Files
wasmtime/lib/codegen/src/legalizer/libcall.rs
Dan Gohman c21af29c79 Legalize libcall signatures.
Explicitly legalize signatures created for libcalls.
2018-05-29 10:21:52 -07:00

32 lines
1.1 KiB
Rust

//! Expanding instructions as runtime library calls.
use ir;
use ir::{get_libcall_funcref, InstBuilder};
use isa::TargetIsa;
use legalizer::boundary::legalize_libcall_signature;
use std::vec::Vec;
/// Try to expand `inst` as a library call, returning true is successful.
pub fn expand_as_libcall(inst: ir::Inst, func: &mut ir::Function, isa: &TargetIsa) -> bool {
// Does the opcode/ctrl_type combo even have a well-known runtime library name.
let libcall = match ir::LibCall::for_inst(func.dfg[inst].opcode(), func.dfg.ctrl_typevar(inst))
{
Some(lc) => lc,
None => return false,
};
// Now we convert `inst` to a call. First save the arguments.
let mut args = Vec::new();
args.extend_from_slice(func.dfg.inst_args(inst));
// The replace builder will preserve the instruction result values.
let funcref = get_libcall_funcref(libcall, func, inst, isa);
func.dfg.replace(inst).call(funcref, &args);
// Ask the ISA to legalize the signature.
let fn_data = &func.dfg.ext_funcs[funcref];
let sig_data = &mut func.dfg.signatures[fn_data.signature];
legalize_libcall_signature(sig_data, isa);
true
}