Files
sx/vendors/ffi_large_struct/ffi_large_struct.h
agra 2463eea1d4 ffi 0.3: large struct baseline (Big24, Big48) through sret return path
90/90 regression tests pass (+ffi-03-large-struct).

vendors/ffi_large_struct/{.h,.c} defines:
  Big24 — 24 B, three s64    (byval params + sret return)
  Big48 — 48 B, six s64      (same path, larger)

`make / rotate-or-reverse / sum` helpers per shape. The sx-side
example imports via `#source` only and declares matching structs +
hand-written #foreign decls.

Snapshot pins today's >16-byte aggregate ABI now that the
emit_llvm.zig sret-return transform is in place (previous commit).
That gives us a regression net for all four C-ABI aggregate slots
in one place:

  ≤8 B int       — i64 coercion          (ffi-01 vec-likes)
  9..16 B int    — [2 x i64] coercion    (ffi-02 Pair64/Quad32, 101)
  16 B HFA       — struct, no coercion    (ffi-02 Vec2/Vec4f)
  >16 B          — byval params + sret    (this commit)
2026-05-19 11:41:06 +03:00

23 lines
1.0 KiB
C

// FFI large-struct (>16 B) by-value roundtrips. These route through
// the byval-pointer ABI path (caller copies onto its stack, hands the
// callee a pointer; on AAPCS64 a separate `x8` indirect-return
// register; on SysV AMD64 a hidden first arg). Distinct from the
// register-pair / [2 x i64] / HFA paths the small-struct baseline
// covers — locking those in here keeps the byval path honest.
//
// Big24 — 24 B, three s64
// Big48 — 48 B, six s64
typedef struct { long long a; long long b; long long c; } Big24;
typedef struct { long long a; long long b; long long c;
long long d; long long e; long long f; } Big48;
Big24 ffi_big24_make (long long a, long long b, long long c);
Big24 ffi_big24_rotate(Big24 v);
long long ffi_big24_sum (Big24 v);
Big48 ffi_big48_make (long long a, long long b, long long c,
long long d, long long e, long long f);
Big48 ffi_big48_reverse(Big48 v);
long long ffi_big48_sum (Big48 v);