Improve computations of interval_div to prevent rounding problem on AIX.

bmomjian · bmomjian · commit f76f24dfffe6 · 2005-07-23T14:53:21.000Z
diff --git a/src/backend/utils/adt/timestamp.c b/src/backend/utils/adt/timestamp.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.144 2005/07/23 14:25:34 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.145 2005/07/23 14:53:21 momjian Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2308,9 +2308,9 @@ interval_div(PG_FUNCTION_ARGS)
 	result->day = span->day / factor;
 	result->time = span->time / factor;
 
-	/* Computer remainders */
-	month_remainder = (span->month - result->month * factor) / factor;
-	day_remainder = (span->day - result->day * factor) / factor;
+	/* Compute remainders */
+	month_remainder = span->month / factor - result->month;
+	day_remainder = span->day / factor - result->day;
 
 	/* Cascade fractions to lower units */
 	/* fractional months full days into days */

Original file line number	Diff line number	Diff line change
`@@ -8,7 +8,7 @@`
`8`	`8`	`*`
`9`	`9`	`*`
`10`	`10`	`* IDENTIFICATION`
`11`		`- * $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.144 2005/07/23 14:25:34 momjian Exp $`
	`11`	`+ * $PostgreSQL: pgsql/src/backend/utils/adt/timestamp.c,v 1.145 2005/07/23 14:53:21 momjian Exp $`
`12`	`12`	`*`
`13`	`13`	`*-------------------------------------------------------------------------`
`14`	`14`	`*/`
`@@ -2308,9 +2308,9 @@ interval_div(PG_FUNCTION_ARGS)`
`2308`	`2308`	`result->day = span->day / factor;`
`2309`	`2309`	`result->time = span->time / factor;`
`2310`	`2310`
`2311`		`- /* Computer remainders */`
`2312`		`- month_remainder = (span->month - result->month * factor) / factor;`
`2313`		`- day_remainder = (span->day - result->day * factor) / factor;`
	`2311`	`+ /* Compute remainders */`
	`2312`	`+ month_remainder = span->month / factor - result->month;`
	`2313`	`+ day_remainder = span->day / factor - result->day;`
`2314`	`2314`
`2315`	`2315`	`/* Cascade fractions to lower units */`
`2316`	`2316`	`/* fractional months full days into days */`