https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102605
--- Comment #6 from rguenther at suse dot de <rguenther at suse dot de> --- On Wed, 6 Oct 2021, aldyh at redhat dot com wrote: > https://gcc.gnu.org/bugzilla/show_bug.cgi?id=102605 > > --- Comment #5 from Aldy Hernandez <aldyh at redhat dot com> --- > > > BTW, the __MEM_REF output from the dumps does not work in -fgimple either. > > > More errors. > > > > Can you share an example? > > This is from gcc.c-torture/execute/961125-1.c compiled with -fgimple: > > char * begfield (int tab, char * ptr, char * lim, int sword, int schar); > > int __GIMPLE (ssa) > main () > { > char * lim; > char * s; > char * _1; > > __BB(2): > _1 = begfield (58, ":ab", &__MEM <char[4]> ((void *)":ab" + _Literal > (void *) 3), 1, 1); OK, here we're eliding the & before the ":ab" in duming, so it should read _1 = begfield (58, ":ab", &__MEM <char[4]> ((void *)&":ab" + _Literal (void *) 3), 1, 1); > if (_1 != &__MEM <char[4]> ((void *)":ab" + _Literal (void *) 2)) > goto __BB3; Likewise here, and the patch I'm testing should fix the missing _Literal: if (_1 != _Literal (char *) &__MEM <char[4]> ((void *)&":ab" + _Literal (void *) 2)) then there needs to be an adjustment to the C frontend to allow MEM_REFs as lvalue: diff --git a/gcc/c/c-typeck.c b/gcc/c/c-typeck.c index f9eb0e5176f..efe70511b91 100644 --- a/gcc/c/c-typeck.c +++ b/gcc/c/c-typeck.c @@ -4969,6 +4969,8 @@ lvalue_p (const_tree ref) return true; case INDIRECT_REF: + case MEM_REF: + case TARGET_MEM_REF: case ARRAY_REF: case VAR_DECL: case PARM_DECL: Then the code is accepted. Btw, please report cases where -gimple doesn't produce valid GIMPLE FE inputs (OK, there are known cases with mangled symbol names when passes create temporaries whose name includes a '.' for example...)
