From 7148a38f948f3c6a1af855601e51862f1bd81eac Mon Sep 17 00:00:00 2001 From: Raymond Hettinger Date: Mon, 21 Sep 2020 00:14:51 -0700 Subject: [PATCH] Improve order of adding fractional values. Improve variable names. --- Modules/mathmodule.c | 24 ++++++++++++------------ 1 file changed, 12 insertions(+), 12 deletions(-) diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c index 935759ec671ca5..5cd31b7dd4acfb 100644 --- a/Modules/mathmodule.c +++ b/Modules/mathmodule.c @@ -2502,8 +2502,8 @@ exactly equal) was verified for 1 billion random inputs with n=5. [7] static inline double vector_norm(Py_ssize_t n, double *vec, double max, int found_nan) { - const double T27 = 134217729.0; /* ldexp(1.0, 27)+1.0) */ - double x, csum = 1.0, oldcsum, scale, frac=0.0, frac_mid=0.0, frac_lo=0.0; + const double T27 = 134217729.0; /* ldexp(1.0, 27) + 1.0) */ + double x, scale, oldcsum, csum = 1.0, frac1 = 0.0, frac2 = 0.0, frac3 = 0.0; double t, hi, lo, h; int max_e; Py_ssize_t i; @@ -2539,18 +2539,18 @@ vector_norm(Py_ssize_t n, double *vec, double max, int found_nan) assert(fabs(csum) >= fabs(x)); oldcsum = csum; csum += x; - frac += (oldcsum - csum) + x; + frac1 += (oldcsum - csum) + x; x = 2.0 * hi * lo; assert(fabs(csum) >= fabs(x)); oldcsum = csum; csum += x; - frac_mid += (oldcsum - csum) + x; + frac2 += (oldcsum - csum) + x; assert(csum + lo * lo == csum); - frac_lo += lo * lo; + frac3 += lo * lo; } - h = sqrt(csum - 1.0 + (frac_lo + frac_mid + frac)); + h = sqrt(csum - 1.0 + (frac1 + frac2 + frac3)); x = h; t = x * T27; @@ -2562,21 +2562,21 @@ vector_norm(Py_ssize_t n, double *vec, double max, int found_nan) assert(fabs(csum) >= fabs(x)); oldcsum = csum; csum += x; - frac += (oldcsum - csum) + x; + frac1 += (oldcsum - csum) + x; x = -2.0 * hi * lo; assert(fabs(csum) >= fabs(x)); oldcsum = csum; csum += x; - frac_mid += (oldcsum - csum) + x; + frac2 += (oldcsum - csum) + x; x = -lo * lo; assert(fabs(csum) >= fabs(x)); oldcsum = csum; csum += x; - frac_lo += (oldcsum - csum) + x; + frac3 += (oldcsum - csum) + x; - x = csum - 1.0 + (frac_lo + frac_mid + frac); + x = csum - 1.0 + (frac1 + frac2 + frac3); return (h + x / (2.0 * h)) / scale; } /* When max_e < -1023, ldexp(1.0, -max_e) overflows. @@ -2591,9 +2591,9 @@ vector_norm(Py_ssize_t n, double *vec, double max, int found_nan) assert(fabs(csum) >= fabs(x)); oldcsum = csum; csum += x; - frac += (oldcsum - csum) + x; + frac1 += (oldcsum - csum) + x; } - return max * sqrt(csum - 1.0 + frac); + return max * sqrt(csum - 1.0 + frac1); } #define NUM_STACK_ELEMS 16 pFad - Phonifier reborn

Pfad - The Proxy pFad of © 2024 Garber Painting. All rights reserved.

Note: This service is not intended for secure transactions such as banking, social media, email, or purchasing. Use at your own risk. We assume no liability whatsoever for broken pages.

Alternative Proxies:

Alternative Proxy

pFad Proxy

pFad v3 Proxy

pFad v4 Proxy