[Mesa-dev] [PATCH 18/22] i965/fs: Communicate the pull constant block read parameters through fs_regs.

[Eric Anholt]

I wanted to add the surface index as a variable value for UBO support,
and a reg seemed like the obvious way to go.  This exposes more of the
information to CSE, which we'll probably want to apply to pull
constant loads for UBOs eventually (you might access 4 floats in a
row, each of which would produce an oword block read of the same
block).
---
 src/mesa/drivers/dri/i965/brw_fs.cpp      |    6 ++++--
 src/mesa/drivers/dri/i965/brw_fs.h        |    4 +++-
 src/mesa/drivers/dri/i965/brw_fs_emit.cpp |   16 +++++++++++++---
 3 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
index d06858e..cb89d74 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
@@ -1214,9 +1214,11 @@ fs_visitor::setup_pull_constants()
 	    continue;
 
 	 fs_reg dst = fs_reg(this, glsl_type::float_type);
+	 fs_reg index = fs_reg((unsigned)SURF_INDEX_FRAG_CONST_BUFFER);
+	 fs_reg offset = fs_reg((unsigned)(((uniform_nr -
+					     pull_uniform_base) * 4) & ~15));
 	 fs_inst *pull = new(mem_ctx) fs_inst(FS_OPCODE_PULL_CONSTANT_LOAD,
-					      dst);
-	 pull->offset = ((uniform_nr - pull_uniform_base) * 4) & ~15;
+					      dst, index, offset);
 	 pull->ir = inst->ir;
 	 pull->annotation = inst->annotation;
 	 pull->base_mrf = 14;
diff --git a/src/mesa/drivers/dri/i965/brw_fs.h b/src/mesa/drivers/dri/i965/brw_fs.h
index 031d541..f1c719d 100644
--- a/src/mesa/drivers/dri/i965/brw_fs.h
+++ b/src/mesa/drivers/dri/i965/brw_fs.h
@@ -291,7 +291,9 @@ public:
                      bool negate_value);
    void generate_spill(fs_inst *inst, struct brw_reg src);
    void generate_unspill(fs_inst *inst, struct brw_reg dst);
-   void generate_pull_constant_load(fs_inst *inst, struct brw_reg dst);
+   void generate_pull_constant_load(fs_inst *inst, struct brw_reg dst,
+				    struct brw_reg index,
+				    struct brw_reg offset);
    void generate_mov_dispatch_to_flags();
 
    void emit_dummy_fs();
diff --git a/src/mesa/drivers/dri/i965/brw_fs_emit.cpp b/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
index dc5f3e1..62745a4 100644
--- a/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
+++ b/src/mesa/drivers/dri/i965/brw_fs_emit.cpp
@@ -562,7 +562,9 @@ fs_visitor::generate_unspill(fs_inst *inst, struct brw_reg dst)
 }
 
 void
-fs_visitor::generate_pull_constant_load(fs_inst *inst, struct brw_reg dst)
+fs_visitor::generate_pull_constant_load(fs_inst *inst, struct brw_reg dst,
+					struct brw_reg index,
+					struct brw_reg offset)
 {
    assert(inst->mlen != 0);
 
@@ -579,8 +581,16 @@ fs_visitor::generate_pull_constant_load(fs_inst *inst, struct brw_reg dst)
    if (intel->gen == 4 && !intel->is_g4x)
       brw_MOV(p, brw_null_reg(), dst);
 
+   assert(index.file == BRW_IMMEDIATE_VALUE &&
+	  index.type == BRW_REGISTER_TYPE_UD);
+   uint32_t surf_index = index.dw1.ud;
+
+   assert(offset.file == BRW_IMMEDIATE_VALUE &&
+	  offset.type == BRW_REGISTER_TYPE_UD);
+   uint32_t read_offset = offset.dw1.ud;
+
    brw_oword_block_read(p, dst, brw_message_reg(inst->base_mrf),
-			inst->offset, SURF_INDEX_FRAG_CONST_BUFFER);
+			read_offset, surf_index);
 
    if (intel->gen == 4 && !intel->is_g4x) {
       /* gen4 errata: destination from a send can't be used as a
@@ -947,7 +957,7 @@ fs_visitor::generate_code()
 	 break;
 
       case FS_OPCODE_PULL_CONSTANT_LOAD:
-	 generate_pull_constant_load(inst, dst);
+	 generate_pull_constant_load(inst, dst, src[0], src[1]);
 	 break;
 
       case FS_OPCODE_FB_WRITE:
-- 
1.7.10.4