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>
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 {
diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index 9ad2dd1..d82b5d2 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -372,9 +372,8 @@
block->RemoveInstruction(equal);
RecordSimplification();
} else if (input_const->AsIntConstant()->IsZero()) {
- // Replace (bool_value == false) with !bool_value
- block->ReplaceAndRemoveInstructionWith(
- equal, new (block->GetGraph()->GetArena()) HBooleanNot(input_value));
+ equal->ReplaceWith(GetGraph()->InsertOppositeCondition(input_value, equal));
+ block->RemoveInstruction(equal);
RecordSimplification();
} else {
// Replace (bool_value == integer_not_zero_nor_one_constant) with false
@@ -399,9 +398,8 @@
// We are comparing the boolean to a constant which is of type int and can
// be any constant.
if (input_const->AsIntConstant()->IsOne()) {
- // Replace (bool_value != true) with !bool_value
- block->ReplaceAndRemoveInstructionWith(
- not_equal, new (block->GetGraph()->GetArena()) HBooleanNot(input_value));
+ not_equal->ReplaceWith(GetGraph()->InsertOppositeCondition(input_value, not_equal));
+ block->RemoveInstruction(not_equal);
RecordSimplification();
} else if (input_const->AsIntConstant()->IsZero()) {
// Replace (bool_value != false) with bool_value
diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 0a39ff3..1680c07 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -2090,4 +2090,43 @@
env_uses_.Clear();
}
+// Returns an instruction with the opposite boolean value from 'cond'.
+HInstruction* HGraph::InsertOppositeCondition(HInstruction* cond, HInstruction* cursor) {
+ ArenaAllocator* allocator = GetArena();
+
+ if (cond->IsCondition() &&
+ !Primitive::IsFloatingPointType(cond->InputAt(0)->GetType())) {
+ // Can't reverse floating point conditions. We have to use HBooleanNot in that case.
+ HInstruction* lhs = cond->InputAt(0);
+ HInstruction* rhs = cond->InputAt(1);
+ HInstruction* replacement;
+ switch (cond->AsCondition()->GetOppositeCondition()) { // get *opposite*
+ case kCondEQ: replacement = new (allocator) HEqual(lhs, rhs); break;
+ case kCondNE: replacement = new (allocator) HNotEqual(lhs, rhs); break;
+ case kCondLT: replacement = new (allocator) HLessThan(lhs, rhs); break;
+ case kCondLE: replacement = new (allocator) HLessThanOrEqual(lhs, rhs); break;
+ case kCondGT: replacement = new (allocator) HGreaterThan(lhs, rhs); break;
+ case kCondGE: replacement = new (allocator) HGreaterThanOrEqual(lhs, rhs); break;
+ case kCondB: replacement = new (allocator) HBelow(lhs, rhs); break;
+ case kCondBE: replacement = new (allocator) HBelowOrEqual(lhs, rhs); break;
+ case kCondA: replacement = new (allocator) HAbove(lhs, rhs); break;
+ case kCondAE: replacement = new (allocator) HAboveOrEqual(lhs, rhs); break;
+ }
+ cursor->GetBlock()->InsertInstructionBefore(replacement, cursor);
+ return replacement;
+ } else if (cond->IsIntConstant()) {
+ HIntConstant* int_const = cond->AsIntConstant();
+ if (int_const->IsZero()) {
+ return GetIntConstant(1);
+ } else {
+ DCHECK(int_const->IsOne());
+ return GetIntConstant(0);
+ }
+ } else {
+ HInstruction* replacement = new (allocator) HBooleanNot(cond);
+ cursor->GetBlock()->InsertInstructionBefore(replacement, cursor);
+ return replacement;
+ }
+}
+
} // namespace art
diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 4f894b0..744067f 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -371,6 +371,11 @@
bool HasTryCatch() const { return has_try_catch_; }
void SetHasTryCatch(bool value) { has_try_catch_ = value; }
+ // Returns an instruction with the opposite boolean value from 'cond'.
+ // The instruction has been inserted into the graph, either as a constant, or
+ // before cursor.
+ HInstruction* InsertOppositeCondition(HInstruction* cond, HInstruction* cursor);
+
private:
void FindBackEdges(ArenaBitVector* visited);
void RemoveInstructionsAsUsersFromDeadBlocks(const ArenaBitVector& visited) const;