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Print value aliases at referrent definition (#492)

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* Print value aliases at referrent definition

Closes #488.
This commit is contained in:
Kaz Wesley
2018-09-04 15:02:46 -07:00
committed by Dan Gohman
parent 4045d50b7b
commit 7e571f4a49
4 changed files with 131 additions and 24 deletions
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91
lib/codegen/src/write.rs
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@@ -3,6 +3,7 @@
//! The `write` module provides the `write_function` function which converts an IR `Function` to an
//! equivalent textual form. This textual form can be read back by the `cranelift-reader` crate.
use entity::EntityMap;
use ir::entities::AnyEntity;
use ir::{DataFlowGraph, Ebb, Function, Inst, SigRef, Type, Value, ValueDef};
use isa::{RegInfo, TargetIsa};
@@ -17,6 +18,7 @@ pub trait FuncWriter {
&mut self,
w: &mut Write,
func: &Function,
aliases: &EntityMap<Value, Vec<Value>>,
isa: Option<&TargetIsa>,
inst: Inst,
ident: usize,
@@ -94,11 +96,12 @@ impl FuncWriter for PlainWriter {
&mut self,
w: &mut Write,
func: &Function,
aliases: &EntityMap<Value, Vec<Value>>,
isa: Option<&TargetIsa>,
inst: Inst,
indent: usize,
) -> fmt::Result {
write_instruction(w, func, isa, inst, indent)
write_instruction(w, func, aliases, isa, inst, indent)
}
}
@@ -108,6 +111,18 @@ pub fn write_function(w: &mut Write, func: &Function, isa: Option<&TargetIsa>) -
decorate_function(&mut PlainWriter, w, func, isa)
}
/// Create a reverse-alias map from a value to all aliases having that value as a direct target
fn alias_map(func: &Function) -> EntityMap<Value, Vec<Value>> {
let mut aliases = EntityMap::<_, Vec<_>>::new();
for v in func.dfg.values() {
// VADFS returns the immediate target of an alias
if let Some(k) = func.dfg.value_alias_dest_for_serialization(v) {
aliases[k].push(v);
}
}
aliases
}
/// Writes `func` to `w` as text.
/// write_function_plain is passed as 'closure' to print instructions as text.
/// pretty_function_error is passed as 'closure' to add error decoration.
@@ -123,12 +138,13 @@ pub fn decorate_function<FW: FuncWriter>(
write!(w, "function ")?;
write_spec(w, func, regs)?;
writeln!(w, " {{")?;
let aliases = alias_map(func);
let mut any = func_w.write_preamble(w, func, regs)?;
for ebb in &func.layout {
if any {
writeln!(w)?;
}
decorate_ebb(func_w, w, func, isa, ebb)?;
decorate_ebb(func_w, w, func, &aliases, isa, ebb)?;
any = true;
}
writeln!(w, "}}")
@@ -195,6 +211,7 @@ fn decorate_ebb<FW: FuncWriter>(
func_w: &mut FW,
w: &mut Write,
func: &Function,
aliases: &EntityMap<Value, Vec<Value>>,
isa: Option<&TargetIsa>,
ebb: Ebb,
) -> fmt::Result {
@@ -206,8 +223,11 @@ fn decorate_ebb<FW: FuncWriter>(
};
write_ebb_header(w, func, isa, ebb, indent)?;
for a in func.dfg.ebb_params(ebb).iter().cloned() {
write_value_aliases(w, aliases, a, indent)?;
}
for inst in func.layout.ebb_insts(ebb) {
func_w.write_instruction(w, func, isa, inst, indent)?;
func_w.write_instruction(w, func, aliases, isa, inst, indent)?;
}
Ok(())
@@ -251,13 +271,16 @@ fn type_suffix(func: &Function, inst: Inst) -> Option<Type> {
Some(rtype)
}
// Write out any value aliases appearing in `inst`.
fn write_value_aliases(w: &mut Write, func: &Function, inst: Inst, indent: usize) -> fmt::Result {
for &arg in func.dfg.inst_args(inst) {
let resolved = func.dfg.resolve_aliases(arg);
if resolved != arg {
writeln!(w, "{1:0$}{2} -> {3}", indent, "", arg, resolved)?;
}
/// Write out any aliases to the given target, including indirect aliases
fn write_value_aliases(
w: &mut Write,
aliases: &EntityMap<Value, Vec<Value>>,
target: Value,
indent: usize,
) -> fmt::Result {
for &a in &aliases[target] {
writeln!(w, "{1:0$}{2} -> {3}", indent, "", a, target)?;
write_value_aliases(w, aliases, a, indent)?;
}
Ok(())
}
@@ -265,13 +288,11 @@ fn write_value_aliases(w: &mut Write, func: &Function, inst: Inst, indent: usize
fn write_instruction(
w: &mut Write,
func: &Function,
aliases: &EntityMap<Value, Vec<Value>>,
isa: Option<&TargetIsa>,
inst: Inst,
indent: usize,
) -> fmt::Result {
// Value aliases come out on lines before the instruction using them.
write_value_aliases(w, func, inst, indent)?;
// Prefix containing source location, encoding, and value locations.
let mut s = String::with_capacity(16);
@@ -324,7 +345,13 @@ fn write_instruction(
}
write_operands(w, &func.dfg, isa, inst)?;
writeln!(w)
writeln!(w)?;
// Value aliases come out on lines after the instruction defining the referrent.
for r in func.dfg.inst_results(inst) {
write_value_aliases(w, aliases, *r, indent)?;
}
Ok(())
}
/// Write the operands of `inst` to `w` with a prepended space.
@@ -623,4 +650,40 @@ mod tests {
"function %foo() fast {\n ss0 = explicit_slot 4\n\nebb0(v0: i8, v1: f32x4):\n return\n}\n"
);
}
#[test]
fn aliases() {
use ir::InstBuilder;
let mut func = Function::new();
{
let ebb0 = func.dfg.make_ebb();
let mut pos = FuncCursor::new(&mut func);
pos.insert_ebb(ebb0);
// make some detached values for change_to_alias
let v0 = pos.func.dfg.append_ebb_param(ebb0, types::I32);
let v1 = pos.func.dfg.append_ebb_param(ebb0, types::I32);
let v2 = pos.func.dfg.append_ebb_param(ebb0, types::I32);
pos.func.dfg.detach_ebb_params(ebb0);
// alias to a param--will be printed at beginning of ebb defining param
let v3 = pos.func.dfg.append_ebb_param(ebb0, types::I32);
pos.func.dfg.change_to_alias(v0, v3);
// alias to an alias--should print attached to alias, not ultimate target
pos.func.dfg.make_value_alias_for_serialization(v0, v2); // v0 <- v2
// alias to a result--will be printed after instruction producing result
let _dummy0 = pos.ins().iconst(types::I32, 42);
let v4 = pos.ins().iadd(v0, v0);
pos.func.dfg.change_to_alias(v1, v4);
let _dummy1 = pos.ins().iconst(types::I32, 23);
let _v7 = pos.ins().iadd(v1, v1);
}
assert_eq!(
func.to_string(),
"function u0:0() fast {\nebb0(v3: i32):\n v0 -> v3\n v2 -> v0\n v4 = iconst.i32 42\n v5 = iadd v0, v0\n v1 -> v5\n v6 = iconst.i32 23\n v7 = iadd v1, v1\n}\n"
);
}
}