Mesa (master): vc4: Refuse to merge instructions involving 32-bit immediate loads.

[Eric Anholt]

Module: Mesa
Branch: master
Commit: cff8c96a0d418f41e00aa97a13dc55e3ed213eb7
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=cff8c96a0d418f41e00aa97a13dc55e3ed213eb7

Author: Eric Anholt <eric at anholt.net>
Date:   Tue Dec  9 16:34:37 2014 -0800

vc4: Refuse to merge instructions involving 32-bit immediate loads.

An immediate load overwrites the mul and add operations, so you can't
merge with them.

---

 src/gallium/drivers/vc4/vc4_qpu.c |    5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/gallium/drivers/vc4/vc4_qpu.c b/src/gallium/drivers/vc4/vc4_qpu.c
index 6daa072..faf8790 100644
--- a/src/gallium/drivers/vc4/vc4_qpu.c
+++ b/src/gallium/drivers/vc4/vc4_qpu.c
@@ -356,6 +356,11 @@ qpu_merge_inst(uint64_t a, uint64_t b)
         if (qpu_num_sf_accesses(a) && qpu_num_sf_accesses(b))
                 return 0;
 
+        if (QPU_GET_FIELD(a, QPU_SIG) == QPU_SIG_LOAD_IMM ||
+            QPU_GET_FIELD(b, QPU_SIG) == QPU_SIG_LOAD_IMM) {
+                return 0;
+        }
+
         ok = ok && merge_fields(&merge, a, b, QPU_SIG_MASK,
                                 QPU_SET_FIELD(QPU_SIG_NONE, QPU_SIG));