Mesa (master): freedreno/a4xx: add ARB_texture_query_lod support

[Ilia Mirkin]

Module: Mesa
Branch: master
Commit: 190acb34ca165c840f87a25149eab1d1b7dc85c4
URL:    http://cgit.freedesktop.org/mesa/mesa/commit/?id=190acb34ca165c840f87a25149eab1d1b7dc85c4

Author: Ilia Mirkin <imirkin at alum.mit.edu>
Date:   Sun Nov 22 16:47:25 2015 -0500

freedreno/a4xx: add ARB_texture_query_lod support

Signed-off-by: Ilia Mirkin <imirkin at alum.mit.edu>

---

 src/gallium/drivers/freedreno/freedreno_screen.c   |    2 +-
 .../drivers/freedreno/ir3/ir3_compiler_nir.c       |   24 ++++++++++++++++----
 2 files changed, 20 insertions(+), 6 deletions(-)

diff --git a/src/gallium/drivers/freedreno/freedreno_screen.c b/src/gallium/drivers/freedreno/freedreno_screen.c
index da7dbc9..5bbe401 100644
--- a/src/gallium/drivers/freedreno/freedreno_screen.c
+++ b/src/gallium/drivers/freedreno/freedreno_screen.c
@@ -198,6 +198,7 @@ fd_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 	case PIPE_CAP_CUBE_MAP_ARRAY:
 	case PIPE_CAP_START_INSTANCE:
 	case PIPE_CAP_SAMPLER_VIEW_TARGET:
+	case PIPE_CAP_TEXTURE_QUERY_LOD:
 		return is_a4xx(screen);
 
 	case PIPE_CAP_CONSTANT_BUFFER_OFFSET_ALIGNMENT:
@@ -221,7 +222,6 @@ fd_screen_get_param(struct pipe_screen *pscreen, enum pipe_cap param)
 	case PIPE_CAP_TGSI_VS_LAYER_VIEWPORT:
 	case PIPE_CAP_MAX_TEXTURE_GATHER_COMPONENTS:
 	case PIPE_CAP_TEXTURE_GATHER_SM5:
-	case PIPE_CAP_TEXTURE_QUERY_LOD:
 	case PIPE_CAP_SAMPLE_SHADING:
 	case PIPE_CAP_TEXTURE_GATHER_OFFSETS:
 	case PIPE_CAP_TGSI_VS_WINDOW_SPACE_POSITION:
diff --git a/src/gallium/drivers/freedreno/ir3/ir3_compiler_nir.c b/src/gallium/drivers/freedreno/ir3/ir3_compiler_nir.c
index 25e8412..fc163b4 100644
--- a/src/gallium/drivers/freedreno/ir3/ir3_compiler_nir.c
+++ b/src/gallium/drivers/freedreno/ir3/ir3_compiler_nir.c
@@ -1547,10 +1547,10 @@ tex_info(nir_tex_instr *tex, unsigned *flagsp, unsigned *coordsp)
 		unreachable("bad sampler_dim");
 	}
 
-	if (tex->is_shadow)
+	if (tex->is_shadow && tex->op != nir_texop_lod)
 		flags |= IR3_INSTR_S;
 
-	if (tex->is_array)
+	if (tex->is_array && tex->op != nir_texop_lod)
 		flags |= IR3_INSTR_A;
 
 	*flagsp = flags;
@@ -1618,9 +1618,9 @@ emit_tex(struct ir3_compile *ctx, nir_tex_instr *tex)
 	case nir_texop_txl:      opc = OPC_SAML;     break;
 	case nir_texop_txd:      opc = OPC_SAMGQ;    break;
 	case nir_texop_txf:      opc = OPC_ISAML;    break;
+	case nir_texop_lod:      opc = OPC_GETLOD;   break;
 	case nir_texop_txf_ms:
 	case nir_texop_txs:
-	case nir_texop_lod:
 	case nir_texop_tg4:
 	case nir_texop_query_levels:
 	case nir_texop_texture_samples:
@@ -1666,10 +1666,10 @@ emit_tex(struct ir3_compile *ctx, nir_tex_instr *tex)
 		src0[nsrc0++] = create_immed(b, fui(0.5));
 	}
 
-	if (tex->is_shadow)
+	if (tex->is_shadow && tex->op != nir_texop_lod)
 		src0[nsrc0++] = compare;
 
-	if (tex->is_array)
+	if (tex->is_array && tex->op != nir_texop_lod)
 		src0[nsrc0++] = coord[coords];
 
 	if (has_proj) {
@@ -1726,12 +1726,26 @@ emit_tex(struct ir3_compile *ctx, nir_tex_instr *tex)
 		unreachable("bad dest_type");
 	}
 
+	if (opc == OPC_GETLOD)
+		type = TYPE_U32;
+
 	sam = ir3_SAM(b, opc, type, TGSI_WRITEMASK_XYZW,
 			flags, tex->sampler_index, tex->sampler_index,
 			create_collect(b, src0, nsrc0),
 			create_collect(b, src1, nsrc1));
 
 	split_dest(b, dst, sam, 4);
+
+	/* GETLOD returns results in 4.8 fixed point */
+	if (opc == OPC_GETLOD) {
+		struct ir3_instruction *factor = create_immed(b, fui(1.0 / 256));
+
+		compile_assert(ctx, tex->dest_type == nir_type_float);
+		for (i = 0; i < 2; i++) {
+			dst[i] = ir3_MUL_F(b, ir3_COV(b, dst[i], TYPE_U32, TYPE_F32), 0,
+							   factor, 0);
+		}
+	}
 }
 
 static void