Add Support for 2/3/8-bit GPTQ Quantization Models (#2330)

csrc/quantization/gptq/qdq_8.cuh

@@ -0,0 +1,40 @@
+/*
+Copied from https://github.com/turboderp/exllamav2
+*/
+
+#ifndef _qdq_8_cuh
+#define _qdq_8_cuh
+
+#include "qdq_util.cuh"
+
+namespace vllm {
+namespace gptq {
+
+__forceinline__ __device__ void shuffle_8bit_4
+(
+    uint32_t* q,
+    int stride
+)
+{
+}
+
+__forceinline__ __device__ void dequant_8bit_8
+(
+    const uint32_t q_0,
+    const uint32_t q_1,
+    half2 (&dq)[4],
+    int stride,
+    const uint32_t zero
+)
+{
+    half dqh[8];
+    for (int i = 0; i < 4; i++) dqh[i    ] = dq_ns(exb(q_0, i * 8, 0xff), zero);
+    for (int i = 0; i < 4; i++) dqh[i + 4] = dq_ns(exb(q_1, i * 8, 0xff), zero);
+
+    for (int i = 0; i < 4; i++) dq[i] = __halves2half2(dqh[i * 2], dqh[i * 2 + 1]);
+}
+
+}  // namespace gptq
+}  // namespace vllm
+
+#endif