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-rw-r--r--vendor/half/src/bfloat/convert.rs148
1 files changed, 0 insertions, 148 deletions
diff --git a/vendor/half/src/bfloat/convert.rs b/vendor/half/src/bfloat/convert.rs
deleted file mode 100644
index 8f258f5..0000000
--- a/vendor/half/src/bfloat/convert.rs
+++ /dev/null
@@ -1,148 +0,0 @@
-use crate::leading_zeros::leading_zeros_u16;
-use core::mem;
-
-#[inline]
-pub(crate) const fn f32_to_bf16(value: f32) -> u16 {
- // TODO: Replace mem::transmute with to_bits() once to_bits is const-stabilized
- // Convert to raw bytes
- let x: u32 = unsafe { mem::transmute(value) };
-
- // check for NaN
- if x & 0x7FFF_FFFFu32 > 0x7F80_0000u32 {
- // Keep high part of current mantissa but also set most significiant mantissa bit
- return ((x >> 16) | 0x0040u32) as u16;
- }
-
- // round and shift
- let round_bit = 0x0000_8000u32;
- if (x & round_bit) != 0 && (x & (3 * round_bit - 1)) != 0 {
- (x >> 16) as u16 + 1
- } else {
- (x >> 16) as u16
- }
-}
-
-#[inline]
-pub(crate) const fn f64_to_bf16(value: f64) -> u16 {
- // TODO: Replace mem::transmute with to_bits() once to_bits is const-stabilized
- // Convert to raw bytes, truncating the last 32-bits of mantissa; that precision will always
- // be lost on half-precision.
- let val: u64 = unsafe { mem::transmute(value) };
- let x = (val >> 32) as u32;
-
- // Extract IEEE754 components
- let sign = x & 0x8000_0000u32;
- let exp = x & 0x7FF0_0000u32;
- let man = x & 0x000F_FFFFu32;
-
- // Check for all exponent bits being set, which is Infinity or NaN
- if exp == 0x7FF0_0000u32 {
- // Set mantissa MSB for NaN (and also keep shifted mantissa bits).
- // We also have to check the last 32 bits.
- let nan_bit = if man == 0 && (val as u32 == 0) {
- 0
- } else {
- 0x0040u32
- };
- return ((sign >> 16) | 0x7F80u32 | nan_bit | (man >> 13)) as u16;
- }
-
- // The number is normalized, start assembling half precision version
- let half_sign = sign >> 16;
- // Unbias the exponent, then bias for bfloat16 precision
- let unbiased_exp = ((exp >> 20) as i64) - 1023;
- let half_exp = unbiased_exp + 127;
-
- // Check for exponent overflow, return +infinity
- if half_exp >= 0xFF {
- return (half_sign | 0x7F80u32) as u16;
- }
-
- // Check for underflow
- if half_exp <= 0 {
- // Check mantissa for what we can do
- if 7 - half_exp > 21 {
- // No rounding possibility, so this is a full underflow, return signed zero
- return half_sign as u16;
- }
- // Don't forget about hidden leading mantissa bit when assembling mantissa
- let man = man | 0x0010_0000u32;
- let mut half_man = man >> (14 - half_exp);
- // Check for rounding
- let round_bit = 1 << (13 - half_exp);
- if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 {
- half_man += 1;
- }
- // No exponent for subnormals
- return (half_sign | half_man) as u16;
- }
-
- // Rebias the exponent
- let half_exp = (half_exp as u32) << 7;
- let half_man = man >> 13;
- // Check for rounding
- let round_bit = 0x0000_1000u32;
- if (man & round_bit) != 0 && (man & (3 * round_bit - 1)) != 0 {
- // Round it
- ((half_sign | half_exp | half_man) + 1) as u16
- } else {
- (half_sign | half_exp | half_man) as u16
- }
-}
-
-#[inline]
-pub(crate) const fn bf16_to_f32(i: u16) -> f32 {
- // TODO: Replace mem::transmute with from_bits() once from_bits is const-stabilized
- // If NaN, keep current mantissa but also set most significiant mantissa bit
- if i & 0x7FFFu16 > 0x7F80u16 {
- unsafe { mem::transmute((i as u32 | 0x0040u32) << 16) }
- } else {
- unsafe { mem::transmute((i as u32) << 16) }
- }
-}
-
-#[inline]
-pub(crate) const fn bf16_to_f64(i: u16) -> f64 {
- // TODO: Replace mem::transmute with from_bits() once from_bits is const-stabilized
- // Check for signed zero
- if i & 0x7FFFu16 == 0 {
- return unsafe { mem::transmute((i as u64) << 48) };
- }
-
- let half_sign = (i & 0x8000u16) as u64;
- let half_exp = (i & 0x7F80u16) as u64;
- let half_man = (i & 0x007Fu16) as u64;
-
- // Check for an infinity or NaN when all exponent bits set
- if half_exp == 0x7F80u64 {
- // Check for signed infinity if mantissa is zero
- if half_man == 0 {
- return unsafe { mem::transmute((half_sign << 48) | 0x7FF0_0000_0000_0000u64) };
- } else {
- // NaN, keep current mantissa but also set most significiant mantissa bit
- return unsafe {
- mem::transmute((half_sign << 48) | 0x7FF8_0000_0000_0000u64 | (half_man << 45))
- };
- }
- }
-
- // Calculate double-precision components with adjusted exponent
- let sign = half_sign << 48;
- // Unbias exponent
- let unbiased_exp = ((half_exp as i64) >> 7) - 127;
-
- // Check for subnormals, which will be normalized by adjusting exponent
- if half_exp == 0 {
- // Calculate how much to adjust the exponent by
- let e = leading_zeros_u16(half_man as u16) - 9;
-
- // Rebias and adjust exponent
- let exp = ((1023 - 127 - e) as u64) << 52;
- let man = (half_man << (46 + e)) & 0xF_FFFF_FFFF_FFFFu64;
- return unsafe { mem::transmute(sign | exp | man) };
- }
- // Rebias exponent for a normalized normal
- let exp = ((unbiased_exp + 1023) as u64) << 52;
- let man = (half_man & 0x007Fu64) << 45;
- unsafe { mem::transmute(sign | exp | man) }
-}