This reinstates commit d7d829c059 with a fix for C tail-allocated arrays.
Replace a call of the getter of AnyKeyPath._storedInlineOffset with a "constant" offset, in case of a keypath literal.
"Constant" offset means a series of struct_element_addr and tuple_element_addr instructions with a 0-pointer as base address.
These instructions can then be lowered to "real" constants in IRGen for concrete types, or to metatype offset lookups for generic or resilient types.
Replace:
%kp = keypath ...
%offset = apply %_storedInlineOffset_method(%kp)
with:
%zero = integer_literal $Builtin.Word, 0
%null_ptr = unchecked_trivial_bit_cast %zero to $Builtin.RawPointer
%null_addr = pointer_to_address %null_ptr
%projected_addr = struct_element_addr %null_addr
... // other address projections
%offset_ptr = address_to_pointer %projected_addr
%offset_builtin_int = unchecked_trivial_bit_cast %offset_ptr
%offset_int = struct $Int (%offset_builtin_int)
%offset = enum $Optional<Int>, #Optional.some!enumelt, %offset_int
rdar://problem/53309403
Replace a call of the getter of AnyKeyPath._storedInlineOffset with a "constant" offset, in case of a keypath literal.
"Constant" offset means a series of struct_element_addr and tuple_element_addr instructions with a 0-pointer as base address.
These instructions can then be lowered to "real" constants in IRGen for concrete types, or to metatype offset lookups for generic or resilient types.
Replace:
%kp = keypath ...
%offset = apply %_storedInlineOffset_method(%kp)
with:
%zero = integer_literal $Builtin.Word, 0
%null_ptr = unchecked_trivial_bit_cast %zero to $Builtin.RawPointer
%null_addr = pointer_to_address %null_ptr
%projected_addr = struct_element_addr %null_addr
... // other address projections
%offset_ptr = address_to_pointer %projected_addr
%offset_builtin_int = unchecked_trivial_bit_cast %offset_ptr
%offset_int = struct $Int (%offset_builtin_int)
%offset = enum $Optional<Int>, #Optional.some!enumelt, %offset_int
rdar://problem/53309403
