diff --git a/README-EN.md b/README-EN.md
index 0daf261..bb9e901 100644
--- a/README-EN.md
+++ b/README-EN.md
@@ -17,7 +17,7 @@ ShangMi (SM) cipher suites for Golang, referred to as **GMSM**, is a secure, hig
 ## Packages
 - **SM2** - This is a SM2 sm2p256v1 implementation whose performance is similar like golang native NIST P256 under **amd64**, **arm64**, **s390x** and **ppc64le**, for implementation detail, please refer [SM2实现细节](https://github.com/emmansun/gmsm/wiki/SM2%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96). It supports ShangMi sm2 digital signature, public key encryption algorithm and also key exchange.
 
-- **SM3** - This is also a SM3 implementation whose performance is similar like golang native SHA 256 with SIMD under **amd64** and **arm64**, for implementation detail, please refer [SM3性能优化](https://github.com/emmansun/gmsm/wiki/SM3%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96). It also provides A64 cryptographic instructions SM3 tested with QEMU.
+- **SM3** - This is also a SM3 implementation whose performance is similar like golang native SHA 256 with SIMD under **amd64**, **arm64**, **s390x**, **ppc64x**, for implementation detail, please refer [SM3性能优化](https://github.com/emmansun/gmsm/wiki/SM3%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96). It also provides A64 cryptographic instructions SM3 tested with QEMU.
 
 - **SM4** - For SM4 implementation, SIMD & AES-NI are used under **amd64** and **arm64**, for detail please refer [SM4性能优化](https://github.com/emmansun/gmsm/wiki/SM4%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96). It is optimized for **ECB/CBC/GCM/XTS** operation modes. It also provides A64 cryptographic instructions SM4 tested with QEMU.
 
diff --git a/README.md b/README.md
index a7d872c..a5b9719 100644
--- a/README.md
+++ b/README.md
@@ -26,7 +26,7 @@ Go语言商用密码软件，简称**GMSM**，一个安全、高性能、易于
 ## 包结构
 - **SM2** - SM2椭圆曲线公钥密码算法，曲线的具体实现位于[internal/sm2ec](https://github.com/emmansun/gmsm/tree/main/internal/sm2ec) package中。SM2曲线实现性能和Golang SDK中的NIST P256椭圆曲线原生实现（非BoringCrypto）类似，也对**amd64**，**arm64**，**s390x**和**ppc64le**架构做了专门汇编优化实现，您也可以参考[SM2实现细节](https://github.com/emmansun/gmsm/wiki/SM2%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96)及相关Wiki和代码，以获得更多实现细节。SM2包实现了SM2椭圆曲线公钥密码算法的数字签名算法、公钥加密算法、密钥交换算法，以及《GB/T 35276-2017信息安全技术 SM2密码算法使用规范》中的密钥对保护数据格式。
 
-- **SM3** - SM3密码杂凑算法实现。**amd64**下分别针对**AVX2+BMI2、AVX、SSE2+SSSE3**做了消息扩展部分的SIMD实现； **arm64**下使用NEON指令做了消息扩展部分的SIMD实现，同时也提供了基于**A64扩展密码指令**的汇编实现。您也可以参考[SM3性能优化](https://github.com/emmansun/gmsm/wiki/SM3%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96)及相关Wiki和代码，以获得更多实现细节。
+- **SM3** - SM3密码杂凑算法实现。**amd64**下分别针对**AVX2+BMI2、AVX、SSE2+SSSE3**做了消息扩展部分的SIMD实现； **arm64**下使用NEON指令做了消息扩展部分的SIMD实现，同时也提供了基于**A64扩展密码指令**的汇编实现；**s390x**和**ppc64x**通过向量指令做了消息扩展部分的优化实现。您也可以参考[SM3性能优化](https://github.com/emmansun/gmsm/wiki/SM3%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96)及相关Wiki和代码，以获得更多实现细节。
 
 - **SM4** - SM4分组密码算法实现。**amd64**下使用**AES**指令加上**AVX2、AVX、SSE2+SSSE3**实现了比较好的性能。**arm64**下使用**AES**指令加上NEON指令实现了比较好的性能，同时也提供了基于**A64扩展密码指令**的汇编实现。针对**ECB/CBC/GCM/XTS**加密模式，做了和SM4分组密码算法的融合汇编优化实现。您也可以参考[SM4性能优化](https://github.com/emmansun/gmsm/wiki/SM4%E6%80%A7%E8%83%BD%E4%BC%98%E5%8C%96)及相关Wiki和代码，以获得更多实现细节。
 
diff --git a/sm3/sm3block_s390x.s b/sm3/sm3block_s390x.s
index 5f6e35a..68cdf5c 100644
--- a/sm3/sm3block_s390x.s
+++ b/sm3/sm3block_s390x.s
@@ -138,6 +138,9 @@
 	; \ // 4 words message schedule result
 	VX XTMP1, XTMP0, XWORD0;           \ // XWORD0 = {w[0], w[1], w[2], w[3]}
 
+// For the usage of tmp-xx(SP), I referred to the code of
+// https://github.com/golang/go/blob/master/src/crypto/md5/md5block_s390x.s
+//
 // func block(dig *digest, p []byte)
 TEXT ·block(SB),NOSPLIT,$72-32
 	MOVD	dig+0(FP), CTX