[Mesa-dev] [PATCH v2] i965/skl: Always use a header for SIMD4x2 sampler messages
Kenneth Graunke
kenneth at whitecape.org
Thu Jan 8 01:52:16 PST 2015
On Wednesday, January 07, 2015 10:43:25 PM Kristian Høgsberg wrote:
> SKL+ overloads the SIMD4x2 SIMD mode to mean either SIMD8D or SIMD4x2
> depending on bit 22 in the message header. If the bit is 0 or there is
> no header we get SIMD8D. We always wand SIMD4x2 in vec4 and for fs pull
> constants, so use a message header in those cases and set bit 22 there.
>
> Signed-off-by: Kristian Høgsberg <krh at bitplanet.net>
> ---
> src/mesa/drivers/dri/i965/brw_defines.h | 5 ++++
> src/mesa/drivers/dri/i965/brw_fs.cpp | 8 ++++++
> src/mesa/drivers/dri/i965/brw_fs_generator.cpp | 32 +++++++++++++++++++-----
> src/mesa/drivers/dri/i965/brw_vec4_generator.cpp | 15 ++++++++---
> src/mesa/drivers/dri/i965/brw_vec4_visitor.cpp | 4 ++-
> 5 files changed, 53 insertions(+), 11 deletions(-)
>
> diff --git a/src/mesa/drivers/dri/i965/brw_defines.h b/src/mesa/drivers/dri/i965/brw_defines.h
> index 28e398d..f02a0b8 100644
> --- a/src/mesa/drivers/dri/i965/brw_defines.h
> +++ b/src/mesa/drivers/dri/i965/brw_defines.h
> @@ -1373,6 +1373,11 @@ enum brw_message_target {
> #define BRW_SAMPLER_SIMD_MODE_SIMD16 2
> #define BRW_SAMPLER_SIMD_MODE_SIMD32_64 3
>
> +/* GEN9 changes SIMD mode 0 to mean SIMD8D, but lets us get the SIMD4x2
> + * behavior by setting bit 22 of dword 2 in the message header. */
> +#define GEN9_SAMPLER_SIMD_MODE_SIMD8D 0
> +#define GEN9_SAMPLER_SIMD_MODE_EXTENSION_SIMD4X2 (1 << 22)
> +
> #define BRW_DATAPORT_OWORD_BLOCK_1_OWORDLOW 0
> #define BRW_DATAPORT_OWORD_BLOCK_1_OWORDHIGH 1
> #define BRW_DATAPORT_OWORD_BLOCK_2_OWORDS 2
> diff --git a/src/mesa/drivers/dri/i965/brw_fs.cpp b/src/mesa/drivers/dri/i965/brw_fs.cpp
> index 8c7d780..9dfb7b7 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs.cpp
> @@ -2994,6 +2994,14 @@ fs_visitor::lower_uniform_pull_constant_loads()
> const_offset_reg.fixed_hw_reg.dw1.ud /= 4;
> fs_reg payload = fs_reg(this, glsl_type::uint_type);
>
> + /* We have to use a message header on Skylake to get SIMD4x2 mode.
> + * Reserve space for the register.
> + */
> + if (brw->gen >= 9) {
> + payload.reg_offset++;
> + virtual_grf_sizes[payload.reg] = 2;
> + }
> +
> /* This is actually going to be a MOV, but since only the first dword
> * is accessed, we have a special opcode to do just that one. Note
> * that this needs to be an operation that will be considered a def
> diff --git a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
> index c652d65..7b4ac8d 100644
> --- a/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_fs_generator.cpp
> @@ -1017,6 +1017,26 @@ fs_generator::generate_uniform_pull_constant_load_gen7(fs_inst *inst,
> */
> dst.width = BRW_WIDTH_4;
>
> + struct brw_reg src = offset;
> + bool header_present = false;
> + int mlen = 1;
> +
> + if (brw->gen >= 9) {
> + /* Skylake requires a message header in order to use SIMD4x2 mode. */
> + src = retype(brw_vec8_grf(offset.nr - 1, 0), BRW_REGISTER_TYPE_UD);
> + mlen = 2;
> + header_present = true;
> +
> + brw_push_insn_state(p);
> + brw_set_default_mask_control(p, BRW_MASK_DISABLE);
> + brw_MOV(p, src, retype(brw_vec8_grf(0, 0), BRW_REGISTER_TYPE_UD));
> + brw_set_default_access_mode(p, BRW_ALIGN_1);
> +
> + brw_MOV(p, get_element_ud(src, 2),
> + brw_imm_ud(GEN9_SAMPLER_SIMD_MODE_EXTENSION_SIMD4X2));
> + brw_pop_insn_state(p);
> + }
> +
> if (index.file == BRW_IMMEDIATE_VALUE) {
>
> uint32_t surf_index = index.dw1.ud;
> @@ -1028,14 +1048,14 @@ fs_generator::generate_uniform_pull_constant_load_gen7(fs_inst *inst,
> brw_pop_insn_state(p);
>
> brw_set_dest(p, send, dst);
> - brw_set_src0(p, send, offset);
> + brw_set_src0(p, send, src);
> brw_set_sampler_message(p, send,
> surf_index,
> 0, /* LD message ignores sampler unit */
> GEN5_SAMPLER_MESSAGE_SAMPLE_LD,
> 1, /* rlen */
> - 1, /* mlen */
> - false, /* no header */
> + mlen,
> + header_present,
> BRW_SAMPLER_SIMD_MODE_SIMD4X2,
> 0);
>
> @@ -1064,8 +1084,8 @@ fs_generator::generate_uniform_pull_constant_load_gen7(fs_inst *inst,
> 0 /* sampler */,
> GEN5_SAMPLER_MESSAGE_SAMPLE_LD,
> 1 /* rlen */,
> - 1 /* mlen */,
> - false /* header */,
> + mlen,
> + header_present,
> BRW_SAMPLER_SIMD_MODE_SIMD4X2,
> 0);
> brw_inst_set_exec_size(p->brw, insn_or, BRW_EXECUTE_1);
> @@ -1077,7 +1097,7 @@ fs_generator::generate_uniform_pull_constant_load_gen7(fs_inst *inst,
> /* dst = send(offset, a0.0) */
> brw_inst *insn_send = brw_next_insn(p, BRW_OPCODE_SEND);
> brw_set_dest(p, insn_send, dst);
> - brw_set_src0(p, insn_send, offset);
> + brw_set_src0(p, insn_send, src);
> brw_set_indirect_send_descriptor(p, insn_send, BRW_SFID_SAMPLER, addr);
>
> brw_pop_insn_state(p);
> diff --git a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
> index b88a579..19e82ef 100644
> --- a/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
> +++ b/src/mesa/drivers/dri/i965/brw_vec4_generator.cpp
> @@ -328,6 +328,7 @@ vec4_generator::generate_tex(vec4_instruction *inst,
> } else {
> struct brw_reg header =
> retype(brw_message_reg(inst->base_mrf), BRW_REGISTER_TYPE_UD);
> + uint32_t dw2 = 0;
>
> /* Explicitly set up the message header by copying g0 to the MRF. */
> brw_push_insn_state(p);
> @@ -336,11 +337,17 @@ vec4_generator::generate_tex(vec4_instruction *inst,
>
> brw_set_default_access_mode(p, BRW_ALIGN_1);
>
> - if (inst->offset) {
> + if (inst->offset)
> /* Set the texel offset bits in DWord 2. */
> - brw_MOV(p, get_element_ud(header, 2),
> - brw_imm_ud(inst->offset));
> - }
> + dw2 = inst->offset;
> +
> + if (brw->gen >= 9)
> + /* SKL+ overloads BRW_SAMPLER_SIMD_MODE_SIMD4X2 to also do SIMD8D,
> + * based on bit 22 in the header. */
*/ goes on its own line.
Thanks for porting this to the new (or old, if you prefer) generator framework.
Reviewed-by: Kenneth Graunke <kenneth at whitecape.org>
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