Don't use is_infinite() where isinf() will do.

tglsfdc · tglsfdc · commit 0209f0285d9b · 2018-10-06T13:18:38.000-04:00
Places that aren't testing for sign should not use the more expensive
function; it's just wasteful, not to mention being a cognitive load
for readers who may know what isinf() is but not is_infinite().

As things stand, we actually don't need is_infinite() anyplace except
float4out/float8out, which means it could potentially go away altogether
after the changes I proposed in &lt;13178.1538794717@sss.pgh.pa.us&gt;.
diff --git a/src/backend/utils/adt/formatting.c b/src/backend/utils/adt/formatting.c
@@ -5731,7 +5731,7 @@ float4_to_char(PG_FUNCTION_ARGS)
 		numstr = orgnum = int_to_roman((int) rint(value));
 	else if (IS_EEEE(&Num))
 	{
-		if (isnan(value) || is_infinite(value))
+		if (isnan(value) || isinf(value))
 		{
 			/*
 			 * Allow 6 characters for the leading sign, the decimal point,
@@ -5835,7 +5835,7 @@ float8_to_char(PG_FUNCTION_ARGS)
 		numstr = orgnum = int_to_roman((int) rint(value));
 	else if (IS_EEEE(&Num))
 	{
-		if (isnan(value) || is_infinite(value))
+		if (isnan(value) || isinf(value))
 		{
 			/*
 			 * Allow 6 characters for the leading sign, the decimal point,
diff --git a/src/backend/utils/adt/rangetypes_selfuncs.c b/src/backend/utils/adt/rangetypes_selfuncs.c
@@ -17,6 +17,8 @@
  */
 #include "postgres.h"
 
+#include <math.h>
+
 #include "access/htup_details.h"
 #include "catalog/pg_operator.h"
 #include "catalog/pg_statistic.h"
@@ -750,27 +752,27 @@ get_position(TypeCacheEntry *typcache, RangeBound *value, RangeBound *hist1,
 static double
 get_len_position(double value, double hist1, double hist2)
 {
-	if (!is_infinite(hist1) && !is_infinite(hist2))
+	if (!isinf(hist1) && !isinf(hist2))
 	{
 		/*
 		 * Both bounds are finite. The value should be finite too, because it
 		 * lies somewhere between the bounds. If it doesn't, just return
 		 * something.
 		 */
-		if (is_infinite(value))
+		if (isinf(value))
 			return 0.5;
 
 		return 1.0 - (hist2 - value) / (hist2 - hist1);
 	}
-	else if (is_infinite(hist1) && !is_infinite(hist2))
+	else if (isinf(hist1) && !isinf(hist2))
 	{
 		/*
 		 * Lower bin boundary is -infinite, upper is finite. Return 1.0 to
 		 * indicate the value is infinitely far from the lower bound.
 		 */
 		return 1.0;
 	}
-	else if (is_infinite(hist1) && is_infinite(hist2))
+	else if (isinf(hist1) && isinf(hist2))
 	{
 		/* same as above, but in reverse */
 		return 0.0;
@@ -851,7 +853,7 @@ calc_length_hist_frac(Datum *length_hist_values, int length_hist_nvalues,
 		return 0.0;				/* shouldn't happen, but doesn't hurt to check */
 
 	/* All lengths in the table are <= infinite. */
-	if (is_infinite(length2) && equal)
+	if (isinf(length2) && equal)
 		return 1.0;
 
 	/*----------
@@ -978,7 +980,7 @@ calc_length_hist_frac(Datum *length_hist_values, int length_hist_nvalues,
 	 * length2 is infinite. It's not clear what the correct value would be in
 	 * that case, so 0.5 seems as good as any value.
 	 */
-	if (is_infinite(area) && is_infinite(length2))
+	if (isinf(area) && isinf(length2))
 		frac = 0.5;
 	else
 		frac = area / (length2 - length1);

Original file line number	Diff line number	Diff line change
`@@ -5731,7 +5731,7 @@ float4_to_char(PG_FUNCTION_ARGS)`
`5731`	`5731`	`numstr = orgnum = int_to_roman((int) rint(value));`
`5732`	`5732`	`else if (IS_EEEE(&Num))`
`5733`	`5733`	`{`
`5734`		`- if (isnan(value) \|\| is_infinite(value))`
	`5734`	`+ if (isnan(value) \|\| isinf(value))`
`5735`	`5735`	`{`
`5736`	`5736`	`/*`
`5737`	`5737`	`* Allow 6 characters for the leading sign, the decimal point,`
`@@ -5835,7 +5835,7 @@ float8_to_char(PG_FUNCTION_ARGS)`
`5835`	`5835`	`numstr = orgnum = int_to_roman((int) rint(value));`
`5836`	`5836`	`else if (IS_EEEE(&Num))`
`5837`	`5837`	`{`
`5838`		`- if (isnan(value) \|\| is_infinite(value))`
	`5838`	`+ if (isnan(value) \|\| isinf(value))`
`5839`	`5839`	`{`
`5840`	`5840`	`/*`
`5841`	`5841`	`* Allow 6 characters for the leading sign, the decimal point,`