From 02ad841dd82bd644b12efa168ad9fc4c623d6b37 Mon Sep 17 00:00:00 2001 From: Brian Kessler Date: Thu, 13 Dec 2018 09:19:11 -0700 Subject: [PATCH] math: correct mPi4 comment The previous comment mis-stated the number of bits in mPi4. The correct value is 19*64 + 1 == 1217 bits. Change-Id: Ife971ff6936ce2d5b81ce663ce48044749d592a0 Reviewed-on: https://go-review.googlesource.com/c/154017 Reviewed-by: Brad Fitzpatrick --- src/math/trig_reduce.go | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/src/math/trig_reduce.go b/src/math/trig_reduce.go index 7bc72e986d..6f8eaba9b9 100644 --- a/src/math/trig_reduce.go +++ b/src/math/trig_reduce.go @@ -68,8 +68,8 @@ func trigReduce(x float64) (j uint64, z float64) { // mPi4 is the binary digits of 4/pi as a uint64 array, // that is, 4/pi = Sum mPi4[i]*2^(-64*i) -// 19 64-bit digits gives 1153 bits of precision to handle -// the largest possible float64 exponent. +// 19 64-bit digits and the leading one bit give 1217 bits +// of precision to handle the largest possible float64 exponent. var mPi4 = [...]uint64{ 0x0000000000000001, 0x45f306dc9c882a53, -- 2.50.0