Wrap indices around max value for tosa.gather creation.

Author: sahas3

lib/Conversion/TorchToTosa/TorchToTosa.cpp

@@ -4006,41 +4006,6 @@ LogicalResult ConvertAtenOp<AtenGatherOp>::matchAndRewrite(
   return success();
 }
 
-Value wrapIndicesAroundMax(Value index, int maxIndex, Operation *op,
-                           ConversionPatternRewriter &rewriter) {
-  // performs the operation : index = index % maxIndex to wrap index around
-  // maxIndex
-
-  auto maxIndexValue =
-      tosa::getConstTensor<int32_t>(rewriter, op, maxIndex, {}).value();
-  auto maxIndexValueMinusOne =
-      tosa::getConstTensor<int32_t>(rewriter, op, maxIndex - 1, {}).value();
-
-  auto indexType = dyn_cast<RankedTensorType>(index.getType());
-  auto boolType = indexType.clone(rewriter.getIntegerType(1));
-
-  auto isBeyondMaxIndices = tosa::CreateOpAndInfer<tosa::GreaterOp>(
-      rewriter, op->getLoc(), boolType, index, maxIndexValueMinusOne);
-  auto wrappedBeyondMaxIndicesQuotient =
-      tosa::CreateOpAndInfer<tosa::IntDivOp>(rewriter, op->getLoc(), indexType,
-                                             index, maxIndexValue)
-          .getResult();
-  auto wrappedBeyondMaxIndicesQuotientTimesIndices =
-      tosa::CreateOpAndInfer<tosa::MulOp>(rewriter, op->getLoc(), indexType,
-                                          wrappedBeyondMaxIndicesQuotient,
-                                          maxIndexValue, /*shift=*/0)
-          .getResult();
-  auto wrappedBeyondMaxIndices =
-      tosa::CreateOpAndInfer<tosa::SubOp>(
-          rewriter, op->getLoc(), indexType, index,
-          wrappedBeyondMaxIndicesQuotientTimesIndices)
-          .getResult();
-
-  return tosa::CreateOpAndInfer<tosa::SelectOp>(rewriter, op->getLoc(),
-                                                indexType, isBeyondMaxIndices,
-                                                wrappedBeyondMaxIndices, index);
-}
-
 template <>
 LogicalResult ConvertAtenOp<AtenIndexSelectOp>::matchAndRewrite(
     AtenIndexSelectOp op, OpAdaptor adaptor,
@@ -4084,10 +4049,6 @@ LogicalResult ConvertAtenOp<AtenIndexSelectOp>::matchAndRewrite(
         RankedTensorType::get(indexShape, rewriter.getIntegerType(32)), index);
   }
 
-  int64_t selfNumElems = std::accumulate(inputShape.begin(), inputShape.end(),
-                                         1, std::multiplies<int64_t>());
-  index = wrapIndicesAroundMax(index, selfNumElems, op, rewriter);
-
   // Get positive dim
   int64_t dim;
   if (!matchPattern(op.getDim(), m_TorchConstantInt(&dim)))

lib/Conversion/TorchToTosa/TosaLegalizeCommon.cpp

@@ -216,6 +216,41 @@ std::optional<Value> convertTorchIndexToTfIndices(PatternRewriter &rewriter,
   return indicesTf.getResult();
 }
 
+Value wrapIndicesAroundMax(Value index, int maxIndex, Operation *op,
+                           PatternRewriter &rewriter) {
+  // performs the operation : index = index % maxIndex to wrap index around
+  // maxIndex
+
+  auto maxIndexValue =
+      tosa::getConstTensor<int32_t>(rewriter, op, maxIndex, {}).value();
+  auto maxIndexValueMinusOne =
+      tosa::getConstTensor<int32_t>(rewriter, op, maxIndex - 1, {}).value();
+
+  auto indexType = dyn_cast<RankedTensorType>(index.getType());
+  auto boolType = indexType.clone(rewriter.getIntegerType(1));
+
+  auto isBeyondMaxIndices = tosa::CreateOpAndInfer<tosa::GreaterOp>(
+      rewriter, op->getLoc(), boolType, index, maxIndexValueMinusOne);
+  auto wrappedBeyondMaxIndicesQuotient =
+      tosa::CreateOpAndInfer<tosa::IntDivOp>(rewriter, op->getLoc(), indexType,
+                                             index, maxIndexValue)
+          .getResult();
+  auto wrappedBeyondMaxIndicesQuotientTimesIndices =
+      tosa::CreateOpAndInfer<tosa::MulOp>(rewriter, op->getLoc(), indexType,
+                                          wrappedBeyondMaxIndicesQuotient,
+                                          maxIndexValue, /*shift=*/0)
+          .getResult();
+  auto wrappedBeyondMaxIndices =
+      tosa::CreateOpAndInfer<tosa::SubOp>(
+          rewriter, op->getLoc(), indexType, index,
+          wrappedBeyondMaxIndicesQuotientTimesIndices)
+          .getResult();
+
+  return tosa::CreateOpAndInfer<tosa::SelectOp>(rewriter, op->getLoc(),
+                                                indexType, isBeyondMaxIndices,
+                                                wrappedBeyondMaxIndices, index);
+}
+
 // Lowers Gather operators to a sequence of TOSA ops.
 // taken from
 // https://github.com/tensorflow/tensorflow/blob/master/tensorflow/compiler/mlir/tosa/transforms/legalize_common.cc
@@ -403,14 +438,17 @@ std::optional<Value> convertGatherNdOp(PatternRewriter &rewriter, Operation *op,
       flattenedIndicesReduceOp.getResult(),
       rewriter.getDenseI64ArrayAttr(tosaIndicesShape));
 
+  auto wrappedIndices = wrapIndicesAroundMax(tosaIndicesReshapeOp.getResult(),
+                                             K + 1, op, rewriter);
+
   // Now the gather op itself
   // %9 = "tosa.gather"(%2, %7) : (tensor<1x12x1xf32>, tensor<1x8xi32>) ->
   // tensor<1x8x1xf32>
   auto tosaGatherOp = tosa::CreateOpAndInfer<tosa::GatherOp>(
       rewriter, op->getLoc(),
       GetTypeFromTensorShape(tosaGatherResultShape,
                              resultType.getElementType()),
-      tosaValuesReshapeOp.getResult(), tosaIndicesReshapeOp.getResult());
+      tosaValuesReshapeOp.getResult(), wrappedIndices);
 
   // Finally, reshape back to the original output shape of [Indices,
   // ParamChannels]. %10 = "tosa.reshape"(%9) {new_shape = [1, 4, 2]} :