On Fri, 17 Nov 2017, Joshua Kinard wrote:

Ah!  I thought that when writing inline assembler, it was taken as-is by the
compiler and not messed with.  I didn't think that gas would still move things
around w/o the 'noreorder' directive being set.  Thank you for the explanation.

 GCC always sets the `reorder' mode for inline assembly pieces even if it 
has chosen to use the `noreorder' mode outside.  This is required for 
compatibility with code written before GCC started using the `noreorder' 
mode if nothing else.

  Maciej