I will retest ASAP and report with, I hope, an attachment to fix both IA64.asm and ia64/atomic.h
With the bogus cast removed in both places, I can now run ring_c on linux/ia64.
The attached patch is against trunk, but applies cleanly to v1.7.
I fact, since the code has been incorrect for a long time it applies cleanly to v1.6 too.
The code was broken by r3448, which apparently fixed some warnings but also added the incorrect narrowing casts to the 64-bit cmpset code. So, IA64 *did* work prior to April 2010.
Given the timeline, this can't possibly be a regression in the 1.7 series.
Additionally, with Sylvesrte Ledru having given up on ia64 nobody may care at all.
So, CMR to 1.7.4 vs .5 seems like a potentially moot point.