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const std = @import("std");
const builtin = @import("builtin");
const common = @import("common.zig");
const udivmod = @import("udivmodei4.zig").divmod;
comptime {
@export(&__divei4, .{ .name = "__divei4", .linkage = common.linkage, .visibility = common.visibility });
@export(&__modei4, .{ .name = "__modei4", .linkage = common.linkage, .visibility = common.visibility });
}
const endian = builtin.cpu.arch.endian();
inline fn limb(x: []u32, i: usize) *u32 {
return if (endian == .little) &x[i] else &x[x.len - 1 - i];
}
inline fn neg(x: []u32) void {
var ov: u1 = 1;
for (0..x.len) |limb_index| {
const l = limb(x, limb_index);
l.*, ov = @addWithOverflow(~l.*, ov);
}
}
/// Mutates the arguments!
fn divmod(q: ?[]u32, r: ?[]u32, u: []u32, v: []u32) !void {
const u_sign: i32 = @bitCast(u[u.len - 1]);
const v_sign: i32 = @bitCast(v[v.len - 1]);
if (u_sign < 0) neg(u);
if (v_sign < 0) neg(v);
try @call(.always_inline, udivmod, .{ q, r, u, v });
if (q) |x| if (u_sign ^ v_sign < 0) neg(x);
if (r) |x| if (u_sign < 0) neg(x);
}
pub fn __divei4(q_p: [*]u8, u_p: [*]u8, v_p: [*]u8, bits: usize) callconv(.c) void {
@setRuntimeSafety(common.test_safety);
const byte_size = std.zig.target.intByteSize(&builtin.target, @intCast(bits));
const q: []u32 = @ptrCast(@alignCast(q_p[0..byte_size]));
const u: []u32 = @ptrCast(@alignCast(u_p[0..byte_size]));
const v: []u32 = @ptrCast(@alignCast(v_p[0..byte_size]));
@call(.always_inline, divmod, .{ q, null, u, v }) catch unreachable;
}
pub fn __modei4(r_p: [*]u8, u_p: [*]u8, v_p: [*]u8, bits: usize) callconv(.c) void {
@setRuntimeSafety(common.test_safety);
const byte_size = std.zig.target.intByteSize(&builtin.target, @intCast(bits));
const r: []u32 = @ptrCast(@alignCast(r_p[0..byte_size]));
const u: []u32 = @ptrCast(@alignCast(u_p[0..byte_size]));
const v: []u32 = @ptrCast(@alignCast(v_p[0..byte_size]));
@call(.always_inline, divmod, .{ null, r, u, v }) catch unreachable;
}
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