Module Name: src
Committed By: maya
Date: Sat Dec 31 20:01:15 UTC 2016
Modified Files:
src/lib/libm/complex: csqrt.c csqrtf.c
Log Message:
csqrt has a branch cut on the negative real axis, and this requires
delicacy in order to maintain continuity around it.
we have an initial case to deal with a fairly common case: getting
a real number. Avoid dealing with the branch cut in this case by
checking if the real part is negative.
later, -0.0 < 0 is not met, so instead, test for a negative number
using signbit, so negative zero is also treated as a negative number.
Fixes last part of PR lib/51427: libm issues triggered by py-numpy
ok riastradh
To generate a diff of this commit:
cvs rdiff -u -r1.2 -r1.3 src/lib/libm/complex/csqrt.c
cvs rdiff -u -r1.1 -r1.2 src/lib/libm/complex/csqrtf.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/lib/libm/complex/csqrt.c
diff -u src/lib/libm/complex/csqrt.c:1.2 src/lib/libm/complex/csqrt.c:1.3
--- src/lib/libm/complex/csqrt.c:1.2 Sat Dec 31 15:33:03 2016
+++ src/lib/libm/complex/csqrt.c Sat Dec 31 20:01:15 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: csqrt.c,v 1.2 2016/12/31 15:33:03 maya Exp $ */
+/* $NetBSD: csqrt.c,v 1.3 2016/12/31 20:01:15 maya Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -41,7 +41,8 @@ csqrt(double complex z)
x = creal (z);
y = cimag (z);
- if (y == 0.0) {
+ /* Input is a real number that isn't on the branch cut */
+ if ((y == 0.0) && !signbit(y)) {
if (x == 0.0) {
w = 0.0 + y * I;
} else {
@@ -92,7 +93,7 @@ csqrt(double complex z)
t = scale * fabs((0.5 * y) / r);
r *= scale;
}
- if (y < 0)
+ if (signbit(y))
w = t - r * I;
else
w = t + r * I;
Index: src/lib/libm/complex/csqrtf.c
diff -u src/lib/libm/complex/csqrtf.c:1.1 src/lib/libm/complex/csqrtf.c:1.2
--- src/lib/libm/complex/csqrtf.c:1.1 Mon Aug 20 16:01:37 2007
+++ src/lib/libm/complex/csqrtf.c Sat Dec 31 20:01:15 2016
@@ -1,4 +1,4 @@
-/* $NetBSD: csqrtf.c,v 1.1 2007/08/20 16:01:37 drochner Exp $ */
+/* $NetBSD: csqrtf.c,v 1.2 2016/12/31 20:01:15 maya Exp $ */
/*-
* Copyright (c) 2007 The NetBSD Foundation, Inc.
@@ -41,7 +41,8 @@ csqrtf(float complex z)
x = crealf (z);
y = cimagf (z);
- if (y == 0.0f) {
+ /* Input is a real number that isn't on the branch cut */
+ if ((y == 0.0f) && !signbit(y)) {
if (x < 0.0f) {
w = 0.0f + sqrtf(-x) * I;
return w;
@@ -91,7 +92,7 @@ csqrtf(float complex z)
r *= scale;
}
- if (y < 0)
+ if (signbit(y))
w = t - r * I;
else
w = t + r * I;
