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Merge pull request #1494 from cfallin/arm64-merge

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Add new `MachInst` backend and ARM64 support.
This commit is contained in:
Chris Fallin
2020-04-16 10:02:02 -07:00
committed by GitHub
parent c268704743 48cf2c2f50
commit 7da6101732
63 changed files with 16668 additions and 322 deletions
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33
crates/jit/src/link.rs
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@@ -2,7 +2,7 @@
use crate::Compilation;
use cranelift_codegen::binemit::Reloc;
use std::ptr::write_unaligned;
use std::ptr::{read_unaligned, write_unaligned};
use wasmtime_environ::{Module, Relocation, RelocationTarget};
use wasmtime_runtime::libcalls;
use wasmtime_runtime::VMFunctionBody;
@@ -101,6 +101,23 @@ fn apply_reloc(
Reloc::X86PCRelRodata4 => {
// ignore
}
Reloc::Arm64Call => unsafe {
let reloc_address = body.add(r.offset as usize) as usize;
let reloc_addend = r.addend as isize;
let reloc_delta = (target_func_address as u64).wrapping_sub(reloc_address as u64);
// TODO: come up with a PLT-like solution for longer calls. We can't extend the
// code segment at this point, but we could conservatively allocate space at the
// end of the function during codegen, a fixed amount per call, to allow for
// potential branch islands.
assert!((reloc_delta as i64) < (1 << 27));
assert!((reloc_delta as i64) >= -(1 << 27));
let reloc_delta = reloc_delta as u32;
let reloc_delta = reloc_delta.wrapping_add(reloc_addend as u32);
let delta_bits = reloc_delta >> 2;
let insn = read_unaligned(reloc_address as *const u32);
let new_insn = (insn & 0xfc00_0000) | (delta_bits & 0x03ff_ffff);
write_unaligned(reloc_address as *mut u32, new_insn);
},
_ => panic!("unsupported reloc kind"),
}
}
@@ -108,14 +125,11 @@ fn apply_reloc(
// A declaration for the stack probe function in Rust's standard library, for
// catching callstack overflow.
cfg_if::cfg_if! {
if #[cfg(any(
target_arch="aarch64",
all(
if #[cfg(all(
target_os = "windows",
target_env = "msvc",
target_pointer_width = "64"
)
))] {
))] {
extern "C" {
pub fn __chkstk();
}
@@ -128,6 +142,13 @@ cfg_if::cfg_if! {
pub fn ___chkstk();
}
const PROBESTACK: unsafe extern "C" fn() = ___chkstk;
} else if #[cfg(not(any(target_arch = "x86_64", target_arch = "x86")))] {
// As per
// https://github.com/rust-lang/compiler-builtins/blob/cae3e6ea23739166504f9f9fb50ec070097979d4/src/probestack.rs#L39,
// LLVM only has stack-probe support on x86-64 and x86. Thus, on any other CPU
// architecture, we simply use an empty stack-probe function.
extern "C" fn empty_probestack() {}
const PROBESTACK: unsafe extern "C" fn() = empty_probestack;
} else {
extern "C" {
pub fn __rust_probestack();