r300/compiler: Clear loop registers in vertex shaders w/o loops

The loop registers weren't being cleared, so any shader that was
executed after a shader containing loops was at risk of having a loop
randomly inserted into it.

This fixes over one hundred piglit tests, although these test
only failed during full piglit runs and would pass if
run individually.  The exact number of piglit tests that this patch
fixes will vary depending on the version of piglit and the order the
tests are run.

NOTE: This is a candidate for the stable branches.

diff --git a/src/gallium/drivers/r300/r300_emit.c b/src/gallium/drivers/r300/r300_emit.c
index 3897e990b1cb0f8c412902b30bb90f27d619b3aa..e4afe786d65bb77d523a15e831c9f7e1dc57992a 100644 (file)
--- a/src/gallium/drivers/r300/r300_emit.c
+++ b/src/gallium/drivers/r300/r300_emit.c
@@ -1030,20 +1030,18 @@ void r300_emit_vs_state(struct r300_context* r300, unsigned size, void* state)
             R300_PVS_VF_MAX_VTX_NUM(12) |
             (r300screen->caps.is_r500 ? R500_TCL_STATE_OPTIMIZATION : 0));
 
-    /* Emit flow control instructions. */
-    if (code->num_fc_ops) {
-
-        OUT_CS_REG(R300_VAP_PVS_FLOW_CNTL_OPC, code->fc_ops);
-        if (r300screen->caps.is_r500) {
-            OUT_CS_REG_SEQ(R500_VAP_PVS_FLOW_CNTL_ADDRS_LW_0, code->num_fc_ops * 2);
-            OUT_CS_TABLE(code->fc_op_addrs.r500, code->num_fc_ops * 2);
-        } else {
-            OUT_CS_REG_SEQ(R300_VAP_PVS_FLOW_CNTL_ADDRS_0, code->num_fc_ops);
-            OUT_CS_TABLE(code->fc_op_addrs.r300, code->num_fc_ops);
-        }
-        OUT_CS_REG_SEQ(R300_VAP_PVS_FLOW_CNTL_LOOP_INDEX_0, code->num_fc_ops);
-        OUT_CS_TABLE(code->fc_loop_index, code->num_fc_ops);
+    /* Emit flow control instructions.  Even if there are no fc instructions,
+     * we still need to write the registers to make sure they are cleared. */
+    OUT_CS_REG(R300_VAP_PVS_FLOW_CNTL_OPC, code->fc_ops);
+    if (r300screen->caps.is_r500) {
+        OUT_CS_REG_SEQ(R500_VAP_PVS_FLOW_CNTL_ADDRS_LW_0, R300_VS_MAX_FC_OPS * 2);
+        OUT_CS_TABLE(code->fc_op_addrs.r500, R300_VS_MAX_FC_OPS * 2);
+    } else {
+        OUT_CS_REG_SEQ(R300_VAP_PVS_FLOW_CNTL_ADDRS_0, R300_VS_MAX_FC_OPS);
+        OUT_CS_TABLE(code->fc_op_addrs.r300, R300_VS_MAX_FC_OPS);
     }
+    OUT_CS_REG_SEQ(R300_VAP_PVS_FLOW_CNTL_LOOP_INDEX_0, R300_VS_MAX_FC_OPS);
+    OUT_CS_TABLE(code->fc_loop_index, R300_VS_MAX_FC_OPS);
 
     END_CS;
 }

diff --git a/src/gallium/drivers/r300/r300_state.c b/src/gallium/drivers/r300/r300_state.c
index 4101523c5422cce9e9b5e54cbe899fc9c8d7a4bc..10625b45e3e5c1c13762ed4aabec470ccb275c1b 100644 (file)
--- a/src/gallium/drivers/r300/r300_state.c
+++ b/src/gallium/drivers/r300/r300_state.c
@@ -1796,9 +1796,8 @@ static void r300_bind_vs_state(struct pipe_context* pipe, void* shader)
     if (r300->screen->caps.has_tcl) {
         unsigned fc_op_dwords = r300->screen->caps.is_r500 ? 3 : 2;
         r300_mark_atom_dirty(r300, &r300->vs_state);
-        r300->vs_state.size =
-                vs->code.length + 9 +
-        (vs->code.num_fc_ops ? vs->code.num_fc_ops * fc_op_dwords + 4 : 0);
+        r300->vs_state.size = vs->code.length + 9 +
+                       (R300_VS_MAX_FC_OPS * fc_op_dwords + 4);
 
         r300_mark_atom_dirty(r300, &r300->vs_constants);
         r300->vs_constants.size =