Integer width is asumed to be 32 bit at some points

[Jomosoto]

I'm building for a target that has an int width of 16 bit. Compilation fails at some points, because an integer width of 32 bit is assumed.

Here (and similar builtins just below):

rustc_codegen_gcc/src/int.rs

Lines 277 to 291 in 9aec231

	OverflowOp::Add => match new_kind {
	Int(I8) => "__builtin_add_overflow",
	Int(I16) => "__builtin_add_overflow",
	Int(I32) => "__builtin_sadd_overflow",
	Int(I64) => "__builtin_saddll_overflow",
	Int(I128) => "__builtin_add_overflow",
	Uint(U8) => "__builtin_add_overflow",
	Uint(U16) => "__builtin_add_overflow",
	Uint(U32) => "__builtin_uadd_overflow",
	Uint(U64) => "__builtin_uaddll_overflow",
	Uint(U128) => "__builtin_add_overflow",
	_ => unreachable!(),
	},

__builtin_s/uadd_overflow takes ints, but on my platform they are only 16 bit long.

And here:

rustc_codegen_gcc/src/builder.rs

Lines 1388 to 1393 in 9aec231

	let fill_byte = self.context.new_cast(self.location, fill_byte, self.i32_type);
	let size = self.intcast(size, self.type_size_t(), false);
	self.block.add_eval(
	self.location,
	self.context.new_call(self.location, memset, &[ptr, fill_byte, size]),
	);

memset takes an int, but the fill_byte is hardcoded to i32.

(PS: Thank you for your work! This project makes it possible to use rust on my architecture at all <3 )

[antoyo]

Thanks for reporting this issue!

Could you please share which architecture you test on so that I can try to make its support better?

[Jomosoto]

Sure: I'm testing on cr16 that was dropped and I reintroduced off tree for a project, but in tree there's m68k (with -mshort) and avr, that have the same int size.

[antoyo]

Ok. I'll take a look at AVR, but that might take some time before I do.