svga: fix swizzling for texture gather

Texture swizzling for texture gather needs to be done to the selected texels
rather than to the returned vector. This patch has specical cases
for the different swizzles in emit_tg4().

Fixes a lot of piglit texture gather tests.

Reviewed-by: Neha Bhende <[email protected]>
Reviewed-by: Brian Paul <[email protected]>

1 files changed, 33 insertions, 20 deletions

diff --git a/src/gallium/drivers/svga/svga_tgsi_vgpu10.c b/src/gallium/drivers/svga/svga_tgsi_vgpu10.c
index 7422db247ae..03ea67cad65 100644
--- a/src/gallium/drivers/svga/svga_tgsi_vgpu10.c
+++ b/src/gallium/drivers/svga/svga_tgsi_vgpu10.c
@@ -5327,9 +5327,8 @@ emit_tg4(struct svga_shader_emitter_v10 *emit,
 {
    const uint unit = inst->Src[2].Register.Index;
    unsigned target = inst->Texture.Texture;
-   struct tgsi_full_src_register coord;
+   struct tgsi_full_src_register src;
    int offsets[3];
-   struct tex_swizzle_info swz_info;
 
    /* check that the sampler returns a float */
    if (!is_valid_tex_instruction(emit, inst))
@@ -5340,25 +5339,39 @@ emit_tg4(struct svga_shader_emitter_v10 *emit,
       return TRUE;
    }
 
-   begin_tex_swizzle(emit, unit, inst, FALSE, &swz_info);
-
-   get_texel_offsets(emit, inst, offsets);
-
-   coord = setup_texcoord(emit, unit, &inst->Src[0]);
-
-   /* Gather dst, coord, resource, sampler */
-   begin_emit_instruction(emit);
-   emit_sample_opcode(emit, VGPU10_OPCODE_GATHER4,
-                      inst->Instruction.Saturate, offsets);
-   emit_dst_register(emit, get_tex_swizzle_dst(&swz_info));
-   emit_src_register(emit, &coord);
-   emit_resource_register(emit, unit);
-   emit_sampler_register(emit, unit);
-   end_emit_instruction(emit);
-
-   end_tex_swizzle(emit, &swz_info);
+   /* Only single channel is supported in SM4_1.
+    * Only the 0th component will be gathered.
+    */
+   switch (emit->key.tex[unit].swizzle_r) {
+   case PIPE_SWIZZLE_X:
+      get_texel_offsets(emit, inst, offsets);
+      src = setup_texcoord(emit, unit, &inst->Src[0]);
 
-   free_temp_indexes(emit);
+      /* Gather dst, coord, resource, sampler */
+      begin_emit_instruction(emit);
+      emit_sample_opcode(emit, VGPU10_OPCODE_GATHER4,
+                         inst->Instruction.Saturate, offsets);
+      emit_dst_register(emit, &inst->Dst[0]);
+      emit_src_register(emit, &src);
+      emit_resource_register(emit, unit);
+      emit_sampler_register(emit, unit);
+      end_emit_instruction(emit);
+      break;
+   case PIPE_SWIZZLE_W:
+   case PIPE_SWIZZLE_1:
+      src = make_immediate_reg_float(emit, 1.0);
+      emit_instruction_op1(emit, VGPU10_OPCODE_MOV,
+                           &inst->Dst[0], &src, FALSE);
+      break;
+   case PIPE_SWIZZLE_Y:
+   case PIPE_SWIZZLE_Z:
+   case PIPE_SWIZZLE_0:
+   default:
+      src = make_immediate_reg_float(emit, 0.0);
+      emit_instruction_op1(emit, VGPU10_OPCODE_MOV,
+                           &inst->Dst[0], &src, FALSE);
+      break;
+   }
 
    return TRUE;
 }