From f5c4671bfbad96bf346bd7e9a21fc4317b4959df Mon Sep 17 00:00:00 2001
From: Indrajith K L
Date: Sat, 3 Dec 2022 17:00:20 +0530
Subject: Adds most of the tools

---
 v_windows/v/old/vlib/strconv/atof.v | 441 ++++++++++++++++++++++++++++++++++++
 1 file changed, 441 insertions(+)
 create mode 100644 v_windows/v/old/vlib/strconv/atof.v

(limited to 'v_windows/v/old/vlib/strconv/atof.v')

diff --git a/v_windows/v/old/vlib/strconv/atof.v b/v_windows/v/old/vlib/strconv/atof.v
new file mode 100644
index 0000000..dd994bd
--- /dev/null
+++ b/v_windows/v/old/vlib/strconv/atof.v
@@ -0,0 +1,441 @@
+module strconv
+
+/*
+atof util
+
+Copyright (c) 2019-2021 Dario Deledda. All rights reserved.
+Use of this source code is governed by an MIT license
+that can be found in the LICENSE file.
+
+This file contains utilities for convert a string in a f64 variable
+IEEE 754 standard is used
+
+Know limitation:
+- limited to 18 significant digits
+
+The code is inspired by:
+Grzegorz Kraszewski krashan@teleinfo.pb.edu.pl
+URL: http://krashan.ppa.pl/articles/stringtofloat/
+Original license: MIT
+
+96 bit operation utilities
+Note: when u128 will be available these function can be refactored
+*/
+
+// right logical shift 96 bit
+fn lsr96(s2 u32, s1 u32, s0 u32) (u32, u32, u32) {
+	mut r0 := u32(0)
+	mut r1 := u32(0)
+	mut r2 := u32(0)
+	r0 = (s0 >> 1) | ((s1 & u32(1)) << 31)
+	r1 = (s1 >> 1) | ((s2 & u32(1)) << 31)
+	r2 = s2 >> 1
+	return r2, r1, r0
+}
+
+// left logical shift 96 bit
+fn lsl96(s2 u32, s1 u32, s0 u32) (u32, u32, u32) {
+	mut r0 := u32(0)
+	mut r1 := u32(0)
+	mut r2 := u32(0)
+	r2 = (s2 << 1) | ((s1 & (u32(1) << 31)) >> 31)
+	r1 = (s1 << 1) | ((s0 & (u32(1) << 31)) >> 31)
+	r0 = s0 << 1
+	return r2, r1, r0
+}
+
+// sum on 96 bit
+fn add96(s2 u32, s1 u32, s0 u32, d2 u32, d1 u32, d0 u32) (u32, u32, u32) {
+	mut w := u64(0)
+	mut r0 := u32(0)
+	mut r1 := u32(0)
+	mut r2 := u32(0)
+	w = u64(s0) + u64(d0)
+	r0 = u32(w)
+	w >>= 32
+	w += u64(s1) + u64(d1)
+	r1 = u32(w)
+	w >>= 32
+	w += u64(s2) + u64(d2)
+	r2 = u32(w)
+	return r2, r1, r0
+}
+
+// subtraction on 96 bit
+fn sub96(s2 u32, s1 u32, s0 u32, d2 u32, d1 u32, d0 u32) (u32, u32, u32) {
+	mut w := u64(0)
+	mut r0 := u32(0)
+	mut r1 := u32(0)
+	mut r2 := u32(0)
+	w = u64(s0) - u64(d0)
+	r0 = u32(w)
+	w >>= 32
+	w += u64(s1) - u64(d1)
+	r1 = u32(w)
+	w >>= 32
+	w += u64(s2) - u64(d2)
+	r2 = u32(w)
+	return r2, r1, r0
+}
+
+/*
+Constants
+*/
+
+pub const (
+	//
+	// f32 constants
+	//
+	single_plus_zero      = u32(0x0000_0000)
+	single_minus_zero     = u32(0x8000_0000)
+	single_plus_infinity  = u32(0x7F80_0000)
+	single_minus_infinity = u32(0xFF80_0000)
+	//
+	// f64 constants
+	//
+	digits                = 18
+	double_plus_zero      = u64(0x0000000000000000)
+	double_minus_zero     = u64(0x8000000000000000)
+	double_plus_infinity  = u64(0x7FF0000000000000)
+	double_minus_infinity = u64(0xFFF0000000000000)
+	//
+	// Possible parser return values.
+	//
+	parser_ok             = 0 // parser finished OK
+	parser_pzero          = 1 // no digits or number is smaller than +-2^-1022
+	parser_mzero          = 2 // number is negative, module smaller
+	parser_pinf           = 3 // number is higher than +HUGE_VAL
+	parser_minf           = 4 // number is lower than -HUGE_VAL
+	//
+	// char constants
+	// Note: Modify these if working with non-ASCII encoding
+	//
+	c_dpoint              = `.`
+	c_plus                = `+`
+	c_minus               = `-`
+	c_zero                = `0`
+	c_nine                = `9`
+	c_ten                 = u32(10)
+)
+
+/*
+Utility
+*/
+
+// NOTE: Modify these if working with non-ASCII encoding
+fn is_digit(x byte) bool {
+	return (x >= strconv.c_zero && x <= strconv.c_nine) == true
+}
+
+fn is_space(x byte) bool {
+	return (x == `\t` || x == `\n` || x == `\v` || x == `\f` || x == `\r` || x == ` `)
+}
+
+fn is_exp(x byte) bool {
+	return (x == `E` || x == `e`) == true
+}
+
+/*
+Support struct
+*/
+
+/*
+String parser
+NOTE: #TOFIX need one char after the last char of the number
+*/
+
+fn parser(s string) (int, PrepNumber) {
+	mut digx := 0
+	mut result := strconv.parser_ok
+	mut expneg := false
+	mut expexp := 0
+	mut i := 0
+	mut pn := PrepNumber{}
+
+	// skip spaces
+	for i < s.len && s[i].is_space() {
+		i++
+	}
+
+	// check negatives
+	if s[i] == `-` {
+		pn.negative = true
+		i++
+	}
+
+	// positive sign ignore it
+	if s[i] == `+` {
+		i++
+	}
+
+	// read mantissa
+	for i < s.len && s[i].is_digit() {
+		// println("$i => ${s[i]}")
+		if digx < strconv.digits {
+			pn.mantissa *= 10
+			pn.mantissa += u64(s[i] - strconv.c_zero)
+			digx++
+		} else if pn.exponent < 2147483647 {
+			pn.exponent++
+		}
+		i++
+	}
+
+	// read mantissa decimals
+	if (i < s.len) && (s[i] == `.`) {
+		i++
+		for i < s.len && s[i].is_digit() {
+			if digx < strconv.digits {
+				pn.mantissa *= 10
+				pn.mantissa += u64(s[i] - strconv.c_zero)
+				pn.exponent--
+				digx++
+			}
+			i++
+		}
+	}
+
+	// read exponent
+	if (i < s.len) && ((s[i] == `e`) || (s[i] == `E`)) {
+		i++
+		if i < s.len {
+			// esponent sign
+			if s[i] == strconv.c_plus {
+				i++
+			} else if s[i] == strconv.c_minus {
+				expneg = true
+				i++
+			}
+
+			for i < s.len && s[i].is_digit() {
+				if expexp < 214748364 {
+					expexp *= 10
+					expexp += int(s[i] - strconv.c_zero)
+				}
+				i++
+			}
+		}
+	}
+
+	if expneg {
+		expexp = -expexp
+	}
+	pn.exponent += expexp
+	if pn.mantissa == 0 {
+		if pn.negative {
+			result = strconv.parser_mzero
+		} else {
+			result = strconv.parser_pzero
+		}
+	} else if pn.exponent > 309 {
+		if pn.negative {
+			result = strconv.parser_minf
+		} else {
+			result = strconv.parser_pinf
+		}
+	} else if pn.exponent < -328 {
+		if pn.negative {
+			result = strconv.parser_mzero
+		} else {
+			result = strconv.parser_pzero
+		}
+	}
+	return result, pn
+}
+
+/*
+Converter to the bit form of the f64 number
+*/
+
+// converter return a u64 with the bit image of the f64 number
+fn converter(mut pn PrepNumber) u64 {
+	mut binexp := 92
+	mut s2 := u32(0) // 96-bit precision integer
+	mut s1 := u32(0)
+	mut s0 := u32(0)
+	mut q2 := u32(0) // 96-bit precision integer
+	mut q1 := u32(0)
+	mut q0 := u32(0)
+	mut r2 := u32(0) // 96-bit precision integer
+	mut r1 := u32(0)
+	mut r0 := u32(0)
+	mask28 := u32(u64(0xF) << 28)
+	mut result := u64(0)
+	// working on 3 u32 to have 96 bit precision
+	s0 = u32(pn.mantissa & u64(0x00000000FFFFFFFF))
+	s1 = u32(pn.mantissa >> 32)
+	s2 = u32(0)
+	// so we take the decimal exponent off
+	for pn.exponent > 0 {
+		q2, q1, q0 = lsl96(s2, s1, s0) // q = s * 2
+		r2, r1, r0 = lsl96(q2, q1, q0) // r = s * 4 <=> q * 2
+		s2, s1, s0 = lsl96(r2, r1, r0) // s = s * 8 <=> r * 2
+		s2, s1, s0 = add96(s2, s1, s0, q2, q1, q0) // s = (s * 8) + (s * 2) <=> s*10
+		pn.exponent--
+		for (s2 & mask28) != 0 {
+			q2, q1, q0 = lsr96(s2, s1, s0)
+			binexp++
+			s2 = q2
+			s1 = q1
+			s0 = q0
+		}
+	}
+	for pn.exponent < 0 {
+		for !((s2 & (u32(1) << 31)) != 0) {
+			q2, q1, q0 = lsl96(s2, s1, s0)
+			binexp--
+			s2 = q2
+			s1 = q1
+			s0 = q0
+		}
+		q2 = s2 / strconv.c_ten
+		r1 = s2 % strconv.c_ten
+		r2 = (s1 >> 8) | (r1 << 24)
+		q1 = r2 / strconv.c_ten
+		r1 = r2 % strconv.c_ten
+		r2 = ((s1 & u32(0xFF)) << 16) | (s0 >> 16) | (r1 << 24)
+		r0 = r2 / strconv.c_ten
+		r1 = r2 % strconv.c_ten
+		q1 = (q1 << 8) | ((r0 & u32(0x00FF0000)) >> 16)
+		q0 = r0 << 16
+		r2 = (s0 & u32(0xFFFF)) | (r1 << 16)
+		q0 |= r2 / strconv.c_ten
+		s2 = q2
+		s1 = q1
+		s0 = q0
+		pn.exponent++
+	}
+	// C.printf("mantissa before normalization: %08x%08x%08x binexp: %d \n", s2,s1,s0,binexp)
+	// normalization, the 28 bit in s2 must the leftest one in the variable
+	if s2 != 0 || s1 != 0 || s0 != 0 {
+		for (s2 & mask28) == 0 {
+			q2, q1, q0 = lsl96(s2, s1, s0)
+			binexp--
+			s2 = q2
+			s1 = q1
+			s0 = q0
+		}
+	}
+	// rounding if needed
+	/*
+	* "round half to even" algorithm
+	* Example for f32, just a reminder
+	*
+	* If bit 54 is 0, round down
+	* If bit 54 is 1
+	*	If any bit beyond bit 54 is 1, round up
+	*	If all bits beyond bit 54 are 0 (meaning the number is halfway between two floating-point numbers)
+	*		If bit 53 is 0, round down
+	*		If bit 53 is 1, round up
+	*/
+	/*
+	test case 1 complete
+	s2=0x1FFFFFFF
+	s1=0xFFFFFF80
+	s0=0x0
+	*/
+
+	/*
+	test case 1 check_round_bit
+	s2=0x18888888
+	s1=0x88888880
+	s0=0x0
+	*/
+
+	/*
+	test case  check_round_bit + normalization
+	s2=0x18888888
+	s1=0x88888F80
+	s0=0x0
+	*/
+
+	// C.printf("mantissa before rounding: %08x%08x%08x binexp: %d \n", s2,s1,s0,binexp)
+	// s1 => 0xFFFFFFxx only F are rapresented
+	nbit := 7
+	check_round_bit := u32(1) << u32(nbit)
+	check_round_mask := u32(0xFFFFFFFF) << u32(nbit)
+	if (s1 & check_round_bit) != 0 {
+		// C.printf("need round!! cehck mask: %08x\n", s1 & ~check_round_mask )
+		if (s1 & ~check_round_mask) != 0 {
+			// C.printf("Add 1!\n")
+			s2, s1, s0 = add96(s2, s1, s0, 0, check_round_bit, 0)
+		} else {
+			// C.printf("All 0!\n")
+			if (s1 & (check_round_bit << u32(1))) != 0 {
+				// C.printf("Add 1 form -1 bit control!\n")
+				s2, s1, s0 = add96(s2, s1, s0, 0, check_round_bit, 0)
+			}
+		}
+		s1 = s1 & check_round_mask
+		s0 = u32(0)
+		// recheck normalization
+		if s2 & (mask28 << u32(1)) != 0 {
+			// C.printf("Renormalize!!")
+			q2, q1, q0 = lsr96(s2, s1, s0)
+			binexp--
+			s2 = q2
+			s1 = q1
+			s0 = q0
+		}
+	}
+	// tmp := ( u64(s2 & ~mask28) << 24) | ((u64(s1) + u64(128)) >> 8)
+	// C.printf("mantissa after rounding : %08x%08x%08x binexp: %d \n", s2,s1,s0,binexp)
+	// C.printf("Tmp result: %016x\n",tmp)
+	// end rounding
+	// offset the binary exponent IEEE 754
+	binexp += 1023
+	if binexp > 2046 {
+		if pn.negative {
+			result = strconv.double_minus_infinity
+		} else {
+			result = strconv.double_plus_infinity
+		}
+	} else if binexp < 1 {
+		if pn.negative {
+			result = strconv.double_minus_zero
+		} else {
+			result = strconv.double_plus_zero
+		}
+	} else if s2 != 0 {
+		mut q := u64(0)
+		binexs2 := u64(binexp) << 52
+		q = (u64(s2 & ~mask28) << 24) | ((u64(s1) + u64(128)) >> 8) | binexs2
+		if pn.negative {
+			q |= (u64(1) << 63)
+		}
+		result = q
+	}
+	return result
+}
+
+/*
+Public functions
+*/
+
+// atof64 return a f64 from a string doing a parsing operation
+pub fn atof64(s string) f64 {
+	mut pn := PrepNumber{}
+	mut res_parsing := 0
+	mut res := Float64u{}
+
+	res_parsing, pn = parser(s)
+	match res_parsing {
+		strconv.parser_ok {
+			res.u = converter(mut pn)
+		}
+		strconv.parser_pzero {
+			res.u = strconv.double_plus_zero
+		}
+		strconv.parser_mzero {
+			res.u = strconv.double_minus_zero
+		}
+		strconv.parser_pinf {
+			res.u = strconv.double_plus_infinity
+		}
+		strconv.parser_minf {
+			res.u = strconv.double_minus_infinity
+		}
+		else {}
+	}
+	return unsafe { res.f }
+}
-- 
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