CLJ-2670 - Use Math exact methods where possible for perf

puredanger · puredanger · commit 0cbf655d181c · 2022-01-13T13:59:02.000-06:00
Signed-off-by: Alex Miller &lt;alex.miller@cognitect.com&gt;
diff --git a/src/jvm/clojure/lang/Numbers.java b/src/jvm/clojure/lang/Numbers.java
@@ -1915,10 +1915,7 @@ static public Number unchecked_dec(Object x){
 static public double remainder(long x, double y){return remainder((double)x,y);}
 
 static public long add(long x, long y){
-	long ret = x + y;
-	if ((ret ^ x) < 0 && (ret ^ y) < 0)
-		return throwIntOverflow();
-	return ret;
+	return Math.addExact(x, y);
 }
 
 static public Number addP(long x, long y){
@@ -1929,10 +1926,7 @@ static public Number addP(long x, long y){
 }
 
 static public long minus(long x, long y){
-	long ret = x - y;
-	if (((ret ^ x) < 0 && (ret ^ ~y) < 0))
-		return throwIntOverflow();
-	return ret;
+	return Math.subtractExact(x, y);
 }
 
 static public Number minusP(long x, long y){
@@ -1943,9 +1937,7 @@ static public Number minusP(long x, long y){
 }
 
 static public long minus(long x){
-	if(x == Long.MIN_VALUE)
-		return throwIntOverflow();
-	return -x;
+	return Math.negateExact(x);
 }
 
 static public Number minusP(long x){
@@ -1955,9 +1947,7 @@ static public Number minusP(long x){
 }
 
 static public long inc(long x){
-	if(x == Long.MAX_VALUE)
-		return throwIntOverflow();
-	return x + 1;
+	return Math.incrementExact(x);
 }
 
 static public Number incP(long x){
@@ -1967,9 +1957,7 @@ static public Number incP(long x){
 }
 
 static public long dec(long x){
-	if(x == Long.MIN_VALUE)
-		return throwIntOverflow();
-	return x - 1;
+	return Math.decrementExact(x);
 }
 
 static public Number decP(long x){
@@ -1980,12 +1968,7 @@ static public Number decP(long x){
 
 
 static public long multiply(long x, long y){
-  if (x == Long.MIN_VALUE && y < 0)
-		return throwIntOverflow();
-	long ret = x * y;
-	if (y != 0 && ret/y != x)
-		return throwIntOverflow();
-	return ret;
+	return Math.multiplyExact(x, y);
 }
 
 static public Number multiplyP(long x, long y){
diff --git a/src/jvm/clojure/lang/RT.java b/src/jvm/clojure/lang/RT.java
@@ -1244,10 +1244,7 @@ static public int intCast(float x){
 }
 
 static public int intCast(long x){
-	int i = (int) x;
-	if(i != x)
-		throw new IllegalArgumentException("Value out of range for int: " + x);
-	return i;
+	return Math.toIntExact(x);
 }
 
 static public int intCast(double x){
diff --git a/test/clojure/test_clojure/numbers.clj b/test/clojure/test_clojure/numbers.clj
@@ -181,7 +181,7 @@
       (let [wrapped (fn [x]
                       (try
                        (f x)
-                       (catch IllegalArgumentException e :error)))]
+                       (catch RuntimeException e :error)))]
         (is (= vals (map wrapped inputs)))))))
 
 ;; *** Functions ***

Original file line number	Diff line number	Diff line change
`@@ -1915,10 +1915,7 @@ static public Number unchecked_dec(Object x){`
`1915`	`1915`	`static public double remainder(long x, double y){return remainder((double)x,y);}`
`1916`	`1916`
`1917`	`1917`	`static public long add(long x, long y){`
`1918`		`- long ret = x + y;`
`1919`		`- if ((ret ^ x) < 0 && (ret ^ y) < 0)`
`1920`		`- return throwIntOverflow();`
`1921`		`- return ret;`
	`1918`	`+ return Math.addExact(x, y);`
`1922`	`1919`	`}`
`1923`	`1920`
`1924`	`1921`	`static public Number addP(long x, long y){`
`@@ -1929,10 +1926,7 @@ static public Number addP(long x, long y){`
`1929`	`1926`	`}`
`1930`	`1927`
`1931`	`1928`	`static public long minus(long x, long y){`
`1932`		`- long ret = x - y;`
`1933`		`- if (((ret ^ x) < 0 && (ret ^ ~y) < 0))`
`1934`		`- return throwIntOverflow();`
`1935`		`- return ret;`
	`1929`	`+ return Math.subtractExact(x, y);`
`1936`	`1930`	`}`
`1937`	`1931`
`1938`	`1932`	`static public Number minusP(long x, long y){`
`@@ -1943,9 +1937,7 @@ static public Number minusP(long x, long y){`
`1943`	`1937`	`}`
`1944`	`1938`
`1945`	`1939`	`static public long minus(long x){`
`1946`		`- if(x == Long.MIN_VALUE)`
`1947`		`- return throwIntOverflow();`
`1948`		`- return -x;`
	`1940`	`+ return Math.negateExact(x);`
`1949`	`1941`	`}`
`1950`	`1942`
`1951`	`1943`	`static public Number minusP(long x){`
`@@ -1955,9 +1947,7 @@ static public Number minusP(long x){`
`1955`	`1947`	`}`
`1956`	`1948`
`1957`	`1949`	`static public long inc(long x){`
`1958`		`- if(x == Long.MAX_VALUE)`
`1959`		`- return throwIntOverflow();`
`1960`		`- return x + 1;`
	`1950`	`+ return Math.incrementExact(x);`
`1961`	`1951`	`}`
`1962`	`1952`
`1963`	`1953`	`static public Number incP(long x){`
`@@ -1967,9 +1957,7 @@ static public Number incP(long x){`
`1967`	`1957`	`}`
`1968`	`1958`
`1969`	`1959`	`static public long dec(long x){`
`1970`		`- if(x == Long.MIN_VALUE)`
`1971`		`- return throwIntOverflow();`
`1972`		`- return x - 1;`
	`1960`	`+ return Math.decrementExact(x);`
`1973`	`1961`	`}`
`1974`	`1962`
`1975`	`1963`	`static public Number decP(long x){`
`@@ -1980,12 +1968,7 @@ static public Number decP(long x){`
`1980`	`1968`
`1981`	`1969`
`1982`	`1970`	`static public long multiply(long x, long y){`
`1983`		`- if (x == Long.MIN_VALUE && y < 0)`
`1984`		`- return throwIntOverflow();`
`1985`		`- long ret = x * y;`
`1986`		`- if (y != 0 && ret/y != x)`
`1987`		`- return throwIntOverflow();`
`1988`		`- return ret;`
	`1971`	`+ return Math.multiplyExact(x, y);`
`1989`	`1972`	`}`
`1990`	`1973`
`1991`	`1974`	`static public Number multiplyP(long x, long y){`
Original file line number	Diff line number	Diff line change
`@@ -1244,10 +1244,7 @@ static public int intCast(float x){`
`1244`	`1244`	`}`
`1245`	`1245`
`1246`	`1246`	`static public int intCast(long x){`
`1247`		`- int i = (int) x;`
`1248`		`- if(i != x)`
`1249`		`- throw new IllegalArgumentException("Value out of range for int: " + x);`
`1250`		`- return i;`
	`1247`	`+ return Math.toIntExact(x);`
`1251`	`1248`	`}`
`1252`	`1249`
`1253`	`1250`	`static public int intCast(double x){`