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