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[PATCH] Fix non-portable usage of `isinf' in `max' and `min'
From: |
Mark H Weaver |
Subject: |
[PATCH] Fix non-portable usage of `isinf' in `max' and `min' |
Date: |
Wed, 02 Feb 2011 19:38:50 -0500 |
User-agent: |
Gnus/5.13 (Gnus v5.13) Emacs/23.1 (gnu/linux) |
Andy Wingo <address@hidden> writes:
> BTW: did you see the failures on darwin?
>
> http://hydra.nixos.org/build/882506/nixlog/1
>
> Seems there were errors in:
>
> FAIL: numbers.test: max: infinities and NaNs: (real-nan? (max +nan.0
> -inf.0))
> FAIL: numbers.test: max: infinities and NaNs: (real-nan? (max -inf.0
> +nan.0))
> FAIL: numbers.test: min: infinities and NaNs: (eqv? -inf.0 (min -inf.0
> +nan.0))
> FAIL: numbers.test: min: infinities and NaNs: (eqv? -inf.0 (min +nan.0
> -inf.0))
Ah, I was using a non-portable extension of isinf(x) to determine the
sign of the infinity. This patch should fix it.
Thanks,
Mark
>From 6801f4c8503be81c03f503520c8e2d70944f371d Mon Sep 17 00:00:00 2001
From: Mark H Weaver <address@hidden>
Date: Wed, 2 Feb 2011 19:32:16 -0500
Subject: [PATCH] Fix non-portable usage of `isinf' in `max' and `min'
* numbers.c: Add new macros DOUBLE_IS_POSITIVE_INFINITY and
DOUBLE_IS_NEGATIVE_INFINITY.
(scm_max, scm_min): Use the new macros to detect particular
infinities. Previously we checked the return value of `isinf'
to determine the sign of the infinity, but that is not portable.
---
libguile/numbers.c | 13 +++++++++----
1 files changed, 9 insertions(+), 4 deletions(-)
diff --git a/libguile/numbers.c b/libguile/numbers.c
index 18d5755..3be4478 100644
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -83,6 +83,11 @@ typedef scm_t_signed_bits scm_t_inum;
TODO: if it's available, use C99's isfinite(x) instead */
#define DOUBLE_IS_FINITE(x) (!isinf(x) && !isnan(x))
+/* On some platforms, isinf(x) returns 0, 1 or -1, indicating the sign
+ of the infinity, but other platforms return a boolean only. */
+#define DOUBLE_IS_POSITIVE_INFINITY(x) (isinf(x) && ((x) > 0))
+#define DOUBLE_IS_NEGATIVE_INFINITY(x) (isinf(x) && ((x) < 0))
+
/*
@@ -5251,9 +5256,9 @@ scm_max (SCM x, SCM y)
/* If neither (xx > yy) nor (xx < yy), then
either they're equal or one is a NaN */
else if (SCM_UNLIKELY (isnan (xx)))
- return (isinf (yy) == 1) ? y : x;
+ return DOUBLE_IS_POSITIVE_INFINITY (yy) ? y : x;
else if (SCM_UNLIKELY (isnan (yy)))
- return (isinf (xx) == 1) ? x : y;
+ return DOUBLE_IS_POSITIVE_INFINITY (xx) ? x : y;
/* xx == yy, but handle signed zeroes properly */
else if (double_is_non_negative_zero (yy))
return y;
@@ -5411,9 +5416,9 @@ scm_min (SCM x, SCM y)
/* If neither (xx < yy) nor (xx > yy), then
either they're equal or one is a NaN */
else if (SCM_UNLIKELY (isnan (xx)))
- return (isinf (yy) == -1) ? y : x;
+ return DOUBLE_IS_NEGATIVE_INFINITY (yy) ? y : x;
else if (SCM_UNLIKELY (isnan (yy)))
- return (isinf (xx) == -1) ? x : y;
+ return DOUBLE_IS_NEGATIVE_INFINITY (xx) ? x : y;
/* xx == yy, but handle signed zeroes properly */
else if (double_is_non_negative_zero (xx))
return y;
--
1.5.6.5
Re: [PATCH] Complex numbers with inexact zero imaginary part, etc, Andy Wingo, 2011/02/02