mirror of
https://github.com/ziglang/zig.git
synced 2025-12-07 06:43:07 +00:00
ec95e00e28
stage2: change logic for detecting whether the main package is inside
the std package. Previously it relied on realpath() which is not portable.
This uses resolve() which is how imports already work.
* stage2: fix cleanup bug when creating Module
* flatten lib/std/special/* to lib/*
- this was motivated by making main_pkg_is_inside_std false for
compiler_rt & friends.
* rename "mini libc" to "universal libc"
43 lines
1.1 KiB
Zig
43 lines
1.1 KiB
Zig
const std = @import("std");
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const builtin = @import("builtin");
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// parity - if number of bits set is even => 0, else => 1
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// - pariytXi2_generic for big and little endian
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inline fn parityXi2(comptime T: type, a: T) i32 {
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@setRuntimeSafety(builtin.is_test);
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var x = switch (@bitSizeOf(T)) {
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32 => @bitCast(u32, a),
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64 => @bitCast(u64, a),
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128 => @bitCast(u128, a),
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else => unreachable,
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};
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// Bit Twiddling Hacks: Compute parity in parallel
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comptime var shift: u8 = @bitSizeOf(T) / 2;
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inline while (shift > 2) {
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x ^= x >> shift;
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shift = shift >> 1;
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}
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x &= 0xf;
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return (@intCast(u16, 0x6996) >> @intCast(u4, x)) & 1; // optimization for >>2 and >>1
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}
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pub fn __paritysi2(a: i32) callconv(.C) i32 {
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return parityXi2(i32, a);
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}
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pub fn __paritydi2(a: i64) callconv(.C) i32 {
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return parityXi2(i64, a);
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}
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pub fn __parityti2(a: i128) callconv(.C) i32 {
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return parityXi2(i128, a);
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}
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test {
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_ = @import("paritysi2_test.zig");
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_ = @import("paritydi2_test.zig");
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_ = @import("parityti2_test.zig");
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}
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