From: Conor McCarthy cmccarthy@codeweavers.com
--- libs/vkd3d-shader/ir.c | 56 +++++++++++++++++++ libs/vkd3d-shader/vkd3d_shader_private.h | 25 +++++++++ .../hlsl/arithmetic-float-uniform.shader_test | 2 +- 3 files changed, 82 insertions(+), 1 deletion(-)
diff --git a/libs/vkd3d-shader/ir.c b/libs/vkd3d-shader/ir.c index 8af537390..704cd8387 100644 --- a/libs/vkd3d-shader/ir.c +++ b/libs/vkd3d-shader/ir.c @@ -1825,6 +1825,8 @@ struct cf_flattener unsigned int control_flow_depth; struct cf_flattener_info *control_flow_info; size_t control_flow_info_size; + + unsigned int precise_mad_temp_idx; };
static void cf_flattener_set_error(struct cf_flattener *flattener, enum vkd3d_result error) @@ -2036,6 +2038,54 @@ static void VKD3D_PRINTF_FUNC(3, 4) cf_flattener_create_block_name(struct cf_fla flattener->block_names[block_id] = buffer.buffer; }
+/* The Shader Model 5 Assembly documentation states: "If components of a mad + * instruction are tagged as precise, the hardware must execute a mad instruction + * or the exact equivalent, and it cannot split it into a multiply followed by an add." + * But DXIL.rst states the opposite: "Floating point multiply & add. This operation is + * not fused for "precise" operations." + * Windows drivers seem to conform with the latter, for SM 4-5 and SM 6. */ +static bool cf_flattener_handle_precise_mad(struct cf_flattener *flattener, + const struct vkd3d_shader_instruction *instruction) +{ + struct vkd3d_shader_instruction *mul_ins, *add_ins; + struct vsir_program *program = flattener->program; + struct vkd3d_shader_dst_param *mul_dst; + + if (!(instruction->flags & VKD3DSI_PRECISE_XYZW)) + return cf_flattener_copy_instruction(flattener, instruction); + + if (!(mul_ins = cf_flattener_require_space(flattener, 2))) + return false; + add_ins = mul_ins + 1; + + if (!flattener->precise_mad_temp_idx) + flattener->precise_mad_temp_idx = 1 + program->temp_count++; + + *mul_ins = *instruction; + mul_ins->handler_idx = VKD3DSIH_MUL; + mul_ins->src_count = 2; + + if (!(vsir_instruction_init_with_params(program, add_ins, &instruction->location, VKD3DSIH_ADD, 1, 2))) + return false; + add_ins->flags = instruction->flags & VKD3DSI_PRECISE_XYZW; + + mul_dst = mul_ins->dst; + *add_ins->dst = *mul_dst; + + mul_dst->modifiers = 0; + vsir_register_init(&mul_dst->reg, VKD3DSPR_TEMP, instruction->src[0].reg.data_type, 1); + mul_dst->reg.dimension = add_ins->dst->reg.dimension; + mul_dst->reg.idx[0].offset = flattener->precise_mad_temp_idx - 1; + + add_ins->src[0].reg = mul_dst->reg; + add_ins->src[0].swizzle = vsir_swizzle_from_writemask(mul_dst->write_mask); + add_ins->src[0].modifiers = 0; + add_ins->src[1] = mul_ins->src[2]; + + flattener->instruction_count += 2; + return true; +} + static enum vkd3d_result cf_flattener_iterate_instruction_array(struct cf_flattener *flattener, struct vkd3d_shader_message_context *message_context) { @@ -2375,6 +2425,12 @@ static enum vkd3d_result cf_flattener_iterate_instruction_array(struct cf_flatte main_block_open = false; break;
+ /* Handle precise MAD here because it requires insertion of an extra instruction. */ + case VKD3DSIH_MAD: + if (!cf_flattener_handle_precise_mad(flattener, instruction)) + return VKD3D_ERROR_OUT_OF_MEMORY; + break; + default: if (!cf_flattener_copy_instruction(flattener, instruction)) return VKD3D_ERROR_OUT_OF_MEMORY; diff --git a/libs/vkd3d-shader/vkd3d_shader_private.h b/libs/vkd3d-shader/vkd3d_shader_private.h index b07a7bff7..f401fd7a3 100644 --- a/libs/vkd3d-shader/vkd3d_shader_private.h +++ b/libs/vkd3d-shader/vkd3d_shader_private.h @@ -1761,6 +1761,31 @@ static inline unsigned int vkd3d_compact_swizzle(uint32_t swizzle, uint32_t writ return compacted_swizzle; }
+static inline uint32_t vsir_swizzle_from_writemask(unsigned int writemask) +{ + static const unsigned int swizzles[16] = + { + 0, + VKD3D_SHADER_SWIZZLE(X, X, X, X), + VKD3D_SHADER_SWIZZLE(Y, Y, Y, Y), + VKD3D_SHADER_SWIZZLE(X, Y, X, X), + VKD3D_SHADER_SWIZZLE(Z, Z, Z, Z), + VKD3D_SHADER_SWIZZLE(X, Z, X, X), + VKD3D_SHADER_SWIZZLE(Y, Z, X, X), + VKD3D_SHADER_SWIZZLE(X, Y, Z, X), + VKD3D_SHADER_SWIZZLE(W, W, W, W), + VKD3D_SHADER_SWIZZLE(X, W, X, X), + VKD3D_SHADER_SWIZZLE(Y, W, X, X), + VKD3D_SHADER_SWIZZLE(X, Y, W, X), + VKD3D_SHADER_SWIZZLE(Z, W, X, X), + VKD3D_SHADER_SWIZZLE(X, Z, W, X), + VKD3D_SHADER_SWIZZLE(Y, Z, W, X), + VKD3D_SHADER_SWIZZLE(X, Y, Z, W), + }; + + return swizzles[writemask & 0xf]; +} + struct vkd3d_struct { enum vkd3d_shader_structure_type type; diff --git a/tests/hlsl/arithmetic-float-uniform.shader_test b/tests/hlsl/arithmetic-float-uniform.shader_test index 8bc3992e7..c6b7caaae 100644 --- a/tests/hlsl/arithmetic-float-uniform.shader_test +++ b/tests/hlsl/arithmetic-float-uniform.shader_test @@ -121,7 +121,7 @@ uniform 0 float4 1.00000007 -42.1 4.0 45.0 uniform 4 float4 1.625 -5.0 4.125 5.0 uniform 8 float4 1.00000007 -1.0 0.5 -0.5 todo(sm<6) draw quad -todo probe all rgba (2.62500048, 209.5, 17.0, 224.5) +probe all rgba (2.62500048, 209.5, 17.0, 224.5)
[require] shader model >= 5.0