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Pass ByRef values at fixed stack offset for extern "C" #1068

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Merged
merged 1 commit into from
Jul 17, 2020
Merged

Pass ByRef values at fixed stack offset for extern "C" #1068

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44 changes: 22 additions & 22 deletions Cargo.lock
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2 changes: 1 addition & 1 deletion cargo.sh
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Expand Up @@ -20,4 +20,4 @@ fi
cmd=$1
shift

cargo +${TOOLCHAIN} $cmd --target $TARGET_TRIPLE $@
cargo +${TOOLCHAIN} $cmd $@
22 changes: 13 additions & 9 deletions src/abi/mod.rs
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Expand Up @@ -6,7 +6,7 @@ mod returning;
use rustc_target::spec::abi::Abi;
use rustc_middle::middle::codegen_fn_attrs::CodegenFnAttrFlags;

use cranelift_codegen::ir::AbiParam;
use cranelift_codegen::ir::{AbiParam, ArgumentPurpose};

use self::pass_mode::*;
use crate::prelude::*;
Expand Down Expand Up @@ -123,7 +123,11 @@ fn clif_sig_from_fn_sig<'tcx>(
if abi != Abi::Rust && abi != Abi::RustCall && abi != Abi::RustIntrinsic {
match pass_mode {
PassMode::NoPass | PassMode::ByVal(_) => {}
PassMode::ByValPair(_, _) | PassMode::ByRef { sized: _ } => {
PassMode::ByRef { size: Some(size) } => {
let purpose = ArgumentPurpose::StructArgument(u32::try_from(size.bytes()).expect("struct too big to pass on stack"));
return EmptySinglePair::Single(AbiParam::special(pointer_ty(tcx), purpose)).into_iter();
}
PassMode::ByValPair(_, _) | PassMode::ByRef { size: None } => {
tcx.sess.span_warn(
span,
&format!(
Expand All @@ -137,34 +141,34 @@ fn clif_sig_from_fn_sig<'tcx>(
}
}
}
pass_mode.get_param_ty(tcx).into_iter()
pass_mode.get_param_ty(tcx).map(AbiParam::new).into_iter()
})
.flatten();

let (mut params, returns): (Vec<_>, Vec<_>) = match get_pass_mode(
tcx,
tcx.layout_of(ParamEnv::reveal_all().and(output)).unwrap(),
) {
PassMode::NoPass => (inputs.map(AbiParam::new).collect(), vec![]),
PassMode::NoPass => (inputs.collect(), vec![]),
PassMode::ByVal(ret_ty) => (
inputs.map(AbiParam::new).collect(),
inputs.collect(),
vec![AbiParam::new(ret_ty)],
),
PassMode::ByValPair(ret_ty_a, ret_ty_b) => (
inputs.map(AbiParam::new).collect(),
inputs.collect(),
vec![AbiParam::new(ret_ty_a), AbiParam::new(ret_ty_b)],
),
PassMode::ByRef { sized: true } => {
PassMode::ByRef { size: Some(_) } => {
(
Some(pointer_ty(tcx)) // First param is place to put return val
.into_iter()
.map(|ty| AbiParam::special(ty, ArgumentPurpose::StructReturn))
.chain(inputs)
.map(AbiParam::new)
.collect(),
vec![],
)
}
PassMode::ByRef { sized: false } => todo!(),
PassMode::ByRef { size: None } => todo!(),
};

if requires_caller_location {
Expand Down
19 changes: 10 additions & 9 deletions src/abi/pass_mode.rs
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Expand Up @@ -7,7 +7,7 @@ pub(super) enum PassMode {
NoPass,
ByVal(Type),
ByValPair(Type, Type),
ByRef { sized: bool },
ByRef { size: Option<Size> },
}

#[derive(Copy, Clone, Debug)]
Expand Down Expand Up @@ -70,8 +70,8 @@ impl PassMode {
PassMode::NoPass => Empty,
PassMode::ByVal(clif_type) => Single(clif_type),
PassMode::ByValPair(a, b) => Pair(a, b),
PassMode::ByRef { sized: true } => Single(pointer_ty(tcx)),
PassMode::ByRef { sized: false } => Pair(pointer_ty(tcx), pointer_ty(tcx)),
PassMode::ByRef { size: Some(_) } => Single(pointer_ty(tcx)),
PassMode::ByRef { size: None } => Pair(pointer_ty(tcx), pointer_ty(tcx)),
}
}
}
Expand All @@ -93,16 +93,17 @@ pub(super) fn get_pass_mode<'tcx>(tcx: TyCtxt<'tcx>, layout: TyAndLayout<'tcx>)
// Returning (i128, i128) by-val-pair would take 4 regs, while only 3 are
// available on x86_64. Cranelift gets confused when too many return params
// are used.
PassMode::ByRef { sized: true }
PassMode::ByRef { size: Some(layout.size) }
} else {
PassMode::ByValPair(a, b)
}
}

// FIXME implement Vector Abi in a cg_llvm compatible way
Abi::Vector { .. } => PassMode::ByRef { sized: true },
Abi::Vector { .. } => PassMode::ByRef { size: Some(layout.size) },

&Abi::Aggregate { sized } => PassMode::ByRef { sized },
Abi::Aggregate { sized: true } => PassMode::ByRef { size: Some(layout.size) },
Abi::Aggregate { sized: false } => PassMode::ByRef { size: None },
}
}
}
Expand All @@ -118,7 +119,7 @@ pub(super) fn adjust_arg_for_abi<'tcx>(
let (a, b) = arg.load_scalar_pair(fx);
Pair(a, b)
}
PassMode::ByRef { sized: _ } => {
PassMode::ByRef { size: _ } => {
match arg.force_stack(fx) {
(ptr, None) => Single(ptr.get_addr(fx)),
(ptr, Some(meta)) => Pair(ptr.get_addr(fx), meta),
Expand Down Expand Up @@ -164,8 +165,8 @@ pub(super) fn cvalue_for_param<'tcx>(
let (a, b) = block_params.assert_pair();
Some(CValue::by_val_pair(a, b, layout))
}
PassMode::ByRef { sized: true } => Some(CValue::by_ref(Pointer::new(block_params.assert_single()), layout)),
PassMode::ByRef { sized: false } => {
PassMode::ByRef { size: Some(_) } => Some(CValue::by_ref(Pointer::new(block_params.assert_single()), layout)),
PassMode::ByRef { size: None } => {
let (ptr, meta) = block_params.assert_pair();
Some(CValue::by_ref_unsized(Pointer::new(ptr), meta, layout))
}
Expand Down
20 changes: 10 additions & 10 deletions src/abi/returning.rs
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Expand Up @@ -9,7 +9,7 @@ pub(crate) fn can_return_to_ssa_var<'tcx>(tcx: TyCtxt<'tcx>, dest_layout: TyAndL
match get_pass_mode(tcx, dest_layout) {
PassMode::NoPass | PassMode::ByVal(_) => true,
// FIXME Make it possible to return ByValPair and ByRef to an ssa var.
PassMode::ByValPair(_, _) | PassMode::ByRef { sized: _ } => false
PassMode::ByValPair(_, _) | PassMode::ByRef { size: _ } => false
}
}

Expand All @@ -33,14 +33,14 @@ pub(super) fn codegen_return_param(

Empty
}
PassMode::ByRef { sized: true } => {
PassMode::ByRef { size: Some(_) } => {
let ret_param = fx.bcx.append_block_param(start_block, fx.pointer_type);
fx.local_map
.insert(RETURN_PLACE, CPlace::for_ptr(Pointer::new(ret_param), ret_layout));

Single(ret_param)
}
PassMode::ByRef { sized: false } => todo!(),
PassMode::ByRef { size: None } => todo!(),
};

#[cfg(not(debug_assertions))]
Expand Down Expand Up @@ -69,11 +69,11 @@ pub(super) fn codegen_with_call_return_arg<'tcx, B: Backend, T>(
let output_pass_mode = get_pass_mode(fx.tcx, ret_layout);
let return_ptr = match output_pass_mode {
PassMode::NoPass => None,
PassMode::ByRef { sized: true } => match ret_place {
PassMode::ByRef { size: Some(_)} => match ret_place {
Some(ret_place) => Some(ret_place.to_ptr().get_addr(fx)),
None => Some(fx.bcx.ins().iconst(fx.pointer_type, 43)),
None => Some(fx.bcx.ins().iconst(fx.pointer_type, 43)), // FIXME allocate temp stack slot
},
PassMode::ByRef { sized: false } => todo!(),
PassMode::ByRef { size: None } => todo!(),
PassMode::ByVal(_) | PassMode::ByValPair(_, _) => None,
};

Expand All @@ -94,19 +94,19 @@ pub(super) fn codegen_with_call_return_arg<'tcx, B: Backend, T>(
ret_place.write_cvalue(fx, CValue::by_val_pair(ret_val_a, ret_val_b, ret_layout));
}
}
PassMode::ByRef { sized: true } => {}
PassMode::ByRef { sized: false } => todo!(),
PassMode::ByRef { size: Some(_) } => {}
PassMode::ByRef { size: None } => todo!(),
}

(call_inst, meta)
}

pub(crate) fn codegen_return(fx: &mut FunctionCx<'_, '_, impl Backend>) {
match get_pass_mode(fx.tcx, return_layout(fx)) {
PassMode::NoPass | PassMode::ByRef { sized: true } => {
PassMode::NoPass | PassMode::ByRef { size: Some(_) } => {
fx.bcx.ins().return_(&[]);
}
PassMode::ByRef { sized: false } => todo!(),
PassMode::ByRef { size: None } => todo!(),
PassMode::ByVal(_) => {
let place = fx.get_local_place(RETURN_PLACE);
let ret_val = place.to_cvalue(fx).load_scalar(fx);
Expand Down
1 change: 1 addition & 0 deletions src/debuginfo/mod.rs
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Expand Up @@ -313,6 +313,7 @@ impl<'tcx> DebugContext<'tcx> {
use cranelift_codegen::ir::ArgumentPurpose;
let base_name = match param.purpose {
ArgumentPurpose::Normal => "arg",
ArgumentPurpose::StructArgument(_) => "struct_arg",
ArgumentPurpose::StructReturn => "sret",
ArgumentPurpose::Link | ArgumentPurpose::FramePointer | ArgumentPurpose::CalleeSaved => continue,
ArgumentPurpose::VMContext | ArgumentPurpose::SignatureId | ArgumentPurpose::StackLimit => unreachable!(),
Expand Down
6 changes: 3 additions & 3 deletions test.sh
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Expand Up @@ -74,12 +74,12 @@ $RUSTC example/mod_bench.rs --crate-type bin --target $TARGET_TRIPLE
pushd simple-raytracer
if [[ "$HOST_TRIPLE" = "$TARGET_TRIPLE" ]]; then
echo "[BENCH COMPILE] ebobby/simple-raytracer"
hyperfine --runs ${RUN_RUNS:-10} --warmup 1 --prepare "rm -r target/*/debug || true" \
"RUSTFLAGS='' cargo build --target $TARGET_TRIPLE" \
hyperfine --runs ${RUN_RUNS:-10} --warmup 1 --prepare "cargo clean" \
"RUSTFLAGS='' cargo build" \
"../cargo.sh build"

echo "[BENCH RUN] ebobby/simple-raytracer"
cp ./target/*/debug/main ./raytracer_cg_clif
cp ./target/debug/main ./raytracer_cg_clif
hyperfine --runs ${RUN_RUNS:-10} ./raytracer_cg_llvm ./raytracer_cg_clif
else
echo "[BENCH COMPILE] ebobby/simple-raytracer (skipped)"
Expand Down