nickdesaulniers added a comment. In D145416#4173258 <https://reviews.llvm.org/D145416#4173258>, @jyknight wrote:
>> ‘p’ in the constraint must be accompanied by address_operand as the >> predicate in the match_operand. This predicate interprets the mode specified >> in the match_operand as the mode of the memory reference for which the >> address would be valid. > > How do you do that with inline-asm? Good question. The only tests I see GCC using with "=p" or "p" (no "+p" AFAICT) are: 1. https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/testsuite/gcc.dg/pr58805.c;h=b46f7764260b29bc82fc8226d20019f05c5e05c0;hb=HEAD 2. https://gcc.gnu.org/git/?p=gcc.git;a=blob;f=gcc/testsuite/gcc.dg/asm-4.c;h=180578e64e1dd68c2f5619f31fa46ac3433fd226;hb=HEAD (maybe my grep-fu is weak). These didn't help explain what that sentence means (though maybe my comprehension skills are weak). AFAICT, the docs were added in this massive commit: https://gcc.gnu.org/git/?p=gcc.git;a=commit;h=03dda8e3c3b2f Looking at why the kernel ever used it, it looks like: https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/commit/?h=v6.3-rc1&id=97b67ae559947f1e208439a1bf6a734da3087006 introduced it. That commit refers to an issue that was fixed in gcc 4.9: https://gcc.gnu.org/bugzilla/show_bug.cgi?id=63637 The linux kernel only support gcc 5.1+, so that issue is now irrelevant from the kernel's standpoint. Maybe it is time to unwind that change (97b67ae559947f1e208439a1bf6a734da3087006)... Repository: rG LLVM Github Monorepo CHANGES SINCE LAST ACTION https://reviews.llvm.org/D145416/new/ https://reviews.llvm.org/D145416 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
