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@@ -339,45 +339,37 @@ Converts a decimal number to its floating-point representation with the given fo
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- b: The bits representing the floating-point number
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- overflow: A boolean indicating whether an overflow occurred during conversion
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*/
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-@(private)
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decimal_to_float_bits :: proc(d: ^decimal.Decimal, info: ^Float_Info) -> (b: u64, overflow: bool) {
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- end :: proc "contextless" (d: ^decimal.Decimal, mant: u64, exp: int, info: ^Float_Info) -> (bits: u64) {
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+ overflow_end :: proc "contextless" (d: ^decimal.Decimal, info: ^Float_Info) -> (u64, bool) {
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+ mant: u64 = 0
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+ exp: int = 1<<info.expbits - 1 + info.bias
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+ return end(d, mant, exp, info, true)
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+ }
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+ end :: proc "contextless" (d: ^decimal.Decimal, mant: u64, exp: int, info: ^Float_Info, is_overflow: bool) -> (bits: u64, overflow: bool) {
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bits = mant & (u64(1)<<info.mantbits - 1)
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bits |= u64((exp-info.bias) & (1<<info.expbits - 1)) << info.mantbits
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if d.neg {
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- bits |= 1<< info.mantbits << info.expbits
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+ bits |= 1 << info.mantbits << info.expbits
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}
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+ overflow = is_overflow
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return
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}
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- set_overflow :: proc "contextless" (mant: ^u64, exp: ^int, info: ^Float_Info) -> bool {
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- mant^ = 0
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- exp^ = 1<<info.expbits - 1 + info.bias
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- return true
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- }
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- mant: u64
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- exp: int
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if d.count == 0 {
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- mant = 0
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- exp = info.bias
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- b = end(d, mant, exp, info)
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- return
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+ return end(d, 0, info.bias, info, false)
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}
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+
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if d.decimal_point > 310 {
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- set_overflow(&mant, &exp, info)
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- b = end(d, mant, exp, info)
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- return
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+ return overflow_end(d, info)
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} else if d.decimal_point < -330 {
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- mant = 0
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- exp = info.bias
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- b = end(d, mant, exp, info)
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- return
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+ return end(d, 0, info.bias, info, false)
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}
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@(static, rodata) power_table := [?]int{1, 3, 6, 9, 13, 16, 19, 23, 26}
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- exp = 0
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+
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+ exp := 0
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for d.decimal_point > 0 {
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n := 27 if d.decimal_point >= len(power_table) else power_table[d.decimal_point]
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decimal.shift(d, -n)
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@@ -392,35 +384,34 @@ decimal_to_float_bits :: proc(d: ^decimal.Decimal, info: ^Float_Info) -> (b: u64
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// go from [0.5, 1) to [1, 2)
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exp -= 1
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+ // Min rep exp is 1+bias
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if exp < info.bias + 1 {
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n := info.bias + 1 - exp
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- decimal.shift(d, n)
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+ decimal.shift(d, -n)
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exp += n
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}
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if (exp-info.bias) >= (1<<info.expbits - 1) {
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- set_overflow(&mant, &exp, info)
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- b = end(d, mant, exp, info)
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- return
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+ return overflow_end(d, info)
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}
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+ // Extract 1 + mantbits
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decimal.shift(d, int(1 + info.mantbits))
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- mant = decimal.rounded_integer(d)
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+ mant := decimal.rounded_integer(d)
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+ // Rounding for shift down
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if mant == 2<<info.mantbits {
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mant >>= 1
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exp += 1
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if (exp-info.bias) >= (1<<info.expbits - 1) {
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- set_overflow(&mant, &exp, info)
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- b = end(d, mant, exp, info)
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- return
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+ return overflow_end(d, info)
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}
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}
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+ // Check for denormalized mantissa
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if mant & (1<<info.mantbits) == 0 {
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exp = info.bias
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}
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- b = end(d, mant, exp, info)
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- return
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+ return end(d, mant, exp, info, false)
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}
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