1fdb24827f
* `@clz`, `@ctz`, `@popCount`, `@bswap`, `@bitreverse` now have a type parameter * rename @bitreverse to @bitReverse * rename @bswap to @byteSwap Closes #2119 Closes #2120
30 lines
844 B
Zig
30 lines
844 B
Zig
const builtin = @import("builtin");
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const is_test = builtin.is_test;
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const std = @import("std");
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pub extern fn __floatunsitf(a: u64) f128 {
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@setRuntimeSafety(is_test);
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if (a == 0) {
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return 0;
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}
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const mantissa_bits = std.math.floatMantissaBits(f128);
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const exponent_bits = std.math.floatExponentBits(f128);
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const exponent_bias = (1 << (exponent_bits - 1)) - 1;
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const implicit_bit = 1 << mantissa_bits;
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const exp = (u64.bit_count - 1) - @clz(u64, a);
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const shift = mantissa_bits - @intCast(u7, exp);
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// TODO(#1148): @bitCast alignment error
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var result align(16) = (@intCast(u128, a) << shift) ^ implicit_bit;
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result += (@intCast(u128, exp) + exponent_bias) << mantissa_bits;
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return @bitCast(f128, result);
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}
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test "import floatunsitf" {
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_ = @import("floatunsitf_test.zig");
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}
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