pan/midgard: Add mir_is_written_before helper

Signed-off-by: Alyssa Rosenzweig <[email protected]>

1 files changed, 19 insertions, 0 deletions

diff --git a/src/panfrost/midgard/mir.c b/src/panfrost/midgard/mir.c
index d8e52982b68..61427e7c3d5 100644
--- a/src/panfrost/midgard/mir.c
+++ b/src/panfrost/midgard/mir.c
@@ -175,3 +175,22 @@ mir_special_index(compiler_context *ctx, unsigned idx)
 
         return false;
 }
+
+/* Is a node written before a given instruction? */
+
+bool
+mir_is_written_before(compiler_context *ctx, midgard_instruction *ins, unsigned node)
+{
+        if ((node < 0) || (node >= SSA_FIXED_MINIMUM))
+                return true;
+
+        mir_foreach_instr_global(ctx, q) {
+                if (q == ins)
+                        break;
+
+                if (q->ssa_args.dest == node)
+                        return true;
+        }
+
+        return false;
+}