36e929101b
Surfaced while writing the ffi-02-small-struct.sx baseline. The sx
#foreign decl lowers `{ s64, s64 }` (and other 16-byte integer-only
shapes like `{ s32, s32, s32, s32 }`) to `[2 x i64]` for the small-
struct register-pair ABI on AAPCS64 / SysV AMD64, but the call site
loads the struct as `{ i64, i64 }`. The two types must agree for the
LLVM verifier to accept the call:
Call parameter type does not match function signature!
%load = load { i64, i64 }, ptr %alloca, align 8
[2 x i64] %call = call [2 x i64] @issue0036_swap({ i64, i64 } %load)
Float-only 16-byte aggregates (e.g. Vec4f) work because they route
through the HFA path which keeps the struct representation. See
examples/ffi-02-small-struct.sx for the working cases.
Phase 1's #foreign lowering rework is the natural place to unify
these representations; check there before fixing inline.
39 lines
1.3 KiB
Plaintext
39 lines
1.3 KiB
Plaintext
// 16-byte integer-only struct by value through `#foreign` trips
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// the LLVM verifier:
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//
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// Call parameter type does not match function signature!
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// %loadN = load { i64, i64 }, ptr %allocaM, align 8
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// [2 x i64] %callN = call [2 x i64] @issue0036_swap({ i64, i64 } %load...)
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//
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// The foreign-decl side lowers `Pair64` to `[2 x i64]` (ABI-coercion
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// for the small-struct register-pair return on AAPCS64 / SysV AMD64),
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// while the call site loads the sx struct as `{ i64, i64 }`. The two
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// representations need to agree.
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//
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// Float-only aggregates of the same total size (e.g. Vec4f, 4×f32 =
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// 16 B) work today because they're routed through the HFA path which
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// keeps the struct representation. See `examples/ffi-02-small-struct.sx`
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// for the working cases.
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//
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// Expected once fixed: print "ok = true" with exit 0. Today this
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// example fails at codegen with a non-zero exit; the snapshot captures
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// that failure so the test suite stays honest.
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#import "modules/std.sx";
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#import c {
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#source "vendors/issue_0036/issue_0036.c";
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};
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Pair64 :: struct { a: s64; b: s64; }
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issue0036_swap :: (p: Pair64) -> Pair64 #foreign;
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main :: () -> s32 {
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p : Pair64 = .{ a = 1, b = 2 };
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q := issue0036_swap(p);
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print("swap = ({}, {})\n", q.a, q.b);
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print("ok = {}\n", q.a == 2 and q.b == 1);
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0;
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}
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