commit e82549b14c7def0a45461183964f7e6a34cbb70c
author Mark Mendell <mark.p.mendell@intel.com> Wed May 06 10:55:34 2015 -0400
committer Mark Mendell <mark.p.mendell@intel.com> Wed May 13 16:20:48 2015 -0400
tree 9293e5bf58657883923fe08ff1964e92e81e8851
parent c3912c8a2db109a15603554fd456f56cd0a69ad0

[optimizing] Fold HTypeConversion of constants

While looking into optimizing long shifts on x86, I found that the
compiler wasn't folding HTypeConversion of constants.  Add simple
conversions of constants, taking care of float/double values
with NaNs and small/large values, ensuring Java conversion semantics.

Add checker cases to see that constant folding of HTypeConversion is
done.

Ensure 422-type-conversion type conversion routiness don't get
inlined to avoid compile time folding.

Change-Id: I5a4eb376b64bc4e41bf908af5875bed312efb228
Signed-off-by: Mark Mendell <mark.p.mendell@intel.com>

compiler/optimizing/nodes.cc

diff --git a/compiler/optimizing/nodes.cc b/compiler/optimizing/nodes.cc
index 41adc72..47da9cc 100644
--- a/compiler/optimizing/nodes.cc
+++ b/compiler/optimizing/nodes.cc
@@ -16,6 +16,7 @@
 
 #include "nodes.h"
 
+#include "code_generator.h"
 #include "ssa_builder.h"
 #include "base/bit_vector-inl.h"
 #include "utils/growable_array.h"
@@ -794,6 +795,84 @@
   }
 }
 
+HConstant* HTypeConversion::TryStaticEvaluation() const {
+  HGraph* graph = GetBlock()->GetGraph();
+  if (GetInput()->IsIntConstant()) {
+    int32_t value = GetInput()->AsIntConstant()->GetValue();
+    switch (GetResultType()) {
+      case Primitive::kPrimLong:
+        return graph->GetLongConstant(static_cast<int64_t>(value));
+      case Primitive::kPrimFloat:
+        return graph->GetFloatConstant(static_cast<float>(value));
+      case Primitive::kPrimDouble:
+        return graph->GetDoubleConstant(static_cast<double>(value));
+      default:
+        return nullptr;
+    }
+  } else if (GetInput()->IsLongConstant()) {
+    int64_t value = GetInput()->AsLongConstant()->GetValue();
+    switch (GetResultType()) {
+      case Primitive::kPrimInt:
+        return graph->GetIntConstant(static_cast<int32_t>(value));
+      case Primitive::kPrimFloat:
+        return graph->GetFloatConstant(static_cast<float>(value));
+      case Primitive::kPrimDouble:
+        return graph->GetDoubleConstant(static_cast<double>(value));
+      default:
+        return nullptr;
+    }
+  } else if (GetInput()->IsFloatConstant()) {
+    float value = GetInput()->AsFloatConstant()->GetValue();
+    switch (GetResultType()) {
+      case Primitive::kPrimInt:
+        if (std::isnan(value))
+          return graph->GetIntConstant(0);
+        if (value >= kPrimIntMax)
+          return graph->GetIntConstant(kPrimIntMax);
+        if (value <= kPrimIntMin)
+          return graph->GetIntConstant(kPrimIntMin);
+        return graph->GetIntConstant(static_cast<int32_t>(value));
+      case Primitive::kPrimLong:
+        if (std::isnan(value))
+          return graph->GetLongConstant(0);
+        if (value >= kPrimLongMax)
+          return graph->GetLongConstant(kPrimLongMax);
+        if (value <= kPrimLongMin)
+          return graph->GetLongConstant(kPrimLongMin);
+        return graph->GetLongConstant(static_cast<int64_t>(value));
+      case Primitive::kPrimDouble:
+        return graph->GetDoubleConstant(static_cast<double>(value));
+      default:
+        return nullptr;
+    }
+  } else if (GetInput()->IsDoubleConstant()) {
+    double value = GetInput()->AsDoubleConstant()->GetValue();
+    switch (GetResultType()) {
+      case Primitive::kPrimInt:
+        if (std::isnan(value))
+          return graph->GetIntConstant(0);
+        if (value >= kPrimIntMax)
+          return graph->GetIntConstant(kPrimIntMax);
+        if (value <= kPrimLongMin)
+          return graph->GetIntConstant(kPrimIntMin);
+        return graph->GetIntConstant(static_cast<int32_t>(value));
+      case Primitive::kPrimLong:
+        if (std::isnan(value))
+          return graph->GetLongConstant(0);
+        if (value >= kPrimLongMax)
+          return graph->GetLongConstant(kPrimLongMax);
+        if (value <= kPrimLongMin)
+          return graph->GetLongConstant(kPrimLongMin);
+        return graph->GetLongConstant(static_cast<int64_t>(value));
+      case Primitive::kPrimFloat:
+        return graph->GetFloatConstant(static_cast<float>(value));
+      default:
+        return nullptr;
+    }
+  }
+  return nullptr;
+}
+
 HConstant* HUnaryOperation::TryStaticEvaluation() const {
   if (GetInput()->IsIntConstant()) {
     int32_t value = Evaluate(GetInput()->AsIntConstant()->GetValue());