[mlir][tosa] Fix tosa::Select to linalg::generic indexingMaps bug

[AmosLewis]

Summary

The tosa to linalg generic ops indexingMaps rank use is wrong.

	 Find this bug in gpt2 pytorch model lowering to tosa.
	 issue link is here https://github.com/llvm/llvm-project/issues/58154

[rsuderman]

Could you include a test case that demonstrates the failure?

[AmosLewis]

[mlir][tosa] Fix tosa::Select to linalg::generic indexingMaps bug

[AmosLewis]

In D135343#3840381, @rsuderman wrote:

Could you include a test case that demonstrates the failure?

Done

[jpienaar]

LG, we can simplify the test a bit. I'll do that during landing.

mlir/lib/Conversion/TosaToLinalg/TosaToLinalg.cpp

for (Value operand : operation->getOperands()) {
     if (newShape.size() != rank) {
       operand = rewriter.create<tosa::ReshapeOp>(
           loc, RankedTensorType::get(newShape, type.getElementType()), operand,
           rewriter.getI64ArrayAttr(newShape));
     }
 
     operands.push_back(operand);
     indexingMaps.push_back(AffineMap::get(
-        /*dimCount=*/type.getRank(), /*symbolCount=*/0, affineExprs,
+        /*dimCount=*/rank, /*symbolCount=*/0, affineExprs,
         rewriter.getContext()));
   }
 
   indexingMaps.append(operation->getNumResults(),
                       rewriter.getMultiDimIdentityMap(rank));
 
   bool didEncounterError = false;
   auto linalgOp = rewriter.create<linalg::GenericOp>(

mlir/test/Conversion/TosaToLinalg/tosa-to-linalg.mlir

 func.func @resize_dyn(%input: tensor<?x2x2x1xi8>) -> () {
   // CHECK: %[[C0:.+]] = arith.constant 0
   // CHECK: %[[BATCH:.+]] = tensor.dim %arg0, %[[C0]]
   // CHECK: %[[INIT:.+]] = tensor.empty(%[[BATCH]]) : tensor<?x4x4x1xi32>
   // CHECK: %[[GENERIC:.+]] = linalg.generic
   %output = "tosa.resize"(%input) { scale = [4, 2, 4, 2], offset = [-1, -1], border = [1, 1], mode = "BILINEAR" } : (tensor<?x2x2x1xi8>)  -> (tensor<?x4x4x1xi32>)
   return
 }
+
+// -----
+
+// Regression test for using the wrong rank.
+
+// CHECK-DAG: affine_map<(d0, d1, d2, d3) -> (d0, d2, d3)>
+// CHECK-DAG: affine_map<(d0, d1, d2, d3) -> (d0, d1, d2, d3)>
+// CHECK-DAG: affine_map<(d0, d1, d2, d3) -> ()>
+// CHECK-LABEL: @select_fp32
+func.func @select_fp32(%arg0: tensor<1x1x5x5xi1>, %arg1: tensor<1x12x5x5xf32>, %arg2: tensor<f32>) -> tensor<1x12x5x5xf32> {
+  // CHECK: linalg.generic
+  %0 = "tosa.select"(%arg0, %arg1, %arg2) : (tensor<1x1x5x5xi1>, tensor<1x12x5x5xf32>, tensor<f32>) -> tensor<1x12x5x5xf32>
+  return %0 : tensor<1x12x5x5xf32>
+}
+