From: Andoni Arregi <andoni.arregui@gtd-gmbh.de>
To: newlib@sourceware.org
Cc: Andoni Arregi <andoni.arregui@gtd-gmbh.de>
Subject: [PATCH 2/4] Fix x close to 1, y between 2^31 and 2^64
Date: Wed, 12 Apr 2023 17:34:43 +0200 [thread overview]
Message-ID: <20230412153445.161047-3-andoni.arregui@gtd-gmbh.de> (raw)
In-Reply-To: <20230412153445.161047-1-andoni.arregui@gtd-gmbh.de>
E.g. known errors:
x = 0x1.000002c5e2e99p+0, y = 0x1.c9eee35374af6p+31 had an error of 639
ULP and is now correctly rounded.
x = 0x1.fffffd2e3e669p-1, y = 0x1.344c9823eb66cp+32 had an error of 428
ULP and is now correctly rounded.
---
newlib/libm/math/e_pow.c | 4 ++--
1 file changed, 2 insertions(+), 2 deletions(-)
diff --git a/newlib/libm/math/e_pow.c b/newlib/libm/math/e_pow.c
index f02f76dc0..f24a98f6e 100644
--- a/newlib/libm/math/e_pow.c
+++ b/newlib/libm/math/e_pow.c
@@ -196,8 +196,8 @@ ivln2_l = 1.92596299112661746887e-08; /* 0x3E54AE0B, 0xF85DDF44 =1/ln2 tail*/
}
/* |y| is huge */
- if(iy>0x41e00000) { /* if |y| > 2**31 */
- if(iy>0x43f00000){ /* if |y| > 2**64, must o/uflow and y is an even integer */
+ if(iy>0x42000000) { /* if |y| > ~2**33 (does not regard mantissa) */
+ if(iy>0x43f00000){ /* if |y| > ~2**64, must o/uflow and y is an even integer */
if(ix<=0x3fefffff) return (hy<0)? __math_oflow(0):__math_uflow(0);
if(ix>=0x3ff00000) return (hy>0)? __math_oflow(0):__math_uflow(0);
}
--
2.40.0
next prev parent reply other threads:[~2023-04-12 15:36 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2023-04-12 15:34 [PATCH 0/4] Fix huge error for pow detected by Paul Zimmermann Andoni Arregi
2023-04-12 15:34 ` [PATCH 1/4] Fix missing sign for overflow/underflow where x is negative and y is large odd integer Andoni Arregi
2023-04-12 15:34 ` Andoni Arregi [this message]
2023-04-12 15:34 ` [PATCH 3/4] Compare j as unsigned Andoni Arregi
2023-04-12 15:34 ` [PATCH 4/4] Replace always true if with else Andoni Arregi
2023-04-13 5:46 ` [PATCH 0/4] Fix huge error for pow detected by Paul Zimmermann Paul Zimmermann
2023-04-13 12:16 ` Paul Zimmermann
2023-04-13 14:39 ` Andoni Arregi
2023-04-13 17:37 ` Jeff Johnston
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