This is a reminder message on fix for PR 61561 which is ICE while 
compiling something which is valid* 'C' code. 
(https://gcc.gnu.org/bugzilla/show_bug.cgi?id=61561).

Ramana, Richard, I am very appreciated for your attention and error 
indication, your work made my patch simple and tiny. And I hope that 
this patch will save somebody's time.

Additional info about the issue:

By adding constrain 'k' we want to make gcc work properly with stack 
register in HI and QI mode. This is need because CSE an RTL phase in 
some cases propagates sp register directly to HI/QI memory set. Next 
reload an RTL phase trying to build HI/QI move sp into some general 
purpose register which is fail due to pattern absence. You may ask who 
needs part of sp register? Nevertheless it is legitimate operation and 
there is simple example of practical usage. Imagine you put some local 
variable 'a' into hash table which has < 256 bunches. In this case 
'operator []' of some hash class may take QI from sp register which is 
directly pointing on 'a'.

Patch was reg. tested on --build=x86_64-pc-linux-gnu 
--host=x86_64-pc-linux-gnu --target=arm-v7a15v5r2-linux-gnueabi for 
c,c++,fortran languages w/o bootstrap.

* According to 'C' Standard [ISO/IEC 9899:2011] 6.3.2.3
"Any pointer type may be converted to an integer type. Except as 
previously specified, the result is implementation-defined". As we know 
'char' and 'short' (also called 'short int') are both integers.

Thank for your attention.
Marat.