diff --git a/SM3性能优化.md b/SM3性能优化.md
index 834b1ea..4cbc571 100644
--- a/SM3性能优化.md
+++ b/SM3性能优化.md
@@ -48,4 +48,8 @@
     VPXOR   XTMP3, XTMP2, XTMP2;         \
     VPXOR   XTMP2, XTMP5, XTMP5;         \ // XTMP5 = s1 {xDxC}
     VPSHUFB shuff_DC00<>(SB), XTMP5, XTMP5;\ // XTMP5 = s1 {DC00}
-    VPADDD  XTMP0, XTMP5, XDWORD0;       \ // XDWORD0 = {W[3], W[2], W[1], W[0]}
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+    VPADDD  XTMP0, XTMP5, XDWORD0;       \ // XDWORD0 = {W[3], W[2], W[1], W[0]}
+
+SM3的message scheduler有两个显著差别：
+1. Wi+3依赖Wi，所以也和SHA256类似，不能一次生成四个DWORDs，但和SHA256不完全一样。
+1. 比SHA256需要多算4个DWORDs。
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