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agx: Implement fsin/fcos 

First, we lower to fsin_agx and some ALU in NIR. Then, we implement
fsin_agx with the underlying transcental ops.

Signed-off-by: Alyssa Rosenzweig <alyssa@rosenzweig.io>
Acked-by: Jason Ekstrand <jason@jlekstrand.net>
Acked-by: Bas Nieuwenhuizen <bas@basnieuwenhuizen.nl>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/10582>
This commit is contained in:
Alyssa Rosenzweig 2021-04-15 22:51:47 -04:00 committed by Alyssa Rosenzweig
parent b5a3845f9a
commit 1f77aa95ec
1 changed files with 48 additions and 0 deletions
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48
src/asahi/compiler/agx_compile.c
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@ -257,6 +257,13 @@ agx_emit_alu(agx_builder *b, nir_alu_instr *instr)
return I;
}
case nir_op_fsin_agx:
{
agx_index fixup = agx_sin_pt_1(b, s0);
agx_index sinc = agx_sin_pt_2(b, fixup);
return agx_fmul_to(b, dst, sinc, fixup);
}
case nir_op_vec2:
case nir_op_vec3:
case nir_op_vec4:
@ -403,6 +410,46 @@ glsl_type_size(const struct glsl_type *type, bool bindless)
return glsl_count_attribute_slots(type, false);
}
static bool
agx_lower_sincos_filter(const nir_instr *instr, UNUSED const void *_)
{
if (instr->type != nir_instr_type_alu)
return false;
nir_alu_instr *alu = nir_instr_as_alu(instr);
return alu->op == nir_op_fsin || alu->op == nir_op_fcos;
}
/* Sine and cosine are implemented via the sin_pt_1 and sin_pt_2 opcodes for
* heavy lifting. sin_pt_2 implements sinc in the first quadrant, expressed in
* turns (sin (tau x) / x), while sin_pt_1 implements a piecewise sign/offset
* fixup to transform a quadrant angle [0, 4] to [-1, 1]. The NIR opcode
* fsin_agx models the fixup, sinc, and multiply to obtain sine, so we just
* need to change units from radians to quadrants modulo turns. Cosine is
* implemented by shifting by one quadrant: cos(x) = sin(x + tau/4).
*/
static nir_ssa_def *
agx_lower_sincos_impl(struct nir_builder *b, nir_instr *instr, UNUSED void *_)
{
nir_alu_instr *alu = nir_instr_as_alu(instr);
nir_ssa_def *x = nir_mov_alu(b, alu->src[0], 1);
nir_ssa_def *turns = nir_fmul_imm(b, x, M_1_PI * 0.5f);
if (alu->op == nir_op_fcos)
turns = nir_fadd_imm(b, turns, 0.25f);
nir_ssa_def *quadrants = nir_fmul_imm(b, nir_ffract(b, turns), 4.0);
return nir_fsin_agx(b, quadrants);
}
static bool
agx_lower_sincos(nir_shader *shader)
{
return nir_shader_lower_instructions(shader,
agx_lower_sincos_filter, agx_lower_sincos_impl, NULL);
}
static void
agx_optimize_nir(nir_shader *nir)
{
@ -419,6 +466,7 @@ agx_optimize_nir(nir_shader *nir)
NIR_PASS_V(nir, nir_lower_alu_to_scalar, NULL, NULL);
NIR_PASS_V(nir, nir_lower_load_const_to_scalar);
NIR_PASS_V(nir, nir_lower_flrp, 16 | 32 | 64, false);
NIR_PASS_V(nir, agx_lower_sincos);
do {
progress = false;