Auto merge of #119459 - cjgillot:inline-mir-utils, r=compiler-errors

Inline a few utility functions around MIR

Most of them are small enough to benefit from inlining.

compiler/rustc_data_structures/src/graph/dominators/mod.rs

@@ -394,6 +394,7 @@ impl<Node: Idx> Dominators<Node> {
     /// # Panics
     ///
     /// Panics if `b` is unreachable.
+    #[inline]
     pub fn dominates(&self, a: Node, b: Node) -> bool {
         match &self.kind {
             Kind::Path => a.index() <= b.index(),

compiler/rustc_middle/src/mir/mod.rs

@@ -1576,6 +1576,7 @@ impl Location {
     ///
     /// Note that if this location represents a terminator, then the
     /// resulting location would be out of bounds and invalid.
+    #[inline]
     pub fn successor_within_block(&self) -> Location {
         Location { block: self.block, statement_index: self.statement_index + 1 }
     }
@@ -1612,6 +1613,7 @@ impl Location {
         false
     }
 
+    #[inline]
     pub fn dominates(&self, other: Location, dominators: &Dominators<BasicBlock>) -> bool {
         if self.block == other.block {
             self.statement_index <= other.statement_index
@@ -1631,6 +1633,7 @@ pub enum DefLocation {
 }
 
 impl DefLocation {
+    #[inline]
     pub fn dominates(self, location: Location, dominators: &Dominators<BasicBlock>) -> bool {
         match self {
             DefLocation::Argument => true,

compiler/rustc_middle/src/mir/terminator.rs

@@ -26,6 +26,7 @@ impl SwitchTargets {
     }
 
     /// Inverse of `SwitchTargets::static_if`.
+    #[inline]
     pub fn as_static_if(&self) -> Option<(u128, BasicBlock, BasicBlock)> {
         if let &[value] = &self.values[..]
             && let &[then, else_] = &self.targets[..]
@@ -37,6 +38,7 @@ impl SwitchTargets {
     }
 
     /// Returns the fallback target that is jumped to when none of the values match the operand.
+    #[inline]
     pub fn otherwise(&self) -> BasicBlock {
         *self.targets.last().unwrap()
     }
@@ -47,15 +49,18 @@ impl SwitchTargets {
     /// including the `otherwise` fallback target.
     ///
     /// Note that this may yield 0 elements. Only the `otherwise` branch is mandatory.
+    #[inline]
     pub fn iter(&self) -> SwitchTargetsIter<'_> {
         SwitchTargetsIter { inner: iter::zip(&self.values, &self.targets) }
     }
 
     /// Returns a slice with all possible jump targets (including the fallback target).
+    #[inline]
     pub fn all_targets(&self) -> &[BasicBlock] {
         &self.targets
     }
 
+    #[inline]
     pub fn all_targets_mut(&mut self) -> &mut [BasicBlock] {
         &mut self.targets
     }
@@ -63,6 +68,7 @@ impl SwitchTargets {
     /// Finds the `BasicBlock` to which this `SwitchInt` will branch given the
     /// specific value. This cannot fail, as it'll return the `otherwise`
     /// branch if there's not a specific match for the value.
+    #[inline]
     pub fn target_for_value(&self, value: u128) -> BasicBlock {
         self.iter().find_map(|(v, t)| (v == value).then_some(t)).unwrap_or_else(|| self.otherwise())
     }
@@ -75,10 +81,12 @@ pub struct SwitchTargetsIter<'a> {
 impl<'a> Iterator for SwitchTargetsIter<'a> {
     type Item = (u128, BasicBlock);
 
+    #[inline]
     fn next(&mut self) -> Option<Self::Item> {
         self.inner.next().map(|(val, bb)| (*val, *bb))
     }
 
+    #[inline]
     fn size_hint(&self) -> (usize, Option<usize>) {
         self.inner.size_hint()
     }
@@ -330,28 +338,34 @@ pub type SuccessorsMut<'a> =
     iter::Chain<std::option::IntoIter<&'a mut BasicBlock>, slice::IterMut<'a, BasicBlock>>;
 
 impl<'tcx> Terminator<'tcx> {
+    #[inline]
     pub fn successors(&self) -> Successors<'_> {
         self.kind.successors()
     }
 
+    #[inline]
     pub fn successors_mut(&mut self) -> SuccessorsMut<'_> {
         self.kind.successors_mut()
     }
 
+    #[inline]
     pub fn unwind(&self) -> Option<&UnwindAction> {
         self.kind.unwind()
     }
 
+    #[inline]
     pub fn unwind_mut(&mut self) -> Option<&mut UnwindAction> {
         self.kind.unwind_mut()
     }
 }
 
 impl<'tcx> TerminatorKind<'tcx> {
+    #[inline]
     pub fn if_(cond: Operand<'tcx>, t: BasicBlock, f: BasicBlock) -> TerminatorKind<'tcx> {
         TerminatorKind::SwitchInt { discr: cond, targets: SwitchTargets::static_if(0, f, t) }
     }
 
+    #[inline]
     pub fn successors(&self) -> Successors<'_> {
         use self::TerminatorKind::*;
         match *self {
@@ -392,6 +406,7 @@ impl<'tcx> TerminatorKind<'tcx> {
         }
     }
 
+    #[inline]
     pub fn successors_mut(&mut self) -> SuccessorsMut<'_> {
         use self::TerminatorKind::*;
         match *self {
@@ -430,6 +445,7 @@ impl<'tcx> TerminatorKind<'tcx> {
         }
     }
 
+    #[inline]
     pub fn unwind(&self) -> Option<&UnwindAction> {
         match *self {
             TerminatorKind::Goto { .. }
@@ -449,6 +465,7 @@ impl<'tcx> TerminatorKind<'tcx> {
         }
     }
 
+    #[inline]
     pub fn unwind_mut(&mut self) -> Option<&mut UnwindAction> {
         match *self {
             TerminatorKind::Goto { .. }
@@ -468,6 +485,7 @@ impl<'tcx> TerminatorKind<'tcx> {
         }
     }
 
+    #[inline]
     pub fn as_switch(&self) -> Option<(&Operand<'tcx>, &SwitchTargets)> {
         match self {
             TerminatorKind::SwitchInt { discr, targets } => Some((discr, targets)),
@@ -475,6 +493,7 @@ impl<'tcx> TerminatorKind<'tcx> {
         }
     }
 
+    #[inline]
     pub fn as_goto(&self) -> Option<BasicBlock> {
         match self {
             TerminatorKind::Goto { target } => Some(*target),

compiler/rustc_mir_transform/src/ssa.rs

@@ -94,6 +94,7 @@ impl SsaLocals {
         self.direct_uses[local]
     }
 
+    #[inline]
     pub fn assignment_dominates(
         &self,
         dominators: &Dominators<BasicBlock>,