34 lines
1.1 KiB
Zig
34 lines
1.1 KiB
Zig
// Ported from:
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//
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// https://github.com/llvm/llvm-project/blob/2ffb1b0413efa9a24eb3c49e710e36f92e2cb50b/compiler-rt/lib/builtins/modti3.c
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const udivmod = @import("udivmod.zig").udivmod;
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const builtin = @import("builtin");
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const compiler_rt = @import("../compiler_rt.zig");
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pub fn __modti3(a: i128, b: i128) callconv(.C) i128 {
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@setRuntimeSafety(builtin.is_test);
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const s_a = a >> (i128.bit_count - 1); // s = a < 0 ? -1 : 0
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const s_b = b >> (i128.bit_count - 1); // s = b < 0 ? -1 : 0
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const an = (a ^ s_a) -% s_a; // negate if s == -1
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const bn = (b ^ s_b) -% s_b; // negate if s == -1
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var r: u128 = undefined;
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_ = udivmod(u128, @bitCast(u128, an), @bitCast(u128, bn), &r);
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return (@bitCast(i128, r) ^ s_a) -% s_a; // negate if s == -1
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}
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const v128 = @Vector(2, u64);
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pub fn __modti3_windows_x86_64(a: v128, b: v128) callconv(.C) v128 {
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return @bitCast(v128, @call(.{ .modifier = .always_inline }, __modti3, .{
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@bitCast(i128, a),
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@bitCast(i128, b),
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}));
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}
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test "import modti3" {
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_ = @import("modti3_test.zig");
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}
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