From 61e48a25dac28d1d63c0b084d448e18e07da34cc Mon Sep 17 00:00:00 2001 From: Trevor Gross Date: Sat, 14 Dec 2024 00:32:39 +0000 Subject: [PATCH] Windows x86: Change `i128` to return via the vector ABI Clang and GCC both return `i128` in xmm0 on windows-msvc and windows-gnu. Currently, Rust returns the type on the stack. Add a calling convention adjustment so we also return scalar `i128`s using the vector ABI, which makes our `i128` compatible with C. In the future, Clang may change to return `i128` on the stack for its `-msvc` targets (more at [1]). If this happens, the change here will need to be adjusted to only affect MinGW. Link: https://github.com/rust-lang/rust/issues/134288 --- src/abi/mod.rs | 22 +++++++++++++--------- src/cast.rs | 22 +++------------------- src/codegen_i128.rs | 30 ++++++++---------------------- 3 files changed, 24 insertions(+), 50 deletions(-) diff --git a/src/abi/mod.rs b/src/abi/mod.rs index 2466bfe60c7a..983584f58aba 100644 --- a/src/abi/mod.rs +++ b/src/abi/mod.rs @@ -122,7 +122,7 @@ impl<'tcx> FunctionCx<'_, '_, 'tcx> { &mut self, name: &str, params: Vec, - returns: Vec, + mut returns: Vec, args: &[Value], ) -> Cow<'_, [Value]> { // Pass i128 arguments by-ref on Windows. @@ -146,15 +146,19 @@ impl<'tcx> FunctionCx<'_, '_, 'tcx> { (params, args.into()) }; - // Return i128 using a return area pointer on Windows and s390x. - let adjust_ret_param = - if self.tcx.sess.target.is_like_windows || self.tcx.sess.target.arch == "s390x" { - returns.len() == 1 && returns[0].value_type == types::I128 - } else { - false - }; + let ret_single_i128 = returns.len() == 1 && returns[0].value_type == types::I128; + if ret_single_i128 && self.tcx.sess.target.is_like_windows { + // Return i128 using the vector ABI on Windows + returns[0].value_type = types::I64X2; - if adjust_ret_param { + let ret = self.lib_call_unadjusted(name, params, returns, &args)[0]; + + // FIXME(bytecodealliance/wasmtime#6104) use bitcast instead of store to get from i64x2 to i128 + let ret_ptr = self.create_stack_slot(16, 16); + ret_ptr.store(self, ret, MemFlags::trusted()); + Cow::Owned(vec![ret_ptr.load(self, types::I128, MemFlags::trusted())]) + } else if ret_single_i128 && self.tcx.sess.target.arch == "s390x" { + // Return i128 using a return area pointer on s390x. let mut params = params; let mut args = args.to_vec(); diff --git a/src/cast.rs b/src/cast.rs index 0b5cb1547fc6..4463631c524b 100644 --- a/src/cast.rs +++ b/src/cast.rs @@ -96,25 +96,9 @@ pub(crate) fn clif_int_or_float_cast( }, ); - if fx.tcx.sess.target.is_like_windows { - let ret = fx.lib_call( - &name, - vec![AbiParam::new(from_ty)], - vec![AbiParam::new(types::I64X2)], - &[from], - )[0]; - // FIXME(bytecodealliance/wasmtime#6104) use bitcast instead of store to get from i64x2 to i128 - let ret_ptr = fx.create_stack_slot(16, 16); - ret_ptr.store(fx, ret, MemFlags::trusted()); - ret_ptr.load(fx, types::I128, MemFlags::trusted()) - } else { - fx.lib_call( - &name, - vec![AbiParam::new(from_ty)], - vec![AbiParam::new(types::I128)], - &[from], - )[0] - } + fx.lib_call(&name, vec![AbiParam::new(from_ty)], vec![AbiParam::new(types::I128)], &[ + from, + ])[0] } else if to_ty == types::I8 || to_ty == types::I16 { // FIXME implement fcvt_to_*int_sat.i8/i16 let val = if to_signed { diff --git a/src/codegen_i128.rs b/src/codegen_i128.rs index dcfd7ddabbc4..df5a79086fa3 100644 --- a/src/codegen_i128.rs +++ b/src/codegen_i128.rs @@ -33,28 +33,14 @@ pub(crate) fn maybe_codegen<'tcx>( (BinOp::Rem, true) => "__modti3", _ => unreachable!(), }; - if fx.tcx.sess.target.is_like_windows { - let args = [lhs.load_scalar(fx), rhs.load_scalar(fx)]; - let ret = fx.lib_call( - name, - vec![AbiParam::new(types::I128), AbiParam::new(types::I128)], - vec![AbiParam::new(types::I64X2)], - &args, - )[0]; - // FIXME(bytecodealliance/wasmtime#6104) use bitcast instead of store to get from i64x2 to i128 - let ret_place = CPlace::new_stack_slot(fx, lhs.layout()); - ret_place.to_ptr().store(fx, ret, MemFlags::trusted()); - Some(ret_place.to_cvalue(fx)) - } else { - let args = [lhs.load_scalar(fx), rhs.load_scalar(fx)]; - let ret_val = fx.lib_call( - name, - vec![AbiParam::new(types::I128), AbiParam::new(types::I128)], - vec![AbiParam::new(types::I128)], - &args, - )[0]; - Some(CValue::by_val(ret_val, lhs.layout())) - } + let args = [lhs.load_scalar(fx), rhs.load_scalar(fx)]; + let ret_val = fx.lib_call( + name, + vec![AbiParam::new(types::I128), AbiParam::new(types::I128)], + vec![AbiParam::new(types::I128)], + &args, + )[0]; + Some(CValue::by_val(ret_val, lhs.layout())) } BinOp::Lt | BinOp::Le | BinOp::Eq | BinOp::Ge | BinOp::Gt | BinOp::Ne | BinOp::Cmp => None, BinOp::Shl | BinOp::ShlUnchecked | BinOp::Shr | BinOp::ShrUnchecked => None,