sunggg commented on code in PR #14548:
URL: https://github.com/apache/tvm/pull/14548#discussion_r1161802430
##########
include/tvm/topi/transform.h:
##########
@@ -2035,6 +2034,73 @@ inline Tensor adv_index(const Tensor& data, const
Array<Tensor>& indices,
name, tag);
}
+namespace relax {
+// relax dynamic slice
+inline te::Tensor dynamic_strided_slice(const te::Tensor& x, const te::Tensor&
begin,
+ const te::Tensor& end, const
te::Tensor& strides,
+ Array<PrimExpr> output_shape,
+ std::string name =
"T_strided_slice_dynamic",
+ std::string tag = kInjective) {
+ const size_t num_dynamic_axes = x.ndim();
+ ICHECK_EQ(begin.ndim(), 1);
+ ICHECK_EQ(end.ndim(), 1);
+ ICHECK_EQ(strides.ndim(), 1);
+ const auto* len_begin = begin->shape[0].as<IntImmNode>();
+ const auto* len_end = end->shape[0].as<IntImmNode>();
+ const auto* len_strides = strides->shape[0].as<IntImmNode>();
+ ICHECK(len_begin);
+ ICHECK(len_end);
+ ICHECK(len_strides);
+ ICHECK_EQ(len_begin->value, num_dynamic_axes);
+ ICHECK_EQ(len_end->value, num_dynamic_axes);
+ ICHECK_EQ(len_strides->value, num_dynamic_axes);
+
+ return te::compute(
+ output_shape,
+ [&](const Array<tvm::tir::Var>& indices) {
+ Array<PrimExpr> real_indices;
+ for (size_t i = 0; i < num_dynamic_axes; ++i) {
+ auto ind = make_const(DataType::Int(64), i);
+ real_indices.push_back(indices[i] * strides(ind) +
tvm::min(begin(ind), x->shape[i] - 1));
+ }
+ return x(real_indices);
+ },
+ name, tag);
+}
+
+inline te::Tensor shape_func_dynamic_strided_slice(
+ const te::Tensor& data, const te::Tensor& begin, const te::Tensor& end,
+ const te::Tensor& strides, std::string name =
"T_shape_func_strided_slice_dynamic") {
+ return te::compute(
+ {begin->shape[0]},
+ [&](const Array<tvm::tir::Var>& indices) {
+ ICHECK(indices.size() == 1);
+ auto CanonicalizeIndex = [&](PrimExpr index, PrimExpr extent, PrimExpr
stride) {
+ PrimExpr begin_range = if_then_else(stride < 0, -1, 0);
+ PrimExpr end_range = if_then_else(stride < 0, extent - 1, extent);
+ index = if_then_else(index < 0, index + extent, index);
+ return min(max(index, begin_range), end_range);
+ };
+
+ auto GetLength = [&](PrimExpr begin, PrimExpr end, PrimExpr stride,
PrimExpr length) {
+ begin = CanonicalizeIndex(begin, length, stride);
+ end = CanonicalizeIndex(end, length, stride);
+ PrimExpr len1 = ceildiv(begin - end, -stride);
+ PrimExpr len2 = ceildiv(end - begin, stride);
+ return if_then_else(stride < 0, len1, len2);
+ };
+ PrimExpr length(-1);
+ int ndim = data.ndim();
+ for (int i = 0; i < ndim; i++) {
+ length = if_then_else(indices[0] == i, data->shape[i], length);
+ }
+ return GetLength(begin(indices), end(indices), strides(indices),
length);
Review Comment:
Since this PR lets the legalizer define the output shape of dynamic slice
and pass it to TOPI, we wanted to make sure this is not a breaking change for
PR https://github.com/apache/tvm/pull/14278 as it leverages the output
computation logics in TOPI. We checked that since there are already operators
like `reshape` that TOPI takes its output shape defined elsewhere, this change
won't put any extra complication to his PR.
--
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.
To unsubscribe, e-mail: [email protected]
For queries about this service, please contact Infrastructure at:
[email protected]
