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x64 and aarch64: allow StructArgument and StructReturn args.

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The StructReturn ABI is fairly simple at the codegen/isel level: we only
need to take care to return the sret pointer as one of the return values
if that wasn't specified in the initial function signature.

Struct arguments are a little more complex. A struct argument is stored
as a chunk of memory in the stack-args space. However, the CLIF
semantics are slightly special: on the caller side, the parameter passed
in is a pointer to an arbitrary memory block, and we must memcpy this
data to the on-stack struct-argument; and on the callee side, we provide
a pointer to the passed-in struct-argument as the CLIF block param
value.

This is necessary to support various ABIs other than Wasm, such as that
of Rust (with the cg_clif codegen backend).
This commit is contained in:
Chris Fallin
2020-12-13 18:50:59 -08:00
parent 25088dee9d
commit 456561f431
14 changed files with 641 additions and 166 deletions
Download Patch File Download Diff File Expand all files Collapse all files

11
cranelift/codegen/src/isa/aarch64/lower_inst.rs
View File

@@ -7,6 +7,7 @@ use crate::ir::Inst as IRInst;
use crate::ir::{InstructionData, Opcode, TrapCode};
use crate::machinst::lower::*;
use crate::machinst::*;
use crate::settings::Flags;
use crate::{CodegenError, CodegenResult};
use crate::isa::aarch64::abi::*;
@@ -24,6 +25,7 @@ use super::lower::*;
pub(crate) fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
ctx: &mut C,
insn: IRInst,
flags: &Flags,
) -> CodegenResult<()> {
let op = ctx.data(insn).opcode();
let inputs = insn_inputs(ctx, insn);
@@ -1803,7 +1805,7 @@ pub(crate) fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
assert!(inputs.len() == sig.params.len());
assert!(outputs.len() == sig.returns.len());
(
AArch64ABICaller::from_func(sig, &extname, dist, caller_conv)?,
AArch64ABICaller::from_func(sig, &extname, dist, caller_conv, flags)?,
&inputs[..],
)
}
@@ -1813,7 +1815,7 @@ pub(crate) fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
assert!(inputs.len() - 1 == sig.params.len());
assert!(outputs.len() == sig.returns.len());
(
AArch64ABICaller::from_ptr(sig, ptr, op, caller_conv)?,
AArch64ABICaller::from_ptr(sig, ptr, op, caller_conv, flags)?,
&inputs[1..],
)
}
@@ -1822,8 +1824,9 @@ pub(crate) fn lower_insn_to_regs<C: LowerCtx<I = Inst>>(
abi.emit_stack_pre_adjust(ctx);
assert!(inputs.len() == abi.num_args());
for (i, input) in inputs.iter().enumerate() {
let arg_reg = put_input_in_reg(ctx, *input, NarrowValueMode::None);
for i in abi.get_copy_to_arg_order() {
let input = inputs[i];
let arg_reg = put_input_in_reg(ctx, input, NarrowValueMode::None);
abi.emit_copy_regs_to_arg(ctx, i, ValueRegs::one(arg_reg));
}
abi.emit_call(ctx);