Speed up multiplication

kimwalisch · kimwalisch · commit 02957faebd4a · 2017-11-23T23:05:12.000+01:00
diff --git a/include/int256_t.hpp b/include/int256_t.hpp
@@ -157,10 +157,11 @@ class int256_t
 
         if (low <= max64 &&
             other.low <= max64 &&
-            high == other.high &&
-            (high == 0 || high == -1))
+            ((high == 0 || high == -1) &&
+             (other.high == 0 || other.high == -1)))
         {
-            return int256_t(low * other.low, high);
+          return int256_t(low * other.low,
+                          (high == other.high) ? 0 : -1);
         }
         else
         {

Original file line number	Diff line number	Diff line change
`@@ -157,10 +157,11 @@ class int256_t`
`157`	`157`
`158`	`158`	`if (low <= max64 &&`
`159`	`159`	`other.low <= max64 &&`
`160`		`- high == other.high &&`
`161`		`- (high == 0 \|\| high == -1))`
	`160`	`+ ((high == 0 \|\| high == -1) &&`
	`161`	`+ (other.high == 0 \|\| other.high == -1)))`
`162`	`162`	`{`
`163`		`- return int256_t(low * other.low, high);`
	`163`	`+ return int256_t(low * other.low,`
	`164`	`+ (high == other.high) ? 0 : -1);`
`164`	`165`	`}`
`165`	`166`	`else`
`166`	`167`	`{`