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https://github.com/ziglang/zig.git
synced 2025-12-06 14:23:09 +00:00
f5edaa96dd
This moves functions that LLVM generates calls to, to the compiler_rt implementation itself, rather than c.zig. This is a prerequisite for native backends to link with compiler-rt. This also allows native backends to generate calls to `memcpy` and the like.
32 lines
908 B
Zig
32 lines
908 B
Zig
const std = @import("std");
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const common = @import("./common.zig");
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comptime {
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@export(memcmp, .{ .name = "memcmp", .linkage = common.linkage });
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}
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pub fn memcmp(vl: ?[*]const u8, vr: ?[*]const u8, n: usize) callconv(.C) c_int {
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@setRuntimeSafety(false);
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var index: usize = 0;
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while (index != n) : (index += 1) {
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const compare_val = @bitCast(i8, vl.?[index] -% vr.?[index]);
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if (compare_val != 0) {
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return compare_val;
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}
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}
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return 0;
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}
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test "memcmp" {
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const base_arr = &[_]u8{ 1, 1, 1 };
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const arr1 = &[_]u8{ 1, 1, 1 };
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const arr2 = &[_]u8{ 1, 0, 1 };
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const arr3 = &[_]u8{ 1, 2, 1 };
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try std.testing.expect(memcmp(base_arr[0..], arr1[0..], base_arr.len) == 0);
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try std.testing.expect(memcmp(base_arr[0..], arr2[0..], base_arr.len) > 0);
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try std.testing.expect(memcmp(base_arr[0..], arr3[0..], base_arr.len) < 0);
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}
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