Files
wasmtime/lib/filetests/src/test_binemit.rs
2018-03-28 22:48:30 -07:00

311 lines
10 KiB
Rust

//! Test command for testing the binary machine code emission.
//!
//! The `binemit` test command generates binary machine code for every instruction in the input
//! functions and compares the results to the expected output.
use std::borrow::Cow;
use std::collections::HashMap;
use std::fmt::Write;
use cretonne::binemit;
use cretonne::dbg::DisplayList;
use cretonne::ir;
use cretonne::ir::entities::AnyEntity;
use cretonne::binemit::RegDiversions;
use cretonne::print_errors::pretty_error;
use cton_reader::TestCommand;
use subtest::{SubTest, Context, Result};
use match_directive::match_directive;
struct TestBinEmit;
pub fn subtest(parsed: &TestCommand) -> Result<Box<SubTest>> {
assert_eq!(parsed.command, "binemit");
if !parsed.options.is_empty() {
Err(format!("No options allowed on {}", parsed))
} else {
Ok(Box::new(TestBinEmit))
}
}
/// Code sink that generates text.
struct TextSink {
offset: binemit::CodeOffset,
text: String,
}
impl TextSink {
/// Create a new empty TextSink.
pub fn new() -> Self {
Self {
offset: 0,
text: String::new(),
}
}
}
impl binemit::CodeSink for TextSink {
fn offset(&self) -> binemit::CodeOffset {
self.offset
}
fn put1(&mut self, x: u8) {
write!(self.text, "{:02x} ", x).unwrap();
self.offset += 1;
}
fn put2(&mut self, x: u16) {
write!(self.text, "{:04x} ", x).unwrap();
self.offset += 2;
}
fn put4(&mut self, x: u32) {
write!(self.text, "{:08x} ", x).unwrap();
self.offset += 4;
}
fn put8(&mut self, x: u64) {
write!(self.text, "{:016x} ", x).unwrap();
self.offset += 8;
}
fn reloc_ebb(&mut self, reloc: binemit::Reloc, ebb_offset: binemit::CodeOffset) {
write!(self.text, "{}({}) ", reloc, ebb_offset).unwrap();
}
fn reloc_external(
&mut self,
reloc: binemit::Reloc,
name: &ir::ExternalName,
addend: binemit::Addend,
) {
write!(
self.text,
"{}({}",
reloc,
name,
).unwrap();
if addend != 0 {
write!(
self.text,
"{:+}",
addend,
).unwrap();
}
write!(
self.text,
") ",
).unwrap();
}
fn reloc_jt(&mut self, reloc: binemit::Reloc, jt: ir::JumpTable) {
write!(self.text, "{}({}) ", reloc, jt).unwrap();
}
fn trap(&mut self, code: ir::TrapCode, _srcloc: ir::SourceLoc) {
write!(self.text, "{} ", code).unwrap();
}
}
impl SubTest for TestBinEmit {
fn name(&self) -> Cow<str> {
Cow::from("binemit")
}
fn is_mutating(&self) -> bool {
true
}
fn needs_isa(&self) -> bool {
true
}
fn run(&self, func: Cow<ir::Function>, context: &Context) -> Result<()> {
let isa = context.isa.expect("binemit needs an ISA");
let encinfo = isa.encoding_info();
// TODO: Run a verifier pass over the code first to detect any bad encodings or missing/bad
// value locations. The current error reporting is just crashing...
let mut func = func.into_owned();
// Fix the stack frame layout so we can test spill/fill encodings.
let min_offset = func.stack_slots
.keys()
.map(|ss| func.stack_slots[ss].offset.unwrap())
.min();
func.stack_slots.frame_size = min_offset.map(|off| (-off) as u32);
let is_compressed = isa.flags().is_compressed();
// Give an encoding to any instruction that doesn't already have one.
let mut divert = RegDiversions::new();
for ebb in func.layout.ebbs() {
divert.clear();
for inst in func.layout.ebb_insts(ebb) {
if !func.encodings[inst].is_legal() {
// Find an encoding that satisfies both immediate field and register
// constraints.
if let Some(enc) = {
let mut legal_encodings = isa.legal_encodings(
&func.dfg,
&func.dfg[inst],
func.dfg.ctrl_typevar(inst),
).filter(|e| {
let recipe_constraints = &encinfo.constraints[e.recipe()];
recipe_constraints.satisfied(inst, &divert, &func)
});
if is_compressed {
// Get the smallest legal encoding
legal_encodings.min_by_key(|&e| encinfo.bytes(e))
} else {
// If not using compressed, just use the first encoding.
legal_encodings.next()
}
}
{
func.encodings[inst] = enc;
}
}
divert.apply(&func.dfg[inst]);
}
}
// Relax branches and compute EBB offsets based on the encodings.
let code_size = binemit::relax_branches(&mut func, isa).map_err(|e| {
pretty_error(&func, context.isa, e)
})?;
// Collect all of the 'bin:' directives on instructions.
let mut bins = HashMap::new();
for comment in &context.details.comments {
if let Some(want) = match_directive(comment.text, "bin:") {
match comment.entity {
AnyEntity::Inst(inst) => {
if let Some(prev) = bins.insert(inst, want) {
return Err(format!(
"multiple 'bin:' directives on {}: '{}' and '{}'",
func.dfg.display_inst(inst, isa),
prev,
want
));
}
}
_ => {
return Err(format!(
"'bin:' directive on non-inst {}: {}",
comment.entity,
comment.text
))
}
}
}
}
if bins.is_empty() {
return Err("No 'bin:' directives found".to_string());
}
// Now emit all instructions.
let mut sink = TextSink::new();
for ebb in func.layout.ebbs() {
divert.clear();
// Correct header offsets should have been computed by `relax_branches()`.
assert_eq!(
sink.offset,
func.offsets[ebb],
"Inconsistent {} header offset",
ebb
);
for (offset, inst, enc_bytes) in func.inst_offsets(ebb, &encinfo) {
assert_eq!(sink.offset, offset);
sink.text.clear();
let enc = func.encodings[inst];
// Send legal encodings into the emitter.
if enc.is_legal() {
// Generate a better error message if output locations are not specified.
if let Some(&v) = func.dfg.inst_results(inst).iter().find(|&&v| {
!func.locations[v].is_assigned()
})
{
return Err(format!(
"Missing register/stack slot for {} in {}",
v,
func.dfg.display_inst(inst, isa)
));
}
let before = sink.offset;
isa.emit_inst(&func, inst, &mut divert, &mut sink);
let emitted = sink.offset - before;
// Verify the encoding recipe sizes against the ISAs emit_inst implementation.
assert_eq!(
emitted,
enc_bytes,
"Inconsistent size for [{}] {}",
encinfo.display(enc),
func.dfg.display_inst(inst, isa)
);
}
// Check against bin: directives.
if let Some(want) = bins.remove(&inst) {
if !enc.is_legal() {
// A possible cause of an unencoded instruction is a missing location for
// one of the input operands.
if let Some(&v) = func.dfg.inst_args(inst).iter().find(|&&v| {
!func.locations[v].is_assigned()
})
{
return Err(format!(
"Missing register/stack slot for {} in {}",
v,
func.dfg.display_inst(inst, isa)
));
}
// Do any encodings exist?
let encodings = isa.legal_encodings(
&func.dfg,
&func.dfg[inst],
func.dfg.ctrl_typevar(inst),
).map(|e| encinfo.display(e))
.collect::<Vec<_>>();
if encodings.is_empty() {
return Err(format!(
"No encodings found for: {}",
func.dfg.display_inst(inst, isa)
));
}
return Err(format!(
"No matching encodings for {} in {}",
func.dfg.display_inst(inst, isa),
DisplayList(&encodings),
));
}
let have = sink.text.trim();
if have != want {
return Err(format!(
"Bad machine code for {}: {}\nWant: {}\nGot: {}",
inst,
func.dfg.display_inst(inst, isa),
want,
have
));
}
}
}
}
if sink.offset != code_size {
return Err(format!(
"Expected code size {}, got {}",
code_size,
sink.offset
));
}
Ok(())
}
}