strconv: float functions cleaning and speed optimization (#10076)
parent
3b062388ba
commit
d60a55d30b
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@ -1,6 +1,5 @@
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module strconv
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/*
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/*=============================================================================
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f32 to string
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@ -18,8 +17,7 @@ Pages 270–282 https://doi.org/10.1145/3192366.3192369
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inspired by the Go version here:
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https://github.com/cespare/ryu/tree/ba56a33f39e3bbbfa409095d0f9ae168a595feea
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*/
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=============================================================================*/
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// pow of ten table used by n_digit reduction
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const(
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@ -39,11 +37,9 @@ const(
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]
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)
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/*
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Conversion Functions
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*/
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//=============================================================================
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// Conversion Functions
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//=============================================================================
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const(
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mantbits32 = u32(23)
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expbits32 = u32(8)
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@ -53,11 +49,13 @@ const(
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// max 46 char
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// -3.40282346638528859811704183484516925440e+38
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[direct_array_access]
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pub fn (d Dec32) get_string_32(neg bool, i_n_digit int, i_pad_digit int) string {
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n_digit := i_n_digit + 1
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pad_digit := i_pad_digit + 1
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mut out := d.m
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mut out_len := decimal_len_32(out)
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//mut out_len := decimal_len_32(out)
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mut out_len := dec_digits(out)
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out_len_original := out_len
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mut fw_zeros := 0
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@ -119,15 +117,6 @@ pub fn (d Dec32) get_string_32(neg bool, i_n_digit int, i_pad_digit int) string
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fw_zeros--
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}
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/*
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x=0
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for x<buf.len {
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C.printf("d:%c\n",buf[x])
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x++
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}
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C.printf("\n")
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*/
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buf[i]=`e`
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i++
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@ -150,13 +139,6 @@ pub fn (d Dec32) get_string_32(neg bool, i_n_digit int, i_pad_digit int) string
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i++
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buf[i]=0
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/*
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x=0
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for x<buf.len {
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C.printf("d:%c\n",buf[x])
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x++
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}
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*/
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return unsafe {
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tos(byteptr(&buf[0]), i)
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}
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@ -233,7 +215,7 @@ pub fn f32_to_decimal(mant u32, exp u32) Dec32 {
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// The largest power of 5 that fits in 24 bits is 5^10,
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// but q <= 9 seems to be safe as well. Only one of mp,
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// mv, and mm can be a multiple of 5, if any.
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if mv%5 == 0 {
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if mv % 5 == 0 {
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vr_is_trailing_zeros = multiple_of_power_of_five_32(mv, q)
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} else if accept_bounds {
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vm_is_trailing_zeros = multiple_of_power_of_five_32(mm, q)
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@ -327,15 +309,19 @@ pub fn f32_to_decimal(mant u32, exp u32) Dec32 {
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return Dec32{m: out e: e10 + removed}
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}
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//=============================================================================
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// String Functions
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//=============================================================================
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// f32_to_str return a string in scientific notation with max n_digit after the dot
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pub fn f32_to_str(f f32, n_digit int) string {
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mut u1 := Uf32{}
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u1.f = f
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u := unsafe {u1.u}
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neg := (u>>(mantbits32+expbits32)) != 0
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mant := u & ((u32(1)<<mantbits32) - u32(1))
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exp := (u >> mantbits32) & ((u32(1)<<expbits32) - u32(1))
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neg := (u >> (mantbits32 + expbits32)) != 0
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mant := u & ((u32(1) << mantbits32) - u32(1))
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exp := (u >> mantbits32) & ((u32(1) << expbits32) - u32(1))
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//println("${neg} ${mant} e ${exp-bias32}")
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@ -360,9 +346,9 @@ pub fn f32_to_str_pad(f f32, n_digit int) string {
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u1.f = f
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u := unsafe {u1.u}
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neg := (u>>(mantbits32+expbits32)) != 0
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mant := u & ((u32(1)<<mantbits32) - u32(1))
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exp := (u >> mantbits32) & ((u32(1)<<expbits32) - u32(1))
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neg := (u >> (mantbits32 + expbits32)) != 0
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mant := u & ((u32(1) << mantbits32) - u32(1))
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exp := (u >> mantbits32) & ((u32(1) << expbits32) - u32(1))
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//println("${neg} ${mant} e ${exp-bias32}")
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@ -1,8 +1,7 @@
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module strconv
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/*=============================================================================
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/*
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f32 to string
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f64 to string
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Copyright (c) 2019-2021 Dario Deledda. All rights reserved.
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Use of this source code is governed by an MIT license
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@ -18,7 +17,7 @@ Pages 270–282 https://doi.org/10.1145/3192366.3192369
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inspired by the Go version here:
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https://github.com/cespare/ryu/tree/ba56a33f39e3bbbfa409095d0f9ae168a595feea
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*/
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=============================================================================*/
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// pow of ten table used by n_digit reduction
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const(
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@ -46,11 +45,9 @@ const(
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]
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)
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/*
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Conversion Functions
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*/
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//=============================================================================
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// Conversion Functions
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//=============================================================================
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const(
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mantbits64 = u32(52)
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expbits64 = u32(11)
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@ -58,12 +55,14 @@ const(
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maxexp64 = 2047
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)
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[direct_array_access]
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fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
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mut n_digit := i_n_digit + 1
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pad_digit := i_pad_digit + 1
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mut out := d.m
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mut d_exp := d.e
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mut out_len := decimal_len_64(out)
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// mut out_len := decimal_len_64(out)
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mut out_len := dec_digits(out)
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out_len_original := out_len
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mut fw_zeros := 0
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@ -75,7 +74,7 @@ fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
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mut i := 0
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if neg {
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buf[i]=`-`
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buf[i] = `-`
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i++
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}
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@ -88,9 +87,9 @@ fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
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if n_digit < out_len {
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//println("out:[$out]")
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out += ten_pow_table_64[out_len - n_digit - 1] * 5 // round to up
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out /= ten_pow_table_64[out_len - n_digit ]
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out /= ten_pow_table_64[out_len - n_digit]
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//println("out1:[$out] ${d.m / ten_pow_table_64[out_len - n_digit ]}")
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if d.m / ten_pow_table_64[out_len - n_digit ] < out {
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if d.m / ten_pow_table_64[out_len - n_digit] < out {
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d_exp++
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n_digit++
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}
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@ -103,8 +102,8 @@ fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
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y := i + out_len
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mut x := 0
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for x < (out_len-disp-1) {
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buf[y - x] = `0` + byte(out%10)
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for x < (out_len - disp - 1) {
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buf[y - x] = `0` + byte(out % 10)
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out /= 10
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i++
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x++
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@ -125,7 +124,7 @@ fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
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}
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if y-x >= 0 {
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buf[y - x] = `0` + byte(out%10)
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buf[y - x] = `0` + byte(out % 10)
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i++
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}
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@ -135,15 +134,6 @@ fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
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fw_zeros--
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}
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/*
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x=0
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for x<buf.len {
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C.printf("d:%c\n",buf[x])
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x++
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}
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C.printf("\n")
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*/
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buf[i]=`e`
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i++
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@ -172,14 +162,6 @@ fn (d Dec64) get_string_64(neg bool, i_n_digit int, i_pad_digit int) string {
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i++
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buf[i]=0
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/*
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x=0
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for x<buf.len {
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C.printf("d:%c\n",buf[x])
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x++
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}
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*/
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return unsafe {
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tos(byteptr(&buf[0]), i)
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}
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@ -216,7 +198,7 @@ fn f64_to_decimal(mant u64, exp u64) Dec64 {
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m2 = mant
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} else {
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e2 = int(exp) - bias64 - int(mantbits64) - 2
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m2 = (u64(1)<<mantbits64) | mant
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m2 = (u64(1) << mantbits64) | mant
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}
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even := (m2 & 1) == 0
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accept_bounds := even
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@ -249,14 +231,14 @@ fn f64_to_decimal(mant u64, exp u64) Dec64 {
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// Smaller values may still be safe, but it's more
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// difficult to reason about them. Only one of mp, mv,
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// and mm can be a multiple of 5, if any.
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if mv%5 == 0 {
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if mv % 5 == 0 {
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vr_is_trailing_zeros = multiple_of_power_of_five_64(mv, q)
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} else if accept_bounds {
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// Same as min(e2 + (^mm & 1), pow5Factor64(mm)) >= q
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// <=> e2 + (^mm & 1) >= q && pow5Factor64(mm) >= q
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// <=> true && pow5Factor64(mm) >= q, since e2 >= q.
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vm_is_trailing_zeros = multiple_of_power_of_five_64(mv-1-mm_shift, q)
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} else if multiple_of_power_of_five_64(mv+2, q) {
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vm_is_trailing_zeros = multiple_of_power_of_five_64(mv - 1 - mm_shift, q)
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} else if multiple_of_power_of_five_64(mv + 2, q) {
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vp--
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}
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}
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@ -376,15 +358,19 @@ fn f64_to_decimal(mant u64, exp u64) Dec64 {
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return Dec64{m: out, e: e10 + removed}
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}
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//=============================================================================
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// String Functions
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//=============================================================================
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// f64_to_str return a string in scientific notation with max n_digit after the dot
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pub fn f64_to_str(f f64, n_digit int) string {
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mut u1 := Uf64{}
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u1.f = f
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u := unsafe {u1.u}
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neg := (u>>(mantbits64+expbits64)) != 0
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mant := u & ((u64(1)<<mantbits64) - u64(1))
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exp := (u >> mantbits64) & ((u64(1)<<expbits64) - u64(1))
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neg := (u >> (mantbits64 + expbits64)) != 0
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mant := u & ((u64(1) << mantbits64) - u64(1))
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exp := (u >> mantbits64) & ((u64(1) << expbits64) - u64(1))
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//println("s:${neg} mant:${mant} exp:${exp} float:${f} byte:${u1.u:016lx}")
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// Exit early for easy cases.
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@ -407,9 +393,9 @@ pub fn f64_to_str_pad(f f64, n_digit int) string {
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u1.f = f
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u := unsafe {u1.u}
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neg := (u>>(mantbits64+expbits64)) != 0
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mant := u & ((u64(1)<<mantbits64) - u64(1))
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exp := (u >> mantbits64) & ((u64(1)<<expbits64) - u64(1))
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neg := (u >> (mantbits64 + expbits64)) != 0
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mant := u & ((u64(1) << mantbits64) - u64(1))
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exp := (u >> mantbits64) & ((u64(1) << expbits64) - u64(1))
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//println("s:${neg} mant:${mant} exp:${exp} float:${f} byte:${u1.u:016lx}")
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// Exit early for easy cases.
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