1//! negv - negate oVerflow
 2//! * @panic, if result can not be represented
 3//! - negvXi4_generic for unoptimized version
 4const std = @import("std");
 5const builtin = @import("builtin");
 6const common = @import("common.zig");
 7
 8pub const panic = common.panic;
 9
10comptime {
11    @export(&__negvsi2, .{ .name = "__negvsi2", .linkage = common.linkage, .visibility = common.visibility });
12    @export(&__negvdi2, .{ .name = "__negvdi2", .linkage = common.linkage, .visibility = common.visibility });
13    @export(&__negvti2, .{ .name = "__negvti2", .linkage = common.linkage, .visibility = common.visibility });
14}
15
16pub fn __negvsi2(a: i32) callconv(.c) i32 {
17    return negvXi(i32, a);
18}
19
20pub fn __negvdi2(a: i64) callconv(.c) i64 {
21    return negvXi(i64, a);
22}
23
24pub fn __negvti2(a: i128) callconv(.c) i128 {
25    return negvXi(i128, a);
26}
27
28inline fn negvXi(comptime ST: type, a: ST) ST {
29    const UT = switch (ST) {
30        i32 => u32,
31        i64 => u64,
32        i128 => u128,
33        else => unreachable,
34    };
35    const N: UT = @bitSizeOf(ST);
36    const min: ST = @as(ST, @bitCast((@as(UT, 1) << (N - 1))));
37    if (a == min)
38        @panic("compiler_rt negv: overflow");
39    return -a;
40}
41
42test {
43    _ = @import("negvsi2_test.zig");
44    _ = @import("negvdi2_test.zig");
45    _ = @import("negvti2_test.zig");
46}