tgsi: Return 0.0 for negative constant register indices.

diff --git a/src/gallium/auxiliary/tgsi/tgsi_exec.c b/src/gallium/auxiliary/tgsi/tgsi_exec.c
index 0756d7db1760fd20a59a7f11557d6d825766dc3a..d55c33720773292f27f75e8f28757004ec761f81 100644 (file)
--- a/src/gallium/auxiliary/tgsi/tgsi_exec.c
+++ b/src/gallium/auxiliary/tgsi/tgsi_exec.c
@@ -958,14 +958,22 @@ fetch_src_file_channel(
       switch( file ) {
       case TGSI_FILE_CONSTANT:
          assert(mach->Consts);
-         assert(index->i[0] >= 0);
-         assert(index->i[1] >= 0);
-         assert(index->i[2] >= 0);
-         assert(index->i[3] >= 0);
-         chan->f[0] = mach->Consts[index->i[0]][swizzle];
-         chan->f[1] = mach->Consts[index->i[1]][swizzle];
-         chan->f[2] = mach->Consts[index->i[2]][swizzle];
-         chan->f[3] = mach->Consts[index->i[3]][swizzle];
+         if (index->i[0] < 0)
+            chan->f[0] = 0.0f;
+         else
+            chan->f[0] = mach->Consts[index->i[0]][swizzle];
+         if (index->i[1] < 0)
+            chan->f[1] = 0.0f;
+         else
+            chan->f[1] = mach->Consts[index->i[1]][swizzle];
+         if (index->i[2] < 0)
+            chan->f[2] = 0.0f;
+         else
+            chan->f[2] = mach->Consts[index->i[2]][swizzle];
+         if (index->i[3] < 0)
+            chan->f[3] = 0.0f;
+         else
+            chan->f[3] = mach->Consts[index->i[3]][swizzle];
          break;
 
       case TGSI_FILE_INPUT: