!3720 New optimization pass to remove redundant Min/Max ops

Merge pull request !3720 from thlinh/dev_July29_remove_redundant_minmax

mindspore/ccsrc/frontend/optimizer/irpass.cc

@@ -168,8 +168,8 @@ OptimizeIRPassLib::OptimizeIRPassLib() {
     {prim::kPrimSparseTensorGetIndices, prim::kPrimSparseTensorGetValues, prim::kPrimSparseTensorGetDenseShape});
 
   // Value_Based Eliminate
-  value_based_eliminate_ =
-    MakeSubstitution(std::make_shared<ValueBasedEliminate>(), "value_based_eliminate", {prim::kPrimSelect});
+  value_based_eliminate_ = MakeSubstitution(std::make_shared<ValueBasedEliminate>(), "value_based_eliminate",
+                                            {prim::kPrimSelect, prim::kPrimMinimum, prim::kPrimMaximum});
 }
 
 ResolveIRPassLib::ResolveIRPassLib() {

mindspore/ccsrc/frontend/optimizer/irpass/value_based_eliminate.cc

@@ -19,6 +19,9 @@
 namespace mindspore {
 namespace opt {
 namespace irpass {
+#define UPPER_FLT_LIMIT (FLT_MAX / 2.0)
+#define LOWER_FLT_LIMIT (-FLT_MAX / 2.0)
+
 bool IsCNodePositive(const AnfNodePtr &node) {
   if (IsPrimitiveCNode(node, prim::kPrimReduceSum) || IsPrimitiveCNode(node, prim::kPrimSqueeze)) {
     return IsCNodePositive(node->cast<CNodePtr>()->input(1));
@@ -29,17 +32,94 @@ bool IsCNodePositive(const AnfNodePtr &node) {
   return false;
 }
 
+// check if a value is bigger than UPPER_FLT_LIMIT
+bool IsNodeScalarMaxFLT(const AnfNodePtr &node) {
+  auto value_node = node->cast<ValueNodePtr>();
+  if (value_node == nullptr) {
+    return false;
+  }
+
+  auto value = value_node->value();
+  if (value == nullptr) {
+    return false;
+  }
+
+  auto scalar = value->cast<ScalarPtr>();
+  if (scalar != nullptr) {
+    if (scalar->isa<FloatImm>()) {
+      return GetValue<float>(scalar) > UPPER_FLT_LIMIT;
+    }
+  }
+  // Check for Tensor [] or Tensor [1]
+  auto tensor_ptr = value->cast<tensor::TensorPtr>();
+  if (tensor_ptr == nullptr) {
+    return false;
+  }
+  if (tensor_ptr->DataSize() > 1) {
+    return false;
+  }
+
+  TypeId tensor_type = tensor_ptr->Dtype()->type_id();
+  if ((tensor_type == TypeId::kNumberTypeFloat32) || (tensor_type == TypeId::kNumberTypeFloat)) {
+    float *data = reinterpret_cast<float *>(tensor_ptr->data_c());
+    return data[0] > UPPER_FLT_LIMIT;
+  }
+
+  return false;
+}
+
+// check if a value is smaller than LOWER_FLT_LIMIT
+bool IsNodeScalarMinFLT(const AnfNodePtr &node) {
+  auto value_node = node->cast<ValueNodePtr>();
+  if (value_node == nullptr) {
+    return false;
+  }
+
+  auto value = value_node->value();
+  if (value == nullptr) {
+    return false;
+  }
+
+  auto scalar = value->cast<ScalarPtr>();
+  if (scalar != nullptr) {
+    if (scalar->isa<FloatImm>()) {
+      return GetValue<float>(scalar) < LOWER_FLT_LIMIT;
+    }
+  }
+  // Check for Tensor [] or Tensor [1]
+  auto tensor_ptr = value->cast<tensor::TensorPtr>();
+  if (tensor_ptr == nullptr) {
+    return false;
+  }
+  if (tensor_ptr->DataSize() > 1) {
+    return false;
+  }
+
+  TypeId tensor_type = tensor_ptr->Dtype()->type_id();
+  if ((tensor_type == TypeId::kNumberTypeFloat32) || (tensor_type == TypeId::kNumberTypeFloat)) {
+    float *data = reinterpret_cast<float *>(tensor_ptr->data_c());
+    return data[0] < LOWER_FLT_LIMIT;
+  }
+
+  return false;
+}
+
 AnfNodePtr ValueBasedEliminate::operator()(const OptimizerPtr &, const AnfNodePtr &node) {
   PatternNode x, y, z;
   PConstant zero_(node, false, 0);
   PConstant zero_scalar_(node, false, 0, true);
 
+  // {prim::kPrimSelect, {prim::kPrimGreater, X, 0}, Y, Z}} -> Y when X is always greater than 0
   MATCH_REPLACE_IF(node, PPrimitive(prim::kPrimSelect, PPrimitive(prim::kPrimGreater, x, zero_), y, z), y,
                    IsCNodePositive(x.GetNode(node)));
 
   MATCH_REPLACE_IF(node, PPrimitive(prim::kPrimSelect, PPrimitive(prim::kPrimGreater, x, zero_scalar_), y, z), y,
                    IsCNodePositive(x.GetNode(node)));
 
+  MATCH_REPLACE_IF(node, PPrimitive(prim::kPrimMaximum, x, y), x, IsNodeScalarMinFLT(y.GetNode(node)));
+
+  MATCH_REPLACE_IF(node, PPrimitive(prim::kPrimMinimum, x, y), x, IsNodeScalarMaxFLT(y.GetNode(node)));
+
   return nullptr;
 }
 

mindspore/ccsrc/frontend/optimizer/irpass/value_based_eliminate.h

@@ -32,6 +32,8 @@ namespace opt {
 namespace irpass {
 
 // {prim::kPrimSelect, {prim::kPrimGreater, X, 0}, Y, Z}} -> Y when X is always greater than 0
+// {prim::kPrimMaximum, X, Y} -> X when Y is smaller than LOWER_FLT_LIMIT
+// {prim::kPrimMinimum, X, Y} -> X when Y is greater than UPPER_FLT_LIMIT
 class ValueBasedEliminate : public OptimizerCaller {
  public:
   AnfNodePtr operator()(const OptimizerPtr &, const AnfNodePtr &node) override;

mindspore/core/ir/pattern_matcher.h

@@ -487,7 +487,7 @@ class PConstant : public PBase<PConstant<T> > {
     TypeId tensor_type = tensor_ptr->Dtype()->type_id();
     if ((tensor_type == TypeId::kNumberTypeFloat32) || (tensor_type == TypeId::kNumberTypeFloat)) {
       float *data2 = reinterpret_cast<float *>(tensor_ptr->data_c());
-      auto threshold = FLT_EPSILON * FLT_EPSILON;
+      auto threshold = FLT_MIN;
       for (int i = 0; i < tensor_ptr->DataSize(); i++) {
         if (fabs(data2[i] - check_value_) > threshold) {
           return false;
@@ -496,7 +496,7 @@ class PConstant : public PBase<PConstant<T> > {
       return true;
     } else if (tensor_type == TypeId::kNumberTypeFloat64) {
       double *data2 = reinterpret_cast<double *>(tensor_ptr->data_c());
-      auto threshold = DBL_EPSILON * DBL_EPSILON;
+      auto threshold = DBL_MIN;
       for (int i = 0; i < tensor_ptr->DataSize(); i++) {
         if (fabs(data2[i] - check_value_) > threshold) {
           return false;