.index];
          outputWrites[inst->dst.index] |= inst->dst.writemask;
       } else if (inst->dst.file == PROGRAM_TEMPORARY) {
-         assert(inst->dst.index < MAX_TEMPS);
+         if (inst->dst.index >= tempWritesSize) {
+            const int inc = 4096;
+
+            tempWrites = (unsigned*)
+                         realloc(tempWrites,
+                                 (tempWritesSize + inc) * sizeof(unsigned));
+            memset(tempWrites + tempWritesSize, 0, inc * sizeof(unsigned));
+            tempWritesSize += inc;
+         }
+
          prevWriteMask = tempWrites[inst->dst.index];
          tempWrites[inst->dst.index] |= inst->dst.writemask;
       } else
@@ -3349,7 +3346,7 @@ glsl_to_tgsi_visitor::simplify_cmp(void)
       }
    }
 
-   delete [] tempWrites;
+   free(tempWrites);
 }
 
 /* Replaces all references to a temporary register index with another index. */
@@ -4158,7 +4155,9 @@ struct label {
 struct st_translate {
    struct ureg_program *ureg;
 
-   struct ureg_dst temps[MAX_TEMPS];
+   unsigned temps_size;
+   struct ureg_dst *temps;
+
    struct ureg_dst arrays[MAX_ARRAYS];
    struct ureg_src *constants;
    struct ureg_src *immediates;
@@ -4299,7 +4298,16 @@ dst_register(struct st_translate *t,
       return ureg_dst_undef();
 
    case PROGRAM_TEMPORARY:
-      assert(index < Elements(t->temps));
+      /* Allocate space for temporaries on demand. */
+      if (index >= t->temps_size) {
+         const int inc = 4096;
+
+         t->temps = (struct ureg_dst*)
+                    realloc(t->temps,
+                            (t->temps_size + inc) * sizeof(struct ureg_dst));
+         memset(t->temps + t->temps_size, 0, inc * sizeof(struct ureg_dst));
+         t->temps_size += inc;
+      }
 
       if (ureg_dst_is_undef(t->temps[index]))
          t->temps[index] = ureg_DECL_local_temporary(t->ureg);
@@ -5158,6 +5166,7 @@ st_translate_program(
 
 out:
    if (t) {
+      free(t->temps);
       free(t->insn);
       free(t->labels);
       free(t->constants);
-- 
1.9.1