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allow in-memory coercion of differently-named floats with same bits

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For example, this allows passing a `*c_longdouble` where a `*f80` is
expected, provided that `c_longdouble` maps to `f80` for this target.
This commit is contained in:
Andrew Kelley
2022-05-08 13:05:16 -07:00
parent 663b67783e
commit 6fde2fcd51
3 changed files with 35 additions and 0 deletions
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20
test/behavior/cast.zig
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@@ -1426,3 +1426,23 @@ test "pointer to empty struct literal to mutable slice" {
var x: []i32 = &.{};
try expect(x.len == 0);
}
test "coerce between pointers of compatible differently-named floats" {
if (builtin.zig_backend == .stage2_c) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_aarch64) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_arm) return error.SkipZigTest; // TODO
if (builtin.zig_backend == .stage2_x86_64) return error.SkipZigTest; // TODO
const F = switch (@typeInfo(c_longdouble).Float.bits) {
16 => f16,
32 => f32,
64 => f64,
80 => f80,
128 => f128,
else => @compileError("unreachable"),
};
var f1: F = 12.34;
var f2: *c_longdouble = &f1;
f2.* += 1;
try expect(f1 == @as(F, 12.34) + 1);
}