vc4: Fix perspective interpolation.

Fixes the mesa reflect demo and 6 tests under interpolation/

diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c
index a527f8b..38d0608 100644 (file)
--- a/src/gallium/drivers/vc4/vc4_program.c
+++ b/src/gallium/drivers/vc4/vc4_program.c
@@ -852,7 +852,7 @@ emit_fragment_varying(struct vc4_compile *c, int index)
         };
 
         /* XXX: multiply by W */
-        return qir_VARY_ADD_C(c, qir_MOV(c, vary));
+        return qir_VARY_ADD_C(c, qir_FMUL(c, vary, qir_FRAG_W(c)));
 }
 
 static void