diff --git a/src/gallium/drivers/swr/rasterizer/common/simdintrin.h b/src/gallium/drivers/swr/rasterizer/common/simdintrin.h
index 8926e665173..ea79902a002 100644
--- a/src/gallium/drivers/swr/rasterizer/common/simdintrin.h
+++ b/src/gallium/drivers/swr/rasterizer/common/simdintrin.h
@@ -1122,6 +1122,19 @@ static INLINE simdscalar InterpolateComponent(simdscalar vI, simdscalar vJ, cons
     return vplaneps(vA, vB, vC, vI, vJ);
 }
 
+//////////////////////////////////////////////////////////////////////////
+/// @brief Interpolates a single component (flat shade).
+/// @param pInterpBuffer - pointer to attribute barycentric coeffs
+template<UINT Attrib, UINT Comp, UINT numComponents = 4>
+static INLINE simdscalar InterpolateComponentFlat(const float *pInterpBuffer)
+{
+    const float *pInterpA = &pInterpBuffer[Attrib * 3 * numComponents + 0 + Comp];
+
+    simdscalar vA = _simd_broadcast_ss(pInterpA);
+
+    return vA;
+}
+
 //////////////////////////////////////////////////////////////////////////
 /// @brief Interpolates a single component.
 /// @param vI - barycentric I