From dbb1ad039cfa48f5594737c91fb7937dfb68d742 Mon Sep 17 00:00:00 2001
From: Jiawei Shao <jiawei.shao@intel.com>
Date: Fri, 28 Nov 2025 21:01:31 +0800
Subject: [PATCH] [webgpu] Get data from bias with `GetByOffset()` in
 `gemm_utils.cc`

---
 onnxruntime/core/providers/webgpu/math/gemm_utils.cc    | 5 +++--
 onnxruntime/core/providers/webgpu/math/matmul_packed.cc | 7 -------
 2 files changed, 3 insertions(+), 9 deletions(-)

diff --git a/onnxruntime/core/providers/webgpu/math/gemm_utils.cc b/onnxruntime/core/providers/webgpu/math/gemm_utils.cc
index 7cbc7f6a4a821..7390f7cda35f8 100644
--- a/onnxruntime/core/providers/webgpu/math/gemm_utils.cc
+++ b/onnxruntime/core/providers/webgpu/math/gemm_utils.cc
@@ -34,7 +34,7 @@ void HandleMaybeHaveBiasForGEMM(ShaderHelper& shader,
     } else if (c_is_scalar) {
       shader.AdditionalImplementation() << "output_value_t(C[0]);\n";
     } else {
-      shader.AdditionalImplementation() << "output_value_t(C[row]);\n";
+      shader.AdditionalImplementation() << "output_value_t(" << C.GetByOffset("row") << ");\n";
     }
   }
   shader.AdditionalImplementation() << output.SetByIndices("coords", "value") << "\n";
@@ -47,7 +47,8 @@ void HandleMaybeBiasForMatMul(ShaderHelper& shader,
                               bool is_channels_last) {
   shader.AdditionalImplementation() << "    let coords = vec3(u32(batch), u32(row), u32(colIn));\n";
   if (has_bias) {
-    shader.AdditionalImplementation() << "    value = value + output_value_t(" << (is_channels_last ? "bias[colIn]" : "bias[row]") << ");\n";
+    const ShaderVariableHelper& bias = shader.AddInput("bias", ShaderUsage::UseUniform);
+    shader.AdditionalImplementation() << "    value = value + output_value_t(" << (is_channels_last ? bias.GetByOffset("colIn") : bias.GetByOffset("row")) << ");\n";
   }
   shader.AdditionalImplementation() << "    " << activation_snippet << "\n"
                                     << output.SetByIndices("coords", "value") << "\n";
diff --git a/onnxruntime/core/providers/webgpu/math/matmul_packed.cc b/onnxruntime/core/providers/webgpu/math/matmul_packed.cc
index 4daabe8246aa7..c75b5c0efc1e9 100644
--- a/onnxruntime/core/providers/webgpu/math/matmul_packed.cc
+++ b/onnxruntime/core/providers/webgpu/math/matmul_packed.cc
@@ -26,9 +26,6 @@ Status MatMulProgram::GenerateShaderCode(ShaderHelper& shader) const {
 
   const auto& batch_dims = shader.AddIndices("batch_dims", ShaderUsage::UseUniform | ShaderUsage::UseIndicesTypeAlias);
 
-  if (has_bias_) {
-    shader.AddInput("bias", ShaderUsage::UseUniform);
-  }
   std::string apply_activation = GetActivationSnippet(activation_, "output_value_t", "output_element_t");
   ProgramVariableDataType output_var_type = this->Outputs()[0].var_type;
   // declare the read and write functions
@@ -54,10 +51,6 @@ bool MatMulProgram::NeedSplitK() const {
 Status MatMulFillBiasOrZeroBeforeSplitKProgram::GenerateShaderCode(ShaderHelper& shader) const {
   const auto& output = shader.AddOutput("output", ShaderUsage::UseUniform | ShaderUsage::UseIndicesTypeAlias | ShaderUsage::UseValueTypeAlias | ShaderUsage::UseElementTypeAlias);
 
-  if (has_bias_) {
-    shader.AddInput("bias", ShaderUsage::UseUniform);
-  }
-
   // Handle bias with `MatMulWriteFnSource()`.
   // Here `use_split_k` is false because we just initialize `output` with bias.
   // `use_split_k` is true only when we do the actual MatMul with Split-K.