r300/compiler: Verify assumptions about opcode types.

diff --git a/src/mesa/drivers/dri/r300/compiler/radeon_emulate_loops.c b/src/mesa/drivers/dri/r300/compiler/radeon_emulate_loops.c
index 859023a4d8bb2e37a956613f0842731430c31dbc..28b9684e82d3fa95537d28eaf9859b536139e569 100644 (file)
--- a/src/mesa/drivers/dri/r300/compiler/radeon_emulate_loops.c
+++ b/src/mesa/drivers/dri/r300/compiler/radeon_emulate_loops.c
@@ -297,10 +297,31 @@ static int transform_const_loop(struct emulate_loop_state * s,
        /* Remove the first 4 instructions inside the loop, which are part
         * of the conditional and no longer needed.
         */
-       rc_remove_instruction(loop->BeginLoop->Next); /* SLT/SGE */
-       rc_remove_instruction(loop->BeginLoop->Next); /* IF      */
-       rc_remove_instruction(loop->BeginLoop->Next); /* BRK     */
-       rc_remove_instruction(loop->BeginLoop->Next); /* ENDIF   */
+       /* SLT/SGE */
+       if(loop->BeginLoop->Next->U.I.Opcode != RC_OPCODE_SLT &&
+          loop->BeginLoop->Next->U.I.Opcode != RC_OPCODE_SGE){
+               rc_error(s->C,"Unexpected instruction, expected SLT/SGE\n");
+               return 0;
+       }
+       /* IF */
+       rc_remove_instruction(loop->BeginLoop->Next);
+       if(loop->BeginLoop->Next->U.I.Opcode != RC_OPCODE_IF){
+               rc_error(s->C,"Unexpected instruction, expected IF\n");
+               return 0;
+       }
+       rc_remove_instruction(loop->BeginLoop->Next);
+       /* BRK     */
+       if(loop->BeginLoop->Next->U.I.Opcode != RC_OPCODE_BRK){
+               rc_error(s->C,"Unexpected instruction, expected BRK\n");
+               return 0;
+       }
+       rc_remove_instruction(loop->BeginLoop->Next);
+       /* ENDIF   */
+       if(loop->BeginLoop->Next->U.I.Opcode != RC_OPCODE_ENDIF){
+               rc_error(s->C,"Unexpected instruction, expected ENDIF\n");
+               return 0;
+       }
+       rc_remove_instruction(loop->BeginLoop->Next);
        
        loop_unroll(s, loop, iterations);
        loop->EndLoop = NULL;
@@ -343,6 +364,10 @@ static struct rc_instruction * transform_loop(struct emulate_loop_state * s,
        case RC_OPCODE_SLT:
                ptr->U.I.Opcode = RC_OPCODE_SGE;
                break;
+       default:
+               rc_error(s->C,
+                       "Loop does not start with a conditional instruction.");
+               break;
        }
        
        /* Check if the number of loops is known at compile time. */
@@ -363,6 +388,10 @@ static struct rc_instruction * transform_loop(struct emulate_loop_state * s,
                        /* The BRK instruction should always be followed by
                         * an ENDIF.  This ENDIF will eventually replace the
                         * ENDLOOP insruction. */
+                       if(ptr->Next->U.I.Opcode != RC_OPCODE_ENDIF){
+                               rc_error(s->C,
+                                       "transform_loop: expected ENDIF\n");
+                       }
                        endif = ptr->Next;
                        rc_remove_instruction(ptr);
                        rc_remove_instruction(endif);