Replace internal C function pg_hypot() by standard hypot()

The code comment said, "It is expected that this routine will
eventually be replaced with the C99 hypot() function.", so let's do
that now.

This function is tested via the geometry regression test, so if it is
faulty on any platform, it will show up there.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/170308e6-a7a3-4484-87b2-f960bb564afa%40eisentraut.org

diff --git a/src/backend/access/spgist/spgproc.c b/src/backend/access/spgist/spgproc.c
index 660009291da4df47aa8c0effcf57bc271da8619e..722c17ce2e5eca7adf3566820da611f3ccc5bdc2 100644 (file)
--- a/src/backend/access/spgist/spgproc.c
+++ b/src/backend/access/spgist/spgproc.c
@@ -51,7 +51,7 @@ point_box_distance(Point *point, BOX *box)
        else
                dy = 0.0;
 
-       return HYPOT(dx, dy);
+       return hypot(dx, dy);
 }
 
 /*

diff --git a/src/backend/utils/adt/geo_ops.c b/src/backend/utils/adt/geo_ops.c
index 377a1b3f3ade12858031e18d887133002589c967..9101a720744e2a804e0cb36785af78e9b2174a47 100644 (file)
--- a/src/backend/utils/adt/geo_ops.c
+++ b/src/backend/utils/adt/geo_ops.c
@@ -1276,7 +1276,7 @@ line_distance(PG_FUNCTION_ARGS)
 
        PG_RETURN_FLOAT8(float8_div(fabs(float8_mi(l1->C,
                                                                                           float8_mul(ratio, l2->C))),
-                                                               HYPOT(l1->A, l1->B)));
+                                                               hypot(l1->A, l1->B)));
 }
 
 /* line_interpt()
@@ -2001,7 +2001,7 @@ point_distance(PG_FUNCTION_ARGS)
 static inline float8
 point_dt(Point *pt1, Point *pt2)
 {
-       return HYPOT(float8_mi(pt1->x, pt2->x), float8_mi(pt1->y, pt2->y));
+       return hypot(float8_mi(pt1->x, pt2->x), float8_mi(pt1->y, pt2->y));
 }
 
 Datum
@@ -5005,7 +5005,7 @@ circle_mul_pt(PG_FUNCTION_ARGS)
        result = (CIRCLE *) palloc(sizeof(CIRCLE));
 
        point_mul_point(&result->center, &circle->center, point);
-       result->radius = float8_mul(circle->radius, HYPOT(point->x, point->y));
+       result->radius = float8_mul(circle->radius, hypot(point->x, point->y));
 
        PG_RETURN_CIRCLE_P(result);
 }
@@ -5020,7 +5020,7 @@ circle_div_pt(PG_FUNCTION_ARGS)
        result = (CIRCLE *) palloc(sizeof(CIRCLE));
 
        point_div_point(&result->center, &circle->center, point);
-       result->radius = float8_div(circle->radius, HYPOT(point->x, point->y));
+       result->radius = float8_div(circle->radius, hypot(point->x, point->y));
 
        PG_RETURN_CIRCLE_P(result);
 }
@@ -5492,71 +5492,3 @@ plist_same(int npts, Point *p1, Point *p2)
 
        return false;
 }
-
-
-/*-------------------------------------------------------------------------
- * Determine the hypotenuse.
- *
- * If required, x and y are swapped to make x the larger number. The
- * traditional formula of x^2+y^2 is rearranged to factor x outside the
- * sqrt. This allows computation of the hypotenuse for significantly
- * larger values, and with a higher precision than when using the naive
- * formula.  In particular, this cannot overflow unless the final result
- * would be out-of-range.
- *
- * sqrt( x^2 + y^2 ) = sqrt( x^2( 1 + y^2/x^2) )
- *                                      = x * sqrt( 1 + y^2/x^2 )
- *                                      = x * sqrt( 1 + y/x * y/x )
- *
- * It is expected that this routine will eventually be replaced with the
- * C99 hypot() function.
- *
- * This implementation conforms to IEEE Std 1003.1 and GLIBC, in that the
- * case of hypot(inf,nan) results in INF, and not NAN.
- *-----------------------------------------------------------------------
- */
-float8
-pg_hypot(float8 x, float8 y)
-{
-       float8          yx,
-                               result;
-
-       /* Handle INF and NaN properly */
-       if (isinf(x) || isinf(y))
-               return get_float8_infinity();
-
-       if (isnan(x) || isnan(y))
-               return get_float8_nan();
-
-       /* Else, drop any minus signs */
-       x = fabs(x);
-       y = fabs(y);
-
-       /* Swap x and y if needed to make x the larger one */
-       if (x < y)
-       {
-               float8          temp = x;
-
-               x = y;
-               y = temp;
-       }
-
-       /*
-        * If y is zero, the hypotenuse is x.  This test saves a few cycles in
-        * such cases, but more importantly it also protects against
-        * divide-by-zero errors, since now x >= y.
-        */
-       if (y == 0.0)
-               return x;
-
-       /* Determine the hypotenuse */
-       yx = y / x;
-       result = x * sqrt(1.0 + (yx * yx));
-
-       if (unlikely(isinf(result)))
-               float_overflow_error();
-       if (unlikely(result == 0.0))
-               float_underflow_error();
-
-       return result;
-}

diff --git a/src/backend/utils/adt/geo_spgist.c b/src/backend/utils/adt/geo_spgist.c
index fec33e9537243244c39ddd01d6a9a97de02aba5e..4308a3065cd81e3812be564ab88b3985093b218e 100644 (file)
--- a/src/backend/utils/adt/geo_spgist.c
+++ b/src/backend/utils/adt/geo_spgist.c
@@ -390,7 +390,7 @@ pointToRectBoxDistance(Point *point, RectBox *rect_box)
        else
                dy = 0;
 
-       return HYPOT(dx, dy);
+       return hypot(dx, dy);
 }
 
 

diff --git a/src/include/utils/geo_decls.h b/src/include/utils/geo_decls.h
index 8a9df75c93c9d4275ef3e487139a3c1b6a30fffa..d4f7ea31f62988b513011b79532714e30c352b29 100644 (file)
--- a/src/include/utils/geo_decls.h
+++ b/src/include/utils/geo_decls.h
@@ -88,7 +88,6 @@ FPge(double A, double B)
 #define FPge(A,B)                              ((A) >= (B))
 #endif
 
-#define HYPOT(A, B)                            pg_hypot(A, B)
 
 /*---------------------------------------------------------------------
  * Point - (x,y)
@@ -275,11 +274,4 @@ CirclePGetDatum(const CIRCLE *X)
 #define PG_GETARG_CIRCLE_P(n) DatumGetCircleP(PG_GETARG_DATUM(n))
 #define PG_RETURN_CIRCLE_P(x) return CirclePGetDatum(x)
 
-
-/*
- * in geo_ops.c
- */
-
-extern float8 pg_hypot(float8 x, float8 y);
-
 #endif                                                 /* GEO_DECLS_H */