fdo-mirrors/mesa
1
0
Fork 0
mirror of https://gitlab.freedesktop.org/mesa/mesa.git synced 2026-05-05 11:48:06 +02:00
Code Issues Projects Releases Packages Wiki Activity Actions 2

aco: use v_fma_mix_f32 for v_fma_f32 with 2 fp16 representable, different literals

Browse source 
We can pack two fp16 literals into one 32bit literal and use opsel to select
the correct value. Note that LLVM currently disassembles these instructions
incorrectly.

Foz-DB Navi21:
Totals from 13365 (9.91% of 134913) affected shaders:
VGPRs: 840880 -> 840016 (-0.10%); split: -0.11%, +0.01%
SpillSGPRs: 724 -> 722 (-0.28%)
CodeSize: 82439364 -> 82451336 (+0.01%); split: -0.06%, +0.08%
MaxWaves: 244858 -> 244980 (+0.05%)
Instrs: 15265976 -> 15247201 (-0.12%); split: -0.13%, +0.01%
Latency: 223316180 -> 223272495 (-0.02%); split: -0.03%, +0.02%
InvThroughput: 41981375 -> 41969917 (-0.03%); split: -0.04%, +0.01%
VClause: 266775 -> 266558 (-0.08%); split: -0.14%, +0.06%
SClause: 646602 -> 645996 (-0.09%); split: -0.16%, +0.07%
Copies: 794703 -> 776075 (-2.34%); split: -2.46%, +0.12%
Branches: 296317 -> 296316 (-0.00%)
PreSGPRs: 658796 -> 656479 (-0.35%); split: -0.35%, +0.00%
PreVGPRs: 744014 -> 743679 (-0.05%)

Reviewed-by: Rhys Perry <pendingchaos02@gmail.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/20587>
This commit is contained in:
Georg Lehmann 2023-01-09 12:32:56 +01:00 • committed by Marge Bot
parent ed349951cb
commit ede0630f9e
1 changed files with 63 additions and 4 deletions
Show stats Download patch file Download diff file Expand all files Collapse all files

67
src/amd/compiler/aco_optimizer.cpp
View file

@ -76,9 +76,10 @@ struct mad_info {
aco_ptr<Instruction> add_instr;
uint32_t mul_temp_id;
uint16_t literal_mask;
uint16_t fp16_mask;
mad_info(aco_ptr<Instruction> instr, uint32_t id)
: add_instr(std::move(instr)), mul_temp_id(id), literal_mask(0)
: add_instr(std::move(instr)), mul_temp_id(id), literal_mask(0), fp16_mask(0)
{}
};
@ -4755,8 +4756,7 @@ select_instruction(opt_ctx& ctx, aco_ptr<Instruction>& instr)
mad_info = NULL;
}
/* check literals */
else if (!instr->usesModifiers() && !instr->isVOP3P() &&
instr->opcode != aco_opcode::v_fma_f64 &&
else if (!instr->isDPP() && !instr->isVOP3P() && instr->opcode != aco_opcode::v_fma_f64 &&
instr->opcode != aco_opcode::v_mad_legacy_f32 &&
instr->opcode != aco_opcode::v_fma_legacy_f32) {
/* FMA can only take literals on GFX10+ */
@ -4770,6 +4770,7 @@ select_instruction(opt_ctx& ctx, aco_ptr<Instruction>& instr)
return;
uint32_t literal_mask = 0;
uint32_t fp16_mask = 0;
uint32_t sgpr_mask = 0;
uint32_t vgpr_mask = 0;
uint32_t literal_uses = UINT32_MAX;
@ -4782,6 +4783,13 @@ select_instruction(opt_ctx& ctx, aco_ptr<Instruction>& instr)
continue;
if (ctx.info[op.tempId()].is_literal(get_operand_size(instr, i))) {
uint32_t new_literal = ctx.info[op.tempId()].val;
float value = uif(new_literal);
uint16_t fp16_val = _mesa_float_to_half(value);
bool is_denorm = (fp16_val & 0x7fff) != 0 && (fp16_val & 0x7fff) <= 0x3ff;
if (_mesa_half_to_float(fp16_val) == value &&
(!is_denorm || (ctx.fp_mode.denorm16_64 & fp_denorm_keep_in)))
fp16_mask |= 1 << i;
if (!literal_mask || literal_value == new_literal) {
literal_value = new_literal;
literal_uses = MIN2(literal_uses, ctx.uses[op.tempId()]);
@ -4805,6 +4813,24 @@ select_instruction(opt_ctx& ctx, aco_ptr<Instruction>& instr)
if (!(literal_mask & 0b100) && !(vgpr_mask & 0b100))
literal_mask = 0;
if (instr->usesModifiers())
literal_mask = 0;
/* We can't use three unique fp16 literals */
if (fp16_mask == 0b111)
fp16_mask = 0b11;
if ((instr->opcode == aco_opcode::v_fma_f32 ||
(instr->opcode == aco_opcode::v_mad_f32 && !instr->definitions[0].isPrecise())) &&
!instr->vop3().omod && ctx.program->gfx_level >= GFX10 &&
util_bitcount(fp16_mask) > std::max<uint32_t>(util_bitcount(literal_mask), 1)) {
assert(ctx.program->dev.fused_mad_mix);
u_foreach_bit (i, fp16_mask)
ctx.uses[instr->operands[i].tempId()]--;
mad_info->fp16_mask = fp16_mask;
return;
}
/* Limit the number of literals to apply to not increase the code
* size too much, but always apply literals for v_mad->v_madak
* because both instructions are 64-bit and this doesn't increase
@ -5159,8 +5185,41 @@ apply_literals(opt_ctx& ctx, aco_ptr<Instruction>& instr)
mad_info* info = &ctx.mad_infos[ctx.info[instr->definitions[0].tempId()].instr->pass_flags];
const bool madak = (info->literal_mask & 0b100);
bool has_dead_literal = false;
u_foreach_bit (i, info->literal_mask)
u_foreach_bit (i, info->literal_mask | info->fp16_mask)
has_dead_literal |= ctx.uses[instr->operands[i].tempId()] == 0;
if (has_dead_literal && info->fp16_mask) {
aco_ptr<Instruction> fma_mix(
create_instruction<VOP3P_instruction>(aco_opcode::v_fma_mix_f32, Format::VOP3P, 3, 1));
fma_mix->vop3p().clamp = instr->vop3().clamp;
std::copy(std::cbegin(instr->vop3().abs), std::cend(instr->vop3().abs),
std::begin(fma_mix->vop3p().neg_hi));
std::copy(std::cbegin(instr->vop3().neg), std::cend(instr->vop3().neg),
std::begin(fma_mix->vop3p().neg_lo));
uint32_t literal = 0;
bool second = false;
u_foreach_bit (i, info->fp16_mask) {
float value = uif(ctx.info[instr->operands[i].tempId()].val);
literal |= _mesa_float_to_half(value) << (second * 16);
fma_mix->vop3p().opsel_lo |= second << i;
fma_mix->vop3p().opsel_hi |= 1 << i;
second = true;
}
for (unsigned i = 0; i < 3; i++) {
if (info->fp16_mask & (1 << i))
fma_mix->operands[i] = Operand::literal32(literal);
else
fma_mix->operands[i] = instr->operands[i];
}
fma_mix->definitions[0] = instr->definitions[0];
ctx.instructions.emplace_back(std::move(fma_mix));
return;
}
if (has_dead_literal || madak) {
aco_ptr<Instruction> new_mad;