i965/fs: Handle COMPR4 in LOAD_PAYLOAD

Signed-off-by: Jason Ekstrand <jason.ekstrand@intel.com>
Reviewed-by: Matt Turner <mattst88@gmail.com>

2 files changed, 36 insertions, 1 deletions

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index 56659f3af51..3277b586ede 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -2988,6 +2988,21 @@ fs_visitor::lower_load_payload()
 
             if (inst->src[i].file == BAD_FILE) {
                /* Do nothing but otherwise increment as normal */
+            } else if (dst.file == MRF &&
+                       dst.width == 8 &&
+                       brw->has_compr4 &&
+                       i + 4 < inst->sources &&
+                       inst->src[i + 4].equals(horiz_offset(inst->src[i], 8))) {
+               fs_reg compr4_dst = dst;
+               compr4_dst.reg += BRW_MRF_COMPR4;
+               compr4_dst.width = 16;
+               fs_reg compr4_src = inst->src[i];
+               compr4_src.width = 16;
+               fs_inst *mov = MOV(compr4_dst, compr4_src);
+               mov->force_writemask_all = true;
+               inst->insert_before(block, mov);
+               /* Mark i+4 as BAD_FILE so we don't emit a MOV for it */
+               inst->src[i + 4].file = BAD_FILE;
             } else {
                fs_inst *mov = MOV(dst, inst->src[i]);
                if (inst->src[i].file == GRF) {
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index d4d4aa13856..77d76807f37 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -144,6 +144,26 @@ byte_offset(fs_reg reg, unsigned delta)
 }
 
 static inline fs_reg
+horiz_offset(fs_reg reg, unsigned delta)
+{
+   switch (reg.file) {
+   case BAD_FILE:
+   case UNIFORM:
+   case IMM:
+      /* These only have a single component that is implicitly splatted.  A
+       * horizontal offset should be a harmless no-op.
+       */
+      break;
+   case GRF:
+   case MRF:
+      return byte_offset(reg, delta * reg.stride * type_sz(reg.type));
+   default:
+      assert(delta == 0);
+   }
+   return reg;
+}
+
+static inline fs_reg
 offset(fs_reg reg, unsigned delta)
 {
    assert(reg.stride > 0);
@@ -184,7 +204,7 @@ half(fs_reg reg, unsigned idx)
    assert(idx == 0 || (reg.file != HW_REG && reg.file != IMM));
    assert(reg.width == 16);
    reg.width = 8;
-   return byte_offset(reg, 8 * idx * reg.stride * type_sz(reg.type));
+   return horiz_offset(reg, 8 * idx);
 }
 
 static const fs_reg reg_undef;