Use gcc/clang isnan and isinf builtin functions where available.

lovell · lovell · commit 90c1fb9a9444 · 2016-01-20T19:02:14.000Z
These are used heavily in the building of look-up tables at
start-up time and therefore improve vipsthumbnail perf by ~4%.
diff --git a/libvips/arithmetic/max.c b/libvips/arithmetic/max.c
@@ -322,7 +322,7 @@ vips_max_stop( VipsStatistic *statistic, void *seq )
 	TYPE m; \
 	\
 	for( i = 0; i < sz && values->n < values->size; i++ ) \
-		if( !isnan( p[i] ) ) \
+		if( !VIPS_ISNAN( p[i] ) ) \
 			vips_values_add( values, p[i], x + i / bands, y ); \
 	m = values->value[0]; \
 	\
@@ -342,7 +342,7 @@ vips_max_stop( VipsStatistic *statistic, void *seq )
 	for( i = 0; i < sz && values->n < values->size; i++ ) { \
 		TYPE mod2 = p[0] * p[0] + p[1] * p[1]; \
 		\
-		if( !isnan( mod2 ) ) \
+		if( !VIPS_ISNAN( mod2 ) ) \
 			vips_values_add( values, p[i], x + i / bands, y ); \
 		\
 		p += 2; \
diff --git a/libvips/arithmetic/min.c b/libvips/arithmetic/min.c
@@ -325,7 +325,7 @@ vips_min_stop( VipsStatistic *statistic, void *seq )
 	TYPE m; \
 	\
 	for( i = 0; i < sz && values->n < values->size; i++ ) \
-		if( !isnan( p[i] ) ) \
+		if( !VIPS_ISNAN( p[i] ) ) \
 			vips_values_add( values, p[i], x + i / bands, y ); \
 	m = values->value[0]; \
 	\
@@ -345,7 +345,7 @@ vips_min_stop( VipsStatistic *statistic, void *seq )
 	for( i = 0; i < sz && values->n < values->size; i++ ) { \
 		TYPE mod2 = p[0] * p[0] + p[1] * p[1]; \
 		\
-		if( !isnan( mod2 ) ) \
+		if( !VIPS_ISNAN( mod2 ) ) \
 			vips_values_add( values, p[i], x + i / bands, y ); \
 		\
 		p += 2; \
diff --git a/libvips/colour/LabQ2sRGB.c b/libvips/colour/LabQ2sRGB.c
@@ -273,9 +273,9 @@ vips_col_scRGB2sRGB( int range, int *lut,
 	 * Don't use isnormal(), it is false for 0.0 and for subnormal
 	 * numbers. 
 	 */
-	if( isnan( R ) || isinf( R ) ||
-		isnan( G ) || isinf( G ) ||
-		isnan( B ) || isinf( B ) ) { 
+	if( VIPS_ISNAN( R ) || VIPS_ISINF( R ) ||
+		VIPS_ISNAN( G ) || VIPS_ISINF( G ) ||
+		VIPS_ISNAN( B ) || VIPS_ISINF( B ) ) {
 		*r = 0; 
 		*g = 0; 
 		*b = 0; 
@@ -370,9 +370,9 @@ vips_col_scRGB2BW( int range, int *lut, float R, float G, float B,
 	 * Don't use isnormal(), it is false for 0.0 and for subnormal
 	 * numbers. 
 	 */
-	if( isnan( R ) || isinf( R ) ||
-		isnan( G ) || isinf( G ) ||
-		isnan( B ) || isinf( B ) ) { 
+	if( VIPS_ISNAN( R ) || VIPS_ISINF( R ) ||
+		VIPS_ISNAN( G ) || VIPS_ISINF( G ) ||
+		VIPS_ISNAN( B ) || VIPS_ISINF( B ) ) {
 		*g = 0; 
 
 		return( -1 );
diff --git a/libvips/include/vips/util.h b/libvips/include/vips/util.h
@@ -40,6 +40,7 @@ extern "C" {
 #endif /*__cplusplus*/
 
 #include <stdio.h>
+#include <math.h>
 
 /* Some platforms don't have M_PI :-(
  */
@@ -157,6 +158,17 @@ G_STMT_START { \
 
 #define VIPS_CLIP_NONE( V, SEQ ) {}
 
+/* The built-in isnan and isinf functions provided by gcc 4+ and clang are
+ * up to 7x faster than their libc equivalent included from <math.h>.
+ */
+#if defined(__clang__) || (__GNUC__ >= 4)
+#define VIPS_ISNAN( V ) __builtin_isnan( V )
+#define VIPS_ISINF( V ) __builtin_isinf( V )
+#else
+#define VIPS_ISNAN( V ) isnan( V )
+#define VIPS_ISINF( V ) isinf( V )
+#endif
+
 /* Not all platforms have PATH_MAX (eg. Hurd) and we don't need a platform one
  * anyway, just a static buffer big enough for almost any path.
  */

Original file line number	Diff line number	Diff line change
`@@ -322,7 +322,7 @@ vips_max_stop( VipsStatistic statistic, void seq )`
`322`	`322`	`TYPE m; \`
`323`	`323`	`\`
`324`	`324`	`for( i = 0; i < sz && values->n < values->size; i++ ) \`
`325`		`- if( !isnan( p[i] ) ) \`
	`325`	`+ if( !VIPS_ISNAN( p[i] ) ) \`
`326`	`326`	`vips_values_add( values, p[i], x + i / bands, y ); \`
`327`	`327`	`m = values->value[0]; \`
`328`	`328`	`\`
`@@ -342,7 +342,7 @@ vips_max_stop( VipsStatistic statistic, void seq )`
`342`	`342`	`for( i = 0; i < sz && values->n < values->size; i++ ) { \`
`343`	`343`	`TYPE mod2 = p[0] * p[0] + p[1] * p[1]; \`
`344`	`344`	`\`
`345`		`- if( !isnan( mod2 ) ) \`
	`345`	`+ if( !VIPS_ISNAN( mod2 ) ) \`
`346`	`346`	`vips_values_add( values, p[i], x + i / bands, y ); \`
`347`	`347`	`\`
`348`	`348`	`p += 2; \`
Original file line number	Diff line number	Diff line change
`@@ -325,7 +325,7 @@ vips_min_stop( VipsStatistic statistic, void seq )`
`325`	`325`	`TYPE m; \`
`326`	`326`	`\`
`327`	`327`	`for( i = 0; i < sz && values->n < values->size; i++ ) \`
`328`		`- if( !isnan( p[i] ) ) \`
	`328`	`+ if( !VIPS_ISNAN( p[i] ) ) \`
`329`	`329`	`vips_values_add( values, p[i], x + i / bands, y ); \`
`330`	`330`	`m = values->value[0]; \`
`331`	`331`	`\`
`@@ -345,7 +345,7 @@ vips_min_stop( VipsStatistic statistic, void seq )`
`345`	`345`	`for( i = 0; i < sz && values->n < values->size; i++ ) { \`
`346`	`346`	`TYPE mod2 = p[0] * p[0] + p[1] * p[1]; \`
`347`	`347`	`\`
`348`		`- if( !isnan( mod2 ) ) \`
	`348`	`+ if( !VIPS_ISNAN( mod2 ) ) \`
`349`	`349`	`vips_values_add( values, p[i], x + i / bands, y ); \`
`350`	`350`	`\`
`351`	`351`	`p += 2; \`