From 085ec079e37b0013b421c97b467c6b8ea36a1289 Mon Sep 17 00:00:00 2001 From: Siddhesh Poyarekar Date: Sat, 29 Dec 2012 06:56:04 +0530 Subject: Demystify the magic number 134217729.0 The number 134217729.0 gets used in various places in e_pow.c but there is no explanation of what that number is. Add that explanation. --- sysdeps/ieee754/dbl-64/e_pow.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-) (limited to 'sysdeps/ieee754/dbl-64/e_pow.c') diff --git a/sysdeps/ieee754/dbl-64/e_pow.c b/sysdeps/ieee754/dbl-64/e_pow.c index 513171891c..1d535cb6e3 100644 --- a/sysdeps/ieee754/dbl-64/e_pow.c +++ b/sysdeps/ieee754/dbl-64/e_pow.c @@ -95,10 +95,10 @@ __ieee754_pow(double x, double y) { if (ABS (y) < 0x1p-64) y = y < 0 ? -0x1p-64 : 0x1p-64; z = log1(x,&aa,&error); /* x^y =e^(y log (X)) */ - t = y*134217729.0; + t = y*CN; y1 = t - (t-y); y2 = y - y1; - t = z*134217729.0; + t = z*CN; a1 = t - (t-z); a2 = (z - a1)+aa; a = y1*a1; @@ -182,10 +182,10 @@ SECTION power1(double x, double y) { double z,a,aa,error, t,a1,a2,y1,y2; z = my_log2(x,&aa,&error); - t = y*134217729.0; + t = y*CN; y1 = t - (t-y); y2 = y - y1; - t = z*134217729.0; + t = z*CN; a1 = t - (t-z); a2 = z - a1; a = y*z; -- cgit 1.4.1