This breaks GL45-CTS.texture_gather.plain-gather-int-cube-array, but
my CTS is very old.
Did you test your CTS?
Marek
On Wed, Sep 13, 2017 at 7:04 PM, Nicolai Hähnle <nhaeh...@gmail.com> wrote:
> From: Nicolai Hähnle <nicolai.haeh...@amd.com>
>
> This is the same workaround that radv already applied in commit
> 3ece76f03dc0 ("radv/ac: gather4 cube workaround integer").
>
> Fixes dEQP-GLES31.functional.texture.gather.basic.cube.rgba8i/ui.*
>
> Cc: mesa-sta...@lists.freedesktop.org
> ---
> src/gallium/drivers/radeonsi/si_shader_tgsi_mem.c | 106
> ++++++++++++++++++++--
> 1 file changed, 100 insertions(+), 6 deletions(-)
>
> diff --git a/src/gallium/drivers/radeonsi/si_shader_tgsi_mem.c
> b/src/gallium/drivers/radeonsi/si_shader_tgsi_mem.c
> index 1e44b68b860..a09ebed23d2 100644
> --- a/src/gallium/drivers/radeonsi/si_shader_tgsi_mem.c
> +++ b/src/gallium/drivers/radeonsi/si_shader_tgsi_mem.c
> @@ -1667,35 +1667,80 @@ static void tex_fetch_args(
> }
>
> /* Gather4 should follow the same rules as bilinear filtering, but the
> hardware
> * incorrectly forces nearest filtering if the texture format is integer.
> * The only effect it has on Gather4, which always returns 4 texels for
> * bilinear filtering, is that the final coordinates are off by 0.5 of
> * the texel size.
> *
> * The workaround is to subtract 0.5 from the unnormalized coordinates,
> * or (0.5 / size) from the normalized coordinates.
> + *
> + * However, cube textures with 8_8_8_8 data formats require a different
> + * workaround of overriding the num format to USCALED/SSCALED. This would
> lose
> + * precision in 32-bit data formats, so it needs to be applied dynamically at
> + * runtime. In this case, return an i1 value that indicates whether the
> + * descriptor was overridden (and hence a fixup of the sampler result is
> needed).
> */
> -static void si_lower_gather4_integer(struct si_shader_context *ctx,
> - struct ac_image_args *args,
> - unsigned target)
> +static LLVMValueRef
> +si_lower_gather4_integer(struct si_shader_context *ctx,
> + struct ac_image_args *args,
> + unsigned target,
> + enum tgsi_return_type return_type)
> {
> LLVMBuilderRef builder = ctx->gallivm.builder;
> LLVMValueRef coord = args->addr;
> LLVMValueRef half_texel[2];
> /* Texture coordinates start after:
> * {offset, bias, z-compare, derivatives}
> * Only the offset and z-compare can occur here.
> */
> unsigned coord_vgpr_index = (int)args->offset + (int)args->compare;
> int c;
>
> + assert(return_type == TGSI_RETURN_TYPE_SINT ||
> + return_type == TGSI_RETURN_TYPE_UINT);
> +
> + if (target == TGSI_TEXTURE_CUBE ||
> + target == TGSI_TEXTURE_CUBE_ARRAY) {
> + LLVMValueRef formats;
> + LLVMValueRef data_format;
> + LLVMValueRef wa_formats;
> + LLVMValueRef wa;
> +
> + formats = LLVMBuildExtractElement(builder, args->resource,
> ctx->i32_1, "");
> +
> + data_format = LLVMBuildLShr(builder, formats,
> + LLVMConstInt(ctx->i32, 20,
> false), "");
> + data_format = LLVMBuildAnd(builder, data_format,
> + LLVMConstInt(ctx->i32, (1u << 6) -
> 1, false), "");
> + wa = LLVMBuildICmp(builder, LLVMIntEQ, data_format,
> + LLVMConstInt(ctx->i32,
> V_008F14_IMG_DATA_FORMAT_8_8_8_8, false),
> + "");
> +
> + uint32_t wa_num_format =
> + return_type == TGSI_RETURN_TYPE_UINT ?
> +
> S_008F14_NUM_FORMAT_GFX6(V_008F14_IMG_NUM_FORMAT_USCALED) :
> +
> S_008F14_NUM_FORMAT_GFX6(V_008F14_IMG_NUM_FORMAT_SSCALED);
> + wa_formats = LLVMBuildAnd(builder, formats,
> + LLVMConstInt(ctx->i32,
> C_008F14_NUM_FORMAT_GFX6, false),
> + "");
> + wa_formats = LLVMBuildOr(builder, wa_formats,
> + LLVMConstInt(ctx->i32, wa_num_format,
> false), "");
> +
> + formats = LLVMBuildSelect(builder, wa, wa_formats, formats,
> "");
> + args->resource = LLVMBuildInsertElement(
> + builder, args->resource, formats, ctx->i32_1, "");
> +
> + return wa;
> + }
> +
> if (target == TGSI_TEXTURE_RECT ||
> target == TGSI_TEXTURE_SHADOWRECT) {
> half_texel[0] = half_texel[1] = LLVMConstReal(ctx->f32, -0.5);
> } else {
> struct tgsi_full_instruction txq_inst = {};
> struct lp_build_emit_data txq_emit_data = {};
>
> /* Query the texture size. */
> txq_inst.Texture.Texture = target;
> txq_emit_data.inst = &txq_inst;
> @@ -1724,20 +1769,56 @@ static void si_lower_gather4_integer(struct
> si_shader_context *ctx,
> LLVMValueRef index = LLVMConstInt(ctx->i32, coord_vgpr_index
> + c, 0);
>
> tmp = LLVMBuildExtractElement(builder, coord, index, "");
> tmp = LLVMBuildBitCast(builder, tmp, ctx->f32, "");
> tmp = LLVMBuildFAdd(builder, tmp, half_texel[c], "");
> tmp = LLVMBuildBitCast(builder, tmp, ctx->i32, "");
> coord = LLVMBuildInsertElement(builder, coord, tmp, index,
> "");
> }
>
> args->addr = coord;
> +
> + return NULL;
> +}
> +
> +/* The second half of the cube texture 8_8_8_8 integer workaround: adjust the
> + * result after the gather operation.
> + */
> +static LLVMValueRef
> +si_fix_gather4_integer_result(struct si_shader_context *ctx,
> + LLVMValueRef result,
> + enum tgsi_return_type return_type,
> + LLVMValueRef wa)
> +{
> + LLVMBuilderRef builder = ctx->gallivm.builder;
> +
> + assert(return_type == TGSI_RETURN_TYPE_SINT ||
> + return_type == TGSI_RETURN_TYPE_UINT);
> +
> + for (unsigned chan = 0; chan < 4; ++chan) {
> + LLVMValueRef chanv = LLVMConstInt(ctx->i32, chan, false);
> + LLVMValueRef value;
> + LLVMValueRef wa_value;
> +
> + value = LLVMBuildExtractElement(builder, result, chanv, "");
> +
> + if (return_type == TGSI_RETURN_TYPE_UINT)
> + wa_value = LLVMBuildFPToUI(builder, value, ctx->i32,
> "");
> + else
> + wa_value = LLVMBuildFPToSI(builder, value, ctx->i32,
> "");
> + wa_value = LLVMBuildBitCast(builder, wa_value, ctx->f32, "");
> + value = LLVMBuildSelect(builder, wa, wa_value, value, "");
> +
> + result = LLVMBuildInsertElement(builder, result, value,
> chanv, "");
> + }
> +
> + return result;
> }
>
> static void build_tex_intrinsic(const struct lp_build_tgsi_action *action,
> struct lp_build_tgsi_context *bld_base,
> struct lp_build_emit_data *emit_data)
> {
> struct si_shader_context *ctx = si_shader_context(bld_base);
> const struct tgsi_full_instruction *inst = emit_data->inst;
> struct ac_image_args args;
> unsigned opcode = inst->Instruction.Opcode;
> @@ -1798,31 +1879,44 @@ static void build_tex_intrinsic(const struct
> lp_build_tgsi_action *action,
> case TGSI_OPCODE_TG4:
> args.opcode = ac_image_gather4;
> args.level_zero = true;
> break;
> default:
> assert(0);
> return;
> }
>
> /* The hardware needs special lowering for Gather4 with integer
> formats. */
> + LLVMValueRef gather4_int_result_workaround = NULL;
> +
> if (ctx->screen->b.chip_class <= VI &&
> opcode == TGSI_OPCODE_TG4) {
> assert(inst->Texture.ReturnType != TGSI_RETURN_TYPE_UNKNOWN);
>
> if (inst->Texture.ReturnType == TGSI_RETURN_TYPE_SINT ||
> - inst->Texture.ReturnType == TGSI_RETURN_TYPE_UINT)
> - si_lower_gather4_integer(ctx, &args, target);
> + inst->Texture.ReturnType == TGSI_RETURN_TYPE_UINT) {
> + gather4_int_result_workaround =
> + si_lower_gather4_integer(ctx, &args, target,
> +
> inst->Texture.ReturnType);
> + }
> }
>
> - emit_data->output[emit_data->chan] =
> + LLVMValueRef result =
> ac_build_image_opcode(&ctx->ac, &args);
> +
> + if (gather4_int_result_workaround) {
> + result = si_fix_gather4_integer_result(ctx, result,
> +
> inst->Texture.ReturnType,
> +
> gather4_int_result_workaround);
> + }
> +
> + emit_data->output[emit_data->chan] = result;
> }
>
> static void si_llvm_emit_txqs(
> const struct lp_build_tgsi_action *action,
> struct lp_build_tgsi_context *bld_base,
> struct lp_build_emit_data *emit_data)
> {
> struct si_shader_context *ctx = si_shader_context(bld_base);
> struct gallivm_state *gallivm = &ctx->gallivm;
> LLVMBuilderRef builder = gallivm->builder;
> --
> 2.11.0
>
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