diff options
| -rw-r--r-- | src/install/semver.zig | 83 |
1 files changed, 58 insertions, 25 deletions
diff --git a/src/install/semver.zig b/src/install/semver.zig index 794867f13..bb1e1a8aa 100644 --- a/src/install/semver.zig +++ b/src/install/semver.zig @@ -69,35 +69,68 @@ pub const String = extern struct { SlicedString.init(buf, this.slice(buf)); } + // https://en.wikipedia.org/wiki/Intel_5-level_paging + // https://developer.arm.com/documentation/101811/0101/Address-spaces-in-AArch64#:~:text=0%2DA%2C%20the%20maximum%20size,2%2DA. + // X64 seems to need some of the pointer bits + const max_addressable_space = u63; + + comptime { + if (@sizeOf(usize) != 8) { + @compileError("This code needs to be updated for non-64-bit architectures"); + } + } + pub fn init( buf: string, in: string, ) String { - switch (in.len) { - 0 => return String{}, - 1...max_inline_len => { - var bytes: [max_inline_len]u8 = [max_inline_len]u8{ 0, 0, 0, 0, 0, 0, 0, 0 }; - comptime var i: usize = 0; - - inline while (i < bytes.len) : (i += 1) { - if (i < in.len) bytes[i] = in[i]; - } - - // If they use the final bit, then it's a big string. - // This should only happen for non-ascii strings that are exactly 8 bytes. - // so that's an edge-case - if ((bytes[max_inline_len - 1]) >= 128) { - const ptr_ = Pointer.init(buf, in); - return @bitCast(String, @as(u64, @truncate(u63, @bitCast(u64, ptr_))) | 1 << 63); - } - - return String{ .bytes = bytes }; - }, - else => { - const ptr_ = Pointer.init(buf, in); - return @bitCast(String, @as(u64, @truncate(u63, @bitCast(u64, ptr_))) | 1 << 63); - }, - } + return switch (in.len) { + 0 => String{}, + 1 => String{ .bytes = .{ in[0], 0, 0, 0, 0, 0, 0, 0 } }, + 2 => String{ .bytes = .{ in[0], in[1], 0, 0, 0, 0, 0, 0 } }, + 3 => String{ .bytes = .{ in[0], in[1], in[2], 0, 0, 0, 0, 0 } }, + 4 => String{ .bytes = .{ in[0], in[1], in[2], in[3], 0, 0, 0, 0 } }, + 5 => String{ .bytes = .{ in[0], in[1], in[2], in[3], in[4], 0, 0, 0 } }, + 6 => String{ .bytes = .{ in[0], in[1], in[2], in[3], in[4], in[5], 0, 0 } }, + 7 => String{ .bytes = .{ in[0], in[1], in[2], in[3], in[4], in[5], in[6], 0 } }, + max_inline_len => + // If they use the final bit, then it's a big string. + // This should only happen for non-ascii strings that are exactly 8 bytes. + // so that's an edge-case + if ((in[max_inline_len - 1]) >= 128) + @bitCast(String, (@as( + u64, + 0, + ) | @as( + u64, + @truncate( + max_addressable_space, + @bitCast( + u64, + Pointer.init(buf, in), + ), + ), + )) | 1 << 63) + else + String{ .bytes = .{ in[0], in[1], in[2], in[3], in[4], in[5], in[6], in[7] } }, + + else => @bitCast( + String, + (@as( + u64, + 0, + ) | @as( + u64, + @truncate( + max_addressable_space, + @bitCast( + u64, + Pointer.init(buf, in), + ), + ), + )) | 1 << 63, + ), + }; } pub fn eql(this: String, that: String, this_buf: []const u8, that_buf: []const u8) bool { |