compiler_rt: add __negvsi2, __negvdi2, __negvti2
- neg can only overflow, if a == MIN
- case `-0` is properly handled by hardware, so overflow check by comparing
`a == MIN` is sufficient
- tests: MIN, MIN+1, MIN+4, -42, -7, -1, 0, 1, 7..
See #1290
2021-12-12 21:25:29 +00:00
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const negv = @import("negv.zig");
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const testing = @import("std").testing;
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fn test__negvti2(a: i128, expected: i128) !void {
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2023-11-10 05:27:17 +00:00
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const result = negv.__negvti2(a);
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compiler_rt: add __negvsi2, __negvdi2, __negvti2
- neg can only overflow, if a == MIN
- case `-0` is properly handled by hardware, so overflow check by comparing
`a == MIN` is sufficient
- tests: MIN, MIN+1, MIN+4, -42, -7, -1, 0, 1, 7..
See #1290
2021-12-12 21:25:29 +00:00
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try testing.expectEqual(expected, result);
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}
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test "negvti2" {
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// -2^127 <= i128 <= 2^127-1
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// 2^127 = 170141183460469231731687303715884105728
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// 2^127+1 = 170141183460469231731687303715884105727
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// TODO write panic handler for testing panics
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//try test__negvti2(-170141183460469231731687303715884105728, -5); // tested with return -5; and panic
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try test__negvti2(-170141183460469231731687303715884105727, 170141183460469231731687303715884105727);
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try test__negvti2(-170141183460469231731687303715884105726, 170141183460469231731687303715884105726);
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try test__negvti2(-170141183460469231731687303715884105725, 170141183460469231731687303715884105725);
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try test__negvti2(-170141183460469231731687303715884105724, 170141183460469231731687303715884105724);
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try test__negvti2(-42, 42);
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try test__negvti2(-7, 7);
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try test__negvti2(-1, 1);
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try test__negvti2(0, 0);
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try test__negvti2(1, -1);
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try test__negvti2(7, -7);
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try test__negvti2(42, -42);
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try test__negvti2(170141183460469231731687303715884105724, -170141183460469231731687303715884105724);
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try test__negvti2(170141183460469231731687303715884105725, -170141183460469231731687303715884105725);
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try test__negvti2(170141183460469231731687303715884105726, -170141183460469231731687303715884105726);
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try test__negvti2(170141183460469231731687303715884105727, -170141183460469231731687303715884105727);
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}
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