Sync from v0.13

csrc/quantization/utils.cuh

@@ -0,0 +1,59 @@
+#pragma once
+
+/**
+ * Quantization utilities including:
+ *   Adjusted maximum values for qtypes.
+ *   Minimum scaling factors for qtypes.
+ */
+
+#include <cmath>
+#include <torch/types.h>
+
+#ifndef USE_ROCM
+  #include <c10/util/Float8_e4m3fn.h>
+  #define MAYBE_HOST_DEVICE C10_HOST_DEVICE
+#else
+  #include <ATen/hip/HIPContext.h>
+  #include <c10/util/Float8_e4m3fn.h>
+  #include <c10/util/Float8_e4m3fnuz.h>
+  // ROCm doesn't seem to need C10_HOST_DEVICE for static constexpr
+  #define MAYBE_HOST_DEVICE
+#endif
+
+template <typename T,
+          typename = std::enable_if_t<std::is_same_v<T, c10::Float8_e4m3fn> ||
+                                      std::is_same_v<T, c10::Float8_e4m3fnuz> ||
+                                      std::is_same_v<T, int8_t>>>
+struct quant_type_max {
+  static constexpr T val() { return std::numeric_limits<T>::max(); }
+};
+
+// Using the default max value from pytorch (240.0 0x7F) will cause accuracy
+// issues when running dynamic quantization. Here use 224.0 0x7E for rocm.
+template <>
+struct quant_type_max<c10::Float8_e4m3fnuz> {
+  static constexpr c10::Float8_e4m3fnuz val() {
+    return c10::Float8_e4m3fnuz(0x7E, c10::Float8_e4m3fnuz::from_bits());
+  }
+};
+
+template <typename T>
+MAYBE_HOST_DEVICE static constexpr T quant_type_max_v =
+    quant_type_max<T>::val();
+
+template <typename T,
+          typename = std::enable_if_t<std::is_same_v<T, c10::Float8_e4m3fn> ||
+                                      std::is_same_v<T, c10::Float8_e4m3fnuz> ||
+                                      std::is_same_v<T, int8_t>>>
+struct min_scaling_factor {
+  C10_DEVICE C10_ALWAYS_INLINE static float val() {
+    return 1.0f / (quant_type_max_v<T> * 512.0f);
+  }
+};
+
+template <>
+struct min_scaling_factor<int8_t> {
+  C10_DEVICE C10_ALWAYS_INLINE static float val() {
+    return std::numeric_limits<float>::epsilon();
+  }
+};