diff --git a/CMakeLists.txt b/CMakeLists.txt
index c7e7cd3f..2908103a 100644
--- a/CMakeLists.txt
+++ b/CMakeLists.txt
@@ -256,7 +256,8 @@ if (ENABLE_GMUL_ARM64)
 	message(STATUS "ENABLE_GMUL_ARM64 is ON")
 	add_definitions(-DENABLE_GMUL_ARM64)
 	enable_language(ASM)
-	list(APPEND src src/gf128_arm64.S)
+	#list(APPEND src src/gf128_arm64.S)
+	list(APPEND src src/gf128_arm64.c)
 endif()
 
 
diff --git a/src/gf128_arm64.c b/src/gf128_arm64.c
new file mode 100644
index 00000000..42b0ad67
--- /dev/null
+++ b/src/gf128_arm64.c
@@ -0,0 +1,74 @@
+/*
+ *  Copyright 2014-2024 The GmSSL Project. All Rights Reserved.
+ *
+ *  Licensed under the Apache License, Version 2.0 (the License); you may
+ *  not use this file except in compliance with the License.
+ *
+ *  http://www.apache.org/licenses/LICENSE-2.0
+ */
+
+#include <stdint.h>
+#include <arm_neon.h>
+#include <gmssl/gf128.h>
+
+// this version is converted from the gf128_arm64.S by ChatGPT 4
+// a little slower than the asm version
+
+void gf128_mul(gf128_t r, const gf128_t a, const gf128_t b)
+{
+	// Prepare zero
+	uint8x16_t v0;
+	uint8x16_t vzero = veorq_u8(v0, v0);
+
+	// Set f(x) = x^7 + x^2 + x + 1 (0x87) and prepare it by shifting right
+	uint8x16_t v7 = vdupq_n_u8(0x87);
+	uint64x2_t v7_shifted = vreinterpretq_u64_u8(v7);
+	v7_shifted = vshrq_n_u64(v7_shifted, 56);
+
+	// Load (a0, a1) and (b0, b1)
+	uint8x16_t va = vld1q_u8((const uint8_t*) a);
+	uint8x16_t vb = vld1q_u8((const uint8_t*) b);
+
+
+	// c = a0 * b0
+	poly64x2_t v3 = (poly64x2_t)vmull_p64(vget_low_p64(vreinterpretq_p64_u8(va)), vget_low_p64(vreinterpretq_p64_u8(vb)));
+
+	// a0 + a1 and b0 + b1
+	uint8x16_t va0a1 = vextq_u8(va, va, 8);
+	va0a1 = veorq_u8(va0a1, va);
+	uint8x16_t vb0b1 = vextq_u8(vb, vb, 8);
+	vb0b1 = veorq_u8(vb0b1, vb);
+
+	// d' = a1 * b1
+	poly64x2_t v4 = (poly64x2_t)vmull_high_p64(vreinterpretq_p64_u8(va), vreinterpretq_p64_u8(vb));
+
+	// e = (a0 + a1) * (b0 + b1) - a0 * b0 - a1 * b1
+	poly64x2_t v5 = (poly64x2_t)vmull_p64(vget_low_p64(vreinterpretq_p64_u8(va0a1)), vget_low_p64(vreinterpretq_p64_u8(vb0b1)));
+	v5 = veorq_u64(v5, v3);
+	v5 = veorq_u64(v5, v4);
+
+	// d = d' + e1
+	uint8x16_t ve1 = vextq_u8(vreinterpretq_u8_u64(v5), vzero, 8);
+	v4 = veorq_u64(v4, vreinterpretq_u64_u8(ve1));
+
+	// w = d1 * f0
+	poly64x2_t v6 = (poly64x2_t)vmull_high_p64(vreinterpretq_p64_u8(v4), v7_shifted);
+
+	// (e0 + w0) * x^64
+	v5 = veorq_u64(v5, v6);
+	uint8x16_t ve0w0 = vextq_u8(vzero, vreinterpretq_u8_u64(v5), 8);
+
+	// c = c + (e0 + w0) * x^64
+	v3 = veorq_u64(v3, vreinterpretq_u64_u8(ve0w0));
+
+	// (d0 + w1) * f0
+	uint8x16_t vw1 = vextq_u8(vreinterpretq_u8_u64(v6), vzero, 8);
+	v4 = veorq_u64(v4, vreinterpretq_u64_u8(vw1));
+	v4 = (poly64x2_t)vmull_p64(vget_low_p64(vreinterpretq_p64_u64(v4)), vget_low_p64(v7_shifted));
+
+	// c += (d0 + w1) * f0
+	v3 = veorq_u64(v3, v4);
+
+	// Output the result
+	vst1q_u8((uint8_t*) r, vreinterpretq_u8_u64(v3));
+}
diff --git a/tests/ghashtest.c b/tests/ghashtest.c
index 70991da4..e3a2cab9 100644
--- a/tests/ghashtest.c
+++ b/tests/ghashtest.c
@@ -11,6 +11,7 @@
 #include <stdio.h>
 #include <string.h>
 #include <stdlib.h>
+#include <time.h>
 #include <gmssl/ghash.h>
 #include <gmssl/hex.h>
 #include <gmssl/rand.h>
@@ -180,10 +181,44 @@ int test_gcm(void)
 }
 #endif
 
+static int speed_ghash(void)
+{
+	GHASH_CTX ghash_ctx;
+	uint8_t h[16] = {0};
+	uint8_t aad[20] = {0};
+	uint8_t blocks[4096];
+	uint8_t ghash[16];
+	clock_t start, end;
+	double seconds;
+	int i;
+
+	ghash_init(&ghash_ctx, h, aad, sizeof(aad));
+	for (i = 0; i < 4096; i++) {
+		ghash_update(&ghash_ctx, blocks, sizeof(blocks));
+	}
+	start = clock();
+	ghash_init(&ghash_ctx, h, aad, sizeof(aad));
+	for (i = 0; i < 4096; i++) {
+		ghash_update(&ghash_ctx, blocks, sizeof(blocks));
+	}
+	ghash_finish(&ghash_ctx, ghash);
+	end = clock();
+
+	seconds = (double)(end - start)/CLOCKS_PER_SEC;
+	fprintf(stderr, "%s: %f MiB per second\n", __FUNCTION__, 16/seconds);
+
+	return 1;
+}
+
 
 int main(int argc, char **argv)
 {
 	if (test_ghash() != 1) goto err;
+
+#if ENABLE_TEST_SPEED
+	speed_ghash();
+#endif
+
 	printf("%s all tests passed\n", __FILE__);
 	return 0;
 err: