https://gcc.gnu.org/bugzilla/show_bug.cgi?id=121095
--- Comment #2 from lucier at math dot purdue.edu --- My take, without having any serious knowledge of what's going on, is: If a C function doesn't involve (set, read, manipulate, ...) FP8 values or the fpmr register in any way, then this PRE pass shouldn't be run, because this PRE pass only deals with the fpmr register, and I don't see how any relevant code can be affected by, or can affect, the fpmr register if no FP8 manipulations are involved in a routine. And I suggest that this should be true even if the architecture supports FP8 arithmetic in general. I am ignorant of the details of what's going on here, so my expectation may very well be incorrect. This PRE pass wasn't run on this example function because more than 128MB of memory would have been needed, but when building the Gambit Scheme system there are many relatively large routines where this PRE pass is run. In another large file where this PRE pass was run, the dump file contained: PRE GCSE of ___H___num, 31567 basic blocks, 2524104 bytes needed, 0 substs, 0 insns created Does "0 substs, 0 insns created" mean that running the pass had no effect on the code? Brad
