Updated SM2 MFMM (2) (markdown)

SM2-MFMM-(2).md

@@ -75,4 +75,27 @@ $t_2=t_2 - a_1$
 $t_3=t_3 - a_0$  
 $t_0=t_0 - a_1$  
 
+伪代码： 
+```asm
+	\ // First reduction step, [p3, p2, p1, p0] = [1, -0x100000000, 0, (1 - 0x100000000), -1]
+	MOVQ acc0, AX           \
+	MOVQ acc0, DX           \
+	SHLQ $32, AX            \  // AX = L(acc0 * 2^32), low part
+	SHRQ $32, DX            \  // DX = H(acc0 * 2^32), high part
+	\ // calculate the positive part first: [1, 0, 0, 1] * acc0 + [0, acc3, acc2, acc1], 
+	\ // due to (-1) * acc0 + acc0 == 0, so last lowest lamb 0 is dropped directly, no carry.
+	ADDQ acc0, acc1          \ // acc1' = L (acc0 + acc1)
+	ADCQ $0, acc2            \ // acc2' = acc2 + carry1
+	ADCQ $0, acc3            \ // acc3' = acc3 + carry2
+	ADCQ $0, acc0            \ // acc0' = acc0 + carry3
+	\// calculate the negative part: [0, -0x100000000, 0, -0x100000000] * acc0
+	SUBQ AX, acc1            \ 
+	SBBQ DX, acc2            \
+	SBBQ AX, acc3            \
+	SBBQ DX, acc0            \
+```
+移位: 2  
+加法：4  
+减法：4  
+