From ebbf7b77e852a5fdfd1a4346d552cbb0c0dbde22 Mon Sep 17 00:00:00 2001 From: Camille GILLOT Date: Sun, 31 Dec 2023 02:04:09 +0000 Subject: [PATCH] Extract process_assign. --- .../rustc_mir_transform/src/jump_threading.rs | 168 ++++++++---------- 1 file changed, 79 insertions(+), 89 deletions(-) diff --git a/compiler/rustc_mir_transform/src/jump_threading.rs b/compiler/rustc_mir_transform/src/jump_threading.rs index c491cb22cbe74..e87f68a09057b 100644 --- a/compiler/rustc_mir_transform/src/jump_threading.rs +++ b/compiler/rustc_mir_transform/src/jump_threading.rs @@ -423,6 +423,84 @@ impl<'tcx, 'a> TOFinder<'tcx, 'a> { None } + #[instrument(level = "trace", skip(self))] + fn process_assign( + &mut self, + bb: BasicBlock, + lhs_place: &Place<'tcx>, + rhs: &Rvalue<'tcx>, + state: &mut State>, + ) -> Option { + let lhs = self.map.find(lhs_place.as_ref())?; + match rhs { + Rvalue::Use(operand) => self.process_operand(bb, lhs, operand, state)?, + // Transfer the conditions on the copy rhs. + Rvalue::CopyForDeref(rhs) => { + self.process_operand(bb, lhs, &Operand::Copy(*rhs), state)? + } + Rvalue::Discriminant(rhs) => { + let rhs = self.map.find_discr(rhs.as_ref())?; + state.insert_place_idx(rhs, lhs, self.map); + } + // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`. + Rvalue::Aggregate(box ref kind, ref operands) => { + let agg_ty = lhs_place.ty(self.body, self.tcx).ty; + let lhs = match kind { + // Do not support unions. + AggregateKind::Adt(.., Some(_)) => return None, + AggregateKind::Adt(_, variant_index, ..) if agg_ty.is_enum() => { + if let Some(discr_target) = self.map.apply(lhs, TrackElem::Discriminant) + && let Ok(discr_value) = + self.ecx.discriminant_for_variant(agg_ty, *variant_index) + { + self.process_immediate(bb, discr_target, discr_value, state); + } + self.map.apply(lhs, TrackElem::Variant(*variant_index))? + } + _ => lhs, + }; + for (field_index, operand) in operands.iter_enumerated() { + if let Some(field) = self.map.apply(lhs, TrackElem::Field(field_index)) { + self.process_operand(bb, field, operand, state); + } + } + } + // Transfer the conditions on the copy rhs, after inversing polarity. + Rvalue::UnaryOp(UnOp::Not, Operand::Move(place) | Operand::Copy(place)) => { + let conditions = state.try_get_idx(lhs, self.map)?; + let place = self.map.find(place.as_ref())?; + let conds = conditions.map(self.arena, Condition::inv); + state.insert_value_idx(place, conds, self.map); + } + // We expect `lhs ?= A`. We found `lhs = Eq(rhs, B)`. + // Create a condition on `rhs ?= B`. + Rvalue::BinaryOp( + op, + box (Operand::Move(place) | Operand::Copy(place), Operand::Constant(value)) + | box (Operand::Constant(value), Operand::Move(place) | Operand::Copy(place)), + ) => { + let conditions = state.try_get_idx(lhs, self.map)?; + let place = self.map.find(place.as_ref())?; + let equals = match op { + BinOp::Eq => ScalarInt::TRUE, + BinOp::Ne => ScalarInt::FALSE, + _ => return None, + }; + let value = value.const_.normalize(self.tcx, self.param_env).try_to_scalar_int()?; + let conds = conditions.map(self.arena, |c| Condition { + value, + polarity: if c.matches(equals) { Polarity::Eq } else { Polarity::Ne }, + ..c + }); + state.insert_value_idx(place, conds, self.map); + } + + _ => {} + } + + None + } + #[instrument(level = "trace", skip(self))] fn process_statement( &mut self, @@ -472,95 +550,7 @@ impl<'tcx, 'a> TOFinder<'tcx, 'a> { conditions.iter_matches(ScalarInt::TRUE).for_each(register_opportunity); } StatementKind::Assign(box (lhs_place, rhs)) => { - if let Some(lhs) = self.map.find(lhs_place.as_ref()) { - match rhs { - Rvalue::Use(operand) => self.process_operand(bb, lhs, operand, state)?, - // Transfer the conditions on the copy rhs. - Rvalue::CopyForDeref(rhs) => { - self.process_operand(bb, lhs, &Operand::Copy(*rhs), state)? - } - Rvalue::Discriminant(rhs) => { - let rhs = self.map.find_discr(rhs.as_ref())?; - state.insert_place_idx(rhs, lhs, self.map); - } - // If we expect `lhs ?= A`, we have an opportunity if we assume `constant == A`. - Rvalue::Aggregate(box ref kind, ref operands) => { - let agg_ty = lhs_place.ty(self.body, self.tcx).ty; - let lhs = match kind { - // Do not support unions. - AggregateKind::Adt(.., Some(_)) => return None, - AggregateKind::Adt(_, variant_index, ..) if agg_ty.is_enum() => { - if let Some(discr_target) = - self.map.apply(lhs, TrackElem::Discriminant) - && let Ok(discr_value) = self - .ecx - .discriminant_for_variant(agg_ty, *variant_index) - { - self.process_immediate( - bb, - discr_target, - discr_value, - state, - ); - } - self.map.apply(lhs, TrackElem::Variant(*variant_index))? - } - _ => lhs, - }; - for (field_index, operand) in operands.iter_enumerated() { - if let Some(field) = - self.map.apply(lhs, TrackElem::Field(field_index)) - { - self.process_operand(bb, field, operand, state); - } - } - } - // Transfer the conditions on the copy rhs, after inversing polarity. - Rvalue::UnaryOp(UnOp::Not, Operand::Move(place) | Operand::Copy(place)) => { - let conditions = state.try_get_idx(lhs, self.map)?; - let place = self.map.find(place.as_ref())?; - let conds = conditions.map(self.arena, Condition::inv); - state.insert_value_idx(place, conds, self.map); - } - // We expect `lhs ?= A`. We found `lhs = Eq(rhs, B)`. - // Create a condition on `rhs ?= B`. - Rvalue::BinaryOp( - op, - box ( - Operand::Move(place) | Operand::Copy(place), - Operand::Constant(value), - ) - | box ( - Operand::Constant(value), - Operand::Move(place) | Operand::Copy(place), - ), - ) => { - let conditions = state.try_get_idx(lhs, self.map)?; - let place = self.map.find(place.as_ref())?; - let equals = match op { - BinOp::Eq => ScalarInt::TRUE, - BinOp::Ne => ScalarInt::FALSE, - _ => return None, - }; - let value = value - .const_ - .normalize(self.tcx, self.param_env) - .try_to_scalar_int()?; - let conds = conditions.map(self.arena, |c| Condition { - value, - polarity: if c.matches(equals) { - Polarity::Eq - } else { - Polarity::Ne - }, - ..c - }); - state.insert_value_idx(place, conds, self.map); - } - - _ => {} - } - } + self.process_assign(bb, lhs_place, rhs, state)?; } _ => {} }