remove unnecessary add

src/fp_generator.hpp

@@ -1428,11 +1428,12 @@ private:
 		ret();
 	}
 	/*
-		c[n+2] = c[n+1] + px[n] * rdx
+		c[n..0] = c[n..0] + px[n-1..0] * rdx
 		use rax, t0
 	*/
 	void mulAdd(const Pack& c, int n, const RegExp& px, const Reg64& t0)
 	{
+		assert(!isFullBit_);
 		const Reg64& a = rax;
 		xor_(c[n + 1], c[n + 1]); // c[n + 1] = 0
 		for (int i = 0; i < n; i++) {
@@ -1441,17 +1442,16 @@ private:
 			if (i == n - 1) break;
 			adcx(c[i + 1], t0);
 		}
-		adox(t0, c[n + 1]); // carry o
-		adcx(c[n], t0);
-		adc(c[n + 1], 0);
+		adox(c[n], t0);
+		adc(c[n], 0);
 	}
 	/*
 		input
-		c[6..0]
+		c[5..0]
 		rdx = yi
 		use rax, rdx
 		output
-		c[7..1]
+		c[6..1]
 
 		if first:
 		  c = x[5..0] * rdx
@@ -1463,6 +1463,7 @@ private:
 	*/
 	void montgomery6_1(const Pack& c, const RegExp& px, const Reg64& t0, const Reg64& t1, bool isFirst)
 	{
+		assert(!isFullBit_);
 		const int n = 6;
 		const Reg64& a = rax;
 		const Reg64& d = rdx;
@@ -1483,13 +1484,13 @@ private:
 			adc(*pt0, 0);
 			mov(c[n], *pt0);
 		} else {
-			// c[7..0] = c[6..0] + px[5..0] * rdx
+			// c[5..0] = c[5..0] + px[5..0] * rdx because of not fuill bit
 			mulAdd(c, 6, px, t1);
 		}
 		mov(d, rp_);
 		imul(d, c[0]); // q = d
 		lea(t0, ptr[rip+pL_]);
-		// c += p * q
+		// c[5..0] += p * q because of not fuill bit
 		mulAdd(c, 6, t0, t1);
 	}
 	/*
@@ -1520,22 +1521,16 @@ private:
 	L(fp_mulL);
 		mov(rdx, ptr [py + 0 * 8]);
 		montgomery6_1(Pack(t7, t6, t5, t4, t3, t2, t1, t0), px, t8, t9, true);
-xor_(t7, t7);
 		mov(rdx, ptr [py + 1 * 8]);
 		montgomery6_1(Pack(t0, t7, t6, t5, t4, t3, t2, t1), px, t8, t9, false);
-xor_(t0, t0);
 		mov(rdx, ptr [py + 2 * 8]);
 		montgomery6_1(Pack(t1, t0, t7, t6, t5, t4, t3, t2), px, t8, t9, false);
-xor_(t1, t1);
 		mov(rdx, ptr [py + 3 * 8]);
 		montgomery6_1(Pack(t2, t1, t0, t7, t6, t5, t4, t3), px, t8, t9, false);
-xor_(t2, t2);
 		mov(rdx, ptr [py + 4 * 8]);
 		montgomery6_1(Pack(t3, t2, t1, t0, t7, t6, t5, t4), px, t8, t9, false);
-xor_(t3, t3);
 		mov(rdx, ptr [py + 5 * 8]);
 		montgomery6_1(Pack(t4, t3, t2, t1, t0, t7, t6, t5), px, t8, t9, false);
-xor_(t4, t4);
 		// [t4:t3:t2:t1:t0:t7:t6]
 		const Pack z = Pack(t3, t2, t1, t0, t7, t6);
 		const Pack keep = Pack(rdx, rax, px, py, t8, t9);