never_inline call modifier ignored

[vadim-za]

Zig Version

0.13.0

Steps to Reproduce and Observed Behavior

Take the following code and compile in ReleaseFast.

const std = @import("std");

const A = struct { data: usize = 0 };
const B = struct { data: *usize };

fn getA(a: *A) usize {
    const maybe_data: ?*usize = &a.data;
    return if (maybe_data) |data| data.* else 0xFFFF;
}

fn getB(b: *B) usize {
    const maybe_data: ?*usize = b.data;
    return if (maybe_data) |data| data.* else 0xFFFF;
}

pub fn main() void {
    var a = A{};
    var b = B{ .data = &a.data };
    std.mem.doNotOptimizeAway(&a);
    std.mem.doNotOptimizeAway(&b);
    @breakpoint();
    std.mem.doNotOptimizeAway(@call(.never_inline, getA, .{&a}));
    std.mem.doNotOptimizeAway(@call(.never_inline, getB, .{&b}));
}

Inspect the generated machine code at the breakpoint (so far reproed on x64). The call to getB is not inlined, as expected, but the call to getA has been fully inlined.

Expected Behavior

Both calls are not inlined.

Notes:

• The code is coming from here, but with the export keywords removed. I tried to strip down the repro further, but the compiler kept doing extra "smart things" in the optimized build, which was resulting in less demonstrative results.
• Could the issue be related to C backend hits unreachable compiling @call to lazy function with never_inline modifier #19905?