Delete ConstDebugInfo pass
This commit is contained in:
Scott McMurray
parent
476f46a8e6
commit
8fbab183d7
@ -1,103 +0,0 @@
|
||||
//! Finds locals which are assigned once to a const and unused except for debuginfo and converts
|
||||
//! their debuginfo to use the const directly, allowing the local to be removed.
|
||||
|
||||
use rustc_middle::{
|
||||
mir::{
|
||||
visit::{PlaceContext, Visitor},
|
||||
Body, ConstOperand, Local, Location, Operand, Rvalue, StatementKind, VarDebugInfoContents,
|
||||
},
|
||||
ty::TyCtxt,
|
||||
};
|
||||
|
||||
use crate::MirPass;
|
||||
use rustc_index::{bit_set::BitSet, IndexVec};
|
||||
|
||||
pub struct ConstDebugInfo;
|
||||
|
||||
impl<'tcx> MirPass<'tcx> for ConstDebugInfo {
|
||||
fn is_enabled(&self, sess: &rustc_session::Session) -> bool {
|
||||
// Disabled in favour of `SingleUseConsts`
|
||||
sess.mir_opt_level() > 2
|
||||
}
|
||||
|
||||
fn run_pass(&self, _tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
|
||||
trace!("running ConstDebugInfo on {:?}", body.source);
|
||||
|
||||
for (local, constant) in find_optimization_opportunities(body) {
|
||||
for debuginfo in &mut body.var_debug_info {
|
||||
if let VarDebugInfoContents::Place(p) = debuginfo.value {
|
||||
if p.local == local && p.projection.is_empty() {
|
||||
trace!(
|
||||
"changing debug info for {:?} from place {:?} to constant {:?}",
|
||||
debuginfo.name,
|
||||
p,
|
||||
constant
|
||||
);
|
||||
debuginfo.value = VarDebugInfoContents::Const(constant);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
struct LocalUseVisitor {
|
||||
local_mutating_uses: IndexVec<Local, u8>,
|
||||
local_assignment_locations: IndexVec<Local, Option<Location>>,
|
||||
}
|
||||
|
||||
fn find_optimization_opportunities<'tcx>(body: &Body<'tcx>) -> Vec<(Local, ConstOperand<'tcx>)> {
|
||||
let mut visitor = LocalUseVisitor {
|
||||
local_mutating_uses: IndexVec::from_elem(0, &body.local_decls),
|
||||
local_assignment_locations: IndexVec::from_elem(None, &body.local_decls),
|
||||
};
|
||||
|
||||
visitor.visit_body(body);
|
||||
|
||||
let mut locals_to_debuginfo = BitSet::new_empty(body.local_decls.len());
|
||||
for debuginfo in &body.var_debug_info {
|
||||
if let VarDebugInfoContents::Place(p) = debuginfo.value
|
||||
&& let Some(l) = p.as_local()
|
||||
{
|
||||
locals_to_debuginfo.insert(l);
|
||||
}
|
||||
}
|
||||
|
||||
let mut eligible_locals = Vec::new();
|
||||
for (local, mutating_uses) in visitor.local_mutating_uses.drain_enumerated(..) {
|
||||
if mutating_uses != 1 || !locals_to_debuginfo.contains(local) {
|
||||
continue;
|
||||
}
|
||||
|
||||
if let Some(location) = visitor.local_assignment_locations[local] {
|
||||
let bb = &body[location.block];
|
||||
|
||||
// The value is assigned as the result of a call, not a constant
|
||||
if bb.statements.len() == location.statement_index {
|
||||
continue;
|
||||
}
|
||||
|
||||
if let StatementKind::Assign(box (p, Rvalue::Use(Operand::Constant(box c)))) =
|
||||
&bb.statements[location.statement_index].kind
|
||||
{
|
||||
if let Some(local) = p.as_local() {
|
||||
eligible_locals.push((local, *c));
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
eligible_locals
|
||||
}
|
||||
|
||||
impl Visitor<'_> for LocalUseVisitor {
|
||||
fn visit_local(&mut self, local: Local, context: PlaceContext, location: Location) {
|
||||
if context.is_mutating_use() {
|
||||
self.local_mutating_uses[local] = self.local_mutating_uses[local].saturating_add(1);
|
||||
|
||||
if context.is_place_assignment() {
|
||||
self.local_assignment_locations[local] = Some(location);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -55,7 +55,6 @@ mod remove_place_mention;
|
||||
// This pass is public to allow external drivers to perform MIR cleanup
|
||||
mod add_subtyping_projections;
|
||||
pub mod cleanup_post_borrowck;
|
||||
mod const_debuginfo;
|
||||
mod copy_prop;
|
||||
mod coroutine;
|
||||
mod cost_checker;
|
||||
@ -595,7 +594,6 @@ fn run_optimization_passes<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
|
||||
&simplify::SimplifyLocals::AfterGVN,
|
||||
&dataflow_const_prop::DataflowConstProp,
|
||||
&single_use_consts::SingleUseConsts,
|
||||
&const_debuginfo::ConstDebugInfo,
|
||||
&o1(simplify_branches::SimplifyConstCondition::AfterConstProp),
|
||||
&jump_threading::JumpThreading,
|
||||
&early_otherwise_branch::EarlyOtherwiseBranch,
|
||||
|
||||
@ -1,5 +1,5 @@
|
||||
- // MIR for `main` before ConstDebugInfo
|
||||
+ // MIR for `main` after ConstDebugInfo
|
||||
- // MIR for `main` before SingleUseConsts
|
||||
+ // MIR for `main` after SingleUseConsts
|
||||
|
||||
fn main() -> () {
|
||||
let mut _0: ();
|
||||
@ -56,39 +56,53 @@
|
||||
|
||||
bb0: {
|
||||
nop;
|
||||
_1 = const 1_u8;
|
||||
- _1 = const 1_u8;
|
||||
nop;
|
||||
_2 = const 2_u8;
|
||||
- _2 = const 2_u8;
|
||||
nop;
|
||||
_3 = const 3_u8;
|
||||
- _3 = const 3_u8;
|
||||
+ nop;
|
||||
+ nop;
|
||||
+ nop;
|
||||
StorageLive(_4);
|
||||
StorageLive(_5);
|
||||
StorageLive(_6);
|
||||
_6 = const 1_u8;
|
||||
- _6 = const 1_u8;
|
||||
+ nop;
|
||||
StorageLive(_7);
|
||||
_7 = const 2_u8;
|
||||
_5 = const 3_u8;
|
||||
- _7 = const 2_u8;
|
||||
- _5 = const 3_u8;
|
||||
+ nop;
|
||||
+ nop;
|
||||
StorageDead(_7);
|
||||
StorageDead(_6);
|
||||
StorageLive(_8);
|
||||
_8 = const 3_u8;
|
||||
_4 = const 6_u8;
|
||||
- _8 = const 3_u8;
|
||||
- _4 = const 6_u8;
|
||||
+ nop;
|
||||
+ nop;
|
||||
StorageDead(_8);
|
||||
StorageDead(_5);
|
||||
StorageLive(_9);
|
||||
_9 = const "hello, world!";
|
||||
- _9 = const "hello, world!";
|
||||
+ nop;
|
||||
StorageLive(_10);
|
||||
_10 = (const true, const false, const 123_u32);
|
||||
StorageLive(_11);
|
||||
_11 = const Option::<u16>::Some(99_u16);
|
||||
- _11 = const Option::<u16>::Some(99_u16);
|
||||
+ nop;
|
||||
StorageLive(_12);
|
||||
_12 = const Point {{ x: 32_u32, y: 32_u32 }};
|
||||
- _12 = const Point {{ x: 32_u32, y: 32_u32 }};
|
||||
+ nop;
|
||||
StorageLive(_13);
|
||||
nop;
|
||||
_14 = const 32_u32;
|
||||
- _14 = const 32_u32;
|
||||
+ nop;
|
||||
StorageLive(_15);
|
||||
_15 = const 32_u32;
|
||||
_13 = const 64_u32;
|
||||
- _15 = const 32_u32;
|
||||
- _13 = const 64_u32;
|
||||
+ nop;
|
||||
+ nop;
|
||||
StorageDead(_15);
|
||||
nop;
|
||||
_0 = const ();
|
||||
@ -1,12 +1,14 @@
|
||||
//@ test-mir-pass: ConstDebugInfo
|
||||
//@ test-mir-pass: SingleUseConsts
|
||||
//@ compile-flags: -C overflow-checks=no -Zmir-enable-passes=+GVN
|
||||
|
||||
#![allow(unused)]
|
||||
|
||||
struct Point {
|
||||
x: u32,
|
||||
y: u32,
|
||||
}
|
||||
|
||||
// EMIT_MIR const_debuginfo.main.ConstDebugInfo.diff
|
||||
// EMIT_MIR const_debuginfo.main.SingleUseConsts.diff
|
||||
fn main() {
|
||||
// CHECK-LABEL: fn main(
|
||||
// CHECK: debug x => const 1_u8;
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
+ let mut _2: bool;
|
||||
+ let mut _3: bool;
|
||||
+ scope 2 {
|
||||
+ debug buffer => const inner::promoted[0];
|
||||
+ debug buffer => _1;
|
||||
+ scope 3 {
|
||||
+ debug index => _0;
|
||||
+ }
|
||||
|
||||
@ -8,7 +8,7 @@
|
||||
+ let mut _2: bool;
|
||||
+ let mut _3: bool;
|
||||
+ scope 2 {
|
||||
+ debug buffer => const inner::promoted[0];
|
||||
+ debug buffer => _1;
|
||||
+ scope 3 {
|
||||
+ debug index => _0;
|
||||
+ }
|
||||
|
||||
Loading…
x
Reference in New Issue
Block a user