commit f652917de5634b30c974c81d35a72871915b352a
author Mark Mendell <mark.p.mendell@intel.com> Tue Nov 17 11:16:56 2015 -0500
committer David Brazdil <dbrazdil@google.com> Fri Nov 20 16:48:04 2015 +0000
tree c50bcaf37c246df633d42a166334c9b6332e5394
parent 60c4c6ad2b892bb00a6016a147b1cc089ba6bcb5

Simplify boolean condition compared to 0

CaffeineMarkRR Logic has some boolean flipping which can be helped by
some simplification.

Simplify non-FP (A COND_OP B) != 0 to A OPPOSITE_COND_OP B.
This is better than the original code, which would use a HBooleanNot
after the condition.

Also simplify non-FP (A COND_OP B) == 1 to A OPPOSITE_COND_OP B.

Move GetOppositeCondition to nodes.h/nodes.cc to share with Boolean
Simplification, renaming it to InsertOppositeCondition, as it inserts
the new HInstruction (unless it is a constant).

Change-Id: I34ded7758836e375de0d6fdba9239d2d451928d0
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>

compiler/optimizing/boolean_simplifier.cc

diff --git a/compiler/optimizing/boolean_simplifier.cc b/compiler/optimizing/boolean_simplifier.cc
index f985745..f0cafc8 100644
--- a/compiler/optimizing/boolean_simplifier.cc
+++ b/compiler/optimizing/boolean_simplifier.cc
@@ -61,40 +61,6 @@
       && input_false->IsIntConstant() && input_false->AsIntConstant()->IsOne();
 }
 
-// Returns an instruction with the opposite boolean value from 'cond'.
-static HInstruction* GetOppositeCondition(HInstruction* cond) {
-  HGraph* graph = cond->GetBlock()->GetGraph();
-  ArenaAllocator* allocator = graph->GetArena();
-
-  if (cond->IsCondition()) {
-    HInstruction* lhs = cond->InputAt(0);
-    HInstruction* rhs = cond->InputAt(1);
-    switch (cond->AsCondition()->GetOppositeCondition()) {  // get *opposite*
-      case kCondEQ: return new (allocator) HEqual(lhs, rhs);
-      case kCondNE: return new (allocator) HNotEqual(lhs, rhs);
-      case kCondLT: return new (allocator) HLessThan(lhs, rhs);
-      case kCondLE: return new (allocator) HLessThanOrEqual(lhs, rhs);
-      case kCondGT: return new (allocator) HGreaterThan(lhs, rhs);
-      case kCondGE: return new (allocator) HGreaterThanOrEqual(lhs, rhs);
-      case kCondB:  return new (allocator) HBelow(lhs, rhs);
-      case kCondBE: return new (allocator) HBelowOrEqual(lhs, rhs);
-      case kCondA:  return new (allocator) HAbove(lhs, rhs);
-      case kCondAE: return new (allocator) HAboveOrEqual(lhs, rhs);
-    }
-  } else if (cond->IsIntConstant()) {
-    HIntConstant* int_const = cond->AsIntConstant();
-    if (int_const->IsZero()) {
-      return graph->GetIntConstant(1);
-    } else {
-      DCHECK(int_const->IsOne());
-      return graph->GetIntConstant(0);
-    }
-  }
-  // General case when 'cond' is another instruction of type boolean,
-  // as verified by SSAChecker.
-  return new (allocator) HBooleanNot(cond);
-}
-
 void HBooleanSimplifier::TryRemovingBooleanSelection(HBasicBlock* block) {
   DCHECK(block->EndsWithIf());
 
@@ -126,10 +92,7 @@
 
   HInstruction* replacement;
   if (NegatesCondition(true_value, false_value)) {
-    replacement = GetOppositeCondition(if_condition);
-    if (replacement->GetBlock() == nullptr) {
-      block->InsertInstructionBefore(replacement, if_instruction);
-    }
+    replacement = graph_->InsertOppositeCondition(if_condition, if_instruction);
   } else if (PreservesCondition(true_value, false_value)) {
     replacement = if_condition;
   } else {