WLS corrupts AST if STEP != 1

Bugzilla Link	1154
Created on	Apr 18, 2015 21:21
Version	svn
OS	Linux
Architecture	PC
Attachments	crud2.sac

Extended Description

Created an attachment (id=1035)
source code to cause failure
This bug can be created several ways. The key seems to be to get WLS
to run in SAACYC, with a non-unit WL_STEP.
This crash relies on extrema being present, allowing the LT function to
be optimized away, after which WLS does its thing (incorrectly).
** 12: Transforming with-loop representation ...
  **** Simplifying with-loops ...
  **** Transforming with-loop representation ...
Internal compiler error
Assertion "! WLSTRIDE_ISMODIFIED( stride1)" failed at wltransform/wltransform.c:3849 -- stride was modified
Please file a bug at: http://bugs.sac-home.org
sac@rattler:~/sac/testsuite/optimizations/pogorelationals$ sac2c -V
sac2c v1.00-beta (Haggis And Apple)
 developer rev 18554 linux-gnu_x86_64
 (Sat Apr 18 16:02:33 EDT 2015 by sac)
sac@rattler:~/sac/testsuite/optimizations/pogorelationals$ sac2c crud2.sac -v4 -extrema
I can also reproduce it using the pogo/pogorelational unit tests, which
also evaporate the relational. Those tests do not use extrema, so that
lets them out of the picture.