From 1f8d51bc03cbc607ae32fadf3a90f385adeffb95 Mon Sep 17 00:00:00 2001
From: Aart Bik <ajcbik@google.com>
Date: Thu, 15 Feb 2018 10:42:37 -0800
Subject: Introduce MIN/MAX/ABS as HIR nodes.

Rationale:
Having explicit MIN/MAX/ABS operations (in contrast
with intrinsics) simplifies recognition and optimization
of these common operations (e.g. constant folding, hoisting,
detection of saturation arithmetic). Furthermore, mapping
conditionals, selectors, intrinsics, etc. (some still TBD)
onto these operations generalizes the way they are optimized
downstream substantially.

Bug: b/65164101

Test: test-art-host,target

Change-Id: I69240683339356e5a012802f179298f0b04c6726
---
 compiler/optimizing/nodes.h | 72 +++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)

(limited to 'compiler/optimizing/nodes.h')

diff --git a/compiler/optimizing/nodes.h b/compiler/optimizing/nodes.h
index 62550be526..9da46206da 100644
--- a/compiler/optimizing/nodes.h
+++ b/compiler/optimizing/nodes.h
@@ -1384,7 +1384,9 @@ class HLoopInformationOutwardIterator : public ValueObject {
   M(LoadException, Instruction)                                         \
   M(LoadString, Instruction)                                            \
   M(LongConstant, Constant)                                             \
+  M(Max, Instruction)                                                   \
   M(MemoryBarrier, Instruction)                                         \
+  M(Min, BinaryOperation)                                               \
   M(MonitorOperation, Instruction)                                      \
   M(Mul, BinaryOperation)                                               \
   M(NativeDebugInfo, Instruction)                                       \
@@ -5017,6 +5019,76 @@ class HRem FINAL : public HBinaryOperation {
   DEFAULT_COPY_CONSTRUCTOR(Rem);
 };
 
+class HMin FINAL : public HBinaryOperation {
+ public:
+  HMin(DataType::Type result_type,
+       HInstruction* left,
+       HInstruction* right,
+       uint32_t dex_pc)
+      : HBinaryOperation(kMin, result_type, left, right, SideEffects::None(), dex_pc) {}
+
+  bool IsCommutative() const OVERRIDE { return true; }
+
+  // Evaluation for integral values.
+  template <typename T> static T ComputeIntegral(T x, T y) {
+    return (x <= y) ? x : y;
+  }
+
+  HConstant* Evaluate(HIntConstant* x, HIntConstant* y) const OVERRIDE {
+    return GetBlock()->GetGraph()->GetIntConstant(
+        ComputeIntegral(x->GetValue(), y->GetValue()), GetDexPc());
+  }
+  HConstant* Evaluate(HLongConstant* x, HLongConstant* y) const OVERRIDE {
+    return GetBlock()->GetGraph()->GetLongConstant(
+        ComputeIntegral(x->GetValue(), y->GetValue()), GetDexPc());
+  }
+  // TODO: Evaluation for floating-point values.
+  HConstant* Evaluate(HFloatConstant* x ATTRIBUTE_UNUSED,
+                      HFloatConstant* y ATTRIBUTE_UNUSED) const OVERRIDE { return nullptr; }
+  HConstant* Evaluate(HDoubleConstant* x ATTRIBUTE_UNUSED,
+                      HDoubleConstant* y ATTRIBUTE_UNUSED) const OVERRIDE { return nullptr; }
+
+  DECLARE_INSTRUCTION(Min);
+
+ protected:
+  DEFAULT_COPY_CONSTRUCTOR(Min);
+};
+
+class HMax FINAL : public HBinaryOperation {
+ public:
+  HMax(DataType::Type result_type,
+       HInstruction* left,
+       HInstruction* right,
+       uint32_t dex_pc)
+      : HBinaryOperation(kMax, result_type, left, right, SideEffects::None(), dex_pc) {}
+
+  bool IsCommutative() const OVERRIDE { return true; }
+
+  // Evaluation for integral values.
+  template <typename T> static T ComputeIntegral(T x, T y) {
+    return (x >= y) ? x : y;
+  }
+
+  HConstant* Evaluate(HIntConstant* x, HIntConstant* y) const OVERRIDE {
+    return GetBlock()->GetGraph()->GetIntConstant(
+        ComputeIntegral(x->GetValue(), y->GetValue()), GetDexPc());
+  }
+  HConstant* Evaluate(HLongConstant* x, HLongConstant* y) const OVERRIDE {
+    return GetBlock()->GetGraph()->GetLongConstant(
+        ComputeIntegral(x->GetValue(), y->GetValue()), GetDexPc());
+  }
+  // TODO: Evaluation for floating-point values.
+  HConstant* Evaluate(HFloatConstant* x ATTRIBUTE_UNUSED,
+                      HFloatConstant* y ATTRIBUTE_UNUSED) const OVERRIDE { return nullptr; }
+  HConstant* Evaluate(HDoubleConstant* x ATTRIBUTE_UNUSED,
+                      HDoubleConstant* y ATTRIBUTE_UNUSED) const OVERRIDE { return nullptr; }
+
+  DECLARE_INSTRUCTION(Max);
+
+ protected:
+  DEFAULT_COPY_CONSTRUCTOR(Max);
+};
+
 class HAbs FINAL : public HUnaryOperation {
  public:
   HAbs(DataType::Type result_type, HInstruction* input, uint32_t dex_pc = kNoDexPc)
-- 
cgit v1.2.3-59-g8ed1b