On Wed, Jun 19, 2024 at 7:44 AM Vaseeharan Vinayagamoorthy <vaseeharan.vinayagamoor...@arm.com> wrote: > > Hi, > > I have found that this patch has introduced a regression in the arm-none-eabi > toolchain for a testcase, which was previously passing: > > PASS->FAIL: gcc.dg/tree-ssa/andnot-2.c scan-tree-dump-not forwprop3 "_expr" > > The toolchain was built with: > Build = x86_64-none-linux-gnu > Host = x86_64-none-linux-gnu > Target = arm-none-eabi > > This is also affecting the gcc-13 and gcc-14 branches. > Could you please let me know the impact of this regression, and whether you > plan to fix the regression?
See the thread starting at https://gcc.gnu.org/pipermail/gcc-patches/2024-February/646587.html for information on the testcase regression and what needs to be done. I suspect this only now effects targets which don't have a vector modes enabled. Note it is a (minor) missed optimization regression so the impact looks to be small. I am not sure if people have written code with this pattern, it requires vectors and it fails only on targets where there is no vector support enabled. https://gcc.gnu.org/bugzilla/show_bug.cgi?id=95906 Thanks, Andrew Pinski > > > Kind regards, > Vasee > > ________________________________________ > From: Richard Biener <rguent...@suse.de> > Sent: 26 February 2024 07:42 > To: gcc-patches@gcc.gnu.org > Subject: [PATCH] middle-end/114070 - folding breaking VEC_COND expansion > > The following properly guards the simplifications that move > operations into VEC_CONDs, in particular when that changes the > type constraints on this operation. > > This needed a genmatch fix which was recording spurious implicit fors > when tcc_comparison is used in a C expression. > > Bootstrapped and tested on x86_64-unknown-linux-gnu, pushed. > > PR middle-end/114070 > * genmatch.cc (parser::parse_c_expr): Do not record operand > lists but only mark operators used. > * match.pd ((c ? a : b) op (c ? d : e) --> c ? (a op d) : (b op e)): > Properly guard the case of tcc_comparison changing the VEC_COND > value operand type. > > * gcc.dg/torture/pr114070.c: New testcase. > --- > gcc/genmatch.cc | 6 ++---- > gcc/match.pd | 15 ++++++++++++--- > gcc/testsuite/gcc.dg/torture/pr114070.c | 12 ++++++++++++ > 3 files changed, 26 insertions(+), 7 deletions(-) > create mode 100644 gcc/testsuite/gcc.dg/torture/pr114070.c > > diff --git a/gcc/genmatch.cc b/gcc/genmatch.cc > index 375ae90ae6c..d9ae436ce5c 100644 > --- a/gcc/genmatch.cc > +++ b/gcc/genmatch.cc > @@ -4760,10 +4760,8 @@ parser::parse_c_expr (cpp_ttype start) > = (const char *)CPP_HASHNODE (token->val.node.node)->ident.str; > if (strcmp (str, "return") == 0) > fatal_at (token, "return statement not allowed in C expression"); > - id_base *idb = get_operator (str); > - user_id *p; > - if (idb && (p = dyn_cast<user_id *> (idb)) && p->is_oper_list) > - record_operlist (token->src_loc, p); > + /* Mark user operators corresponding to 'str' as used. */ > + get_operator (str); > } > > /* Record the token. */ > diff --git a/gcc/match.pd b/gcc/match.pd > index c5b6540f939..67007fc2017 100644 > --- a/gcc/match.pd > +++ b/gcc/match.pd > @@ -5149,15 +5149,24 @@ DEFINE_INT_AND_FLOAT_ROUND_FN (RINT) > /* (c ? a : b) op (c ? d : e) --> c ? (a op d) : (b op e) */ > (simplify > (op (vec_cond:s @0 @1 @2) (vec_cond:s @0 @3 @4)) > - (vec_cond @0 (op! @1 @3) (op! @2 @4))) > + (if (TREE_CODE_CLASS (op) != tcc_comparison > + || types_match (type, TREE_TYPE (@1)) > + || expand_vec_cond_expr_p (type, TREE_TYPE (@0), ERROR_MARK)) > + (vec_cond @0 (op! @1 @3) (op! @2 @4)))) > > /* (c ? a : b) op d --> c ? (a op d) : (b op d) */ > (simplify > (op (vec_cond:s @0 @1 @2) @3) > - (vec_cond @0 (op! @1 @3) (op! @2 @3))) > + (if (TREE_CODE_CLASS (op) != tcc_comparison > + || types_match (type, TREE_TYPE (@1)) > + || expand_vec_cond_expr_p (type, TREE_TYPE (@0), ERROR_MARK)) > + (vec_cond @0 (op! @1 @3) (op! @2 @3)))) > (simplify > (op @3 (vec_cond:s @0 @1 @2)) > - (vec_cond @0 (op! @3 @1) (op! @3 @2)))) > + (if (TREE_CODE_CLASS (op) != tcc_comparison > + || types_match (type, TREE_TYPE (@1)) > + || expand_vec_cond_expr_p (type, TREE_TYPE (@0), ERROR_MARK)) > + (vec_cond @0 (op! @3 @1) (op! @3 @2))))) > > #if GIMPLE > (match (nop_atomic_bit_test_and_p @0 @1 @4) > diff --git a/gcc/testsuite/gcc.dg/torture/pr114070.c > b/gcc/testsuite/gcc.dg/torture/pr114070.c > new file mode 100644 > index 00000000000..cf46ec45a04 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/torture/pr114070.c > @@ -0,0 +1,12 @@ > +/* { dg-do compile } */ > +/* { dg-additional-options "-fno-vect-cost-model" } */ > + > +int unresolved(unsigned dirmask, unsigned mask, int *unresolved_n) > +{ > + for (int i = 0; i < 1024; i++) { > + mask |= 1; > + if (!unresolved_n[i] || unresolved_n[i] & 70000) > + dirmask |= 1; > + } > + return (dirmask == mask); > +} > -- > 2.35.3
