Class ov::pass::ReshapeOptimizations

class ReshapeOptimizations : public ov::pass::MatcherPass

Searches for Flatten-like Reshape operations and simplifies 2nd input of such Reshape using special zero feature. The transformation works in 2 cases:

1. all in/out dims are static, or we can match them via the symbols.

2. only one out dim doesn’t have the corresponding input static dim, and we can’t match it using symbols. Besides that the output shape must not contain zero dims, because then value -1 in 2nd input to Reshape op can’t guarantee an unambiguous determination of the remaining dim value.

    for example:
          Before:
          +-------------+    +----------+
          |data         |    | Concat   |
          |shape: (0, 0)|    | shape (2)|<- the values might be determined in runtime
          +-----+-------+    +-----+----+   the empty data tensor can be reshaped to
                |                  |        any other empty shape, e.g. (0, 800)
          +-----v---------------+  |
          | Reshape             |  |
          | shape (0,-1)        <--+
          | special zero = False|
          +---------------------+
   
          After:
                             +---------------+
         +--------------+    | Constant      |
         | data         |    | shape (2)     |
         | shape: (0, 0)|    | values (0, -1)|<- -1 means copy the corresponding input dim
         +-----+--------+    +-------+-------+
               |                     |
          +----v----------------+    |
          | Reshape             <----+
          | shape (0,0)         |  <- it might cause inconsistency
          | special zero = True |
          +---------------------+