luci::CommonSubExpressionEliminationPass Class Reference

Pass to perform CSE (Common Sub-expression Elimination) More...

#include <CommonSubExpressionEliminationPass.h>

Collaboration diagram for luci::CommonSubExpressionEliminationPass:

Public Member Functions
virtual const char *	name (void) const
bool	run (loco::Graph *graph)
	Run the pass.
Public Member Functions inherited from logo::Pass
virtual	~Pass ()=default

Detailed Description

Pass to perform CSE (Common Sub-expression Elimination)

Definition at line 28 of file CommonSubExpressionEliminationPass.h.

Member Function Documentation

name()

virtual const char * luci::CommonSubExpressionEliminationPass::name ( void  ) const

inlinevirtual

Reimplemented from logo::Pass.

Definition at line 31 of file CommonSubExpressionEliminationPass.h.

{ return "luci::CommonSubExpressionEliminationPass"; }

run()

bool luci::CommonSubExpressionEliminationPass::run ( loco::Graph *  graph )

virtual

Run the pass.

Returns

false if there was nothing changed

Implements logo::Pass.

Definition at line 52 of file CommonSubExpressionEliminationPass.cpp.

{
  // Build cache
  ExpressionCache cache;
 
  bool changed = false;
  for (auto node : loco::active_nodes(loco::output_nodes(g)))
  {
    auto cnode = loco::must_cast<luci::CircleNode *>(node);
 
    // Skip virtual Ops
    // Why? virtual Ops do not perform actual computations
    // NOTE Fix this if the assumption is not true
    if (virtual_op(cnode->opcode()))
      continue;
 
    // Build expression
    auto expr = Expression::build(cnode);
 
    // Invalid (NYI) expression
    if (expr.op == nullptr)
      continue;
 
    // Cache hit
    if (auto saved_node = cache.get(expr))
    {
      loco::replace(cnode).with(saved_node);
      changed = true;
    }
    // Cache miss
    else
    {
      cache.put(expr, cnode);
    }
  }
 
  return changed;
}

References loco::active_nodes(), luci::pass::Expression::build(), luci::pass::ExpressionCache::get(), loco::output_nodes(), luci::pass::ExpressionCache::put(), loco::replace(), and loco::Subst< SubstQualifier::Default >::with().

Referenced by package.infer.session::inference().

---

The documentation for this class was generated from the following files:

• compiler/luci/pass/include/luci/Pass/CommonSubExpressionEliminationPass.h
• compiler/luci/pass/src/CommonSubExpressionEliminationPass.cpp