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const common = @import("./common.zig");
const testing = @import("std").testing;
pub const panic = common.panic;
comptime {
@export(&__addvdi3, .{ .name = "__addvdi3", .linkage = common.linkage, .visibility = common.visibility });
}
pub fn __addvdi3(a: i64, b: i64) callconv(.c) i64 {
const sum = a +% b;
// Overflow occurred iff both operands have the same sign, and the sign of the sum does
// not match it. In other words, iff the sum sign is not the sign of either operand.
if (((sum ^ a) & (sum ^ b)) < 0) @panic("compiler-rt: integer overflow");
return sum;
}
test "addvdi3" {
// const min: i64 = -9223372036854775808
// const max: i64 = 9223372036854775807
// TODO write panic handler for testing panics
// try test__addvdi3(-9223372036854775808, -1, -1); // panic
// try test__addvdi3(9223372036854775807, 1, 1); // panic
try testing.expectEqual(-9223372036854775808, __addvdi3(-9223372036854775807, -1));
try testing.expectEqual(9223372036854775807, __addvdi3(9223372036854775806, 1));
}
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