diff --git a/src/mesa/drivers/dri/i965/brw_fs_dead_code_eliminate.cpp b/src/mesa/drivers/dri/i965/brw_fs_dead_code_eliminate.cpp
index bd57e09fe0c..a1d07ff3e8e 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_dead_code_eliminate.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_dead_code_eliminate.cpp
@@ -77,7 +77,7 @@ fs_visitor::dead_code_eliminate()
          }
 
          if (inst->dst.is_null() && inst->writes_flag()) {
-            if (!BITSET_TEST(flag_live, inst->flag_subreg)) {
+            if (!(flag_live[0] & inst->flags_written())) {
                inst->opcode = BRW_OPCODE_NOP;
                progress = true;
             }
@@ -102,9 +102,8 @@ fs_visitor::dead_code_eliminate()
             }
          }
 
-         if (inst->writes_flag() && !inst->predicate) {
-            BITSET_CLEAR(flag_live, inst->flag_subreg);
-         }
+         if (!inst->predicate && inst->exec_size >= 8)
+            flag_live[0] &= ~inst->flags_written();
 
          if (inst->opcode == BRW_OPCODE_NOP) {
             inst->remove(block);
@@ -121,9 +120,7 @@ fs_visitor::dead_code_eliminate()
             }
          }
 
-         if (inst->reads_flag()) {
-            BITSET_SET(flag_live, inst->flag_subreg);
-         }
+         flag_live[0] |= inst->flags_read(devinfo);
       }
    }
 
diff --git a/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp b/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp
index 66b70a9144b..8bd42298a23 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_live_variables.cpp
@@ -123,19 +123,8 @@ fs_live_variables::setup_def_use()
                reg.reg_offset++;
             }
 	 }
-         if (inst->reads_flag()) {
-            /* The vertical combination predicates read f0.0 and f0.1. */
-            if (inst->predicate == BRW_PREDICATE_ALIGN1_ANYV ||
-                inst->predicate == BRW_PREDICATE_ALIGN1_ALLV) {
-               assert(inst->flag_subreg == 0);
-               if (!BITSET_TEST(bd->flag_def, 1)) {
-                  BITSET_SET(bd->flag_use, 1);
-               }
-            }
-            if (!BITSET_TEST(bd->flag_def, inst->flag_subreg)) {
-               BITSET_SET(bd->flag_use, inst->flag_subreg);
-            }
-         }
+
+         bd->flag_use[0] |= inst->flags_read(v->devinfo) & ~bd->flag_def[0];
 
          /* Set def[] for this instruction */
          if (inst->dst.file == VGRF) {
@@ -145,11 +134,9 @@ fs_live_variables::setup_def_use()
                reg.reg_offset++;
             }
 	 }
-         if (inst->writes_flag()) {
-            if (!BITSET_TEST(bd->flag_use, inst->flag_subreg)) {
-               BITSET_SET(bd->flag_def, inst->flag_subreg);
-            }
-         }
+
+         if (!inst->predicate && inst->exec_size >= 8)
+            bd->flag_def[0] |= inst->flags_written() & ~bd->flag_use[0];
 
 	 ip++;
       }