From f652917de5634b30c974c81d35a72871915b352a Mon Sep 17 00:00:00 2001 From: Mark Mendell Date: Tue, 17 Nov 2015 11:16:56 -0500 Subject: 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 --- compiler/optimizing/boolean_simplifier.cc | 39 +------------------------------ 1 file changed, 1 insertion(+), 38 deletions(-) (limited to 'compiler/optimizing/boolean_simplifier.cc') diff --git a/compiler/optimizing/boolean_simplifier.cc b/compiler/optimizing/boolean_simplifier.cc index f985745e7a..f0cafc847f 100644 --- a/compiler/optimizing/boolean_simplifier.cc +++ b/compiler/optimizing/boolean_simplifier.cc @@ -61,40 +61,6 @@ static bool NegatesCondition(HInstruction* input_true, HInstruction* input_false && 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 @@ void HBooleanSimplifier::TryRemovingBooleanSelection(HBasicBlock* block) { 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 { -- cgit v1.2.3-59-g8ed1b