diff --git a/src/stage1/analyze.cpp b/src/stage1/analyze.cpp index 21ad55b8f7..e1e0c496f6 100644 --- a/src/stage1/analyze.cpp +++ b/src/stage1/analyze.cpp @@ -4770,10 +4770,10 @@ Error type_is_nonnull_ptr2(CodeGen *g, ZigType *type, bool *result) { } static uint32_t get_async_frame_align_bytes(CodeGen *g) { - uint32_t a = g->pointer_size_bytes * 2; - // promises have at least alignment 8 so that we can have 3 extra bits when doing atomicrmw - if (a < 8) a = 8; - return a; + // Due to how the frame structure is built the minimum alignment is the one + // of a usize (or pointer). + // label (grep this): [fn_frame_struct_layout] + return max(g->builtin_types.entry_usize->abi_align, target_fn_align(g->zig_target)); } uint32_t get_ptr_align(CodeGen *g, ZigType *type) { @@ -4789,11 +4789,8 @@ uint32_t get_ptr_align(CodeGen *g, ZigType *type) { return (ptr_type->data.pointer.explicit_alignment == 0) ? get_abi_alignment(g, ptr_type->data.pointer.child_type) : ptr_type->data.pointer.explicit_alignment; } else if (ptr_type->id == ZigTypeIdFn) { - // I tried making this use LLVMABIAlignmentOfType but it trips this assertion in LLVM: - // "Cannot getTypeInfo() on a type that is unsized!" - // when getting the alignment of `?fn() callconv(.C) void`. - // See http://lists.llvm.org/pipermail/llvm-dev/2018-September/126142.html - return (ptr_type->data.fn.fn_type_id.alignment == 0) ? 1 : ptr_type->data.fn.fn_type_id.alignment; + return (ptr_type->data.fn.fn_type_id.alignment == 0) ? + target_fn_ptr_align(g->zig_target) : ptr_type->data.fn.fn_type_id.alignment; } else if (ptr_type->id == ZigTypeIdAnyFrame) { return get_async_frame_align_bytes(g); } else { diff --git a/src/stage1/ir.cpp b/src/stage1/ir.cpp index c59f63399c..176d50dc72 100644 --- a/src/stage1/ir.cpp +++ b/src/stage1/ir.cpp @@ -26079,11 +26079,11 @@ static Error ir_make_type_info_value(IrAnalyze *ira, IrInst* source_instr, ZigTy fields[0]->special = ConstValSpecialStatic; fields[0]->type = get_builtin_type(ira->codegen, "CallingConvention"); bigint_init_unsigned(&fields[0]->data.x_enum_tag, type_entry->data.fn.fn_type_id.cc); - // alignment: u29 + // alignment: comptime_int ensure_field_index(result->type, "alignment", 1); fields[1]->special = ConstValSpecialStatic; fields[1]->type = ira->codegen->builtin_types.entry_num_lit_int; - bigint_init_unsigned(&fields[1]->data.x_bigint, type_entry->data.fn.fn_type_id.alignment); + bigint_init_unsigned(&fields[1]->data.x_bigint, get_ptr_align(ira->codegen, type_entry)); // is_generic: bool ensure_field_index(result->type, "is_generic", 2); bool is_generic = type_entry->data.fn.is_generic; diff --git a/src/stage1/target.cpp b/src/stage1/target.cpp index 028f6e5fa8..6aa3cfcbd0 100644 --- a/src/stage1/target.cpp +++ b/src/stage1/target.cpp @@ -1253,6 +1253,37 @@ bool target_is_ppc(const ZigTarget *target) { target->arch == ZigLLVM_ppc64le; } -unsigned target_fn_align(const ZigTarget *target) { - return 16; +// Returns the minimum alignment for every function pointer on the given +// architecture. +unsigned target_fn_ptr_align(const ZigTarget *target) { + // TODO This is a pessimization but is always correct. + return 1; +} + +// Returns the minimum alignment for every function on the given architecture. +unsigned target_fn_align(const ZigTarget *target) { + switch (target->arch) { + case ZigLLVM_riscv32: + case ZigLLVM_riscv64: + // TODO If the C extension is not present the value is 4. + return 2; + case ZigLLVM_ppc: + case ZigLLVM_ppcle: + case ZigLLVM_ppc64: + case ZigLLVM_ppc64le: + case ZigLLVM_aarch64: + case ZigLLVM_aarch64_be: + case ZigLLVM_aarch64_32: + case ZigLLVM_sparc: + case ZigLLVM_sparcel: + case ZigLLVM_sparcv9: + case ZigLLVM_mips: + case ZigLLVM_mipsel: + case ZigLLVM_mips64: + case ZigLLVM_mips64el: + return 4; + + default: + return 1; + } } diff --git a/src/stage1/target.hpp b/src/stage1/target.hpp index 099c3c1e78..362d63eb32 100644 --- a/src/stage1/target.hpp +++ b/src/stage1/target.hpp @@ -98,6 +98,7 @@ size_t target_libc_count(void); void target_libc_enum(size_t index, ZigTarget *out_target); bool target_libc_needs_crti_crtn(const ZigTarget *target); +unsigned target_fn_ptr_align(const ZigTarget *target); unsigned target_fn_align(const ZigTarget *target); #endif diff --git a/test/stage1/behavior/type_info.zig b/test/stage1/behavior/type_info.zig index 6dec7ca4d2..f944b7904c 100644 --- a/test/stage1/behavior/type_info.zig +++ b/test/stage1/behavior/type_info.zig @@ -306,7 +306,7 @@ test "type info: function type info" { fn testFunction() void { const fn_info = @typeInfo(@TypeOf(foo)); expect(fn_info == .Fn); - expect(fn_info.Fn.alignment == 0); + expect(fn_info.Fn.alignment > 0); expect(fn_info.Fn.calling_convention == .C); expect(!fn_info.Fn.is_generic); expect(fn_info.Fn.args.len == 2);