33 lines
920 B
Python
33 lines
920 B
Python
import torch
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swiglu_fwd_codestring = """
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template <typename T> T swiglu_fwd(T x, T y) {
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return float(x) * float(y) / (1.0f + ::exp(-float(x)));
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}
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"""
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swiglu_bwd_codestring = """
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template <typename T> T swiglu_bwd(T x, T y, T g, T& dx, T& dy) {
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float x_sigmoid = 1.0f / (1.0f + ::exp(-float(x)));
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dx = x_sigmoid * (1 + float(x) * (1.0f - x_sigmoid)) * float(g) * float(y);
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dy = float(x) * x_sigmoid * float(g);
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}
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"""
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swiglu_fwd = torch.cuda.jiterator._create_jit_fn(swiglu_fwd_codestring)
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swiglu_bwd = torch.cuda.jiterator._create_multi_output_jit_fn(swiglu_bwd_codestring, num_outputs=2)
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class SwiGLUFunction(torch.autograd.Function):
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@staticmethod
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def forward(ctx, x, y):
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ctx.save_for_backward(x, y)
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return swiglu_fwd(x, y)
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@staticmethod
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def backward(ctx, dout):
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x, y = ctx.saved_tensors
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return swiglu_bwd(x, y, dout)
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swiglu = SwiGLUFunction.apply
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