Various fixes & minor improvements

src/checker.rs

@@ -78,7 +78,7 @@
 
 use crate::{
     Allocation, AllocationKind, Block, Edit, Function, Inst, InstPosition, Operand,
-    OperandConstraint, OperandKind, OperandPos, Output, PReg, ProgPoint, SpillSlot, VReg,
+    OperandConstraint, OperandKind, OperandPos, Output, PReg, ProgPoint, RegClass, VReg,
 };
 
 use std::collections::{HashMap, HashSet, VecDeque};
@@ -143,11 +143,11 @@ pub enum CheckerError {
     },
     ConflictedValueInStackmap {
         inst: Inst,
-        slot: SpillSlot,
+        alloc: Allocation,
     },
     NonRefValueInStackmap {
         inst: Inst,
-        slot: SpillSlot,
+        alloc: Allocation,
         vreg: VReg,
     },
 }
@@ -332,9 +332,8 @@ impl CheckerState {
                     self.check_val(inst, *op, *alloc, val, allocs)?;
                 }
             }
-            &CheckerInst::Safepoint { inst, ref slots } => {
-                for &slot in slots {
-                    let alloc = Allocation::stack(slot);
+            &CheckerInst::Safepoint { inst, ref allocs } => {
+                for &alloc in allocs {
                     let val = self
                         .allocations
                         .get(&alloc)
@@ -343,17 +342,17 @@ impl CheckerState {
                     log::trace!(
                         "checker: checkinst {:?}: safepoint slot {}, checker value {:?}",
                         checkinst,
-                        slot,
+                        alloc,
                         val
                     );
 
                     match val {
                         CheckerValue::Unknown => {}
                         CheckerValue::Conflicted => {
-                            return Err(CheckerError::ConflictedValueInStackmap { inst, slot });
+                            return Err(CheckerError::ConflictedValueInStackmap { inst, alloc });
                         }
                         CheckerValue::Reg(vreg, false) => {
-                            return Err(CheckerError::NonRefValueInStackmap { inst, slot, vreg });
+                            return Err(CheckerError::NonRefValueInStackmap { inst, alloc, vreg });
                         }
                         CheckerValue::Reg(_, true) => {}
                     }
@@ -405,12 +404,10 @@ impl CheckerState {
                 self.allocations
                     .insert(alloc, CheckerValue::Reg(vreg, reftyped));
             }
-            &CheckerInst::Safepoint { ref slots, .. } => {
+            &CheckerInst::Safepoint { ref allocs, .. } => {
                 for (alloc, value) in &mut self.allocations {
                     if let CheckerValue::Reg(_, true) = *value {
-                        if alloc.is_reg() {
-                            *value = CheckerValue::Conflicted;
-                        } else if alloc.is_stack() && !slots.contains(&alloc.as_stack().unwrap()) {
+                        if !allocs.contains(&alloc) {
                             *value = CheckerValue::Conflicted;
                         }
                     }
@@ -483,9 +480,9 @@ pub(crate) enum CheckerInst {
     /// of a value is logically transferred to a new vreg.
     DefAlloc { alloc: Allocation, vreg: VReg },
 
-    /// A safepoint, with the given SpillSlots specified as containing
+    /// A safepoint, with the given Allocations specified as containing
     /// reftyped values. All other reftyped values become invalid.
-    Safepoint { inst: Inst, slots: Vec<SpillSlot> },
+    Safepoint { inst: Inst, allocs: Vec<Allocation> },
 }
 
 #[derive(Debug)]
@@ -529,7 +526,7 @@ impl<'a, F: Function> Checker<'a, F> {
     pub fn prepare(&mut self, out: &Output) {
         log::trace!("checker: out = {:?}", out);
         // Preprocess safepoint stack-maps into per-inst vecs.
-        let mut safepoint_slots: HashMap<Inst, Vec<SpillSlot>> = HashMap::new();
+        let mut safepoint_slots: HashMap<Inst, Vec<Allocation>> = HashMap::new();
         for &(progpoint, slot) in &out.safepoint_slots {
             safepoint_slots
                 .entry(progpoint.inst())
@@ -551,9 +548,9 @@ impl<'a, F: Function> Checker<'a, F> {
 
                 // If this is a safepoint, then check the spillslots at this point.
                 if self.f.requires_refs_on_stack(inst) {
-                    let slots = safepoint_slots.remove(&inst).unwrap_or_else(|| vec![]);
+                    let allocs = safepoint_slots.remove(&inst).unwrap_or_else(|| vec![]);
 
-                    let checkinst = CheckerInst::Safepoint { inst, slots };
+                    let checkinst = CheckerInst::Safepoint { inst, allocs };
                     self.bb_insts.get_mut(&block).unwrap().push(checkinst);
                 }
 
@@ -727,9 +724,9 @@ impl<'a, F: Function> Checker<'a, F> {
                     &CheckerInst::DefAlloc { alloc, vreg } => {
                         log::trace!("    defalloc: {}:{}", vreg, alloc);
                     }
-                    &CheckerInst::Safepoint { ref slots, .. } => {
+                    &CheckerInst::Safepoint { ref allocs, .. } => {
                         let mut slotargs = vec![];
-                        for &slot in slots {
+                        for &slot in allocs {
                             slotargs.push(format!("{}", slot));
                         }
                         log::trace!("    safepoint: {}", slotargs.join(", "));

src/fuzzing/func.rs

@@ -589,7 +589,6 @@ pub fn machine_env() -> MachineEnv {
         [regs.iter().cloned().skip(24).collect(), vec![]];
     let scratch_by_class: [PReg; 2] = [PReg::new(31, RegClass::Int), PReg::new(0, RegClass::Float)];
     MachineEnv {
-        regs,
         preferred_regs_by_class,
         non_preferred_regs_by_class,
         scratch_by_class,

src/ion/data_structures.rs

@@ -19,7 +19,7 @@ use crate::index::ContainerComparator;
 use crate::indexset::IndexSet;
 use crate::{
     define_index, Allocation, Block, Edit, Function, Inst, MachineEnv, Operand, PReg, ProgPoint,
-    RegClass, SpillSlot, VReg,
+    RegClass, VReg,
 };
 use smallvec::SmallVec;
 use std::cmp::Ordering;
@@ -293,7 +293,6 @@ pub struct Env<'a, F: Function> {
     pub vreg_regs: Vec<VReg>,
     pub pregs: Vec<PRegData>,
     pub allocation_queue: PrioQueue,
-    pub clobbers: Vec<Inst>,   // Sorted list of insts with clobbers.
     pub safepoints: Vec<Inst>, // Sorted list of safepoint insts.
     pub safepoints_per_vreg: HashMap<usize, HashSet<Inst>>,
 
@@ -337,7 +336,7 @@ pub struct Env<'a, F: Function> {
     pub allocs: Vec<Allocation>,
     pub inst_alloc_offsets: Vec<u32>,
     pub num_spillslots: u32,
-    pub safepoint_slots: Vec<(ProgPoint, SpillSlot)>,
+    pub safepoint_slots: Vec<(ProgPoint, Allocation)>,
 
     pub allocated_bundle_count: usize,
 

src/ion/liveranges.rs

@@ -105,8 +105,11 @@ impl<'a, F: Function> Env<'a, F> {
                 allocations: LiveRangeSet::new(),
             },
         );
-        for &preg in &self.env.regs {
-            self.pregs[preg.index()].reg = preg;
+        for i in 0..=PReg::MAX {
+            let preg_int = PReg::new(i, RegClass::Int);
+            self.pregs[preg_int.index()].reg = preg_int;
+            let preg_float = PReg::new(i, RegClass::Float);
+            self.pregs[preg_float.index()].reg = preg_float;
         }
         // Create VRegs from the vreg count.
         for idx in 0..self.func.num_vregs() {
@@ -445,10 +448,6 @@ impl<'a, F: Function> Env<'a, F> {
             // For each instruction, in reverse order, process
             // operands and clobbers.
             for inst in insns.rev().iter() {
-                if self.func.inst_clobbers(inst).len() > 0 {
-                    self.clobbers.push(inst);
-                }
-
                 // Mark clobbers with CodeRanges on PRegs.
                 for i in 0..self.func.inst_clobbers(inst).len() {
                     // don't borrow `self`
@@ -1231,7 +1230,6 @@ impl<'a, F: Function> Env<'a, F> {
             }
         }
 
-        self.clobbers.sort_unstable();
         self.blockparam_ins.sort_unstable();
         self.blockparam_outs.sort_unstable();
         self.prog_move_srcs.sort_unstable_by_key(|(pos, _)| *pos);

src/ion/mod.rs

@@ -62,7 +62,6 @@ impl<'a, F: Function> Env<'a, F> {
             vreg_regs: Vec::with_capacity(n),
             pregs: vec![],
             allocation_queue: PrioQueue::new(),
-            clobbers: vec![],
             safepoints: vec![],
             safepoints_per_vreg: HashMap::new(),
             spilled_bundles: vec![],

src/ion/stackmap.rs

@@ -58,10 +58,8 @@ impl<'a, F: Function> Env<'a, F> {
                     }
                     log::trace!("    -> covers safepoint {:?}", safepoints[safepoint_idx]);
 
-                    let slot = alloc
-                        .as_stack()
-                        .expect("Reference-typed value not in spillslot at safepoint");
-                    self.safepoint_slots.push((safepoints[safepoint_idx], slot));
+                    self.safepoint_slots
+                        .push((safepoints[safepoint_idx], alloc));
                     safepoint_idx += 1;
                 }
             }

src/lib.rs

@@ -108,13 +108,13 @@ impl PReg {
     /// all PRegs and index it efficiently.
     #[inline(always)]
     pub fn index(self) -> usize {
-        ((self.class as u8 as usize) << 5) | (self.hw_enc as usize)
+        ((self.class as u8 as usize) << Self::MAX_BITS) | (self.hw_enc as usize)
     }
 
     /// Construct a PReg from the value returned from `.index()`.
     #[inline(always)]
     pub fn from_index(index: usize) -> Self {
-        let class = (index >> 5) & 1;
+        let class = (index >> Self::MAX_BITS) & 1;
         let class = match class {
             0 => RegClass::Int,
             1 => RegClass::Float,
@@ -1139,12 +1139,6 @@ pub enum Edit {
 /// as well.
 #[derive(Clone, Debug)]
 pub struct MachineEnv {
-    /// Physical registers. Every register that might be mentioned in
-    /// any constraint must be listed here, even if it is not
-    /// allocatable (present in one of
-    /// `{preferred,non_preferred}_regs_by_class`).
-    pub regs: Vec<PReg>,
-
     /// Preferred physical registers for each class. These are the
     /// registers that will be allocated first, if free.
     pub preferred_regs_by_class: [Vec<PReg>; 2],
@@ -1186,8 +1180,11 @@ pub struct Output {
     /// Allocation offset in `allocs` for each instruction.
     pub inst_alloc_offsets: Vec<u32>,
 
-    /// Safepoint records: at a given program point, a reference-typed value lives in the given SpillSlot.
-    pub safepoint_slots: Vec<(ProgPoint, SpillSlot)>,
+    /// Safepoint records: at a given program point, a reference-typed value
+    /// lives in the given Allocation. Currently these are guaranteed to be
+    /// stack slots, but in the future an option may be added to allow
+    /// reftype value to be kept in registers at safepoints.
+    pub safepoint_slots: Vec<(ProgPoint, Allocation)>,
 
     /// Debug info: a labeled value (as applied to vregs by
     /// `Function::debug_value_labels()` on the input side) is located