Possible bug in cse.c affecting pre/post-modify mem access

[Bernd Schmidt]

On 05/12/2018 07:01 PM, Jeff Law wrote:

> No.  We're not supposed to have any auto-inc insns prior to the auto-inc
> pass.  A stack push/pop early in the compiler would have to be
> represented by a PARALLEL.
> 
> It's been this way forever.  It's documented in the internals manual
> somewhere.

Sorry, but you're misremembering this. Stack pushes/pops were always
represented with autoinc, these being the only exception to the rule you
remember. You can easily verify this by looking at a .expand dump from a
32-bit i386 compiler - I just did so with 2.95 and 6.4. It's all pre_dec
for argument passing.


Bernd