[torch.compile] Dynamic fp8 + rms_norm fusion (#10906)

Signed-off-by: luka <luka@neuralmagic.com>
Co-authored-by: Varun Sundar Rabindranath <varun@neuralmagic.com>

csrc/quantization/vectorization.cuh

@@ -0,0 +1,33 @@
+#pragma once
+/**
+ * __device__ datatypes vectorized by 4
+ */
+
+// Include both AMD and NVIDIA fp8 types to avoid circular import
+// TODO(luka/varun) use FP8_TYPE instead after refactoring
+#include <c10/util/Float8_e4m3fnuz.h>
+#include <c10/util/Float8_e4m3fn.h>
+
+namespace vllm {
+
+// Vectorization containers
+template <typename scalar_t>
+struct __align__(8) vec4_t {
+  scalar_t x;
+  scalar_t y;
+  scalar_t z;
+  scalar_t w;
+};
+
+template <typename quant_type_t>
+struct __align__(4) q8x4_t {
+  static_assert(std::is_same_v<quant_type_t, int8_t> ||
+                std::is_same_v<quant_type_t, c10::Float8_e4m3fn> ||
+                std::is_same_v<quant_type_t, c10::Float8_e4m3fnuz>);
+  quant_type_t x;
+  quant_type_t y;
+  quant_type_t z;
+  quant_type_t w;
+};
+
+}  // namespace vllm