[mlir][tosa] Fix several bugs in DepthwiseConv2DIsMul

This PR fixes several bugs in `DepthwiseConv2DIsMul`:
- The DepthwiseConv2DOp should restrict the types to integer or float.
- `notifyMatchFailure` should be called before creating the new `tosa.reshape` operation.

Author: CoTinker

mlir/lib/Dialect/Tosa/Transforms/TosaDecomposeDepthwise.cpp

@@ -48,6 +48,26 @@ struct DepthwiseConv2DIsMul : public OpRewritePattern<tosa::DepthwiseConv2DOp> {
       return failure();
     }
 
+    Type inputETy = inputType.getElementType();
+    Type weightETy = weightType.getElementType();
+    Type resultETy = resultType.getElementType();
+    if (!inputETy.isIntOrFloat() || !weightETy.isIntOrFloat())
+      return rewriter.notifyMatchFailure(op, "unsupported type");
+
+    // Get and verify zero points.
+    int64_t iZp;
+    int64_t wZp;
+
+    if (op.getInputZeroPoint(iZp).failed() ||
+        op.getWeightZeroPoint(wZp).failed())
+      return rewriter.notifyMatchFailure(
+          op, "bail out if zero points cannot statically be determined");
+
+    if (op.verifyInputZeroPoint(iZp).failed() ||
+        op.verifyWeightZeroPoint(wZp).failed())
+      return rewriter.notifyMatchFailure(
+          op, "zero point must be zero for non-int8 integer types");
+
     // Reshape input to [N, H, W, C] -> [N, H, W, C, 1].
     ArrayRef<int64_t> inputShape = inputType.getShape();
     llvm::SmallVector<int64_t, 2> revisedInputShape{
@@ -62,10 +82,6 @@ struct DepthwiseConv2DIsMul : public OpRewritePattern<tosa::DepthwiseConv2DOp> {
                                          revisedInputShapeValue)
                 .getResult();
 
-    Type inputETy = inputType.getElementType();
-    Type weightETy = weightType.getElementType();
-    Type resultETy = resultType.getElementType();
-
     if (inputETy != resultETy) {
       inputType = inputType.clone(resultETy);
       input = rewriter.create<tosa::CastOp>(op.getLoc(), inputType, input);
@@ -76,20 +92,6 @@ struct DepthwiseConv2DIsMul : public OpRewritePattern<tosa::DepthwiseConv2DOp> {
       weight = rewriter.create<tosa::CastOp>(op.getLoc(), weightType, weight);
     }
 
-    // Get and verify zero points.
-    int64_t iZp;
-    int64_t wZp;
-
-    if (op.getInputZeroPoint(iZp).failed() ||
-        op.getWeightZeroPoint(wZp).failed())
-      return rewriter.notifyMatchFailure(
-          op, "bail out if zero points cannot statically be determined");
-
-    if (op.verifyInputZeroPoint(iZp).failed() ||
-        op.verifyWeightZeroPoint(wZp).failed())
-      return rewriter.notifyMatchFailure(
-          op, "zero point must be zero for non-int8 integer types");
-
     if (iZp != 0 || wZp != 0) {
 
       auto applyZp = [&](Value val, int64_t zp) -> Value {