KonstantinSeurer
/
mesa
1
0
Fork 0
Code Issues Pull Requests Packages Projects Releases Wiki Activity

pan/bi: Factor out exp2/log2 code 

Will be reused for fpow.

Signed-off-by: Alyssa Rosenzweig <alyssa@collabora.com>
Part-of: <https://gitlab.freedesktop.org/mesa/mesa/-/merge_requests/11733>
This commit is contained in:
Alyssa Rosenzweig 2021-06-28 10:33:04 -04:00 committed by Marge Bot
parent 0991e9592d
commit 91f130fa1e
1 changed files with 30 additions and 21 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

51
src/panfrost/bifrost/bifrost_compile.c
View File

@ -1477,6 +1477,20 @@ bi_lower_fexp2_32(bi_builder *b, bi_index dst, bi_index s0)
max->sem = BI_SEM_NAN_PROPAGATE;
}
static void
bi_fexp_32(bi_builder *b, bi_index dst, bi_index s0, bi_index log2_base)
{
/* Scale by base, Multiply by 2*24 and convert to integer to get a 8:24
* fixed-point input */
bi_index scale = bi_fma_rscale_f32(b, s0, log2_base, bi_negzero(),
bi_imm_u32(24), BI_ROUND_NONE, BI_SPECIAL_NONE);
bi_index fixed_pt = bi_f32_to_s32(b, scale, BI_ROUND_NONE);
/* Compute the result for the fixed-point input, but pass along
* the original input for correct NaN propagation */
bi_fexp_f32_to(b, dst, fixed_pt, s0);
}
static void
bi_lower_flog2_32(bi_builder *b, bi_index dst, bi_index s0)
{
@ -1511,6 +1525,16 @@ bi_lower_flog2_32(bi_builder *b, bi_index dst, bi_index s0)
bi_fadd_f32_to(b, dst, x1, x2, BI_ROUND_NONE);
}
static void
bi_flog2_32(bi_builder *b, bi_index dst, bi_index s0)
{
bi_index frexp = bi_frexpe_f32(b, s0, true, false);
bi_index frexpi = bi_s32_to_f32(b, frexp, BI_ROUND_RTZ);
bi_index add = bi_fadd_lscale_f32(b, bi_imm_f32(-1.0f), s0);
bi_fma_f32_to(b, dst, bi_flogd_f32(b, s0), add, frexpi,
BI_ROUND_NONE);
}
/* Bifrost has extremely coarse tables for approximating sin/cos, accessible as
* FSIN/COS_TABLE.u6, which multiplies the bottom 6-bits by pi/32 and
* calculates the results. We use them to calculate sin/cos via a Taylor
@ -1816,37 +1840,22 @@ bi_emit_alu(bi_builder *b, nir_alu_instr *instr)
case nir_op_fexp2: {
assert(sz == 32); /* should've been lowered */
if (b->shader->quirks & BIFROST_NO_FP32_TRANSCENDENTALS) {
if (b->shader->quirks & BIFROST_NO_FP32_TRANSCENDENTALS)
bi_lower_fexp2_32(b, dst, s0);
break;
}
else
bi_fexp2_32(b, dst, s0, bi_imm_f32(1.0f));
/* Multiply by 1.0 * 2*24 and convert to integer to get a 8:24
* fixed-point input */
bi_index scale = bi_fma_rscale_f32(b, s0, bi_imm_f32(1.0f),
bi_negzero(), bi_imm_u32(24), BI_ROUND_NONE,
BI_SPECIAL_NONE);
bi_index fixed_pt = bi_f32_to_s32(b, scale, BI_ROUND_NONE);
/* Compute the result for the fixed-point input, but pass along
* the original input for correct NaN propagation */
bi_fexp_f32_to(b, dst, fixed_pt, s0);
break;
}
case nir_op_flog2: {
assert(sz == 32); /* should've been lowered */
if (b->shader->quirks & BIFROST_NO_FP32_TRANSCENDENTALS) {
if (b->shader->quirks & BIFROST_NO_FP32_TRANSCENDENTALS)
bi_lower_flog2_32(b, dst, s0);
break;
}
else
bi_flog2_32_to(b, dst, s0);
bi_index frexp = bi_frexpe_f32(b, s0, true, false);
bi_index frexpi = bi_s32_to_f32(b, frexp, BI_ROUND_RTZ);
bi_index add = bi_fadd_lscale_f32(b, bi_imm_f32(-1.0f), s0);
bi_fma_f32_to(b, dst, bi_flogd_f32(b, s0), add, frexpi,
BI_ROUND_NONE);
break;
}