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Change the return type of can_simplify to Option<()>

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DianQK 2024-03-10 22:23:55 +08:00
parent 032bb742ab
commit f4407370db
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1 changed files with 26 additions and 28 deletions
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54
compiler/rustc_mir_transform/src/match_branches.rs
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@ -37,11 +37,11 @@ impl<'tcx> MirPass<'tcx> for MatchBranchSimplification {
_ => continue, _ => continue,
}; };
if SimplifyToIf.simplify(tcx, body, bb_idx, param_env) { if SimplifyToIf.simplify(tcx, body, bb_idx, param_env).is_some() {
should_cleanup = true; should_cleanup = true;
continue; continue;
} }
if SimplifyToExp::default().simplify(tcx, body, bb_idx, param_env) { if SimplifyToExp::default().simplify(tcx, body, bb_idx, param_env).is_some() {
should_cleanup = true; should_cleanup = true;
continue; continue;
} }
@ -62,7 +62,7 @@ trait SimplifyMatch<'tcx> {
body: &mut Body<'tcx>, body: &mut Body<'tcx>,
switch_bb_idx: BasicBlock, switch_bb_idx: BasicBlock,
param_env: ParamEnv<'tcx>, param_env: ParamEnv<'tcx>,
) -> bool { ) -> Option<()> {
let bbs = &body.basic_blocks; let bbs = &body.basic_blocks;
let (discr, targets) = match bbs[switch_bb_idx].terminator().kind { let (discr, targets) = match bbs[switch_bb_idx].terminator().kind {
TerminatorKind::SwitchInt { ref discr, ref targets, .. } => (discr, targets), TerminatorKind::SwitchInt { ref discr, ref targets, .. } => (discr, targets),
@ -70,9 +70,7 @@ trait SimplifyMatch<'tcx> {
}; };
let discr_ty = discr.ty(body.local_decls(), tcx); let discr_ty = discr.ty(body.local_decls(), tcx);
if !self.can_simplify(tcx, targets, param_env, bbs, discr_ty) { self.can_simplify(tcx, targets, param_env, bbs, discr_ty)?;
return false;
}
let mut patch = MirPatch::new(body); let mut patch = MirPatch::new(body);
@ -92,7 +90,7 @@ trait SimplifyMatch<'tcx> {
patch.add_statement(parent_end, StatementKind::StorageDead(discr_local)); patch.add_statement(parent_end, StatementKind::StorageDead(discr_local));
patch.patch_terminator(switch_bb_idx, bbs[first].terminator().kind.clone()); patch.patch_terminator(switch_bb_idx, bbs[first].terminator().kind.clone());
patch.apply(body); patch.apply(body);
true Some(())
} }
/// Check that the BBs to be simplified satisfies all distinct and /// Check that the BBs to be simplified satisfies all distinct and
@ -105,7 +103,7 @@ trait SimplifyMatch<'tcx> {
param_env: ParamEnv<'tcx>, param_env: ParamEnv<'tcx>,
bbs: &IndexSlice<BasicBlock, BasicBlockData<'tcx>>, bbs: &IndexSlice<BasicBlock, BasicBlockData<'tcx>>,
discr_ty: Ty<'tcx>, discr_ty: Ty<'tcx>,
) -> bool; ) -> Option<()>;
fn new_stmts( fn new_stmts(
&self, &self,
@ -161,19 +159,19 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToIf {
param_env: ParamEnv<'tcx>, param_env: ParamEnv<'tcx>,
bbs: &IndexSlice<BasicBlock, BasicBlockData<'tcx>>, bbs: &IndexSlice<BasicBlock, BasicBlockData<'tcx>>,
_discr_ty: Ty<'tcx>, _discr_ty: Ty<'tcx>,
) -> bool { ) -> Option<()> {
if targets.iter().len() != 1 { if targets.iter().len() != 1 {
return false; return None;
} }
// We require that the possible target blocks all be distinct. // We require that the possible target blocks all be distinct.
let (_, first) = targets.iter().next().unwrap(); let (_, first) = targets.iter().next().unwrap();
let second = targets.otherwise(); let second = targets.otherwise();
if first == second { if first == second {
return false; return None;
} }
// Check that destinations are identical, and if not, then don't optimize this block // Check that destinations are identical, and if not, then don't optimize this block
if bbs[first].terminator().kind != bbs[second].terminator().kind { if bbs[first].terminator().kind != bbs[second].terminator().kind {
return false; return None;
} }
// Check that blocks are assignments of consts to the same place or same statement, // Check that blocks are assignments of consts to the same place or same statement,
@ -181,7 +179,7 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToIf {
let first_stmts = &bbs[first].statements; let first_stmts = &bbs[first].statements;
let second_stmts = &bbs[second].statements; let second_stmts = &bbs[second].statements;
if first_stmts.len() != second_stmts.len() { if first_stmts.len() != second_stmts.len() {
return false; return None;
} }
for (f, s) in iter::zip(first_stmts, second_stmts) { for (f, s) in iter::zip(first_stmts, second_stmts) {
match (&f.kind, &s.kind) { match (&f.kind, &s.kind) {
@ -199,10 +197,10 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToIf {
&& s_c.const_.try_eval_bool(tcx, param_env).is_some() => {} && s_c.const_.try_eval_bool(tcx, param_env).is_some() => {}
// Otherwise we cannot optimize. Try another block. // Otherwise we cannot optimize. Try another block.
_ => return false, _ => return None,
} }
} }
true Some(())
} }
fn new_stmts( fn new_stmts(
@ -340,16 +338,16 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToExp {
param_env: ParamEnv<'tcx>, param_env: ParamEnv<'tcx>,
bbs: &IndexSlice<BasicBlock, BasicBlockData<'tcx>>, bbs: &IndexSlice<BasicBlock, BasicBlockData<'tcx>>,
discr_ty: Ty<'tcx>, discr_ty: Ty<'tcx>,
) -> bool { ) -> Option<()> {
if targets.iter().len() < 2 || targets.iter().len() > 64 { if targets.iter().len() < 2 || targets.iter().len() > 64 {
return false; return None;
} }
// We require that the possible target blocks all be distinct. // We require that the possible target blocks all be distinct.
if !targets.is_distinct() { if !targets.is_distinct() {
return false; return None;
} }
if !bbs[targets.otherwise()].is_empty_unreachable() { if !bbs[targets.otherwise()].is_empty_unreachable() {
return false; return None;
} }
let mut target_iter = targets.iter(); let mut target_iter = targets.iter();
let (first_val, first_target) = target_iter.next().unwrap(); let (first_val, first_target) = target_iter.next().unwrap();
@ -359,7 +357,7 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToExp {
.iter() .iter()
.all(|(_, other_target)| first_terminator_kind == &bbs[other_target].terminator().kind) .all(|(_, other_target)| first_terminator_kind == &bbs[other_target].terminator().kind)
{ {
return false; return None;
} }
let discr_size = tcx.layout_of(param_env.and(discr_ty)).unwrap().size; let discr_size = tcx.layout_of(param_env.and(discr_ty)).unwrap().size;
@ -367,7 +365,7 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToExp {
let (second_val, second_target) = target_iter.next().unwrap(); let (second_val, second_target) = target_iter.next().unwrap();
let second_stmts = &bbs[second_target].statements; let second_stmts = &bbs[second_target].statements;
if first_stmts.len() != second_stmts.len() { if first_stmts.len() != second_stmts.len() {
return false; return None;
} }
fn int_equal(l: ScalarInt, r: impl Into<u128>, size: Size) -> bool { fn int_equal(l: ScalarInt, r: impl Into<u128>, size: Size) -> bool {
@ -412,13 +410,13 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToExp {
} }
} }
_ => { _ => {
return false; return None;
} }
} }
} }
// Otherwise we cannot optimize. Try another block. // Otherwise we cannot optimize. Try another block.
_ => return false, _ => return None,
}; };
compare_types.push(compare_type); compare_types.push(compare_type);
} }
@ -427,7 +425,7 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToExp {
for (other_val, other_target) in target_iter { for (other_val, other_target) in target_iter {
let other_stmts = &bbs[other_target].statements; let other_stmts = &bbs[other_target].statements;
if compare_types.len() != other_stmts.len() { if compare_types.len() != other_stmts.len() {
return false; return None;
} }
for (f, s) in iter::zip(&compare_types, other_stmts) { for (f, s) in iter::zip(&compare_types, other_stmts) {
match (*f, &s.kind) { match (*f, &s.kind) {
@ -443,7 +441,7 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToExp {
StatementKind::Assign(box (lhs_s, Rvalue::Use(Operand::Constant(s_c)))), StatementKind::Assign(box (lhs_s, Rvalue::Use(Operand::Constant(s_c)))),
) if lhs_f == lhs_s && s_c.const_.ty() == f_ty => { ) if lhs_f == lhs_s && s_c.const_.ty() == f_ty => {
let Some(f) = s_c.const_.try_eval_scalar_int(tcx, param_env) else { let Some(f) = s_c.const_.try_eval_scalar_int(tcx, param_env) else {
return false; return None;
}; };
if is_signed if is_signed
&& s_c.const_.ty().is_signed() && s_c.const_.ty().is_signed()
@ -454,14 +452,14 @@ impl<'tcx> SimplifyMatch<'tcx> for SimplifyToExp {
if Some(f) == ScalarInt::try_from_uint(other_val, f.size()) { if Some(f) == ScalarInt::try_from_uint(other_val, f.size()) {
continue; continue;
} }
return false; return None;
} }
_ => return false, _ => return None,
} }
} }
} }
self.transfrom_types = compare_types.into_iter().map(|c| c.into()).collect(); self.transfrom_types = compare_types.into_iter().map(|c| c.into()).collect();
true Some(())
} }
fn new_stmts( fn new_stmts(