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Auto merge of #39648 - Aatch:mir-inlining-2, r=eddyb
[MIR] Implement Inlining Fairly basic implementation of inlining for MIR. Uses conservative heuristics for inlining. Doesn't handle a number of cases, but can be extended later. This is basically the same as the previous inlining PR, but without the span-related changes (as the bugs it was dealing with have since been fixed). /cc @rust-lang/compiler
This commit is contained in:
bors
commit
8c72b7651f
@ -19,6 +19,7 @@ use hir::def::CtorKind;
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use hir::def_id::DefId;
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use ty::subst::Substs;
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use ty::{self, AdtDef, ClosureSubsts, Region, Ty};
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use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
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use util::ppaux;
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use rustc_back::slice;
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use hir::InlineAsm;
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@ -63,8 +64,7 @@ macro_rules! newtype_index {
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}
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/// Lowered representation of a single function.
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// Do not implement clone for Mir, which can be accidently done and kind of expensive.
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#[derive(RustcEncodable, RustcDecodable, Debug)]
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#[derive(Clone, RustcEncodable, RustcDecodable, Debug)]
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pub struct Mir<'tcx> {
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/// List of basic blocks. References to basic block use a newtyped index type `BasicBlock`
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/// that indexes into this vector.
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@ -1333,3 +1333,347 @@ impl Location {
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}
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}
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}
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/*
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* TypeFoldable implementations for MIR types
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*/
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impl<'tcx> TypeFoldable<'tcx> for Mir<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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Mir {
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basic_blocks: self.basic_blocks.fold_with(folder),
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visibility_scopes: self.visibility_scopes.clone(),
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promoted: self.promoted.fold_with(folder),
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return_ty: self.return_ty.fold_with(folder),
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local_decls: self.local_decls.fold_with(folder),
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arg_count: self.arg_count,
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upvar_decls: self.upvar_decls.clone(),
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spread_arg: self.spread_arg,
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span: self.span,
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cache: cache::Cache::new()
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
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self.basic_blocks.visit_with(visitor) ||
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self.promoted.visit_with(visitor) ||
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self.return_ty.visit_with(visitor) ||
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self.local_decls.visit_with(visitor)
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}
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}
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impl<'tcx> TypeFoldable<'tcx> for LocalDecl<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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LocalDecl {
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ty: self.ty.fold_with(folder),
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..self.clone()
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
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self.ty.visit_with(visitor)
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}
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}
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impl<'tcx> TypeFoldable<'tcx> for BasicBlockData<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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BasicBlockData {
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statements: self.statements.fold_with(folder),
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terminator: self.terminator.fold_with(folder),
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is_cleanup: self.is_cleanup
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
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self.statements.visit_with(visitor) || self.terminator.visit_with(visitor)
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}
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}
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impl<'tcx> TypeFoldable<'tcx> for Statement<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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use mir::StatementKind::*;
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let kind = match self.kind {
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Assign(ref lval, ref rval) => Assign(lval.fold_with(folder), rval.fold_with(folder)),
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SetDiscriminant { ref lvalue, variant_index } => SetDiscriminant {
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lvalue: lvalue.fold_with(folder),
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variant_index: variant_index
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},
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StorageLive(ref lval) => StorageLive(lval.fold_with(folder)),
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StorageDead(ref lval) => StorageDead(lval.fold_with(folder)),
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InlineAsm { ref asm, ref outputs, ref inputs } => InlineAsm {
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asm: asm.clone(),
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outputs: outputs.fold_with(folder),
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inputs: inputs.fold_with(folder)
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},
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Nop => Nop,
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};
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Statement {
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source_info: self.source_info,
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kind: kind
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
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use mir::StatementKind::*;
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match self.kind {
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Assign(ref lval, ref rval) => { lval.visit_with(visitor) || rval.visit_with(visitor) }
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SetDiscriminant { ref lvalue, .. } |
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StorageLive(ref lvalue) |
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StorageDead(ref lvalue) => lvalue.visit_with(visitor),
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InlineAsm { ref outputs, ref inputs, .. } =>
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outputs.visit_with(visitor) || inputs.visit_with(visitor),
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Nop => false,
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}
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}
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}
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impl<'tcx> TypeFoldable<'tcx> for Terminator<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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use mir::TerminatorKind::*;
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let kind = match self.kind {
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Goto { target } => Goto { target: target },
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SwitchInt { ref discr, switch_ty, ref values, ref targets } => SwitchInt {
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discr: discr.fold_with(folder),
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switch_ty: switch_ty.fold_with(folder),
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values: values.clone(),
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targets: targets.clone()
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},
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Drop { ref location, target, unwind } => Drop {
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location: location.fold_with(folder),
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target: target,
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unwind: unwind
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},
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DropAndReplace { ref location, ref value, target, unwind } => DropAndReplace {
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location: location.fold_with(folder),
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value: value.fold_with(folder),
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target: target,
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unwind: unwind
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},
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Call { ref func, ref args, ref destination, cleanup } => {
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let dest = destination.as_ref().map(|&(ref loc, dest)| {
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(loc.fold_with(folder), dest)
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});
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Call {
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func: func.fold_with(folder),
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args: args.fold_with(folder),
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destination: dest,
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cleanup: cleanup
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}
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},
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Assert { ref cond, expected, ref msg, target, cleanup } => {
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let msg = if let AssertMessage::BoundsCheck { ref len, ref index } = *msg {
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AssertMessage::BoundsCheck {
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len: len.fold_with(folder),
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index: index.fold_with(folder),
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}
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} else {
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msg.clone()
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};
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Assert {
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cond: cond.fold_with(folder),
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expected: expected,
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msg: msg,
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target: target,
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cleanup: cleanup
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}
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},
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Resume => Resume,
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Return => Return,
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Unreachable => Unreachable,
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};
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Terminator {
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source_info: self.source_info,
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kind: kind
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
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use mir::TerminatorKind::*;
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match self.kind {
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SwitchInt { ref discr, switch_ty, .. } =>
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discr.visit_with(visitor) || switch_ty.visit_with(visitor),
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Drop { ref location, ..} => location.visit_with(visitor),
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DropAndReplace { ref location, ref value, ..} =>
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location.visit_with(visitor) || value.visit_with(visitor),
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Call { ref func, ref args, ref destination, .. } => {
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let dest = if let Some((ref loc, _)) = *destination {
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loc.visit_with(visitor)
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} else { false };
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dest || func.visit_with(visitor) || args.visit_with(visitor)
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},
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Assert { ref cond, ref msg, .. } => {
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if cond.visit_with(visitor) {
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if let AssertMessage::BoundsCheck { ref len, ref index } = *msg {
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len.visit_with(visitor) || index.visit_with(visitor)
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} else {
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false
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}
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} else {
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false
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}
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},
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Goto { .. } |
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Resume |
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Return |
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Unreachable => false
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}
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}
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}
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impl<'tcx> TypeFoldable<'tcx> for Lvalue<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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match self {
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&Lvalue::Projection(ref p) => Lvalue::Projection(p.fold_with(folder)),
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_ => self.clone()
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
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if let &Lvalue::Projection(ref p) = self {
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p.visit_with(visitor)
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} else {
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false
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}
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}
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}
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impl<'tcx> TypeFoldable<'tcx> for Rvalue<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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use mir::Rvalue::*;
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match *self {
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Use(ref op) => Use(op.fold_with(folder)),
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Repeat(ref op, len) => Repeat(op.fold_with(folder), len),
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Ref(region, bk, ref lval) => Ref(region.fold_with(folder), bk, lval.fold_with(folder)),
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Len(ref lval) => Len(lval.fold_with(folder)),
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Cast(kind, ref op, ty) => Cast(kind, op.fold_with(folder), ty.fold_with(folder)),
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BinaryOp(op, ref rhs, ref lhs) =>
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BinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder)),
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CheckedBinaryOp(op, ref rhs, ref lhs) =>
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CheckedBinaryOp(op, rhs.fold_with(folder), lhs.fold_with(folder)),
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UnaryOp(op, ref val) => UnaryOp(op, val.fold_with(folder)),
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Discriminant(ref lval) => Discriminant(lval.fold_with(folder)),
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Box(ty) => Box(ty.fold_with(folder)),
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Aggregate(ref kind, ref fields) => {
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let kind = match *kind {
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AggregateKind::Array(ty) => AggregateKind::Array(ty.fold_with(folder)),
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AggregateKind::Tuple => AggregateKind::Tuple,
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AggregateKind::Adt(def, v, substs, n) =>
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AggregateKind::Adt(def, v, substs.fold_with(folder), n),
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AggregateKind::Closure(id, substs) =>
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AggregateKind::Closure(id, substs.fold_with(folder))
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};
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Aggregate(kind, fields.fold_with(folder))
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}
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
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use mir::Rvalue::*;
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match *self {
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Use(ref op) => op.visit_with(visitor),
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Repeat(ref op, _) => op.visit_with(visitor),
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Ref(region, _, ref lval) => region.visit_with(visitor) || lval.visit_with(visitor),
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Len(ref lval) => lval.visit_with(visitor),
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Cast(_, ref op, ty) => op.visit_with(visitor) || ty.visit_with(visitor),
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BinaryOp(_, ref rhs, ref lhs) |
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CheckedBinaryOp(_, ref rhs, ref lhs) =>
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rhs.visit_with(visitor) || lhs.visit_with(visitor),
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UnaryOp(_, ref val) => val.visit_with(visitor),
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Discriminant(ref lval) => lval.visit_with(visitor),
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Box(ty) => ty.visit_with(visitor),
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Aggregate(ref kind, ref fields) => {
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(match *kind {
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AggregateKind::Array(ty) => ty.visit_with(visitor),
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AggregateKind::Tuple => false,
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AggregateKind::Adt(_, _, substs, _) => substs.visit_with(visitor),
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AggregateKind::Closure(_, substs) => substs.visit_with(visitor)
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}) || fields.visit_with(visitor)
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}
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}
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}
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}
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impl<'tcx> TypeFoldable<'tcx> for Operand<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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match *self {
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Operand::Consume(ref lval) => Operand::Consume(lval.fold_with(folder)),
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Operand::Constant(ref c) => Operand::Constant(c.fold_with(folder)),
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
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match *self {
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Operand::Consume(ref lval) => lval.visit_with(visitor),
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Operand::Constant(ref c) => c.visit_with(visitor)
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}
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}
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}
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impl<'tcx, B, V> TypeFoldable<'tcx> for Projection<'tcx, B, V>
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where B: TypeFoldable<'tcx>, V: TypeFoldable<'tcx>
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{
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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use mir::ProjectionElem::*;
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let base = self.base.fold_with(folder);
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let elem = match self.elem {
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Deref => Deref,
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Field(f, ty) => Field(f, ty.fold_with(folder)),
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Index(ref v) => Index(v.fold_with(folder)),
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ref elem => elem.clone()
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};
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Projection {
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base: base,
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elem: elem
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}
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}
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fn super_visit_with<Vs: TypeVisitor<'tcx>>(&self, visitor: &mut Vs) -> bool {
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use mir::ProjectionElem::*;
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self.base.visit_with(visitor) ||
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match self.elem {
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Field(_, ty) => ty.visit_with(visitor),
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Index(ref v) => v.visit_with(visitor),
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_ => false
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}
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}
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}
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impl<'tcx> TypeFoldable<'tcx> for Constant<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
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Constant {
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span: self.span.clone(),
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ty: self.ty.fold_with(folder),
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literal: self.literal.fold_with(folder)
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}
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}
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fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
|
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self.ty.visit_with(visitor) || self.literal.visit_with(visitor)
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||||
}
|
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}
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impl<'tcx> TypeFoldable<'tcx> for Literal<'tcx> {
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fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
|
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match *self {
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Literal::Item { def_id, substs } => Literal::Item {
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def_id: def_id,
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substs: substs.fold_with(folder)
|
||||
},
|
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_ => self.clone()
|
||||
}
|
||||
}
|
||||
fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
|
||||
match *self {
|
||||
Literal::Item { substs, .. } => substs.visit_with(visitor),
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
@ -2302,6 +2302,20 @@ impl<'a, 'gcx, 'tcx> TyCtxt<'a, 'gcx, 'tcx> {
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||||
queries::mir::get(self, DUMMY_SP, did).borrow()
|
||||
}
|
||||
|
||||
/// Given the DefId of an item, returns its MIR, borrowed immutably.
|
||||
/// Returns None if there is no MIR for the DefId
|
||||
pub fn maybe_item_mir(self, did: DefId) -> Option<Ref<'gcx, Mir<'gcx>>> {
|
||||
if did.is_local() && !self.maps.mir.borrow().contains_key(&did) {
|
||||
return None;
|
||||
}
|
||||
|
||||
if !did.is_local() && !self.sess.cstore.is_item_mir_available(did) {
|
||||
return None;
|
||||
}
|
||||
|
||||
Some(self.item_mir(did))
|
||||
}
|
||||
|
||||
/// If `type_needs_drop` returns true, then `ty` is definitely
|
||||
/// non-copy and *might* have a destructor attached; if it returns
|
||||
/// false, then `ty` definitely has no destructor (i.e. no drop glue).
|
||||
|
||||
@ -12,6 +12,7 @@ use infer::type_variable;
|
||||
use ty::{self, Lift, Ty, TyCtxt};
|
||||
use ty::fold::{TypeFoldable, TypeFolder, TypeVisitor};
|
||||
use rustc_data_structures::accumulate_vec::AccumulateVec;
|
||||
use rustc_data_structures::indexed_vec::{IndexVec, Idx};
|
||||
|
||||
use std::rc::Rc;
|
||||
use syntax::abi;
|
||||
@ -834,3 +835,13 @@ impl<'tcx, T: TypeFoldable<'tcx>> TypeFoldable<'tcx> for ty::error::ExpectedFoun
|
||||
self.expected.visit_with(visitor) || self.found.visit_with(visitor)
|
||||
}
|
||||
}
|
||||
|
||||
impl<'tcx, T: TypeFoldable<'tcx>, I: Idx> TypeFoldable<'tcx> for IndexVec<I, T> {
|
||||
fn super_fold_with<'gcx: 'tcx, F: TypeFolder<'gcx, 'tcx>>(&self, folder: &mut F) -> Self {
|
||||
self.iter().map(|x| x.fold_with(folder)).collect()
|
||||
}
|
||||
|
||||
fn super_visit_with<V: TypeVisitor<'tcx>>(&self, visitor: &mut V) -> bool {
|
||||
self.iter().any(|t| t.visit_with(visitor))
|
||||
}
|
||||
}
|
||||
|
||||
@ -654,11 +654,12 @@ impl<'a, 'tcx> ty::TyS<'tcx> {
|
||||
}
|
||||
|
||||
tcx.layout_depth.set(depth+1);
|
||||
let layout = Layout::compute_uncached(self, infcx)?;
|
||||
let layout = Layout::compute_uncached(self, infcx);
|
||||
tcx.layout_depth.set(depth);
|
||||
let layout = layout?;
|
||||
if can_cache {
|
||||
tcx.layout_cache.borrow_mut().insert(self, layout);
|
||||
}
|
||||
tcx.layout_depth.set(depth);
|
||||
Ok(layout)
|
||||
}
|
||||
|
||||
|
||||
@ -8,6 +8,7 @@
|
||||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
use std::collections::range::RangeArgument;
|
||||
use std::fmt::Debug;
|
||||
use std::iter::{self, FromIterator};
|
||||
use std::slice;
|
||||
@ -145,6 +146,18 @@ impl<I: Idx, T> IndexVec<I, T> {
|
||||
self.raw.iter_mut().enumerate().map(IntoIdx { _marker: PhantomData })
|
||||
}
|
||||
|
||||
#[inline]
|
||||
pub fn drain<'a, R: RangeArgument<usize>>(
|
||||
&'a mut self, range: R) -> impl Iterator<Item=T> + 'a {
|
||||
self.raw.drain(range)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
pub fn drain_enumerated<'a, R: RangeArgument<usize>>(
|
||||
&'a mut self, range: R) -> impl Iterator<Item=(I, T)> + 'a {
|
||||
self.raw.drain(range).enumerate().map(IntoIdx { _marker: PhantomData })
|
||||
}
|
||||
|
||||
#[inline]
|
||||
pub fn last(&self) -> Option<I> {
|
||||
self.len().checked_sub(1).map(I::new)
|
||||
@ -164,6 +177,16 @@ impl<I: Idx, T> IndexVec<I, T> {
|
||||
pub fn truncate(&mut self, a: usize) {
|
||||
self.raw.truncate(a)
|
||||
}
|
||||
|
||||
#[inline]
|
||||
pub fn get(&self, index: I) -> Option<&T> {
|
||||
self.raw.get(index.index())
|
||||
}
|
||||
|
||||
#[inline]
|
||||
pub fn get_mut(&mut self, index: I) -> Option<&mut T> {
|
||||
self.raw.get_mut(index.index())
|
||||
}
|
||||
}
|
||||
|
||||
impl<I: Idx, T> Index<I> for IndexVec<I, T> {
|
||||
|
||||
@ -38,6 +38,7 @@
|
||||
#![feature(associated_consts)]
|
||||
#![feature(unsize)]
|
||||
#![feature(i128_type)]
|
||||
#![feature(conservative_impl_trait)]
|
||||
|
||||
#![cfg_attr(unix, feature(libc))]
|
||||
#![cfg_attr(test, feature(test))]
|
||||
|
||||
@ -1051,6 +1051,7 @@ pub fn phase_4_translate_to_llvm<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
||||
passes.push_pass(box mir::transform::simplify::SimplifyCfg::new("elaborate-drops"));
|
||||
|
||||
// No lifetime analysis based on borrowing can be done from here on out.
|
||||
passes.push_pass(box mir::transform::inline::Inline);
|
||||
passes.push_pass(box mir::transform::instcombine::InstCombine::new());
|
||||
passes.push_pass(box mir::transform::deaggregator::Deaggregator);
|
||||
passes.push_pass(box mir::transform::copy_prop::CopyPropagation);
|
||||
|
||||
252
src/librustc_mir/callgraph.rs
Normal file
252
src/librustc_mir/callgraph.rs
Normal file
@ -0,0 +1,252 @@
|
||||
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
|
||||
// file at the top-level directory of this distribution and at
|
||||
// http://rust-lang.org/COPYRIGHT.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||||
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||||
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
||||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
//! MIR-based callgraph.
|
||||
//!
|
||||
//! This only considers direct calls
|
||||
|
||||
use rustc::hir::def_id::DefId;
|
||||
use rustc_data_structures::graph;
|
||||
|
||||
use rustc::mir::*;
|
||||
use rustc::mir::visit::*;
|
||||
|
||||
use rustc::ty;
|
||||
|
||||
use rustc::util::nodemap::DefIdMap;
|
||||
|
||||
pub struct CallGraph {
|
||||
node_map: DefIdMap<graph::NodeIndex>,
|
||||
graph: graph::Graph<DefId, ()>
|
||||
}
|
||||
|
||||
impl CallGraph {
|
||||
// FIXME: allow for construction of a callgraph that inspects
|
||||
// cross-crate MIRs if available.
|
||||
pub fn build<'a, 'tcx>(tcx: ty::TyCtxt<'a, 'tcx, 'tcx>) -> CallGraph {
|
||||
let def_ids = tcx.maps.mir.borrow().keys();
|
||||
|
||||
let mut callgraph = CallGraph {
|
||||
node_map: DefIdMap(),
|
||||
graph: graph::Graph::new()
|
||||
};
|
||||
|
||||
for def_id in def_ids {
|
||||
if !def_id.is_local() { continue; }
|
||||
|
||||
let idx = callgraph.add_node(def_id);
|
||||
|
||||
let mut call_visitor = CallVisitor {
|
||||
caller: idx,
|
||||
graph: &mut callgraph
|
||||
};
|
||||
|
||||
let mir = tcx.item_mir(def_id);
|
||||
call_visitor.visit_mir(&mir);
|
||||
}
|
||||
|
||||
callgraph
|
||||
}
|
||||
|
||||
// Iterate over the strongly-connected components of the graph
|
||||
pub fn scc_iter(&self) -> SCCIterator {
|
||||
SCCIterator::new(&self.graph)
|
||||
}
|
||||
|
||||
// Get the def_id for the given graph node
|
||||
pub fn def_id(&self, node: graph::NodeIndex) -> DefId {
|
||||
*self.graph.node_data(node)
|
||||
}
|
||||
|
||||
fn add_node(&mut self, id: DefId) -> graph::NodeIndex {
|
||||
let graph = &mut self.graph;
|
||||
*self.node_map.entry(id).or_insert_with(|| {
|
||||
graph.add_node(id)
|
||||
})
|
||||
}
|
||||
}
|
||||
|
||||
struct CallVisitor<'a> {
|
||||
caller: graph::NodeIndex,
|
||||
graph: &'a mut CallGraph
|
||||
}
|
||||
|
||||
impl<'a, 'tcx> Visitor<'tcx> for CallVisitor<'a> {
|
||||
fn visit_terminator_kind(&mut self, _block: BasicBlock,
|
||||
kind: &TerminatorKind<'tcx>, _loc: Location) {
|
||||
if let TerminatorKind::Call {
|
||||
func: Operand::Constant(ref f)
|
||||
, .. } = *kind {
|
||||
if let ty::TyFnDef(def_id, _, _) = f.ty.sty {
|
||||
let callee = self.graph.add_node(def_id);
|
||||
self.graph.graph.add_edge(self.caller, callee, ());
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
struct StackElement<'g> {
|
||||
node: graph::NodeIndex,
|
||||
lowlink: usize,
|
||||
children: graph::AdjacentTargets<'g, DefId, ()>
|
||||
}
|
||||
|
||||
/**
|
||||
* Iterator over strongly-connected-components using Tarjan's algorithm[1]
|
||||
*
|
||||
* [1]: https://en.wikipedia.org/wiki/Tarjan%27s_strongly_connected_components_algorithm
|
||||
*/
|
||||
pub struct SCCIterator<'g> {
|
||||
graph: &'g graph::Graph<DefId, ()>,
|
||||
index: usize,
|
||||
node_indices: Vec<Option<usize>>,
|
||||
scc_stack: Vec<graph::NodeIndex>,
|
||||
current_scc: Vec<graph::NodeIndex>,
|
||||
visit_stack: Vec<StackElement<'g>>,
|
||||
}
|
||||
|
||||
impl<'g> SCCIterator<'g> {
|
||||
pub fn new(graph: &'g graph::Graph<DefId, ()>) -> SCCIterator<'g> {
|
||||
if graph.len_nodes() == 0 {
|
||||
return SCCIterator {
|
||||
graph: graph,
|
||||
index: 0,
|
||||
node_indices: Vec::new(),
|
||||
scc_stack: Vec::new(),
|
||||
current_scc: Vec::new(),
|
||||
visit_stack: Vec::new()
|
||||
};
|
||||
}
|
||||
|
||||
let first = graph::NodeIndex(0);
|
||||
|
||||
SCCIterator::with_entry(graph, first)
|
||||
}
|
||||
|
||||
pub fn with_entry(graph: &'g graph::Graph<DefId, ()>,
|
||||
entry: graph::NodeIndex) -> SCCIterator<'g> {
|
||||
let mut iter = SCCIterator {
|
||||
graph: graph,
|
||||
index: 0,
|
||||
node_indices: Vec::with_capacity(graph.len_nodes()),
|
||||
scc_stack: Vec::new(),
|
||||
current_scc: Vec::new(),
|
||||
visit_stack: Vec::new()
|
||||
};
|
||||
|
||||
iter.visit_one(entry);
|
||||
|
||||
iter
|
||||
}
|
||||
|
||||
fn get_next(&mut self) {
|
||||
self.current_scc.clear();
|
||||
|
||||
while !self.visit_stack.is_empty() {
|
||||
self.visit_children();
|
||||
|
||||
let node = self.visit_stack.pop().unwrap();
|
||||
|
||||
if let Some(last) = self.visit_stack.last_mut() {
|
||||
if last.lowlink > node.lowlink {
|
||||
last.lowlink = node.lowlink;
|
||||
}
|
||||
}
|
||||
|
||||
debug!("TarjanSCC: Popped node {:?} : lowlink = {:?}; index = {:?}",
|
||||
node.node, node.lowlink, self.node_index(node.node).unwrap());
|
||||
|
||||
if node.lowlink != self.node_index(node.node).unwrap() {
|
||||
continue;
|
||||
}
|
||||
|
||||
loop {
|
||||
let n = self.scc_stack.pop().unwrap();
|
||||
self.current_scc.push(n);
|
||||
self.set_node_index(n, !0);
|
||||
if n == node.node { return; }
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn visit_one(&mut self, node: graph::NodeIndex) {
|
||||
self.index += 1;
|
||||
let idx = self.index;
|
||||
self.set_node_index(node, idx);
|
||||
self.scc_stack.push(node);
|
||||
self.visit_stack.push(StackElement {
|
||||
node: node,
|
||||
lowlink: self.index,
|
||||
children: self.graph.successor_nodes(node)
|
||||
});
|
||||
debug!("TarjanSCC: Node {:?} : index = {:?}", node, idx);
|
||||
}
|
||||
|
||||
fn visit_children(&mut self) {
|
||||
while let Some(child) = self.visit_stack.last_mut().unwrap().children.next() {
|
||||
if let Some(child_num) = self.node_index(child) {
|
||||
let cur = self.visit_stack.last_mut().unwrap();
|
||||
if cur.lowlink > child_num {
|
||||
cur.lowlink = child_num;
|
||||
}
|
||||
} else {
|
||||
self.visit_one(child);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn node_index(&self, node: graph::NodeIndex) -> Option<usize> {
|
||||
self.node_indices.get(node.node_id()).and_then(|&idx| idx)
|
||||
}
|
||||
|
||||
fn set_node_index(&mut self, node: graph::NodeIndex, idx: usize) {
|
||||
let i = node.node_id();
|
||||
if i >= self.node_indices.len() {
|
||||
self.node_indices.resize(i + 1, None);
|
||||
}
|
||||
self.node_indices[i] = Some(idx);
|
||||
}
|
||||
}
|
||||
|
||||
impl<'g> Iterator for SCCIterator<'g> {
|
||||
type Item = Vec<graph::NodeIndex>;
|
||||
|
||||
fn next(&mut self) -> Option<Vec<graph::NodeIndex>> {
|
||||
self.get_next();
|
||||
|
||||
if self.current_scc.is_empty() {
|
||||
// Try a new root for the next SCC, if the node_indices
|
||||
// map is doesn't contain all nodes, use the smallest one
|
||||
// with no entry, otherwise find the first empty node.
|
||||
//
|
||||
// FIXME: This should probably use a set of precomputed
|
||||
// roots instead
|
||||
if self.node_indices.len() < self.graph.len_nodes() {
|
||||
let idx = graph::NodeIndex(self.node_indices.len());
|
||||
self.visit_one(idx);
|
||||
} else {
|
||||
for idx in 0..self.node_indices.len() {
|
||||
if self.node_indices[idx].is_none() {
|
||||
let idx = graph::NodeIndex(idx);
|
||||
self.visit_one(idx);
|
||||
break;
|
||||
}
|
||||
}
|
||||
}
|
||||
self.get_next();
|
||||
}
|
||||
|
||||
if self.current_scc.is_empty() {
|
||||
None
|
||||
} else {
|
||||
Some(self.current_scc.clone())
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -46,6 +46,7 @@ extern crate rustc_const_eval;
|
||||
pub mod diagnostics;
|
||||
|
||||
pub mod build;
|
||||
pub mod callgraph;
|
||||
pub mod def_use;
|
||||
pub mod graphviz;
|
||||
mod hair;
|
||||
|
||||
836
src/librustc_mir/transform/inline.rs
Normal file
836
src/librustc_mir/transform/inline.rs
Normal file
@ -0,0 +1,836 @@
|
||||
// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
|
||||
// file at the top-level directory of this distribution and at
|
||||
// http://rust-lang.org/COPYRIGHT.
|
||||
//
|
||||
// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
|
||||
// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
|
||||
// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
|
||||
// option. This file may not be copied, modified, or distributed
|
||||
// except according to those terms.
|
||||
|
||||
//! Inlining pass for MIR functions
|
||||
|
||||
use rustc::hir::def_id::DefId;
|
||||
|
||||
use rustc_data_structures::bitvec::BitVector;
|
||||
use rustc_data_structures::indexed_vec::{Idx, IndexVec};
|
||||
use rustc_data_structures::graph;
|
||||
|
||||
use rustc::dep_graph::DepNode;
|
||||
use rustc::mir::*;
|
||||
use rustc::mir::transform::{MirMapPass, MirPassHook, MirSource, Pass};
|
||||
use rustc::mir::visit::*;
|
||||
use rustc::traits;
|
||||
use rustc::ty::{self, Ty, TyCtxt};
|
||||
use rustc::ty::subst::{Subst,Substs};
|
||||
use rustc::util::nodemap::{DefIdSet};
|
||||
|
||||
use super::simplify::{remove_dead_blocks, CfgSimplifier};
|
||||
|
||||
use syntax::{attr};
|
||||
use syntax::abi::Abi;
|
||||
|
||||
use callgraph;
|
||||
|
||||
const DEFAULT_THRESHOLD: usize = 50;
|
||||
const HINT_THRESHOLD: usize = 100;
|
||||
|
||||
const INSTR_COST: usize = 5;
|
||||
const CALL_PENALTY: usize = 25;
|
||||
|
||||
const UNKNOWN_SIZE_COST: usize = 10;
|
||||
|
||||
pub struct Inline;
|
||||
|
||||
impl<'tcx> MirMapPass<'tcx> for Inline {
|
||||
fn run_pass<'a>(
|
||||
&mut self,
|
||||
tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
||||
hooks: &mut [Box<for<'s> MirPassHook<'s>>]) {
|
||||
|
||||
if tcx.sess.opts.debugging_opts.mir_opt_level < 2 { return; }
|
||||
|
||||
let _ignore = tcx.dep_graph.in_ignore();
|
||||
|
||||
let callgraph = callgraph::CallGraph::build(tcx);
|
||||
|
||||
let mut inliner = Inliner {
|
||||
tcx: tcx,
|
||||
};
|
||||
|
||||
let def_ids = tcx.maps.mir.borrow().keys();
|
||||
for &def_id in &def_ids {
|
||||
if !def_id.is_local() { continue; }
|
||||
|
||||
let _task = tcx.dep_graph.in_task(DepNode::Mir(def_id));
|
||||
let mut mir = if let Some(mir) = tcx.maps.mir.borrow().get(&def_id) {
|
||||
mir.borrow_mut()
|
||||
} else {
|
||||
continue;
|
||||
};
|
||||
|
||||
tcx.dep_graph.write(DepNode::Mir(def_id));
|
||||
|
||||
let id = tcx.hir.as_local_node_id(def_id).unwrap();
|
||||
let src = MirSource::from_node(tcx, id);
|
||||
|
||||
for hook in &mut *hooks {
|
||||
hook.on_mir_pass(tcx, src, &mut mir, self, false);
|
||||
}
|
||||
}
|
||||
|
||||
for scc in callgraph.scc_iter() {
|
||||
inliner.inline_scc(&callgraph, &scc);
|
||||
}
|
||||
|
||||
for def_id in def_ids {
|
||||
if !def_id.is_local() { continue; }
|
||||
|
||||
let _task = tcx.dep_graph.in_task(DepNode::Mir(def_id));
|
||||
let mut mir = tcx.maps.mir.borrow()[&def_id].borrow_mut();
|
||||
tcx.dep_graph.write(DepNode::Mir(def_id));
|
||||
|
||||
let id = tcx.hir.as_local_node_id(def_id).unwrap();
|
||||
let src = MirSource::from_node(tcx, id);
|
||||
|
||||
for hook in &mut *hooks {
|
||||
hook.on_mir_pass(tcx, src, &mut mir, self, true);
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'tcx> Pass for Inline { }
|
||||
|
||||
struct Inliner<'a, 'tcx: 'a> {
|
||||
tcx: TyCtxt<'a, 'tcx, 'tcx>,
|
||||
}
|
||||
|
||||
#[derive(Copy, Clone)]
|
||||
struct CallSite<'tcx> {
|
||||
caller: DefId,
|
||||
callee: DefId,
|
||||
substs: &'tcx Substs<'tcx>,
|
||||
bb: BasicBlock,
|
||||
location: SourceInfo,
|
||||
}
|
||||
|
||||
impl<'a, 'tcx> Inliner<'a, 'tcx> {
|
||||
fn inline_scc(&mut self, callgraph: &callgraph::CallGraph, scc: &[graph::NodeIndex]) -> bool {
|
||||
let mut callsites = Vec::new();
|
||||
let mut in_scc = DefIdSet();
|
||||
|
||||
let mut inlined_into = DefIdSet();
|
||||
|
||||
for &node in scc {
|
||||
let def_id = callgraph.def_id(node);
|
||||
|
||||
// Don't inspect functions from other crates
|
||||
let id = if let Some(id) = self.tcx.hir.as_local_node_id(def_id) {
|
||||
id
|
||||
} else {
|
||||
continue;
|
||||
};
|
||||
let src = MirSource::from_node(self.tcx, id);
|
||||
if let MirSource::Fn(_) = src {
|
||||
if let Some(mir) = self.tcx.maybe_item_mir(def_id) {
|
||||
for (bb, bb_data) in mir.basic_blocks().iter_enumerated() {
|
||||
// Don't inline calls that are in cleanup blocks.
|
||||
if bb_data.is_cleanup { continue; }
|
||||
|
||||
// Only consider direct calls to functions
|
||||
let terminator = bb_data.terminator();
|
||||
if let TerminatorKind::Call {
|
||||
func: Operand::Constant(ref f), .. } = terminator.kind {
|
||||
if let ty::TyFnDef(callee_def_id, substs, _) = f.ty.sty {
|
||||
callsites.push(CallSite {
|
||||
caller: def_id,
|
||||
callee: callee_def_id,
|
||||
substs: substs,
|
||||
bb: bb,
|
||||
location: terminator.source_info
|
||||
});
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
in_scc.insert(def_id);
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Move callsites that are in the the SCC to the end so
|
||||
// they're inlined after calls to outside the SCC
|
||||
let mut first_call_in_scc = callsites.len();
|
||||
|
||||
let mut i = 0;
|
||||
while i < first_call_in_scc {
|
||||
let f = callsites[i].caller;
|
||||
if in_scc.contains(&f) {
|
||||
first_call_in_scc -= 1;
|
||||
callsites.swap(i, first_call_in_scc);
|
||||
} else {
|
||||
i += 1;
|
||||
}
|
||||
}
|
||||
|
||||
let mut local_change;
|
||||
let mut changed = false;
|
||||
|
||||
loop {
|
||||
local_change = false;
|
||||
let mut csi = 0;
|
||||
while csi < callsites.len() {
|
||||
let callsite = callsites[csi];
|
||||
csi += 1;
|
||||
|
||||
let _task = self.tcx.dep_graph.in_task(DepNode::Mir(callsite.caller));
|
||||
self.tcx.dep_graph.write(DepNode::Mir(callsite.caller));
|
||||
|
||||
let callee_mir = {
|
||||
if let Some(callee_mir) = self.tcx.maybe_item_mir(callsite.callee) {
|
||||
if !self.should_inline(callsite, &callee_mir) {
|
||||
continue;
|
||||
}
|
||||
|
||||
callee_mir.subst(self.tcx, callsite.substs)
|
||||
} else {
|
||||
continue;
|
||||
}
|
||||
|
||||
};
|
||||
|
||||
let mut caller_mir = {
|
||||
let map = self.tcx.maps.mir.borrow();
|
||||
let mir = map.get(&callsite.caller).unwrap();
|
||||
mir.borrow_mut()
|
||||
};
|
||||
|
||||
let start = caller_mir.basic_blocks().len();
|
||||
|
||||
if !self.inline_call(callsite, &mut caller_mir, callee_mir) {
|
||||
continue;
|
||||
}
|
||||
|
||||
inlined_into.insert(callsite.caller);
|
||||
|
||||
// Add callsites from inlined function
|
||||
for (bb, bb_data) in caller_mir.basic_blocks().iter_enumerated().skip(start) {
|
||||
// Only consider direct calls to functions
|
||||
let terminator = bb_data.terminator();
|
||||
if let TerminatorKind::Call {
|
||||
func: Operand::Constant(ref f), .. } = terminator.kind {
|
||||
if let ty::TyFnDef(callee_def_id, substs, _) = f.ty.sty {
|
||||
// Don't inline the same function multiple times.
|
||||
if callsite.callee != callee_def_id {
|
||||
callsites.push(CallSite {
|
||||
caller: callsite.caller,
|
||||
callee: callee_def_id,
|
||||
substs: substs,
|
||||
bb: bb,
|
||||
location: terminator.source_info
|
||||
});
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
csi -= 1;
|
||||
if scc.len() == 1 {
|
||||
callsites.swap_remove(csi);
|
||||
} else {
|
||||
callsites.remove(csi);
|
||||
}
|
||||
|
||||
local_change = true;
|
||||
changed = true;
|
||||
}
|
||||
|
||||
if !local_change {
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
// Simplify functions we inlined into.
|
||||
for def_id in inlined_into {
|
||||
let _task = self.tcx.dep_graph.in_task(DepNode::Mir(def_id));
|
||||
self.tcx.dep_graph.write(DepNode::Mir(def_id));
|
||||
|
||||
let mut caller_mir = {
|
||||
let map = self.tcx.maps.mir.borrow();
|
||||
let mir = map.get(&def_id).unwrap();
|
||||
mir.borrow_mut()
|
||||
};
|
||||
|
||||
debug!("Running simplify cfg on {:?}", def_id);
|
||||
CfgSimplifier::new(&mut caller_mir).simplify();
|
||||
remove_dead_blocks(&mut caller_mir);
|
||||
}
|
||||
changed
|
||||
}
|
||||
|
||||
fn should_inline(&self, callsite: CallSite<'tcx>,
|
||||
callee_mir: &'a Mir<'tcx>) -> bool {
|
||||
|
||||
let tcx = self.tcx;
|
||||
|
||||
// Don't inline closures that have captures
|
||||
// FIXME: Handle closures better
|
||||
if callee_mir.upvar_decls.len() > 0 {
|
||||
return false;
|
||||
}
|
||||
|
||||
|
||||
let attrs = tcx.get_attrs(callsite.callee);
|
||||
let hint = attr::find_inline_attr(None, &attrs[..]);
|
||||
|
||||
let hinted = match hint {
|
||||
// Just treat inline(always) as a hint for now,
|
||||
// there are cases that prevent inlining that we
|
||||
// need to check for first.
|
||||
attr::InlineAttr::Always => true,
|
||||
attr::InlineAttr::Never => return false,
|
||||
attr::InlineAttr::Hint => true,
|
||||
attr::InlineAttr::None => false,
|
||||
};
|
||||
|
||||
// Only inline local functions if they would be eligible for cross-crate
|
||||
// inlining. This is to ensure that the final crate doesn't have MIR that
|
||||
// reference unexported symbols
|
||||
if callsite.callee.is_local() {
|
||||
if callsite.substs.types().count() == 0 && !hinted {
|
||||
return false;
|
||||
}
|
||||
}
|
||||
|
||||
let mut threshold = if hinted {
|
||||
HINT_THRESHOLD
|
||||
} else {
|
||||
DEFAULT_THRESHOLD
|
||||
};
|
||||
|
||||
// Significantly lower the threshold for inlining cold functions
|
||||
if attr::contains_name(&attrs[..], "cold") {
|
||||
threshold /= 5;
|
||||
}
|
||||
|
||||
// Give a bonus functions with a small number of blocks,
|
||||
// We normally have two or three blocks for even
|
||||
// very small functions.
|
||||
if callee_mir.basic_blocks().len() <= 3 {
|
||||
threshold += threshold / 4;
|
||||
}
|
||||
|
||||
// FIXME: Give a bonus to functions with only a single caller
|
||||
|
||||
let id = tcx.hir.as_local_node_id(callsite.caller).expect("Caller not local");
|
||||
let param_env = ty::ParameterEnvironment::for_item(tcx, id);
|
||||
|
||||
let mut first_block = true;
|
||||
let mut cost = 0;
|
||||
|
||||
// Traverse the MIR manually so we can account for the effects of
|
||||
// inlining on the CFG.
|
||||
let mut work_list = vec![START_BLOCK];
|
||||
let mut visited = BitVector::new(callee_mir.basic_blocks().len());
|
||||
while let Some(bb) = work_list.pop() {
|
||||
if !visited.insert(bb.index()) { continue; }
|
||||
let blk = &callee_mir.basic_blocks()[bb];
|
||||
|
||||
for stmt in &blk.statements {
|
||||
// Don't count StorageLive/StorageDead in the inlining cost.
|
||||
match stmt.kind {
|
||||
StatementKind::StorageLive(_) |
|
||||
StatementKind::StorageDead(_) |
|
||||
StatementKind::Nop => {}
|
||||
_ => cost += INSTR_COST
|
||||
}
|
||||
}
|
||||
let term = blk.terminator();
|
||||
let mut is_drop = false;
|
||||
match term.kind {
|
||||
TerminatorKind::Drop { ref location, target, unwind } |
|
||||
TerminatorKind::DropAndReplace { ref location, target, unwind, .. } => {
|
||||
is_drop = true;
|
||||
work_list.push(target);
|
||||
// If the location doesn't actually need dropping, treat it like
|
||||
// a regular goto.
|
||||
let ty = location.ty(&callee_mir, tcx).subst(tcx, callsite.substs);
|
||||
let ty = ty.to_ty(tcx);
|
||||
if tcx.type_needs_drop_given_env(ty, ¶m_env) {
|
||||
cost += CALL_PENALTY;
|
||||
if let Some(unwind) = unwind {
|
||||
work_list.push(unwind);
|
||||
}
|
||||
} else {
|
||||
cost += INSTR_COST;
|
||||
}
|
||||
}
|
||||
|
||||
TerminatorKind::Unreachable |
|
||||
TerminatorKind::Call { destination: None, .. } if first_block => {
|
||||
// If the function always diverges, don't inline
|
||||
// unless the cost is zero
|
||||
threshold = 0;
|
||||
}
|
||||
|
||||
TerminatorKind::Call {func: Operand::Constant(ref f), .. } => {
|
||||
if let ty::TyFnDef(.., f) = f.ty.sty {
|
||||
// Don't give intrinsics the extra penalty for calls
|
||||
if f.abi() == Abi::RustIntrinsic || f.abi() == Abi::PlatformIntrinsic {
|
||||
cost += INSTR_COST;
|
||||
} else {
|
||||
cost += CALL_PENALTY;
|
||||
}
|
||||
}
|
||||
}
|
||||
TerminatorKind::Assert { .. } => cost += CALL_PENALTY,
|
||||
_ => cost += INSTR_COST
|
||||
}
|
||||
|
||||
if !is_drop {
|
||||
for &succ in &term.successors()[..] {
|
||||
work_list.push(succ);
|
||||
}
|
||||
}
|
||||
|
||||
first_block = false;
|
||||
}
|
||||
|
||||
// Count up the cost of local variables and temps, if we know the size
|
||||
// use that, otherwise we use a moderately-large dummy cost.
|
||||
|
||||
let ptr_size = tcx.data_layout.pointer_size.bytes();
|
||||
|
||||
for v in callee_mir.vars_and_temps_iter() {
|
||||
let v = &callee_mir.local_decls[v];
|
||||
let ty = v.ty.subst(tcx, callsite.substs);
|
||||
// Cost of the var is the size in machine-words, if we know
|
||||
// it.
|
||||
if let Some(size) = type_size_of(tcx, param_env.clone(), ty) {
|
||||
cost += (size / ptr_size) as usize;
|
||||
} else {
|
||||
cost += UNKNOWN_SIZE_COST;
|
||||
}
|
||||
}
|
||||
|
||||
debug!("Inline cost for {:?} is {}", callsite.callee, cost);
|
||||
|
||||
if let attr::InlineAttr::Always = hint {
|
||||
true
|
||||
} else {
|
||||
cost <= threshold
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
fn inline_call(&self, callsite: CallSite<'tcx>,
|
||||
caller_mir: &mut Mir<'tcx>, mut callee_mir: Mir<'tcx>) -> bool {
|
||||
|
||||
// Don't inline a function into itself
|
||||
if callsite.caller == callsite.callee { return false; }
|
||||
|
||||
let _task = self.tcx.dep_graph.in_task(DepNode::Mir(callsite.caller));
|
||||
|
||||
|
||||
let terminator = caller_mir[callsite.bb].terminator.take().unwrap();
|
||||
match terminator.kind {
|
||||
// FIXME: Handle inlining of diverging calls
|
||||
TerminatorKind::Call { args, destination: Some(destination), cleanup, .. } => {
|
||||
|
||||
debug!("Inlined {:?} into {:?}", callsite.callee, callsite.caller);
|
||||
|
||||
let is_box_free = Some(callsite.callee) == self.tcx.lang_items.box_free_fn();
|
||||
|
||||
let mut local_map = IndexVec::with_capacity(callee_mir.local_decls.len());
|
||||
let mut scope_map = IndexVec::with_capacity(callee_mir.visibility_scopes.len());
|
||||
let mut promoted_map = IndexVec::with_capacity(callee_mir.promoted.len());
|
||||
|
||||
for mut scope in callee_mir.visibility_scopes.iter().cloned() {
|
||||
if scope.parent_scope.is_none() {
|
||||
scope.parent_scope = Some(callsite.location.scope);
|
||||
scope.span = callee_mir.span;
|
||||
}
|
||||
|
||||
scope.span = callsite.location.span;
|
||||
|
||||
let idx = caller_mir.visibility_scopes.push(scope);
|
||||
scope_map.push(idx);
|
||||
}
|
||||
|
||||
for loc in callee_mir.vars_and_temps_iter() {
|
||||
let mut local = callee_mir.local_decls[loc].clone();
|
||||
|
||||
if let Some(ref mut source_info) = local.source_info {
|
||||
source_info.scope = scope_map[source_info.scope];
|
||||
|
||||
source_info.span = callsite.location.span;
|
||||
}
|
||||
|
||||
let idx = caller_mir.local_decls.push(local);
|
||||
local_map.push(idx);
|
||||
}
|
||||
|
||||
for p in callee_mir.promoted.iter().cloned() {
|
||||
let idx = caller_mir.promoted.push(p);
|
||||
promoted_map.push(idx);
|
||||
}
|
||||
|
||||
// If the call is something like `a[*i] = f(i)`, where
|
||||
// `i : &mut usize`, then just duplicating the `a[*i]`
|
||||
// Lvalue could result in two different locations if `f`
|
||||
// writes to `i`. To prevent this we need to create a temporary
|
||||
// borrow of the lvalue and pass the destination as `*temp` instead.
|
||||
fn dest_needs_borrow(lval: &Lvalue) -> bool {
|
||||
match *lval {
|
||||
Lvalue::Projection(ref p) => {
|
||||
match p.elem {
|
||||
ProjectionElem::Deref |
|
||||
ProjectionElem::Index(_) => true,
|
||||
_ => dest_needs_borrow(&p.base)
|
||||
}
|
||||
}
|
||||
// Static variables need a borrow because the callee
|
||||
// might modify the same static.
|
||||
Lvalue::Static(_) => true,
|
||||
_ => false
|
||||
}
|
||||
}
|
||||
|
||||
let dest = if dest_needs_borrow(&destination.0) {
|
||||
debug!("Creating temp for return destination");
|
||||
let dest = Rvalue::Ref(
|
||||
self.tcx.mk_region(ty::ReErased),
|
||||
BorrowKind::Mut,
|
||||
destination.0);
|
||||
|
||||
let ty = dest.ty(caller_mir, self.tcx);
|
||||
|
||||
let temp = LocalDecl::new_temp(ty);
|
||||
|
||||
let tmp = caller_mir.local_decls.push(temp);
|
||||
let tmp = Lvalue::Local(tmp);
|
||||
|
||||
let stmt = Statement {
|
||||
source_info: callsite.location,
|
||||
kind: StatementKind::Assign(tmp.clone(), dest)
|
||||
};
|
||||
caller_mir[callsite.bb]
|
||||
.statements.push(stmt);
|
||||
tmp.deref()
|
||||
} else {
|
||||
destination.0
|
||||
};
|
||||
|
||||
let return_block = destination.1;
|
||||
|
||||
let args : Vec<_> = if is_box_free {
|
||||
assert!(args.len() == 1);
|
||||
// box_free takes a Box, but is defined with a *mut T, inlining
|
||||
// needs to generate the cast.
|
||||
// FIXME: we should probably just generate correct MIR in the first place...
|
||||
|
||||
let arg = if let Operand::Consume(ref lval) = args[0] {
|
||||
lval.clone()
|
||||
} else {
|
||||
bug!("Constant arg to \"box_free\"");
|
||||
};
|
||||
|
||||
let ptr_ty = args[0].ty(caller_mir, self.tcx);
|
||||
vec![self.cast_box_free_arg(arg, ptr_ty, &callsite, caller_mir)]
|
||||
} else {
|
||||
// Copy the arguments if needed.
|
||||
self.make_call_args(args, &callsite, caller_mir)
|
||||
};
|
||||
|
||||
let bb_len = caller_mir.basic_blocks().len();
|
||||
let mut integrator = Integrator {
|
||||
block_idx: bb_len,
|
||||
args: &args,
|
||||
local_map: local_map,
|
||||
scope_map: scope_map,
|
||||
promoted_map: promoted_map,
|
||||
_callsite: callsite,
|
||||
destination: dest,
|
||||
return_block: return_block,
|
||||
cleanup_block: cleanup,
|
||||
in_cleanup_block: false
|
||||
};
|
||||
|
||||
|
||||
for (bb, mut block) in callee_mir.basic_blocks_mut().drain_enumerated(..) {
|
||||
integrator.visit_basic_block_data(bb, &mut block);
|
||||
caller_mir.basic_blocks_mut().push(block);
|
||||
}
|
||||
|
||||
let terminator = Terminator {
|
||||
source_info: callsite.location,
|
||||
kind: TerminatorKind::Goto { target: BasicBlock::new(bb_len) }
|
||||
};
|
||||
|
||||
caller_mir[callsite.bb].terminator = Some(terminator);
|
||||
|
||||
true
|
||||
}
|
||||
kind => {
|
||||
caller_mir[callsite.bb].terminator = Some(Terminator {
|
||||
source_info: terminator.source_info,
|
||||
kind: kind
|
||||
});
|
||||
false
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn cast_box_free_arg(&self, arg: Lvalue<'tcx>, ptr_ty: Ty<'tcx>,
|
||||
callsite: &CallSite<'tcx>, caller_mir: &mut Mir<'tcx>) -> Operand<'tcx> {
|
||||
let arg = Rvalue::Ref(
|
||||
self.tcx.mk_region(ty::ReErased),
|
||||
BorrowKind::Mut,
|
||||
arg.deref());
|
||||
|
||||
let ty = arg.ty(caller_mir, self.tcx);
|
||||
let ref_tmp = LocalDecl::new_temp(ty);
|
||||
let ref_tmp = caller_mir.local_decls.push(ref_tmp);
|
||||
let ref_tmp = Lvalue::Local(ref_tmp);
|
||||
|
||||
let ref_stmt = Statement {
|
||||
source_info: callsite.location,
|
||||
kind: StatementKind::Assign(ref_tmp.clone(), arg)
|
||||
};
|
||||
|
||||
caller_mir[callsite.bb]
|
||||
.statements.push(ref_stmt);
|
||||
|
||||
let pointee_ty = match ptr_ty.sty {
|
||||
ty::TyRawPtr(tm) | ty::TyRef(_, tm) => tm.ty,
|
||||
_ if ptr_ty.is_box() => ptr_ty.boxed_ty(),
|
||||
_ => bug!("Invalid type `{:?}` for call to box_free", ptr_ty)
|
||||
};
|
||||
let ptr_ty = self.tcx.mk_mut_ptr(pointee_ty);
|
||||
|
||||
let raw_ptr = Rvalue::Cast(CastKind::Misc, Operand::Consume(ref_tmp), ptr_ty);
|
||||
|
||||
let cast_tmp = LocalDecl::new_temp(ptr_ty);
|
||||
let cast_tmp = caller_mir.local_decls.push(cast_tmp);
|
||||
let cast_tmp = Lvalue::Local(cast_tmp);
|
||||
|
||||
let cast_stmt = Statement {
|
||||
source_info: callsite.location,
|
||||
kind: StatementKind::Assign(cast_tmp.clone(), raw_ptr)
|
||||
};
|
||||
|
||||
caller_mir[callsite.bb]
|
||||
.statements.push(cast_stmt);
|
||||
|
||||
Operand::Consume(cast_tmp)
|
||||
}
|
||||
|
||||
fn make_call_args(&self, args: Vec<Operand<'tcx>>,
|
||||
callsite: &CallSite<'tcx>, caller_mir: &mut Mir<'tcx>) -> Vec<Operand<'tcx>> {
|
||||
let tcx = self.tcx;
|
||||
// FIXME: Analysis of the usage of the arguments to avoid
|
||||
// unnecessary temporaries.
|
||||
args.into_iter().map(|a| {
|
||||
if let Operand::Consume(Lvalue::Local(local)) = a {
|
||||
if caller_mir.local_kind(local) == LocalKind::Temp {
|
||||
// Reuse the operand if it's a temporary already
|
||||
return a;
|
||||
}
|
||||
}
|
||||
|
||||
debug!("Creating temp for argument");
|
||||
// Otherwise, create a temporary for the arg
|
||||
let arg = Rvalue::Use(a);
|
||||
|
||||
let ty = arg.ty(caller_mir, tcx);
|
||||
|
||||
let arg_tmp = LocalDecl::new_temp(ty);
|
||||
let arg_tmp = caller_mir.local_decls.push(arg_tmp);
|
||||
let arg_tmp = Lvalue::Local(arg_tmp);
|
||||
|
||||
let stmt = Statement {
|
||||
source_info: callsite.location,
|
||||
kind: StatementKind::Assign(arg_tmp.clone(), arg)
|
||||
};
|
||||
caller_mir[callsite.bb].statements.push(stmt);
|
||||
Operand::Consume(arg_tmp)
|
||||
}).collect()
|
||||
}
|
||||
}
|
||||
|
||||
fn type_size_of<'a, 'tcx>(tcx: TyCtxt<'a, 'tcx, 'tcx>, param_env: ty::ParameterEnvironment<'tcx>,
|
||||
ty: Ty<'tcx>) -> Option<u64> {
|
||||
tcx.infer_ctxt(param_env, traits::Reveal::All).enter(|infcx| {
|
||||
ty.layout(&infcx).ok().map(|layout| {
|
||||
layout.size(&tcx.data_layout).bytes()
|
||||
})
|
||||
})
|
||||
}
|
||||
|
||||
/**
|
||||
* Integrator.
|
||||
*
|
||||
* Integrates blocks from the callee function into the calling function.
|
||||
* Updates block indices, references to locals and other control flow
|
||||
* stuff.
|
||||
*/
|
||||
struct Integrator<'a, 'tcx: 'a> {
|
||||
block_idx: usize,
|
||||
args: &'a [Operand<'tcx>],
|
||||
local_map: IndexVec<Local, Local>,
|
||||
scope_map: IndexVec<VisibilityScope, VisibilityScope>,
|
||||
promoted_map: IndexVec<Promoted, Promoted>,
|
||||
_callsite: CallSite<'tcx>,
|
||||
destination: Lvalue<'tcx>,
|
||||
return_block: BasicBlock,
|
||||
cleanup_block: Option<BasicBlock>,
|
||||
in_cleanup_block: bool,
|
||||
}
|
||||
|
||||
impl<'a, 'tcx> Integrator<'a, 'tcx> {
|
||||
fn update_target(&self, tgt: BasicBlock) -> BasicBlock {
|
||||
let new = BasicBlock::new(tgt.index() + self.block_idx);
|
||||
debug!("Updating target `{:?}`, new: `{:?}`", tgt, new);
|
||||
new
|
||||
}
|
||||
|
||||
fn update_local(&self, local: Local) -> Option<Local> {
|
||||
let idx = local.index();
|
||||
if idx < (self.args.len() + 1) {
|
||||
return None;
|
||||
}
|
||||
let idx = idx - (self.args.len() + 1);
|
||||
let local = Local::new(idx);
|
||||
self.local_map.get(local).cloned()
|
||||
}
|
||||
|
||||
fn arg_index(&self, arg: Local) -> Option<usize> {
|
||||
let idx = arg.index();
|
||||
if idx > 0 && idx <= self.args.len() {
|
||||
Some(idx - 1)
|
||||
} else {
|
||||
None
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
impl<'a, 'tcx> MutVisitor<'tcx> for Integrator<'a, 'tcx> {
|
||||
fn visit_lvalue(&mut self,
|
||||
lvalue: &mut Lvalue<'tcx>,
|
||||
_ctxt: LvalueContext<'tcx>,
|
||||
_location: Location) {
|
||||
if let Lvalue::Local(ref mut local) = *lvalue {
|
||||
if let Some(l) = self.update_local(*local) {
|
||||
// Temp or Var; update the local reference
|
||||
*local = l;
|
||||
return;
|
||||
}
|
||||
}
|
||||
if let Lvalue::Local(local) = *lvalue {
|
||||
if local == RETURN_POINTER {
|
||||
// Return pointer; update the lvalue itself
|
||||
*lvalue = self.destination.clone();
|
||||
} else if local.index() < (self.args.len() + 1) {
|
||||
// Argument, once again update the the lvalue itself
|
||||
let idx = local.index() - 1;
|
||||
if let Operand::Consume(ref lval) = self.args[idx] {
|
||||
*lvalue = lval.clone();
|
||||
} else {
|
||||
bug!("Arg operand `{:?}` is not an Lvalue use.", idx)
|
||||
}
|
||||
}
|
||||
} else {
|
||||
self.super_lvalue(lvalue, _ctxt, _location)
|
||||
}
|
||||
}
|
||||
|
||||
fn visit_operand(&mut self, operand: &mut Operand<'tcx>, location: Location) {
|
||||
if let Operand::Consume(Lvalue::Local(arg)) = *operand {
|
||||
if let Some(idx) = self.arg_index(arg) {
|
||||
let new_arg = self.args[idx].clone();
|
||||
*operand = new_arg;
|
||||
return;
|
||||
}
|
||||
}
|
||||
self.super_operand(operand, location);
|
||||
}
|
||||
|
||||
fn visit_basic_block_data(&mut self, block: BasicBlock, data: &mut BasicBlockData<'tcx>) {
|
||||
self.in_cleanup_block = data.is_cleanup;
|
||||
self.super_basic_block_data(block, data);
|
||||
self.in_cleanup_block = false;
|
||||
}
|
||||
|
||||
fn visit_terminator_kind(&mut self, block: BasicBlock,
|
||||
kind: &mut TerminatorKind<'tcx>, loc: Location) {
|
||||
self.super_terminator_kind(block, kind, loc);
|
||||
|
||||
match *kind {
|
||||
TerminatorKind::Goto { ref mut target} => {
|
||||
*target = self.update_target(*target);
|
||||
}
|
||||
TerminatorKind::SwitchInt { ref mut targets, .. } => {
|
||||
for tgt in targets {
|
||||
*tgt = self.update_target(*tgt);
|
||||
}
|
||||
}
|
||||
TerminatorKind::Drop { ref mut target, ref mut unwind, .. } |
|
||||
TerminatorKind::DropAndReplace { ref mut target, ref mut unwind, .. } => {
|
||||
*target = self.update_target(*target);
|
||||
if let Some(tgt) = *unwind {
|
||||
*unwind = Some(self.update_target(tgt));
|
||||
} else if !self.in_cleanup_block {
|
||||
// Unless this drop is in a cleanup block, add an unwind edge to
|
||||
// the orignal call's cleanup block
|
||||
*unwind = self.cleanup_block;
|
||||
}
|
||||
}
|
||||
TerminatorKind::Call { ref mut destination, ref mut cleanup, .. } => {
|
||||
if let Some((_, ref mut tgt)) = *destination {
|
||||
*tgt = self.update_target(*tgt);
|
||||
}
|
||||
if let Some(tgt) = *cleanup {
|
||||
*cleanup = Some(self.update_target(tgt));
|
||||
} else if !self.in_cleanup_block {
|
||||
// Unless this call is in a cleanup block, add an unwind edge to
|
||||
// the orignal call's cleanup block
|
||||
*cleanup = self.cleanup_block;
|
||||
}
|
||||
}
|
||||
TerminatorKind::Assert { ref mut target, ref mut cleanup, .. } => {
|
||||
*target = self.update_target(*target);
|
||||
if let Some(tgt) = *cleanup {
|
||||
*cleanup = Some(self.update_target(tgt));
|
||||
} else if !self.in_cleanup_block {
|
||||
// Unless this assert is in a cleanup block, add an unwind edge to
|
||||
// the orignal call's cleanup block
|
||||
*cleanup = self.cleanup_block;
|
||||
}
|
||||
}
|
||||
TerminatorKind::Return => {
|
||||
*kind = TerminatorKind::Goto { target: self.return_block };
|
||||
}
|
||||
TerminatorKind::Resume => {
|
||||
if let Some(tgt) = self.cleanup_block {
|
||||
*kind = TerminatorKind::Goto { target: tgt }
|
||||
}
|
||||
}
|
||||
TerminatorKind::Unreachable => { }
|
||||
}
|
||||
}
|
||||
|
||||
fn visit_visibility_scope(&mut self, scope: &mut VisibilityScope) {
|
||||
*scope = self.scope_map[*scope];
|
||||
}
|
||||
|
||||
fn visit_literal(&mut self, literal: &mut Literal<'tcx>, loc: Location) {
|
||||
if let Literal::Promoted { ref mut index } = *literal {
|
||||
if let Some(p) = self.promoted_map.get(*index).cloned() {
|
||||
*index = p;
|
||||
}
|
||||
} else {
|
||||
self.super_literal(literal, loc);
|
||||
}
|
||||
}
|
||||
}
|
||||
@ -20,3 +20,4 @@ pub mod dump_mir;
|
||||
pub mod deaggregator;
|
||||
pub mod instcombine;
|
||||
pub mod copy_prop;
|
||||
pub mod inline;
|
||||
|
||||
@ -79,7 +79,7 @@ pub struct CfgSimplifier<'a, 'tcx: 'a> {
|
||||
}
|
||||
|
||||
impl<'a, 'tcx: 'a> CfgSimplifier<'a, 'tcx> {
|
||||
fn new(mir: &'a mut Mir<'tcx>) -> Self {
|
||||
pub fn new(mir: &'a mut Mir<'tcx>) -> Self {
|
||||
let mut pred_count = IndexVec::from_elem(0u32, mir.basic_blocks());
|
||||
|
||||
// we can't use mir.predecessors() here because that counts
|
||||
@ -102,7 +102,7 @@ impl<'a, 'tcx: 'a> CfgSimplifier<'a, 'tcx> {
|
||||
}
|
||||
}
|
||||
|
||||
fn simplify(mut self) {
|
||||
pub fn simplify(mut self) {
|
||||
loop {
|
||||
let mut changed = false;
|
||||
|
||||
@ -137,6 +137,8 @@ impl<'a, 'tcx: 'a> CfgSimplifier<'a, 'tcx> {
|
||||
|
||||
if !changed { break }
|
||||
}
|
||||
|
||||
self.strip_nops()
|
||||
}
|
||||
|
||||
// Collapse a goto chain starting from `start`
|
||||
@ -231,9 +233,19 @@ impl<'a, 'tcx: 'a> CfgSimplifier<'a, 'tcx> {
|
||||
terminator.kind = TerminatorKind::Goto { target: first_succ };
|
||||
true
|
||||
}
|
||||
|
||||
fn strip_nops(&mut self) {
|
||||
for blk in self.basic_blocks.iter_mut() {
|
||||
blk.statements.retain(|stmt| if let StatementKind::Nop = stmt.kind {
|
||||
false
|
||||
} else {
|
||||
true
|
||||
})
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
fn remove_dead_blocks(mir: &mut Mir) {
|
||||
pub fn remove_dead_blocks(mir: &mut Mir) {
|
||||
let mut seen = BitVector::new(mir.basic_blocks().len());
|
||||
for (bb, _) in traversal::preorder(mir) {
|
||||
seen.insert(bb.index());
|
||||
|
||||
Loading…
Reference in New Issue
Block a user