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This PR adds a basic *alias analysis*, and optimizations that use it. This is a "mid-end optimization": it operates on CLIF, the machine-independent IR, before lowering occurs. The alias analysis (or maybe more properly, a sort of memory-value analysis) determines when it can prove a particular memory location is equal to a given SSA value, and when it can, it replaces any loads of that location. This subsumes two common optimizations: * Redundant load elimination: when the same memory address is loaded two times, and it can be proven that no intervening operations will write to that memory, then the second load is *redundant* and its result must be the same as the first. We can use the first load's result and remove the second load. * Store-to-load forwarding: when a load can be proven to access exactly the memory written by a preceding store, we can replace the load's result with the store's data operand, and remove the load. Both of these optimizations rely on a "last store" analysis that is a sort of coloring mechanism, split across disjoint categories of abstract state. The basic idea is that every memory-accessing operation is put into one of N disjoint categories; it is disallowed for memory to ever be accessed by an op in one category and later accessed by an op in another category. (The frontend must ensure this.) Then, given this, we scan the code and determine, for each memory-accessing op, when a single prior instruction is a store to the same category. This "colors" the instruction: it is, in a sense, a static name for that version of memory. This analysis provides an important invariant: if two operations access memory with the same last-store, then *no other store can alias* in the time between that last store and these operations. This must-not-alias property, together with a check that the accessed address is *exactly the same* (same SSA value and offset), and other attributes of the access (type, extension mode) are the same, let us prove that the results are the same. Given last-store info, we scan the instructions and build a table from "memory location" key (last store, address, offset, type, extension) to known SSA value stored in that location. A store inserts a new mapping. A load may also insert a new mapping, if we didn't already have one. Then when a load occurs and an entry already exists for its "location", we can reuse the value. This will be either RLE or St-to-Ld depending on where the value came from. Note that this *does* work across basic blocks: the last-store analysis is a full iterative dataflow pass, and we are careful to check dominance of a previously-defined value before aliasing to it at a potentially redundant load. So we will do the right thing if we only have a "partially redundant" load (loaded already but only in one predecessor block), but we will also correctly reuse a value if there is a store or load above a loop and a redundant load of that value within the loop, as long as no potentially-aliasing stores happen within the loop.pull/4179/head
Chris Fallin
3 years ago
committed by
GitHub
GitHub
17 changed files with 900 additions and 57 deletions
@ -0,0 +1,388 @@ |
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//! Alias analysis, consisting of a "last store" pass and a "memory
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//! values" pass. These two passes operate as one fused pass, and so
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//! are implemented together here.
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//!
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//! We partition memory state into several *disjoint pieces* of
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//! "abstract state". There are a finite number of such pieces:
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//! currently, we call them "heap", "table", "vmctx", and "other".Any
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//! given address in memory belongs to exactly one disjoint piece.
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//!
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//! One never tracks which piece a concrete address belongs to at
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//! runtime; this is a purely static concept. Instead, all
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//! memory-accessing instructions (loads and stores) are labeled with
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//! one of these four categories in the `MemFlags`. It is forbidden
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//! for a load or store to access memory under one category and a
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//! later load or store to access the same memory under a different
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//! category. This is ensured to be true by construction during
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//! frontend translation into CLIF and during legalization.
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//!
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//! Given that this non-aliasing property is ensured by the producer
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//! of CLIF, we can compute a *may-alias* property: one load or store
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//! may-alias another load or store if both access the same category
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//! of abstract state.
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//!
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//! The "last store" pass helps to compute this aliasing: it scans the
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//! code, finding at each program point the last instruction that
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//! *might have* written to a given part of abstract state.
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//!
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//! We can't say for sure that the "last store" *did* actually write
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//! that state, but we know for sure that no instruction *later* than
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//! it (up to the current instruction) did. However, we can get a
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//! must-alias property from this: if at a given load or store, we
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//! look backward to the "last store", *AND* we find that it has
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//! exactly the same address expression and type, then we know that
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//! the current instruction's access *must* be to the same memory
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//! location.
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//!
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//! To get this must-alias property, we compute a sparse table of
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//! "memory values": these are known equivalences between SSA `Value`s
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//! and particular locations in memory. The memory-values table is a
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//! mapping from (last store, address expression, type) to SSA
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//! value. At a store, we can insert into this table directly. At a
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//! load, we can also insert, if we don't already have a value (from
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//! the store that produced the load's value).
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//!
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//! Then we can do two optimizations at once given this table. If a
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//! load accesses a location identified by a (last store, address,
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//! type) key already in the table, we replace it with the SSA value
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//! for that memory location. This is usually known as "redundant load
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//! elimination" if the value came from an earlier load of the same
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//! location, or "store-to-load forwarding" if the value came from an
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//! earlier store to the same location.
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//!
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//! In theory we could also do *dead-store elimination*, where if a
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//! store overwrites a key in the table, *and* if no other load/store
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//! to the abstract state category occurred, *and* no other trapping
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//! instruction occurred (at which point we need an up-to-date memory
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//! state because post-trap-termination memory state can be observed),
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//! *and* we can prove the original store could not have trapped, then
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//! we can eliminate the original store. Because this is so complex,
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//! and the conditions for doing it correctly when post-trap state
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//! must be correct likely reduce the potential benefit, we don't yet
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//! do this.
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use crate::{ |
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cursor::{Cursor, FuncCursor}, |
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dominator_tree::DominatorTree, |
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fx::{FxHashMap, FxHashSet}, |
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inst_predicates::{ |
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has_memory_fence_semantics, inst_addr_offset_type, inst_store_data, visit_block_succs, |
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}, |
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ir::{immediates::Offset32, Block, Function, Inst, Opcode, Type, Value}, |
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}; |
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use cranelift_entity::{packed_option::PackedOption, EntityRef}; |
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/// For a given program point, the vector of last-store instruction
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/// indices for each disjoint category of abstract state.
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#[derive(Clone, Copy, Debug, Default, PartialEq, Eq)] |
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struct LastStores { |
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heap: PackedOption<Inst>, |
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table: PackedOption<Inst>, |
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vmctx: PackedOption<Inst>, |
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other: PackedOption<Inst>, |
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} |
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|
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impl LastStores { |
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fn update(&mut self, func: &Function, inst: Inst) { |
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let opcode = func.dfg[inst].opcode(); |
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if has_memory_fence_semantics(opcode) { |
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self.heap = inst.into(); |
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self.table = inst.into(); |
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self.vmctx = inst.into(); |
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self.other = inst.into(); |
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} else if opcode.can_store() { |
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if let Some(memflags) = func.dfg[inst].memflags() { |
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if memflags.heap() { |
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self.heap = inst.into(); |
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} else if memflags.table() { |
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self.table = inst.into(); |
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} else if memflags.vmctx() { |
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self.vmctx = inst.into(); |
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} else { |
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self.other = inst.into(); |
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} |
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} else { |
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self.heap = inst.into(); |
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self.table = inst.into(); |
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self.vmctx = inst.into(); |
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self.other = inst.into(); |
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} |
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} |
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} |
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fn get_last_store(&self, func: &Function, inst: Inst) -> PackedOption<Inst> { |
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if let Some(memflags) = func.dfg[inst].memflags() { |
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if memflags.heap() { |
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self.heap |
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} else if memflags.table() { |
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self.table |
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} else if memflags.vmctx() { |
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self.vmctx |
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} else { |
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self.other |
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} |
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} else if func.dfg[inst].opcode().can_load() || func.dfg[inst].opcode().can_store() { |
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inst.into() |
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} else { |
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PackedOption::default() |
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} |
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} |
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fn meet_from(&mut self, other: &LastStores, loc: Inst) { |
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let meet = |a: PackedOption<Inst>, b: PackedOption<Inst>| -> PackedOption<Inst> { |
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match (a.into(), b.into()) { |
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(None, None) => None.into(), |
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(Some(a), None) => a, |
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(None, Some(b)) => b, |
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(Some(a), Some(b)) if a == b => a, |
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_ => loc.into(), |
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} |
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}; |
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self.heap = meet(self.heap, other.heap); |
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self.table = meet(self.table, other.table); |
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self.vmctx = meet(self.vmctx, other.vmctx); |
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self.other = meet(self.other, other.other); |
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} |
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} |
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|
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/// A key identifying a unique memory location.
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///
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/// For the result of a load to be equivalent to the result of another
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/// load, or the store data from a store, we need for (i) the
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/// "version" of memory (here ensured by having the same last store
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/// instruction to touch the disjoint category of abstract state we're
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/// accessing); (ii) the address must be the same (here ensured by
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/// having the same SSA value, which doesn't change after computed);
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/// (iii) the offset must be the same; and (iv) the accessed type and
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/// extension mode (e.g., 8-to-32, signed) must be the same.
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#[derive(Clone, Copy, Debug, PartialEq, Eq, Hash)] |
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struct MemoryLoc { |
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last_store: PackedOption<Inst>, |
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address: Value, |
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offset: Offset32, |
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ty: Type, |
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/// We keep the *opcode* of the instruction that produced the
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/// value we record at this key if the opcode is anything other
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/// than an ordinary load or store. This is needed when we
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/// consider loads that extend the value: e.g., an 8-to-32
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/// sign-extending load will produce a 32-bit value from an 8-bit
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/// value in memory, so we can only reuse that (as part of RLE)
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/// for another load with the same extending opcode.
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///
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/// We could improve the transform to insert explicit extend ops
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/// in place of extending loads when we know the memory value, but
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/// we haven't yet done this.
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extending_opcode: Option<Opcode>, |
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} |
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/// An alias-analysis pass.
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pub struct AliasAnalysis<'a> { |
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/// The function we're analyzing.
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func: &'a mut Function, |
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/// The domtree for the function.
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domtree: &'a DominatorTree, |
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/// Input state to a basic block.
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block_input: FxHashMap<Block, LastStores>, |
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/// Known memory-value equivalences. This is the result of the
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/// analysis. This is a mapping from (last store, address
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/// expression, offset, type) to SSA `Value`.
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///
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/// We keep the defining inst around for quick dominance checks.
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mem_values: FxHashMap<MemoryLoc, (Inst, Value)>, |
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} |
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impl<'a> AliasAnalysis<'a> { |
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/// Perform an alias analysis pass.
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pub fn new(func: &'a mut Function, domtree: &'a DominatorTree) -> AliasAnalysis<'a> { |
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log::trace!("alias analysis: input is:\n{:?}", func); |
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let mut analysis = AliasAnalysis { |
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func, |
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domtree, |
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block_input: FxHashMap::default(), |
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mem_values: FxHashMap::default(), |
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}; |
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analysis.compute_block_input_states(); |
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analysis |
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} |
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fn compute_block_input_states(&mut self) { |
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let mut queue = vec![]; |
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let mut queue_set = FxHashSet::default(); |
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let entry = self.func.layout.entry_block().unwrap(); |
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queue.push(entry); |
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queue_set.insert(entry); |
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while let Some(block) = queue.pop() { |
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queue_set.remove(&block); |
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let mut state = self |
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.block_input |
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.entry(block) |
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.or_insert_with(|| LastStores::default()) |
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.clone(); |
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log::trace!( |
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"alias analysis: input to block{} is {:?}", |
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block.index(), |
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state |
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); |
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for inst in self.func.layout.block_insts(block) { |
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state.update(self.func, inst); |
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log::trace!("after inst{}: state is {:?}", inst.index(), state); |
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} |
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visit_block_succs(self.func, block, |_inst, succ| { |
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let succ_first_inst = self |
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.func |
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.layout |
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.block_insts(succ) |
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.into_iter() |
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.next() |
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.unwrap(); |
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let updated = match self.block_input.get_mut(&succ) { |
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Some(succ_state) => { |
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let old = succ_state.clone(); |
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succ_state.meet_from(&state, succ_first_inst); |
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*succ_state != old |
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} |
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None => { |
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self.block_input.insert(succ, state.clone()); |
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true |
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} |
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}; |
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if updated && queue_set.insert(succ) { |
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queue.push(succ); |
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} |
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}); |
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} |
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} |
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/// Make a pass and update known-redundant loads to aliased
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/// values. We interleave the updates with the memory-location
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/// tracking because resolving some aliases may expose others
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/// (e.g. in cases of double-indirection with two separate chains
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/// of loads).
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pub fn compute_and_update_aliases(&mut self) { |
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let mut pos = FuncCursor::new(self.func); |
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while let Some(block) = pos.next_block() { |
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let mut state = self |
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.block_input |
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.get(&block) |
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.cloned() |
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.unwrap_or_else(|| LastStores::default()); |
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while let Some(inst) = pos.next_inst() { |
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log::trace!( |
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"alias analysis: scanning at inst{} with state {:?} ({:?})", |
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inst.index(), |
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state, |
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pos.func.dfg[inst], |
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); |
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if let Some((address, offset, ty)) = inst_addr_offset_type(pos.func, inst) { |
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let address = pos.func.dfg.resolve_aliases(address); |
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let opcode = pos.func.dfg[inst].opcode(); |
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if opcode.can_store() { |
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let store_data = inst_store_data(pos.func, inst).unwrap(); |
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let store_data = pos.func.dfg.resolve_aliases(store_data); |
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let mem_loc = MemoryLoc { |
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last_store: inst.into(), |
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address, |
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offset, |
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ty, |
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extending_opcode: get_ext_opcode(opcode), |
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}; |
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log::trace!( |
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"alias analysis: at inst{}: store with data v{} at loc {:?}", |
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inst.index(), |
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store_data.index(), |
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mem_loc |
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); |
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self.mem_values.insert(mem_loc, (inst, store_data)); |
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} else if opcode.can_load() { |
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let last_store = state.get_last_store(pos.func, inst); |
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let load_result = pos.func.dfg.inst_results(inst)[0]; |
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let mem_loc = MemoryLoc { |
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last_store, |
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address, |
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offset, |
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ty, |
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extending_opcode: get_ext_opcode(opcode), |
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}; |
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log::trace!( |
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"alias analysis: at inst{}: load with last_store inst{} at loc {:?}", |
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inst.index(), |
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last_store.map(|inst| inst.index()).unwrap_or(usize::MAX), |
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mem_loc |
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); |
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// Is there a Value already known to be stored
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// at this specific memory location? If so,
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// we can alias the load result to this
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// already-known Value.
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//
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// Check if the definition dominates this
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// location; it might not, if it comes from a
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// load (stores will always dominate though if
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// their `last_store` survives through
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// meet-points to this use-site).
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let aliased = if let Some((def_inst, value)) = |
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self.mem_values.get(&mem_loc).cloned() |
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{ |
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log::trace!( |
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" -> sees known value v{} from inst{}", |
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value.index(), |
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def_inst.index() |
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); |
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if self.domtree.dominates(def_inst, inst, &pos.func.layout) { |
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log::trace!( |
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" -> dominates; value equiv from v{} to v{} inserted", |
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load_result.index(), |
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value.index() |
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); |
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pos.func.dfg.detach_results(inst); |
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pos.func.dfg.change_to_alias(load_result, value); |
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pos.remove_inst_and_step_back(); |
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true |
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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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// Otherwise, we can keep *this* load around
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// as a new equivalent value.
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if !aliased { |
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log::trace!( |
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" -> inserting load result v{} at loc {:?}", |
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load_result.index(), |
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mem_loc |
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); |
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self.mem_values.insert(mem_loc, (inst, load_result)); |
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} |
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} |
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} |
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state.update(pos.func, inst); |
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} |
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} |
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} |
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} |
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fn get_ext_opcode(op: Opcode) -> Option<Opcode> { |
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debug_assert!(op.can_load() || op.can_store()); |
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match op { |
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Opcode::Load | Opcode::Store => None, |
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_ => Some(op), |
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} |
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} |
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@ -0,0 +1,22 @@ |
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test alias-analysis |
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set opt_level=speed |
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target aarch64 |
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|
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;; Check that aliasing properly respects the last store in each |
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;; "category" separately. |
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function %f0(i64, i64) -> i32, i32 { |
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block0(v0: i64, v1: i64): |
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v2 = iconst.i32 42 |
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v3 = iconst.i32 43 |
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store.i32 heap v2, v0+8 |
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store.i32 table v3, v1+8 |
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|
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v4 = load.i32 heap v0+8 |
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v5 = load.i32 table v1+8 |
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; check: v4 -> v2 |
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; check: v5 -> v3 |
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return v4, v5 |
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} |
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@ -0,0 +1,44 @@ |
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test alias-analysis |
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set opt_level=speed |
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target aarch64 |
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|
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;; Test that extension modes are properly accounted for when deciding |
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;; whether loads alias. |
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|
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function %f0(i64 vmctx, i32) -> i32, i32, i32, i64, i64, i64 { |
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gv0 = vmctx |
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gv1 = load.i64 notrap readonly aligned gv0+8 |
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heap0 = static gv1, bound 0x1_0000_0000, offset_guard 0x8000_0000, index_type i32 |
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|
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block0(v0: i64, v1: i32): |
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v2 = heap_addr.i64 heap0, v1, 0 |
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|
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;; Initial load. This will not be reused by anything below, even |
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;; though it does access the same address. |
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v3 = load.i32 v2+8 |
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|
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;; These loads must remain (must not be removed as redundant). |
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v4 = uload8.i32 v2+8 |
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; check: v4 = uload8.i32 v2+8 |
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v5 = sload8.i32 v2+8 |
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; check: v5 = sload8.i32 v2+8 |
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v6 = load.i64 v2+8 |
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; check: v6 = load.i64 v2+8 |
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|
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;; 8-bit store only partially overwrites the address. |
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istore8 v6, v2+8 |
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|
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;; This must not pick up the store data. |
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v7 = load.i64 v2+8 |
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; check: v7 = load.i64 v2+8 |
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|
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;; Another store, this one non-truncating but actually using an |
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;; `i8` value. |
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v8 = iconst.i8 123 |
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store.i8 v8, v2+8 |
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|
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v9 = load.i64 v2+8 |
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; check: v9 = load.i64 v2+8 |
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return v3, v4, v5, v6, v7, v9 |
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} |
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@ -0,0 +1,45 @@ |
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test alias-analysis |
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set opt_level=speed |
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target aarch64 |
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|
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;; Test that certain instructions act as fences that inhibit alias |
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;; analysis to move accesses across them. |
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|
|||
function %f0(i64 vmctx, i32) -> i32, i32, i32, i32, i32, i32, i32, i32, i32, i32 { |
|||
gv0 = vmctx |
|||
gv1 = load.i64 notrap readonly aligned gv0+8 |
|||
heap0 = static gv1, bound 0x1_0000_0000, offset_guard 0x8000_0000, index_type i32 |
|||
|
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block0(v0: i64, v1: i32): |
|||
v2 = heap_addr.i64 heap0, v1, 0 |
|||
|
|||
v3 = load.i32 v2+8 |
|||
v4 = load.i32 vmctx v0+16 |
|||
|
|||
atomic_store.i32 v1, v0 |
|||
|
|||
v5 = load.i32 vmctx v0+16 |
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; check: v5 = load.i32 vmctx v0+16 |
|||
|
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v6 = atomic_cas.i32 v0, v1, v1 |
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|
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v7 = load.i32 vmctx v0+16 |
|||
; check: v7 = load.i32 vmctx v0+16 |
|||
|
|||
fence |
|||
|
|||
v8 = load.i32 vmctx v0+16 |
|||
; check: v8 = load.i32 vmctx v0+16 |
|||
|
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v9 = atomic_rmw.i32 add v0, v1 |
|||
|
|||
v10 = load.i32 vmctx v0+16 |
|||
; check: v10 = load.i32 vmctx v0+16 |
|||
|
|||
v11 = atomic_load.i32 v0 |
|||
|
|||
v12 = load.i32 vmctx v0+16 |
|||
; check: v12 = load.i32 vmctx v0+16 |
|||
|
|||
return v3, v4, v5, v6, v7, v8, v9, v10, v11, v12 |
|||
} |
|||
@ -0,0 +1,29 @@ |
|||
test alias-analysis |
|||
set opt_level=speed |
|||
target aarch64 |
|||
|
|||
;; Check RLE across basic blocks. |
|||
|
|||
function %f0(i64 vmctx, i32) -> i32 { |
|||
gv0 = vmctx |
|||
gv1 = load.i64 notrap readonly aligned gv0+8 |
|||
heap0 = static gv1, bound 0x1_0000_0000, offset_guard 0x8000_0000, index_type i32 |
|||
|
|||
|
|||
block0(v0: i64, v1: i32): |
|||
v2 = heap_addr.i64 heap0, v1, 0 |
|||
v3 = load.i32 v2+8 |
|||
brz v2, block1 |
|||
jump block2 |
|||
|
|||
block1: |
|||
v4 = load.i32 v2+8 |
|||
; check: v4 -> v3 |
|||
jump block3(v4) |
|||
|
|||
block2: |
|||
jump block3(v3) |
|||
|
|||
block3(v5: i32): |
|||
return v5 |
|||
} |
|||
@ -0,0 +1,35 @@ |
|||
test alias-analysis |
|||
set opt_level=speed |
|||
target aarch64 |
|||
|
|||
;; A test of partial redundancy: we should *not* RLE when an earlier |
|||
;; load to the location is only in one predecessor of multiple. |
|||
|
|||
function %f0(i64 vmctx, i32) -> i32, i32 { |
|||
gv0 = vmctx |
|||
gv1 = load.i64 notrap readonly aligned gv0+8 |
|||
heap0 = static gv1, bound 0x1_0000_0000, offset_guard 0x8000_0000, index_type i32 |
|||
fn0 = %g(i64 vmctx) |
|||
|
|||
block0(v0: i64, v1: i32): |
|||
brz v1, block1 |
|||
jump block2 |
|||
|
|||
block1: |
|||
v2 = heap_addr.i64 heap0, v1, 0 |
|||
v3 = load.i32 v2+64 |
|||
jump block3(v3) |
|||
|
|||
block2: |
|||
v4 = heap_addr.i64 heap0, v1, 0 |
|||
v5 = load.i32 v4+128 |
|||
jump block3(v5) |
|||
|
|||
block3(v6: i32): |
|||
v7 = heap_addr.i64 heap0, v1, 0 |
|||
v8 = load.i32 v7+64 |
|||
;; load should survive: |
|||
; check: v8 = load.i32 v7+64 |
|||
return v6, v8 |
|||
|
|||
} |
|||
@ -0,0 +1,54 @@ |
|||
test alias-analysis |
|||
set opt_level=speed |
|||
target aarch64 |
|||
|
|||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
|||
;; Redundant-load elimination |
|||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
|||
|
|||
function %f0(i64 vmctx, i32) -> i32, i32, i32, i32 { |
|||
gv0 = vmctx |
|||
gv1 = load.i64 notrap readonly aligned gv0+8 |
|||
heap0 = static gv1, bound 0x1_0000_0000, offset_guard 0x8000_0000, index_type i32 |
|||
fn0 = %g(i64 vmctx) |
|||
|
|||
block0(v0: i64, v1: i32): |
|||
v2 = heap_addr.i64 heap0, v1, 0 |
|||
v3 = load.i32 v2+8 |
|||
;; This should reuse the load above. |
|||
v4 = heap_addr.i64 heap0, v1, 0 |
|||
v5 = load.i32 v4+8 |
|||
; check: v5 -> v3 |
|||
|
|||
call fn0(v0) |
|||
|
|||
;; The second load is redundant wrt the first, but the call above |
|||
;; is a barrier that prevents reusing v3 or v5. |
|||
v6 = load.i32 v4+8 |
|||
v7 = load.i32 v4+8 |
|||
; check: v7 -> v6 |
|||
|
|||
return v3, v5, v6, v7 |
|||
} |
|||
|
|||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
|||
;; Store-to-load forwarding |
|||
;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;; |
|||
|
|||
function %f1(i64 vmctx, i32) -> i32 { |
|||
gv0 = vmctx |
|||
gv1 = load.i64 notrap readonly aligned gv0+8 |
|||
heap0 = static gv1, bound 0x1_0000_0000, offset_guard 0x8000_0000, index_type i32 |
|||
fn0 = %g(i64 vmctx) |
|||
|
|||
block0(v0: i64, v1: i32): |
|||
v2 = heap_addr.i64 heap0, v1, 0 |
|||
store.i32 v1, v2+8 |
|||
|
|||
;; This load should pick up the store above. |
|||
v3 = heap_addr.i64 heap0, v1, 0 |
|||
v4 = load.i32 v3+8 |
|||
; check: v4 -> v1 |
|||
|
|||
return v4 |
|||
} |
|||
@ -0,0 +1,48 @@ |
|||
//! Test command for testing the alias analysis pass.
|
|||
//!
|
|||
//! The `alias-analysis` test command runs each function through GVN
|
|||
//! and then alias analysis after ensuring that all instructions are
|
|||
//! legal for the target.
|
|||
//!
|
|||
//! The resulting function is sent to `filecheck`.
|
|||
|
|||
use crate::subtest::{run_filecheck, Context, SubTest}; |
|||
use cranelift_codegen; |
|||
use cranelift_codegen::ir::Function; |
|||
use cranelift_reader::TestCommand; |
|||
use std::borrow::Cow; |
|||
|
|||
struct TestAliasAnalysis; |
|||
|
|||
pub fn subtest(parsed: &TestCommand) -> anyhow::Result<Box<dyn SubTest>> { |
|||
assert_eq!(parsed.command, "alias-analysis"); |
|||
if !parsed.options.is_empty() { |
|||
anyhow::bail!("No options allowed on {}", parsed); |
|||
} |
|||
Ok(Box::new(TestAliasAnalysis)) |
|||
} |
|||
|
|||
impl SubTest for TestAliasAnalysis { |
|||
fn name(&self) -> &'static str { |
|||
"alias-analysis" |
|||
} |
|||
|
|||
fn is_mutating(&self) -> bool { |
|||
true |
|||
} |
|||
|
|||
fn run(&self, func: Cow<Function>, context: &Context) -> anyhow::Result<()> { |
|||
let mut comp_ctx = cranelift_codegen::Context::for_function(func.into_owned()); |
|||
|
|||
comp_ctx.flowgraph(); |
|||
comp_ctx |
|||
.simple_gvn(context.flags_or_isa()) |
|||
.map_err(|e| crate::pretty_anyhow_error(&comp_ctx.func, Into::into(e)))?; |
|||
comp_ctx |
|||
.replace_redundant_loads() |
|||
.map_err(|e| crate::pretty_anyhow_error(&comp_ctx.func, Into::into(e)))?; |
|||
|
|||
let text = comp_ctx.func.display().to_string(); |
|||
run_filecheck(&text, context) |
|||
} |
|||
} |
|||
Loading…
Reference in new issue