ART: Implement HSelect

This patch adds a new HIR instruction to Optimizing. HSelect returns
one of two inputs based on the outcome of a condition.

This is only initial implementation which:
 - defines the new instruction,
 - repurposes BooleanSimplifier to emit it,
 - extends InstructionSimplifier to statically resolve it,
 - updates existing code and tests accordingly.

Code generators currently emit fallback if/then/else code and will be
updated in follow-up CLs to use platform-specific conditional moves
when possible.

Change-Id: Ib61b17146487ebe6b55350c2b589f0b971dcaaee

1 files changed, 16 insertions, 0 deletions

diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 92f758d61d..c057eca434 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -722,6 +722,22 @@ void HBasicBlock::ReplaceAndRemoveInstructionWith(HInstruction* initial,
   RemoveInstruction(initial);
 }
 
+void HBasicBlock::MoveInstructionBefore(HInstruction* insn, HInstruction* cursor) {
+  DCHECK(!cursor->IsPhi());
+  DCHECK(!insn->IsPhi());
+  DCHECK(!insn->IsControlFlow());
+  DCHECK(insn->CanBeMoved());
+  DCHECK(!insn->HasSideEffects());
+
+  HBasicBlock* from_block = insn->GetBlock();
+  HBasicBlock* to_block = cursor->GetBlock();
+  DCHECK(from_block != to_block);
+
+  from_block->RemoveInstruction(insn, /* ensure_safety */ false);
+  insn->SetBlock(to_block);
+  to_block->instructions_.InsertInstructionBefore(insn, cursor);
+}
+
 static void Add(HInstructionList* instruction_list,
                 HBasicBlock* block,
                 HInstruction* instruction) {