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Re: GAWK bugissue report - ROUNDMODE inconsistencies between standard an
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From: |
arnold |
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Subject: |
Re: GAWK bugissue report - ROUNDMODE inconsistencies between standard and bignum invocations |
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Date: |
Thu, 24 Feb 2022 12:04:49 -0700 |
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User-agent: |
Heirloom mailx 12.5 7/5/10 |
This is the final time that I will remind you to send these
messages to bug-gawk@gnu.org and not to my personal emails.
I will delete any further bug reports sent directly to me without
answering or forwarding them.
Arnold
"Jason C. Kwan" <jasonckwan@yahoo.com> wrote:
>
> In the ROUNDMODE = D ( rounding [D]own towards negative infinity),
> using this very straight forward equation, one would end up getting a
> slightly different value.
>
> Regardless of how high or how low a precision I tried to set in gawk -M,
> the only one with the same result is a precision of 39, but using the
> -d print out feature, it reveals an internal value without decimals for
> gawk -M,
>
> while standard gawk -e matches the 16 digit significant digits, and only
> off by 1 at the 17th digit.
>
> I even tested a ridiculous PREC setting of 200 milliion to eliminate
> any chance the value fluctuates depending on PREC, and the result indeed
> matches nearly all other settings, including not setting PREC and assuming
> the default value of 53.
>
> I know I'm being pedantic here since we're talking about the 22nd
> significant digit in octal, so entirely up to you whether this warrants
> any attention.
>
> GNU Awk 5.1.1, API: 3.1 (GNU MPFR 4.1.0, GNU MP 6.2.1)
>
> Darwin MacBook-Pro.local 21.3.0 Darwin Kernel Version 21.3.0: Wed Jan 5
> 21:37:58 PST 2022; root:xnu-8019.80.24~20/RELEASE_ARM64_T6000 arm64
>
> BEGIN {
> ROUNDMODE = "D"
> x = ( 2 ^ -13 ) * ( 2 ^ 52 - 3 ) - 1
> x = -x
> printf( "%o" , 1E0 + x )
> }
>
> ------------------------------------------------------
>
> gawk 5.1.1 -e :: 177777777000000000000 [3]
> <<
>
> ------------------------------------------------------
>
> gawk -M -e :: 177777777000000000000[2]
> gawk -M -v PREC=200000000 -e :: 177777777000000000000 2
>
> ------------------------------------------------------
> gawk -M -v PREC=37 -e :: 17777777700000000000 10
> gawk -M -v PREC=38 -e :: 177777777000000000000 4
> gawk -M -v PREC=39 -e :: 177777777000000000000 [3] <<
> gawk -M -v PREC=40 -e :: 177777777000000000000 2
> ------------------------------------------------------
>
> PREC :: nm
> : 1777777770000000000003
> x: -549755813886.99963
> ^
> standard ^ vs. --bignum v
> v
> PREC :: 0 :: 1777777770000000000002
> x: -549755813886.99964
>
> PREC :: 39 :: 1777777770000000000003
> x: -549755813886
>
> ----------------------------------------------------------
> 1 PREC :: 1 :: 1777777776000000000000
> 2 PREC :: 2 :: 1777777774000000000000
> 3 PREC :: 3 :: 1777777772000000000000
> 4 PREC :: 4 :: 1777777771000000000000
> 5 PREC :: 5 :: 1777777770400000000000
>
> 6 PREC :: 6 :: 1777777770200000000000
> 7 PREC :: 7 :: 1777777770100000000000
> 8 PREC :: 8 :: 1777777770040000000000
> 9 PREC :: 9 :: 1777777770020000000000
> 10 PREC :: 10 :: 1777777770010000000000
>
> 11 PREC :: 11 :: 1777777770004000000000
> 12 PREC :: 12 :: 1777777770002000000000
> 13 PREC :: 13 :: 1777777770001000000000
> 14 PREC :: 14 :: 1777777770000400000000
> 15 PREC :: 15 :: 1777777770000200000000
>
> 16 PREC :: 16 :: 1777777770000100000000
> 17 PREC :: 17 :: 1777777770000040000000
> 18 PREC :: 18 :: 1777777770000020000000
> 19 PREC :: 19 :: 1777777770000010000000
> 20 PREC :: 20 :: 1777777770000004000000
>
> 21 PREC :: 21 :: 1777777770000002000000
> 22 PREC :: 22 :: 1777777770000001000000
> 23 PREC :: 23 :: 1777777770000000400000
> 24 PREC :: 24 :: 1777777770000000200000
> 25 PREC :: 25 :: 1777777770000000100000
>
> 26 PREC :: 26 :: 1777777770000000040000
> 27 PREC :: 27 :: 1777777770000000020000
> 28 PREC :: 28 :: 1777777770000000010000
> 29 PREC :: 29 :: 1777777770000000004000
> 30 PREC :: 30 :: 1777777770000000002000
>
> 31 PREC :: 31 :: 1777777770000000001000
> 32 PREC :: 32 :: 1777777770000000000400
> 33 PREC :: 33 :: 1777777770000000000200
> 34 PREC :: 34 :: 1777777770000000000100
> 35 PREC :: 35 :: 1777777770000000000040
>
> 36 PREC :: 36 :: 1777777770000000000020
> 37 PREC :: 37 :: 1777777770000000000010
> 38 PREC :: 38 :: 1777777770000000000004
> 39 PREC :: 39 :: 1777777770000000000003 <<<<<<
> 40 PREC :: 40 :: 1777777770000000000002
>
> 41 PREC :: 41 :: 1777777770000000000002
> 42 PREC :: 42 :: 1777777770000000000002
> 43 PREC :: 43 :: 1777777770000000000002
> 44 PREC :: 44 :: 1777777770000000000002
> 45 PREC :: 45 :: 1777777770000000000002
>
> 46 PREC :: 46 :: 1777777770000000000002
> 47 PREC :: 47 :: 1777777770000000000002
> 48 PREC :: 48 :: 1777777770000000000002
> 49 PREC :: 49 :: 1777777770000000000002
> 50 PREC :: 50 :: 1777777770000000000002
>
> 51 PREC :: 51 :: 1777777770000000000002
> 52 PREC :: 52 :: 1777777770000000000002
> 53 PREC :: 53 :: 1777777770000000000002 <<<<<<
> 54 PREC :: 54 :: 1777777770000000000002
> 55 PREC :: 55 :: 1777777770000000000002
>
> 56 PREC :: 56 :: 1777777770000000000002
> 57 PREC :: 57 :: 1777777770000000000002
> 58 PREC :: 58 :: 1777777770000000000002
> 59 PREC :: 59 :: 1777777770000000000002
> 60 PREC :: 60 :: 1777777770000000000002
>
> 61 PREC :: 61 :: 1777777770000000000002
> 62 PREC :: 62 :: 1777777770000000000002
> 63 PREC :: 63 :: 1777777770000000000002
> 64 PREC :: 64 :: 1777777770000000000002
> 65 PREC :: 65 :: 1777777770000000000002
>
> 66 PREC :: 66 :: 1777777770000000000002
> 67 PREC :: 67 :: 1777777770000000000002
> 68 PREC :: 68 :: 1777777770000000000002
> 69 PREC :: 69 :: 1777777770000000000002
> 70 PREC :: 70 :: 1777777770000000000002
>
> 71 PREC :: 71 :: 1777777770000000000002
> 72 PREC :: 72 :: 1777777770000000000002
> 73 PREC :: 73 :: 1777777770000000000002
> 74 PREC :: 74 :: 1777777770000000000002
> 75 PREC :: 75 :: 1777777770000000000002
>
> 76 PREC :: 76 :: 1777777770000000000002
> 77 PREC :: 77 :: 1777777770000000000002
> 78 PREC :: 78 :: 1777777770000000000002
> 79 PREC :: 79 :: 1777777770000000000002
> 80 PREC :: 80 :: 1777777770000000000002
>
> 81 PREC :: 81 :: 1777777770000000000002
> 82 PREC :: 82 :: 1777777770000000000002
> 83 PREC :: 83 :: 1777777770000000000002
> 84 PREC :: 84 :: 1777777770000000000002
> 85 PREC :: 85 :: 1777777770000000000002
>
> 86 PREC :: 86 :: 1777777770000000000002
> 87 PREC :: 87 :: 1777777770000000000002
> 88 PREC :: 88 :: 1777777770000000000002
> 89 PREC :: 89 :: 1777777770000000000002
> 90 PREC :: 90 :: 1777777770000000000002
>
> 91 PREC :: 91 :: 1777777770000000000002
> 92 PREC :: 92 :: 1777777770000000000002
> 93 PREC :: 93 :: 1777777770000000000002
> 94 PREC :: 94 :: 1777777770000000000002
> 95 PREC :: 95 :: 1777777770000000000002
>
> 96 PREC :: 96 :: 1777777770000000000002
> 97 PREC :: 97 :: 1777777770000000000002
> 98 PREC :: 98 :: 1777777770000000000002
> 99 PREC :: 99 :: 1777777770000000000002
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- Re: GAWK bugissue report - ROUNDMODE inconsistencies between standard and bignum invocations,
arnold <=