k quant

Author: jiafatom

neural_compressor/adaptor/ox_utils/weight_only.py

@@ -246,6 +246,168 @@ def quant_tensor(data, num_bits=4, group_size=32, scheme="asym", dtype="int", ra
 
     return q_weight, scale, zero_point
 
+def quant_tensor_k_quant_cpu(data, num_bits=4, group_size=32):
+    """Quantize tensor per group based on k quant.
+    Ref: https://github.com/ggml-org/llama.cpp/blob/64eda5deb9859e87a020e56bab5d2f9ca956f1de/ggml/src/ggml-quants.c
+
+    Args:
+        data : input weight
+        num_bits (int, optional): num_bits. Defaults to 4.
+        group_size (int, optional): how many elements share one scale/zp. Defaults to 4.
+
+    Returns:
+        output: quantized weight
+        scale: scale
+        zero_point: zero point
+    """
+    data = np.reshape(data, (-1, group_size)).astype(np.float32)   # (nb, group_size)
+    maxq = 2**num_bits - 1
+    minq = 0
+    sum_x2 = np.sum(data**2, axis=1, keepdims=True) # (nb, 1)
+    av_x = np.sqrt(sum_x2 / group_size) # (nb, 1)
+    weights = np.add(av_x, np.abs(data)) # (nb, group_size)
+    rmin = np.min(data, axis=1, keepdims=True) # (nb, 1)
+    rmax = np.max(data, axis=1, keepdims=True) # (nb, 1)
+    sum_w = np.sum(weights, axis=1, keepdims=True) # (nb, 1)
+    sum_x = np.sum(weights * data, axis=1, keepdims=True) # (nb, group_size)
+    iscale = np.ones(rmax.shape, dtype=data.dtype) # (nb, 1)
+    mask = rmin != rmax
+    iscale[mask] = (maxq - minq) / (rmax[mask] - rmin[mask])
+    scale = 1 / iscale
+    quant_data = np.clip(np.round(iscale * (data - rmin)), minq, maxq) # (nb, group_size)
+    diff = scale * quant_data + rmin - data # (nb, group_size)
+    best_mad = np.sum(weights * diff ** 2, axis=1, keepdims=True) # (nb, 1)
+    nstep = 20
+    rdelta = 0.1
+    # nstep * rdelta = -2 * rrmin, maxq - minq = 2**num_bits - 1
+    rrmin = -1
+    for is_ in range(nstep):
+        iscale_new = np.ones(rmax.shape, dtype=data.dtype) # (nb, 1)
+        factor = np.array([rrmin + rdelta * is_ + maxq - minq]).astype(data.dtype)[0]
+        mask = rmin != rmax
+        iscale_new[mask] = factor / (rmax[mask] - rmin[mask])
+        quant_data_new = np.clip(np.round(iscale_new * (data - rmin)), minq, maxq) # (nb, group_size)
+        mul_weights_quant_data_new = weights * quant_data_new
+        sum_l = np.sum(mul_weights_quant_data_new, axis=1, keepdims=True) # (nb, 1)
+        sum_l2 = np.sum(mul_weights_quant_data_new * quant_data_new, axis=1, keepdims=True) # (nb, 1)
+        sum_xl = np.sum(mul_weights_quant_data_new * data, axis=1, keepdims=True) # (nb, 1)
+        D = np.subtract(sum_w * sum_l2, sum_l ** 2) # (nb, 1)
+
+        this_scale = (sum_w * sum_xl - sum_x * sum_l) / D # (nb, 1)
+        this_min = (sum_l2 * sum_x - sum_l * sum_xl) / D # (nb, 1)
+
+        diff = this_scale * quant_data_new + this_min - data # (nb, group_size)
+        mad = np.sum(weights * diff ** 2, axis=1, keepdims=True) # (nb, 1)
+
+        mad_1 = np.array(mad)
+        best_mad_1 = np.array(best_mad)
+        idx_to_replace = np.where(mad_1 < best_mad_1)[0]
+        quant_data[idx_to_replace, :] = quant_data_new[idx_to_replace, :]
+        best_mad[idx_to_replace] = mad[idx_to_replace]
+        scale[idx_to_replace] = this_scale[idx_to_replace]
+        rmin[idx_to_replace] = this_min[idx_to_replace]
+
+    zero_point = np.clip((( - rmin) / scale).round(), 0, maxq).astype("uint8")
+    scale = scale.astype(np.float64)
+    q_weight = np.empty_like(data, dtype=scale.dtype)
+    np.divide(data, scale, out=q_weight)
+    np.add(q_weight, zero_point, out=q_weight)
+    np.round(q_weight, out=q_weight)
+    np.clip(q_weight, minq, maxq, out=q_weight)
+
+    return q_weight, scale, zero_point
+
+def quant_tensor_k_quant_cuda(data, num_bits=4, group_size=32):
+    """Quantize tensor per group based on k quant.
+    Ref: https://github.com/ggml-org/llama.cpp/blob/64eda5deb9859e87a020e56bab5d2f9ca956f1de/ggml/src/ggml-quants.c
+
+    Args:
+        data : input weight
+        num_bits (int, optional): num_bits. Defaults to 4.
+        group_size (int, optional): how many elements share one scale/zp. Defaults to 4.
+
+    Returns:
+        output: quantized weight
+        scale: scale
+        zero_point: zero point
+    """
+    try:
+        import cupy as cp
+        import torch
+        if torch.cuda.is_available():
+            data = cp.asarray(data)
+            data = data.reshape((-1, group_size)).astype(np.float32)   # (nb, group_size)
+            nb = data.shape[0]
+            maxq = 2**num_bits - 1
+            minq = 0
+            sum_x2 = np.sum(data**2, axis=1, keepdims=True) # (nb, 1)
+            av_x = np.sqrt(sum_x2 / group_size) # (nb, 1)
+            weights = np.add(av_x, np.abs(data)) # (nb, group_size)
+            rmin = np.min(data, axis=1, keepdims=True) # (nb, 1)
+            rmax = np.max(data, axis=1, keepdims=True) # (nb, 1)
+            sum_w = np.sum(weights, axis=1, keepdims=True) # (nb, 1)
+            sum_x = np.sum(weights * data, axis=1, keepdims=True) # (nb, group_size)
+            iscale = cp.ones(rmax.shape, dtype=data.dtype) # (nb, 1)
+            mask = rmin != rmax
+            iscale[mask] = (maxq - minq) / (rmax[mask] - rmin[mask])
+            scale = 1 / iscale
+            quant_data = np.clip(np.round(iscale * (data - rmin)), minq, maxq) # (nb, group_size)
+            diff = scale * quant_data + rmin - data # (nb, group_size)
+            best_mad = np.sum(weights * diff ** 2, axis=1, keepdims=True) # (nb, 1)
+            nstep = 20
+            rdelta = 0.1
+            rrmin = -1
+            for is_ in range(nstep):
+                iscale_new = cp.ones(rmax.shape, dtype=data.dtype) # (nb, 1)
+                factor = cp.array([rrmin + rdelta * is_ + maxq - minq]).astype(data.dtype)[0]
+                mask = rmin != rmax
+                iscale_new[mask] = factor / (rmax[mask] - rmin[mask])
+                quant_data_new = np.clip(np.round(iscale_new * (data - rmin)), minq, maxq) # (nb, group_size)
+                mul_weights_quant_data_new = weights * quant_data_new
+                sum_l = np.sum(mul_weights_quant_data_new, axis=1, keepdims=True) # (nb, 1)
+                sum_l2 = np.sum(mul_weights_quant_data_new * quant_data_new, axis=1, keepdims=True) # (nb, 1)
+                sum_xl = np.sum(mul_weights_quant_data_new * data, axis=1, keepdims=True) # (nb, 1)
+                D = np.subtract(sum_w * sum_l2, sum_l ** 2) # (nb, 1)
+
+                this_scale = (sum_w * sum_xl - sum_x * sum_l) / D # (nb, 1)
+                this_min = (sum_l2 * sum_x - sum_l * sum_xl) / D # (nb, 1)
+
+                diff = this_scale * quant_data_new + this_min - data # (nb, group_size)
+                mad = np.sum(weights * diff ** 2, axis=1, keepdims=True) # (nb, 1)
+
+                mad_1 = cp.array(mad)
+                best_mad_1 = cp.array(best_mad)
+                idx_to_replace = np.where(mad_1 < best_mad_1)[0]
+                quant_data[idx_to_replace, :] = quant_data_new[idx_to_replace, :]
+                best_mad[idx_to_replace] = mad[idx_to_replace]
+                scale[idx_to_replace] = this_scale[idx_to_replace]
+                rmin[idx_to_replace] = this_min[idx_to_replace]
+
+            zero_point = np.clip((( - rmin) / scale).round(), 0, maxq).astype("uint8")
+            scale = scale.astype(np.float64)
+            q_weight = np.empty_like(data, dtype=scale.dtype)
+            np.divide(data, scale, out=q_weight)
+            np.add(q_weight, zero_point, out=q_weight)
+            np.round(q_weight, out=q_weight)
+            np.clip(q_weight, minq, maxq, out=q_weight)
+
+            return q_weight.get(), scale.get(), zero_point.get()
+        else:
+            logger.warning("Try to use k-quant quantization on CUDA. However, CUDA is not available." \
+                           "Fall back to k-quant quantization on CPU.")
+            return quant_tensor_k_quant_cpu(
+                data, num_bits, group_size
+            )
+    except ImportError:
+        logger.info(
+            "Now we are using k-quant quantization on cpu, which is time consuming." \
+            "Please consider install cupy to speed up on CUDA. See https://cupy.dev/" \
+            "Please also install torch to check CUDA availablity."
+            )
+        return quant_tensor_k_quant_cpu(
+            data, num_bits, group_size
+        )
+
 
 def qdq_tensor(data, num_bits=4, group_size=32, scheme="asym", dtype="int", ratio=1.0):
     """Quant dequant tensor per group.
@@ -299,6 +461,7 @@ def rtn_quantize(
     ratios={},
     accuracy_level=0,
     providers=["CPUExecutionProvider"],
+    algorithm="rtn",
 ):
     """Quant the model with round to nearst method.
 
@@ -372,9 +535,15 @@ def rtn_quantize(
             ):  # pragma: no cover
                 # MatMulFpQ4 support 4 bits and 32 group_size with ort 1.16.0 and 1.16.1 versions, supported by CPU EP
                 # MatMulNBits supports 4 bits and 2^n group_size with ort > 1.16.1, supported by CPU EP AND CUDA EP
-                q_weight, scale, zp = quant_tensor(
-                    weight.T, num_bits, group_size, scheme, "uint", ratios.get(node.input[1], 1)
-                )
+                if algorithm == "k_quant":
+                    q_weight, scale, zp = quant_tensor_k_quant_cuda(
+                        weight.T, num_bits, group_size
+                    )
+                else:
+                    q_weight, scale, zp = quant_tensor(
+                        weight.T, num_bits, group_size, scheme, "uint", ratios.get(node.input[1], 1)
+                    )
+
                 q_matmul_node, new_inits = make_matmul_weight_only_node(
                     node=node,
                     weight_shape=org_w_shape,