commit 75bb2f3c85330b2aeba9e0a4a25f7eb059bcd754
author Mingyao Yang <mingyao@google.com> Thu Nov 30 14:45:44 2017 -0800
committer Mingyao Yang <mingyao@google.com> Thu Nov 30 14:45:44 2017 -0800
tree 2e9c2884dc546540c66b057374822a45f7d9a414
parent 1f541bf57dfdfe4faf169b811aadb91298a886ca

Type conversion elimination of constants

A better way of eliminating type conversion for constants.

Test: run-test on host. 711-checker-type-conversion.
Change-Id: I457bc091542a5ac4cc4e77cadb012ee7cb040ce8

compiler/optimizing/constant_folding.cc

diff --git a/compiler/optimizing/constant_folding.cc b/compiler/optimizing/constant_folding.cc
index bb586bf..6f11e62 100644
--- a/compiler/optimizing/constant_folding.cc
+++ b/compiler/optimizing/constant_folding.cc
@@ -113,7 +113,7 @@
 void HConstantFoldingVisitor::VisitTypeConversion(HTypeConversion* inst) {
   // Constant folding: replace `TypeConversion(a)' with a constant at
   // compile time if `a' is a constant.
-  HConstant* constant = inst->AsTypeConversion()->TryStaticEvaluation();
+  HConstant* constant = inst->TryStaticEvaluation();
   if (constant != nullptr) {
     inst->ReplaceWith(constant);
     inst->GetBlock()->RemoveInstruction(inst);

compiler/optimizing/instruction_simplifier.cc

diff --git a/compiler/optimizing/instruction_simplifier.cc b/compiler/optimizing/instruction_simplifier.cc
index bd20d28..7fa0c2b 100644
--- a/compiler/optimizing/instruction_simplifier.cc
+++ b/compiler/optimizing/instruction_simplifier.cc
@@ -1168,16 +1168,6 @@
       RecordSimplification();
       return;
     }
-  } else if (input->IsIntConstant()) {
-    // Try to eliminate type conversion on int constant whose value falls into
-    // the range of the result type.
-    int32_t value = input->AsIntConstant()->GetValue();
-    if (DataType::IsTypeConversionImplicit(value, result_type)) {
-      instruction->ReplaceWith(input);
-      instruction->GetBlock()->RemoveInstruction(instruction);
-      RecordSimplification();
-      return;
-    }
   }
 }
 

compiler/optimizing/nodes.cc

diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index fa580d9..4a9da7e 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -1403,6 +1403,14 @@
   if (GetInput()->IsIntConstant()) {
     int32_t value = GetInput()->AsIntConstant()->GetValue();
     switch (GetResultType()) {
+      case DataType::Type::kInt8:
+        return graph->GetIntConstant(static_cast<int8_t>(value), GetDexPc());
+      case DataType::Type::kUint8:
+        return graph->GetIntConstant(static_cast<uint8_t>(value), GetDexPc());
+      case DataType::Type::kInt16:
+        return graph->GetIntConstant(static_cast<int16_t>(value), GetDexPc());
+      case DataType::Type::kUint16:
+        return graph->GetIntConstant(static_cast<uint16_t>(value), GetDexPc());
       case DataType::Type::kInt64:
         return graph->GetLongConstant(static_cast<int64_t>(value), GetDexPc());
       case DataType::Type::kFloat32:
@@ -1415,6 +1423,14 @@
   } else if (GetInput()->IsLongConstant()) {
     int64_t value = GetInput()->AsLongConstant()->GetValue();
     switch (GetResultType()) {
+      case DataType::Type::kInt8:
+        return graph->GetIntConstant(static_cast<int8_t>(value), GetDexPc());
+      case DataType::Type::kUint8:
+        return graph->GetIntConstant(static_cast<uint8_t>(value), GetDexPc());
+      case DataType::Type::kInt16:
+        return graph->GetIntConstant(static_cast<int16_t>(value), GetDexPc());
+      case DataType::Type::kUint16:
+        return graph->GetIntConstant(static_cast<uint16_t>(value), GetDexPc());
       case DataType::Type::kInt32:
         return graph->GetIntConstant(static_cast<int32_t>(value), GetDexPc());
       case DataType::Type::kFloat32: