rotation merely works when LTeX a PDF file

[goulf-3m]

The PDF is rotated, but the width/height and positioning is not anything one will expect.
And I cannot find a way to fix this without specifying options using explicit image sizes.

What is expected:

When a 4 by 8 PDF (any unit) is used, the width and height of the grid will be 4 and 8, respectively. And this PDF, when displayed, will match the grid.

When it's rotated by pi/2, the grid width and height will be 8 and 4, and the displayed PDF match the grid.