gpu: jit: gemm: remove unnecessary type conversions with sum post-ops

Author: petercad

src/gpu/jit/gemm/gen_gemm_kernel_generator.cpp

@@ -1,5 +1,5 @@
 /*******************************************************************************
-* Copyright 2019-2022 Intel Corporation
+* Copyright 2019-2023 Intel Corporation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -6582,7 +6582,7 @@ void gemm_kernel_generator_t<hw>::outerProductSystolic(int h, int ha, int hb,
 // Decide whether to use the legacy post-op injector inside C update.
 // Needed if we can't convert C to f32 in-place, but doesn't support binary post-ops.
 static inline bool useEltwiseInjector(const GEMMProblem &problem) {
-    return problem.hasPostOp() && (problem.Tc.size() < 4);
+    return problem.hasNonSum1PostOp() && (problem.Tc.size() < 4);
 }
 
 // Perform C update operation on C_acc, given original C data in C_load.
@@ -14546,6 +14546,12 @@ bool gemm_kernel_generator_t<hw>::gemmBodyInternal(
             subproblem.beta_real = 1;
             subproblem.beta_imag = 0;
 
+            if (subproblem.postOps.len() > 0) {
+                auto &lastPO = subproblem.postOps
+                                       .entry_[subproblem.postOps.len() - 1];
+                if (lastPO.kind == primitive_kind::sum) lastPO.sum.scale = 1.0f;
+            }
+
             if (!gemmUpdateC(subproblem, strategy, substate)) return false;
 
             if (checkBeta0) {
@@ -14566,6 +14572,14 @@ bool gemm_kernel_generator_t<hw>::gemmBodyInternal(
             subproblem.beta_real = 0;
             subproblem.beta_imag = 0;
 
+            if (subproblem.postOps.len() > 0) {
+                auto &lastPO = subproblem.postOps
+                                       .entry_[subproblem.postOps.len() - 1];
+                if (lastPO.kind == primitive_kind::sum)
+                    subproblem.postOps.entry_.resize(
+                            subproblem.postOps.len() - 1);
+            }
+
             substrategy.C.atomic = false;
 
             if (!gemmUpdateC(subproblem, substrategy, substate)) return false;

src/gpu/jit/gemm/gen_gemm_kernel_generator.hpp

@@ -1,5 +1,5 @@
 /*******************************************************************************
-* Copyright 2019-2022 Intel Corporation
+* Copyright 2019-2023 Intel Corporation
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
@@ -817,6 +817,11 @@ struct GEMMProblem : public CommonProblem {
     std::vector<bool> binaryBatch;
 
     bool hasPostOp() const { return postOps.len() > 0; }
+    bool hasNonSum1PostOp() const {
+        for (const auto &e : postOps.entry_)
+            if (!e.is_sum()) return true;
+        return false;
+    }
     bool hasBinaryPostOp() const {
         for (int idx = 0; idx < postOps.len(); idx++)
             if (postOps.entry_[idx].is_binary()) return true;
@@ -840,7 +845,7 @@ struct GEMMProblem : public CommonProblem {
         if (!(alpha1() || alphaM1())) return true;
         if (!(beta0() || beta1())) return true;
         if (beta1() && !Tc_ext.isSubsetOf(Tc)) return true;
-        if (hasPostOp()) return true;
+        if (hasNonSum1PostOp()) return true;
         return false;
     }