[PATCH 2/4] Fix x close to 1, y between 2^31 and 2^64

Andoni Arregi andoni.arregui@gtd-gmbh.de
Wed Apr 12 15:34:43 GMT 2023


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




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