https://sourceware.org/bugzilla/show_bug.cgi?id=3298
--- Comment #21 from Quentin Boswank <qubos at outlook dot de> --- (In reply to Joern Rennecke from comment #20) > (In reply to Quentin Boswank from comment #17) > > Created attachment 16107 [details] > > patch for gas bug zeroing 16 or 32 bit width jumptables when relaxing V2 > > max = (1ul << (fixP->fx_size * 8)) - 1; > > There are many ways to avoid shifting by a shiftcount as large or larger than > type bing shifted. This is not one of them. > available / cheaper type can be used. > 2a) Split into rounded down & rounded up halves to make do with half the > type width, > e.g. (1UL << (fixP->fx_size * 4)) << (fixP->fx_size * 4) . > 2b) Where a shift count value (range) is know, use this to cheaper split. > (fixP->fx_size * 8) is in the range [8..32] , so you can subtract one to > get > it into the range [7..31]. Then you can do the left shift of the literal > by 1 first > to get a modified literal: (2UL << (fixP->fx_size * 8 - 1) > 2c) A combination and/or replication of the above strategies to bridge a > wider > difference between type width and shift count. > > 3) Avoid the shift altogether by using an alternate computation, e.g. a > table lookup. > > There is also the further problem that the 'long' type of max is not known > to be > wide enough to accommodate the value 0xffffffff . You can use unsigned long > for that, but then you can't do a defined conversion to a signed type > without widening first. And the comparison to val makes no sense when that > is 32 bit, either. Thats what the if is designed to work around by just disabling the check if we can not fit into the widths. -- You are receiving this mail because: You are on the CC list for the bug.
