Hi Richard,
On 24/01/16 10:54, Richard Henderson wrote:
This looks to be an incomplete transition of the aarch64 backend to
CONST_WIDE_INT. I haven't checked to see if it's a regression from gcc5, but I
suspect not, since there should have been similar checks for CONST_DOUBLE.
FWIW, I defined TARGET_SUPPORTS_WIDE_INT for aarch64 on trunk and the GCC 5
branch in order to fix
PR 68129.
This is probably gcc7 fodder, but it helped me debug another TImode PR.
r~
+ case CONST_WIDE_INT:
+ *cost = 0;
+ for (unsigned int n = CONST_WIDE_INT_NUNITS(x), i = 0; i < n; ++i)
+ {
+ unsigned HOST_WIDE_INT e = CONST_WIDE_INT_ELT(x, i);
+ if (e != 0)
+ *cost += COSTS_N_INSNS (aarch64_internal_mov_immediate
+ (NULL_RTX, GEN_INT (e), false, DImode));
+ }
+ return true;
+
We usually avoid creating intermediate rtxes in the cost function because
it can potentially be called many times during compilation and we want to avoid
creating too many short-lived objects, though I suppose there's no way getting
around this one (the GEN_INT call).
Thanks,
Kyrill
