Auto merge of #116154 - cjgillot:retain-cfg, r=oli-obk

Use Vec::retain in remove_dead_blocks.

r? `@ghost`
This commit is contained in:
bors 2023-09-26 17:16:20 +00:00
commit 6710e3312d

View File

@ -29,6 +29,7 @@
use crate::MirPass; use crate::MirPass;
use rustc_data_structures::fx::{FxHashSet, FxIndexSet}; use rustc_data_structures::fx::{FxHashSet, FxIndexSet};
use rustc_index::bit_set::BitSet;
use rustc_index::{Idx, IndexSlice, IndexVec}; use rustc_index::{Idx, IndexSlice, IndexVec};
use rustc_middle::mir::coverage::*; use rustc_middle::mir::coverage::*;
use rustc_middle::mir::visit::{MutVisitor, MutatingUseContext, PlaceContext, Visitor}; use rustc_middle::mir::visit::{MutVisitor, MutatingUseContext, PlaceContext, Visitor};
@ -345,24 +346,22 @@ pub fn remove_dead_blocks<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
let basic_blocks = body.basic_blocks.as_mut(); let basic_blocks = body.basic_blocks.as_mut();
let source_scopes = &body.source_scopes; let source_scopes = &body.source_scopes;
let mut replacements: Vec<_> = (0..num_blocks).map(BasicBlock::new).collect();
let mut used_blocks = 0;
for alive_index in reachable.iter() {
let alive_index = alive_index.index();
replacements[alive_index] = BasicBlock::new(used_blocks);
if alive_index != used_blocks {
// Swap the next alive block data with the current available slot. Since
// alive_index is non-decreasing this is a valid operation.
basic_blocks.raw.swap(alive_index, used_blocks);
}
used_blocks += 1;
}
if tcx.sess.instrument_coverage() { if tcx.sess.instrument_coverage() {
save_unreachable_coverage(basic_blocks, source_scopes, used_blocks); save_unreachable_coverage(basic_blocks, source_scopes, &reachable);
} }
basic_blocks.raw.truncate(used_blocks); let mut replacements: Vec<_> = (0..num_blocks).map(BasicBlock::new).collect();
let mut orig_index = 0;
let mut used_index = 0;
basic_blocks.raw.retain(|_| {
let keep = reachable.contains(BasicBlock::new(orig_index));
if keep {
replacements[orig_index] = BasicBlock::new(used_index);
used_index += 1;
}
orig_index += 1;
keep
});
for block in basic_blocks { for block in basic_blocks {
for target in block.terminator_mut().successors_mut() { for target in block.terminator_mut().successors_mut() {
@ -404,11 +403,12 @@ pub fn remove_dead_blocks<'tcx>(tcx: TyCtxt<'tcx>, body: &mut Body<'tcx>) {
fn save_unreachable_coverage( fn save_unreachable_coverage(
basic_blocks: &mut IndexSlice<BasicBlock, BasicBlockData<'_>>, basic_blocks: &mut IndexSlice<BasicBlock, BasicBlockData<'_>>,
source_scopes: &IndexSlice<SourceScope, SourceScopeData<'_>>, source_scopes: &IndexSlice<SourceScope, SourceScopeData<'_>>,
first_dead_block: usize, reachable: &BitSet<BasicBlock>,
) { ) {
// Identify instances that still have some live coverage counters left. // Identify instances that still have some live coverage counters left.
let mut live = FxHashSet::default(); let mut live = FxHashSet::default();
for basic_block in &basic_blocks.raw[0..first_dead_block] { for bb in reachable.iter() {
let basic_block = &basic_blocks[bb];
for statement in &basic_block.statements { for statement in &basic_block.statements {
let StatementKind::Coverage(coverage) = &statement.kind else { continue }; let StatementKind::Coverage(coverage) = &statement.kind else { continue };
let CoverageKind::Counter { .. } = coverage.kind else { continue }; let CoverageKind::Counter { .. } = coverage.kind else { continue };
@ -417,7 +417,8 @@ fn save_unreachable_coverage(
} }
} }
for block in &mut basic_blocks.raw[..first_dead_block] { for bb in reachable.iter() {
let block = &mut basic_blocks[bb];
for statement in &mut block.statements { for statement in &mut block.statements {
let StatementKind::Coverage(_) = &statement.kind else { continue }; let StatementKind::Coverage(_) = &statement.kind else { continue };
let instance = statement.source_info.scope.inlined_instance(source_scopes); let instance = statement.source_info.scope.inlined_instance(source_scopes);
@ -433,7 +434,11 @@ fn save_unreachable_coverage(
// Retain coverage for instances that still have some live counters left. // Retain coverage for instances that still have some live counters left.
let mut retained_coverage = Vec::new(); let mut retained_coverage = Vec::new();
for dead_block in &basic_blocks.raw[first_dead_block..] { for dead_block in basic_blocks.indices() {
if reachable.contains(dead_block) {
continue;
}
let dead_block = &basic_blocks[dead_block];
for statement in &dead_block.statements { for statement in &dead_block.statements {
let StatementKind::Coverage(coverage) = &statement.kind else { continue }; let StatementKind::Coverage(coverage) = &statement.kind else { continue };
let Some(code_region) = &coverage.code_region else { continue }; let Some(code_region) = &coverage.code_region else { continue };