Add a spilling pass which lowers register pressure by assigning SSA
values to the stack. Important missing features:
- Resolve conflicts where an instruction uses the same value more than
once in incompatible ways.
- Deal with EBB arguments.
Fix bugs in the reload pass exposed by the first test case:
- Create live ranges for temporary registers.
- Set encodings on created spill and fill instructions.
Add a spilling pass which lowers register pressure by assigning SSA
values to the stack. Important missing features:
- Resolve conflicts where an instruction uses the same value more than
once in incompatible ways.
- Deal with EBB arguments.
Fix bugs in the reload pass exposed by the first test case:
- Create live ranges for temporary registers.
- Set encodings on created spill and fill instructions.
The register pressure tracker now has to separate register counts: base
and transient.
The transient counts are used to track spikes of register pressure, such
as dead defs or temporary registers needed to satisfy instruction
constraints.
The base counts represent long-lived variables.
The register pressure tracker now has to separate register counts: base
and transient.
The transient counts are used to track spikes of register pressure, such
as dead defs or temporary registers needed to satisfy instruction
constraints.
The base counts represent long-lived variables.
Add a Stack() class for specifying operand constraints for values on the
stack.
Add encoding recipes for RISC-V spill and fill instructions. Don't
implement the encoding recipe functions yet since we don't have the
stack slot layout yet.
Add a Stack() class for specifying operand constraints for values on the
stack.
Add encoding recipes for RISC-V spill and fill instructions. Don't
implement the encoding recipe functions yet since we don't have the
stack slot layout yet.
This is now a generic function that can test arbitrary combinations of
instructions and EBBs for dominance.
It can handle anything that converts into an expanded program point,
including a ValueDef.
Also fix a bug if the earlier dominates() function which didn't properly
handle block layouts that were not topologically ordered.
This is now a generic function that can test arbitrary combinations of
instructions and EBBs for dominance.
It can handle anything that converts into an expanded program point,
including a ValueDef.
Also fix a bug if the earlier dominates() function which didn't properly
handle block layouts that were not topologically ordered.
When comparing instructions in the same EBB, behave like the RPO visits
instructions in program order.
- Add a Layout::pp_ebb() method for convenience. It gets the EBB
containing any program point.
- Add a conversion from ValueDef to ExpandedProgramPoint so it can be
used with the rpo_cmp method.
When comparing instructions in the same EBB, behave like the RPO visits
instructions in program order.
- Add a Layout::pp_ebb() method for convenience. It gets the EBB
containing any program point.
- Add a conversion from ValueDef to ExpandedProgramPoint so it can be
used with the rpo_cmp method.
* Function names should start with %
* Create FunctionName from string
* Implement displaying of FunctionName as %nnnn with fallback to #xxxx
* Run rustfmt and fix FunctionName::with_string in parser
* Implement FunctionName::new as a generic function
* Binary function names should start with #
* Implement NameRepr for function name
* Fix examples in docs to reflect that function names start with %
* Rebase and fix filecheck tests
* Function names should start with %
* Create FunctionName from string
* Implement displaying of FunctionName as %nnnn with fallback to #xxxx
* Run rustfmt and fix FunctionName::with_string in parser
* Implement FunctionName::new as a generic function
* Binary function names should start with #
* Implement NameRepr for function name
* Fix examples in docs to reflect that function names start with %
* Rebase and fix filecheck tests
Switch to the new domtree.cfg_postorder() which returns a reference to a
pre-computed post-order instead of allocating memory and computing a new
post-order.
Switch to the new domtree.cfg_postorder() which returns a reference to a
pre-computed post-order instead of allocating memory and computing a new
post-order.
The reload pass inserts spill and fill instructions as needed so
instructions that operate on registers will never see a value with stack
affinity.
This is a very basic implementation, and we can't write good test cases
until we have a spilling pass.
The reload pass inserts spill and fill instructions as needed so
instructions that operate on registers will never see a value with stack
affinity.
This is a very basic implementation, and we can't write good test cases
until we have a spilling pass.
The create_dead() methods can create a live range for a new value, and
extend_local() can extend a live range within an EBB where it is already
live.
This is enough to update liveness for new values as long as they stay
local to their EBB.
The create_dead() methods can create a live range for a new value, and
extend_local() can extend a live range within an EBB where it is already
live.
This is enough to update liveness for new values as long as they stay
local to their EBB.
* LICM pass
* Uses loop analysis to detect loop tree
* For each loop (starting with the inner ones), create a pre-header and move there loop-invariant instructions
* An instruction is loop invariant if it does not use as argument a value defined earlier in the loop
* File tests to check LICM's correctness
* Optimized pre-header creation
If the loop already has a natural pre-header, we use it instead of creating a new one.
The natural pre-header of a loop is the only predecessor of the header it doesn't dominate.
* LICM pass
* Uses loop analysis to detect loop tree
* For each loop (starting with the inner ones), create a pre-header and move there loop-invariant instructions
* An instruction is loop invariant if it does not use as argument a value defined earlier in the loop
* File tests to check LICM's correctness
* Optimized pre-header creation
If the loop already has a natural pre-header, we use it instead of creating a new one.
The natural pre-header of a loop is the only predecessor of the header it doesn't dominate.
* Updated the regex crate to 0.2.2 as per issue #88
* Added potential fix for cryptic CI error.
* Fixed incorrect handling of regex name call.
Fixes#88
* Updated the regex crate to 0.2.2 as per issue #88
* Added potential fix for cryptic CI error.
* Fixed incorrect handling of regex name call.
Fixes#88
The DominatorTree has existing DomNodes per EBB that can be used in lieu
of expensive HastSets for the depth-first traversal of the CFG.
Make the computed and cached post-order available for other passes
through the `cfg_postorder()` method which returns a slice.
The post-order algorithm is essentially the same as the one in
ControlFlowGraph::postorder_ebbs(), except it will never push a
successor node that has already been visited once. This is more
efficient, but it generates a different post-order.
Change the cfg_traversal tests to check this new algorithm.
The DominatorTree has existing DomNodes per EBB that can be used in lieu
of expensive HastSets for the depth-first traversal of the CFG.
Make the computed and cached post-order available for other passes
through the `cfg_postorder()` method which returns a slice.
The post-order algorithm is essentially the same as the one in
ControlFlowGraph::postorder_ebbs(), except it will never push a
successor node that has already been visited once. This is more
efficient, but it generates a different post-order.
Change the cfg_traversal tests to check this new algorithm.
* Implemented in two passes
* First pass discovers the loops headers (they dominate one of their predecessors)
* Second pass traverses the blocks of each loop
* Discovers the loop tree structure
* Offers a new LoopAnalysis data structure queried from outside the module
* Implemented in two passes
* First pass discovers the loops headers (they dominate one of their predecessors)
* Second pass traverses the blocks of each loop
* Discovers the loop tree structure
* Offers a new LoopAnalysis data structure queried from outside the module
* Fix GVN skipping the instruction after a deleted instruction.
* Teach GVN to resolve aliases as it proceeds.
* Clean up an obsolete reference to extended_values.
* Fix GVN skipping the instruction after a deleted instruction.
* Teach GVN to resolve aliases as it proceeds.
* Clean up an obsolete reference to extended_values.
* Skeleton simple_gvn pass.
* Basic testing infrastructure for simple-gvn.
* Add can_load and can_store flags to instructions.
* Move the replace_values function into the DataFlowGraph.
* Make InstructionData derive from Hash, PartialEq, and Eq.
* Make EntityList's hash and eq functions panic.
* Change Ieee32 and Ieee64 to store u32 and u64, respectively.
