[Gmp-commit] /var/hg/gmp: Comment the trick used for ARM submul_1.

[mercurial at gmplib.org]

details:   /var/hg/gmp/rev/747215ea6143
changeset: 15715:747215ea6143
user:      Niels M?ller <nisse at lysator.liu.se>
date:      Sun Apr 14 15:12:59 2013 +0200
description:
Comment the trick used for ARM submul_1.

diffstat:

 mpn/arm/v6/submul_1.asm |  5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)

diffs (15 lines):

diff -r 37082d27ed59 -r 747215ea6143 mpn/arm/v6/submul_1.asm
--- a/mpn/arm/v6/submul_1.asm	Sat Apr 13 23:40:21 2013 +0200
+++ b/mpn/arm/v6/submul_1.asm	Sun Apr 14 15:12:59 2013 +0200
@@ -37,6 +37,11 @@
 define(`n', `r2')
 define(`v0',`r3')
 
+C This loop complements U on the fly,
+C   U' = B^n - 1 - U
+C and then uses that 
+C   R - U*v = R + U'*v + v - B^n v
+
 ASM_START()
 PROLOGUE(mpn_submul_1)
 	stmfd	sp!, { r4, r5, r6, r7 }