On Tue, 21 Nov 2023, Jakub Jelinek wrote: > Hi! > > As the testcase shows, I've missed one spot where initially the code thinks > it could use 2 argument IFN_CLZ/IFN_CTZ form, but then verifies it can't > because it doesn't have the right target value and turns it into the > arg0 ? arg1 : .C[LT]Z (arg0) > form. That form evaluates the argument twice though and so needs save_expr, > which I've missed to call in that case. In other cases where it is known > from the beginning that it will be needed (e.g. the __builtin_clzg case > on types smaller than unsigned int where we'll need to add an addend > to the clz value) or the unsigned __int128 expansion called save_expr > before. > > Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
OK. > 2023-11-21 Jakub Jelinek <ja...@redhat.com> > > PR middle-end/112639 > * builtins.cc (fold_builtin_bit_query): If arg0 has side-effects, arg1 > is specified but cleared, call save_expr on arg0. > > * gcc.dg/torture/pr112639.c: New test. > > --- gcc/builtins.cc.jj 2023-11-20 10:36:18.642625716 +0100 > +++ gcc/builtins.cc 2023-11-20 15:25:59.665718971 +0100 > @@ -9819,6 +9819,8 @@ fold_builtin_bit_query (location_t loc, > if (!direct_internal_fn_supported_p (ifn, arg0_type, > OPTIMIZE_FOR_BOTH)) > arg2 = NULL_TREE; > + if (arg2 == NULL_TREE) > + arg0 = save_expr (arg0); > } > if (fcodei == END_BUILTINS || arg2) > call = build_call_expr_internal_loc (loc, ifn, integer_type_node, > --- gcc/testsuite/gcc.dg/torture/pr112639.c.jj 2023-11-20 > 15:32:24.994391656 +0100 > +++ gcc/testsuite/gcc.dg/torture/pr112639.c 2023-11-20 15:34:14.395882993 > +0100 > @@ -0,0 +1,34 @@ > +/* PR middle-end/112639 */ > +/* { dg-do run } */ > + > +unsigned long long b = 0; > + > +int > +foo (void) > +{ > + return __builtin_clzg (b++, __SIZEOF_LONG_LONG__ * __CHAR_BIT__); > +} > + > +int > +bar (void) > +{ > + return __builtin_ctzg (b++, __SIZEOF_LONG_LONG__ * __CHAR_BIT__); > +} > + > +int > +main () > +{ > + if (foo () != __SIZEOF_LONG_LONG__ * __CHAR_BIT__ || b != 1) > + __builtin_abort (); > + if (foo () != __SIZEOF_LONG_LONG__ * __CHAR_BIT__ - 1 || b != 2) > + __builtin_abort (); > + if (foo () != __SIZEOF_LONG_LONG__ * __CHAR_BIT__ - 2 || b != 3) > + __builtin_abort (); > + b = 0; > + if (bar () != __SIZEOF_LONG_LONG__ * __CHAR_BIT__ || b != 1) > + __builtin_abort (); > + if (bar () != 0 || b != 2) > + __builtin_abort (); > + if (bar () != 1 || b != 3) > + __builtin_abort (); > +} > > Jakub > > -- Richard Biener <rguent...@suse.de> SUSE Software Solutions Germany GmbH, Frankenstrasse 146, 90461 Nuernberg, Germany; GF: Ivo Totev, Andrew McDonald, Werner Knoblich; (HRB 36809, AG Nuernberg)