Updated GCM for SM4 (markdown)

GCM-for-SM4.md

@@ -58,4 +58,35 @@ gcmSm4Enc方法，初步完成AMD64架构非AVX(2)版本开发，正进行更多
 
 **2022年1月18日**
 
-gcmSm4Enc, gcmSm4Dec, 已完成AMD64架构下非AVX(2)版本及AVX(2)版本，代码有点臃肿；ARM64版本也已完成，优化的方向为矩阵行列转换。
+gcmSm4Enc, gcmSm4Dec, 已完成AMD64架构下非AVX(2)版本及AVX(2)版本，代码有点臃肿；ARM64版本也已完成，优化的方向为矩阵行列转换。
+
+**ARM64矩阵转换**
+* [Zip vectors](https://developer.arm.com/documentation/ddi0596/2021-12/SIMD-FP-Instructions/ZIP1--Zip-vectors--primary--)
+* [Add SM4 ARMv8/AArch64 assembly implementation](https://lists.gnupg.org/pipermail/gcrypt-devel/2022-February/005257.html)
+```asm
+// 从高位到低位
+// s0 = s0.S3, s0.S2, s0.S1, s0.S0
+// s1 = s1.S3, s1.S2, s1.S1, s1.S0
+// s2 = s2.S3, s2.S2, s2.S1, s2.S0
+// s3 = s3.S3, s3.S2, s3.S1, s3.S0
+#define transpose_4x4(s0, s1, s2, s3)   \
+        zip1 RTMP0.4s, s0.4s, s1.4s;    \ // RTMP0 = s1.S1, s0.S1, s1.S0, s0.S0
+        zip1 RTMP1.4s, s2.4s, s3.4s;    \ // RTMP1 = s3.S1, s2.S1, s3.S0, s2.S0
+        zip2 RTMP2.4s, s0.4s, s1.4s;    \ // RTMP2 = s1.S3, s0.S3, s1.S2, s0.S2
+        zip2 RTMP3.4s, s2.4s, s3.4s;    \ // RTMP3 = s3.S3, s2.S3, s3.S2, s2.S2
+        zip1 s0.2d, RTMP0.2d, RTMP1.2d; \ // s0 = s3.S0, s2.S0, s1.S0, s0.S0
+        zip2 s1.2d, RTMP0.2d, RTMP1.2d; \ // s1 = s3.S1, s2.S1, s1.S1, s0.S1
+        zip1 s2.2d, RTMP2.2d, RTMP3.2d; \ // s2 = s3.S2, s2.S2, s1.S2, s0.S2
+        zip2 s3.2d, RTMP2.2d, RTMP3.2d;   // s3 = s3.S3, s2.S3, s1.S3, s0.S3
+
+#define rotate_clockwise_90(s0, s1, s2, s3) \
+        zip1 RTMP0.4s, s1.4s, s0.4s;        \ // RTMP0 = s0.S1, s1.S1, s0.S0, s1.S0
+        zip2 RTMP1.4s, s1.4s, s0.4s;        \ // RTMP1 = s0.S3, s1.S3, s0.S2, s1.S2
+        zip1 RTMP2.4s, s3.4s, s2.4s;        \ // RTMP2 = s2.S1, s3.S1, s2.S0, s3.S0
+        zip2 RTMP3.4s, s3.4s, s2.4s;        \ // RTMP3 = s2.S3, s3.S3, s2.S2, s3.S2
+        zip1 s0.2d, RTMP2.2d, RTMP0.2d;     \ // s0 = s0.S0, s1.S0, s2.S0, s3.S0
+        zip2 s1.2d, RTMP2.2d, RTMP0.2d;     \ // s1 = s0.S1, s1.S1, s2.S1, s3.S1
+        zip1 s2.2d, RTMP3.2d, RTMP1.2d;     \ // s2 = s0.S2, s1.S2, s2.S2, s3.S2
+        zip2 s3.2d, RTMP3.2d, RTMP1.2d;	      // s3 = s0.S3, s1.S3, s2.S3, s3.S3
+```
+但VZIP1/VZIP2好像golang asm还没支持。