myatsina added a comment. In https://reviews.llvm.org/D15075#631316, @ahatanak wrote:
> In https://reviews.llvm.org/D15075#631237, @myatsina wrote: > > > In https://reviews.llvm.org/D15075#631207, @vitalybuka wrote: > > > > > These patches break asan tests: > > > http://lab.llvm.org:8011/builders/sanitizer-x86_64-linux/builds/528/steps/check-asan%20in%20gcc%20build/logs/stdio > > > > > > Vitaly , > > > > This patch is a gcc compatibility issue and it changes clang to output an > > error in case of illegal inline assembly syntax related to clobber list. > > > > Commit r290540 changed an asan test (asan_asm_test.cc) that used the > > illegal syntax and fixed it. > > The commit removed from the extended inline assembly clobber list > > registers that also appeared in the input list. > > GCC fails as well on the original inline assembly that appeared in this > > test, so the fix is correct. > > I don't understand why this change has effect the logic of the test - can > > you help? > > > > Thanks, > > Marina > > > I believe asm_rep_movs needs something in the output operand list that tells > the compiler the inline-asm statement changes the contents of the registers > ("S", "D" and "c"). Otherwise, the compiler (register allocator) will not > save the old value of dst_good and src_good so that it can be used later in > the static_assert: > > asm_rep_movs(dst_good, src_good, 4); > ASSERT_EQ(static_cast<T>(0x0), dst_good[0]); // "D" register was > incremented 4 times. > You are right, the "S" and "D" constraint are wrong as well in both DECLARE_ASM_REP_MOVS macros, the right assembly should probably be something like: __asm__("rep movsb \n\t" : "D"(dst), "S"(src) : "S"(src), "c"(size) : "memory"); The different movs instructions change both esi/rsi and edi/rdi (movs copies esi to edi and then also increments/decrements both registers), so esi/rdi is both input and output while edi/rdi is just output. The problem is I am not able to build the AsanSanitizer unit test and check if this fixes the issue. Repository: rL LLVM https://reviews.llvm.org/D15075 _______________________________________________ cfe-commits mailing list cfe-commits@lists.llvm.org http://lists.llvm.org/cgi-bin/mailman/listinfo/cfe-commits
