On Wed, Nov 19, 2014 at 5:23 PM, Andrew Pinski <pins...@gmail.com> wrote: > On Wed, Nov 19, 2014 at 5:11 PM, H.J. Lu <hjl.to...@gmail.com> wrote: >> On Wed, Nov 19, 2014 at 4:54 PM, Andrew Pinski <pins...@gmail.com> wrote: >>> Hi, >>> For ILP32 on AARCH64, we have ptr_mode != Pmode (we have ptr_mode >>> being SImode while Pmode is DImode and POINTER_SIZE is 32). This >>> breaks ipa-polymorphic-call assumption that Pmode is the correct mode >>> for pointers. Right now before this patch we get many testcase >>> failures in the C++ testsuite due to this. Some of the tests fail due >>> to the wrong devirtualization happening (using the base class rather >>> the current class). >>> >>> This patch fixes the issue by using POINTER_SIZE in place of >>> GET_MODE_BITSIZE (Pmode) all over the file. >>> >>> OK? Bootstrapped and tested on x86_64 and cross built and tested for >>> aarch64-elf with no regressions. >>> >>> Thanks, >>> Andrew Pinski >>> >>> ChangeLog: >>> ipa/63981 >>> * ipa-polymorphic-call.c (possible_placement_new): >>> Use POINTER_SIZE instead of GET_MODE_BITSIZE (Pmode). >>> (ipa_polymorphic_call_context::restrict_to_inner_class): Likewise. >>> (extr_type_from_vtbl_ptr_store): Likewise. >> >> Does Pmode affect class layout? > > No only POINTER_SIZE. ILP32 is one of the few ABIs where Pmode != > ptr_mode (sizeof(ptr_mode) == POINTER_SIZE always). > > x32 has a similar issue with -maddress-mode=long but the default for > x32 is -maddress-mode=short.
Pmode shouldn't change class layout, which is determined by ptr_mode. You can mix object files compiled by -maddress-mode=long with -maddress-mode=short. Do those tests fail with -maddress-mode=long under x32? -- H.J.
