[Mesa-dev] [PATCH 1/5] radeonsi: workaround for gather4 on integer cube maps
Nicolai Hähnle
nhaehnle at gmail.com
Wed Sep 13 17:04:30 UTC 2017
From: Nicolai Hähnle <nicolai.haehnle at 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-stable at 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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