1 // Copyright 2022 Google LLC
2 //
3 // This source code is licensed under the BSD-style license found in the
4 // LICENSE file in the root directory of this source tree.
5
6 #include <assert.h>
7 #include <stddef.h>
8 #include <stdint.h>
9
10 #include <wasm_simd128.h>
11
12 #include <xnnpack/math-stubs.h>
13
14
xnn_math_f32_qu8_cvt__wasmsimd(size_t n,const float * input,uint8_t * output,uint8_t output_zero_point)15 void xnn_math_f32_qu8_cvt__wasmsimd(
16 size_t n,
17 const float* input,
18 uint8_t* output,
19 uint8_t output_zero_point)
20 {
21 assert(n % (16 * sizeof(uint8_t)) == 0);
22
23 const v128_t vmin = wasm_f32x4_splat(12582912.0f - (float) (int32_t) output_zero_point);
24 const v128_t vfmagic = wasm_f32x4_const_splat(12582912.0f);
25 const v128_t vimagic = wasm_i32x4_splat(INT32_C(0x4B400000) - (int32_t) output_zero_point);
26 for (; n != 0; n -= 16 * sizeof(uint8_t)) {
27 const v128_t vx_ll = wasm_v128_load(input);
28 const v128_t vx_lh = wasm_v128_load(input + 4);
29 const v128_t vx_hl = wasm_v128_load(input + 8);
30 const v128_t vx_hh = wasm_v128_load(input + 12);
31 input += 16;
32
33 v128_t vy_ll = wasm_f32x4_add(vx_ll, vfmagic);
34 v128_t vy_lh = wasm_f32x4_add(vx_lh, vfmagic);
35 v128_t vy_hl = wasm_f32x4_add(vx_hl, vfmagic);
36 v128_t vy_hh = wasm_f32x4_add(vx_hh, vfmagic);
37
38 vy_ll = wasm_i32x4_max(vy_ll, vmin);
39 vy_lh = wasm_i32x4_max(vy_lh, vmin);
40 vy_hl = wasm_i32x4_max(vy_hl, vmin);
41 vy_hh = wasm_i32x4_max(vy_hh, vmin);
42
43 vy_ll = wasm_i32x4_sub(vy_ll, vimagic);
44 vy_lh = wasm_i32x4_sub(vy_lh, vimagic);
45 vy_hl = wasm_i32x4_sub(vy_hl, vimagic);
46 vy_hh = wasm_i32x4_sub(vy_hh, vimagic);
47
48 const v128_t vy_lo = wasm_i16x8_narrow_i32x4(vy_ll, vy_lh);
49 const v128_t vy_hi = wasm_i16x8_narrow_i32x4(vy_hl, vy_hh);
50
51 const v128_t vout = wasm_u8x16_narrow_i16x8(vy_lo, vy_hi);
52 wasm_v128_store(output, vout);
53 output += 16;
54 }
55 }
56