RELU microkernel to clamp values to 0 for a specialized clamp operator
PiperOrigin-RevId: 321457971
diff --git a/src/f32-relu/wasmsimd.c.in b/src/f32-relu/wasmsimd.c.in
new file mode 100644
index 0000000..6834b00
--- /dev/null
+++ b/src/f32-relu/wasmsimd.c.in
@@ -0,0 +1,68 @@
+// Copyright 2020 Google LLC
+//
+// This source code is licensed under the BSD-style license found in the
+// LICENSE file in the root directory of this source tree.
+
+$assert BATCH_TILE % 4 == 0
+$assert BATCH_TILE >= 4
+$ABC = "0123456789ABCDEFGHIJKLMNOPQRSTUVWXYZ"
+#include <assert.h>
+
+#include <wasm_simd128.h>
+
+#include <xnnpack/vunary.h>
+#include <xnnpack/common.h>
+
+
+void xnn_f32_relu_ukernel__wasmsimd_x${BATCH_TILE}(
+ size_t n,
+ const float* x,
+ float* y,
+ const union xnn_f32_relu_params params[restrict XNN_MIN_ELEMENTS(1)]) XNN_DISABLE_TSAN
+{
+ assert(n != 0);
+ assert(n % sizeof(float) == 0);
+ assert(x != NULL);
+ assert(y != NULL);
+
+ const v128_t vzero = wasm_f32x4_splat(0.0f);
+
+ $if BATCH_TILE > 4:
+ for (; n >= ${BATCH_TILE} * sizeof(float); n -= ${BATCH_TILE} * sizeof(float)) {
+ v128_t vacc${ABC[0:4]} = wasm_v128_load(x);
+ $for N in range(4, BATCH_TILE, 4):
+ v128_t vacc${ABC[N:N+4]} = wasm_v128_load(x + ${N});
+ x += ${BATCH_TILE};
+
+ $for N in range(0, BATCH_TILE, 4):
+ vacc${ABC[N:N+4]} = wasm_i32x4_max(vacc${ABC[N:N+4]}, vzero);
+
+ wasm_v128_store(y, vacc${ABC[0:4]});
+ $for N in range(4, BATCH_TILE, 4):
+ wasm_v128_store(y + ${N}, vacc${ABC[N:N+4]});
+ y += ${BATCH_TILE};
+ }
+ for (; n >= 4 * sizeof(float); n -= 4 * sizeof(float)) {
+ v128_t vacc = wasm_v128_load(x);
+ x += 4;
+
+ vacc = wasm_i32x4_max(vacc, vzero);
+
+ wasm_v128_store(y, vacc);
+ y += 4;
+ }
+ if XNN_UNLIKELY(n != 0) {
+ v128_t vacc = wasm_v128_load(x);
+
+ vacc = wasm_i32x4_max(vacc, vzero);
+
+ if (n & (2 * sizeof(float))) {
+ *((double*) y) = wasm_f64x2_extract_lane(vacc, 0);
+ vacc = wasm_v32x4_shuffle(vacc, vacc, 2, 3, 2, 3);
+ y += 2;
+ }
+ if (n & (1 * sizeof(float))) {
+ *y = wasm_f32x4_extract_lane(vacc, 0);
+ }
+ }
+}