vc4: Fold the 16-bit integer pack into the instructions generating it.

total instructions in shared programs: 97580 -> 96798 (-0.80%)
instructions in affected programs:     52826 -> 52044 (-1.48%)

1 files changed, 10 insertions, 9 deletions

diff --git a/src/gallium/drivers/vc4/vc4_program.c b/src/gallium/drivers/vc4/vc4_program.c
index 6bf4c9eab9b..e002983fdbb 100644
--- a/src/gallium/drivers/vc4/vc4_program.c
+++ b/src/gallium/drivers/vc4/vc4_program.c
@@ -1186,22 +1186,23 @@ emit_frag_end(struct vc4_compile *c)
 static void
 emit_scaled_viewport_write(struct vc4_compile *c, struct qreg rcp_w)
 {
-        struct qreg xyi[2];
+        struct qreg packed = qir_get_temp(c);
 
         for (int i = 0; i < 2; i++) {
                 struct qreg scale =
                         qir_uniform(c, QUNIFORM_VIEWPORT_X_SCALE + i, 0);
 
-                xyi[i] = qir_FTOI(c, qir_FMUL(c,
-                                              qir_FMUL(c,
-                                                       c->outputs[c->output_position_index + i],
-                                                       scale),
-                                              rcp_w));
+                struct qreg packed_chan = packed;
+                packed_chan.pack = QPU_PACK_A_16A + i;
+
+                qir_FTOI_dest(c, packed_chan,
+                              qir_FMUL(c,
+                                       qir_FMUL(c,
+                                                c->outputs[c->output_position_index + i],
+                                                scale),
+                                       rcp_w));
         }
 
-        struct qreg packed = qir_get_temp(c);
-        qir_PACK_16A_I(c, packed, xyi[0]);
-        qir_PACK_16B_I(c, packed, xyi[1]);
         qir_VPM_WRITE(c, packed);
 }