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f26dda2117
Most of this migration was performed automatically with `zig fmt`. There were a few exceptions which I had to manually fix: * `@alignCast` and `@addrSpaceCast` cannot be automatically rewritten * `@truncate`'s fixup is incorrect for vectors * Test cases are not formatted, and their error locations change
34 lines
991 B
Zig
34 lines
991 B
Zig
const math = @import("std").math;
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// Reverse bit-by-bit a N-bit code.
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pub fn bitReverse(comptime T: type, value: T, N: usize) T {
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const r = @bitReverse(value);
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return r >> @as(math.Log2Int(T), @intCast(@typeInfo(T).Int.bits - N));
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}
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test "bitReverse" {
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const std = @import("std");
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const ReverseBitsTest = struct {
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in: u16,
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bit_count: u5,
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out: u16,
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};
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var reverse_bits_tests = [_]ReverseBitsTest{
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.{ .in = 1, .bit_count = 1, .out = 1 },
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.{ .in = 1, .bit_count = 2, .out = 2 },
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.{ .in = 1, .bit_count = 3, .out = 4 },
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.{ .in = 1, .bit_count = 4, .out = 8 },
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.{ .in = 1, .bit_count = 5, .out = 16 },
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.{ .in = 17, .bit_count = 5, .out = 17 },
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.{ .in = 257, .bit_count = 9, .out = 257 },
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.{ .in = 29, .bit_count = 5, .out = 23 },
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};
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for (reverse_bits_tests) |h| {
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var v = bitReverse(u16, h.in, h.bit_count);
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try std.testing.expectEqual(h.out, v);
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}
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}
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