initial progress on pad_rewrite, fixes inceptionv3 onnx perf

src/CMakeLists.txt

@@ -11,6 +11,7 @@ add_library(migraphx
     eliminate_contiguous.cpp
     eliminate_concat.cpp
     eliminate_identity.cpp
+    pad_rewrite.cpp
     fwd_conv_batchnorm_rewrite.cpp
     rewrite_rnn.cpp
     env.cpp

src/eliminate_identity.cpp

@@ -3,7 +3,6 @@
 #include <migraphx/instruction.hpp>
 #include <migraphx/operators.hpp>
 #include <migraphx/iterator_for.hpp>
-#include <migraphx/ranges.hpp>
 #include <migraphx/stringutils.hpp>
 #include <utility>
 
@@ -30,7 +29,7 @@ void eliminate_identity::apply(program& p) const
         {
             if(ins->name() == "identity")
             {
-                const instruction_ref& identity_input = i->inputs().front();
+                const instruction_ref& identity_input = ins->inputs().front();
                 if(identity_input->outputs().size() == 1)
                 {
                     p.move_instruction(identity_input, i);

src/include/migraphx/operators.hpp

@@ -714,6 +714,17 @@ struct pad
         shape s{inputs.front().type(), rdims};
         return s;
     }
+
+    bool symmetric() const
+    {
+        std::size_t num_dims = pads.size()/2;
+        for(std::size_t i = 0; i < num_dims; i++)
+        {
+            if(pads.at(i) != pads.at(i+num_dims))
+                return false;
+        }
+        return true;
+    }
 };
 
 struct as_shape

src/include/migraphx/pad_rewrite.hpp

+#ifndef MIGRAPHX_GUARD_RTGLIB_PAD_REWRITE_HPP
+#define MIGRAPHX_GUARD_RTGLIB_PAD_REWRITE_HPP
+
+#include <string>
+#include <vector>
+#include <array>
+#include <migraphx/instruction_ref.hpp>
+#include <migraphx/config.hpp>
+
+namespace migraphx {
+inline namespace MIGRAPHX_INLINE_NS {
+
+struct program;
+
+/**
+ * Rewrite pads to use attribute from other instructions instead.
+ */
+struct pad_rewrite
+{
+    std::string name() const { return "pad_rewrite"; }
+    void apply(program& p) const;
+    template <class T>
+    void update_op(T, instruction_ref ins, instruction_ref output, program& p) const;
+};
+
+} // namespace MIGRAPHX_INLINE_NS
+} // namespace migraphx
+
+#endif

src/pad_rewrite.cpp

+#include <migraphx/pad_rewrite.hpp>
+#include <migraphx/program.hpp>
+#include <migraphx/instruction.hpp>
+#include <migraphx/operators.hpp>
+#include <migraphx/iterator_for.hpp>
+#include <migraphx/stringutils.hpp>
+
+namespace migraphx {
+inline namespace MIGRAPHX_INLINE_NS {
+
+void pad_rewrite::apply(program& p) const
+{
+    for(auto ins : iterator_for(p))
+    {
+        if(ins->name() != "pad")
+            continue;
+        for (auto output : ins->outputs())
+        {
+            auto op_name = output->name();
+            if(op_name == "convolution")
+                update_op(op::convolution{}, ins, output, p);
+            else if(op_name == "im2col")
+                update_op(op::im2col{}, ins, output, p);
+            else if(op_name == "pooling")
+                update_op(op::pooling{}, ins, output, p);
+        }
+    }
+}
+
+template<class T>
+void pad_rewrite::update_op(T, instruction_ref ins, instruction_ref output, program& p) const
+{
+    auto pad_op = any_cast<op::pad>(ins->get_operator());
+    if(!pad_op.symmetric())
+        return;
+    
+    std::vector<int64_t> pads = pad_op.pads;
+    assert(pads.size() == 8); // ensure input being padded has 4 dims (*2 for font and back padding)
+    std::array<size_t, 2> new_pads{static_cast<size_t>(pads[2]),static_cast<size_t>(pads[3])};
+
+    T op = any_cast<T>(output->get_operator()); 
+    op.padding = new_pads;
+    
+    std::vector<instruction_ref> new_inputs{output->inputs()};
+    new_inputs.front() = ins->inputs().front();
+    
+    p.replace_instruction(output, op, new_inputs);
+} 
+
+} // namespace MIGRAPHX_INLINE_NS
+} // namespace migraphx

src/targets/gpu/target.cpp

@@ -20,6 +20,7 @@
 #include <migraphx/eliminate_identity.hpp>
 #include <migraphx/gpu/concat_gpu_opt.hpp>
 #include <migraphx/gpu/schedule_model.hpp>
+#include <migraphx/pad_rewrite.hpp>
 #include <migraphx/schedule.hpp>
 
 namespace migraphx {
@@ -34,6 +35,8 @@ std::vector<pass> target::get_passes(migraphx::context& gctx) const
     {
         dead_code_elimination{},
         eliminate_identity{},
+        pad_rewrite{},
+        dead_code_elimination{},
         fwd_conv_batchnorm_rewrite{},
         dead_code_elimination{},
         rewrite_rnn{},