PING^5 [PATCH] rs6000: Handle unresolved overloaded builtin [PR105485]

["Kewen.Lin" <linkw@linux.ibm.com>]

Hi,

Gentle ping https://gcc.gnu.org/pipermail/gcc-patches/2022-May/594699.html

I think this is a reasonable fix, the behavior is consistent with what we have in
the previous built-in framework, I'm going to push this a week later if no objections.  :)

BR,
Kewen

>>>
>>>> on 2022/5/13 13:29, Kewen.Lin via Gcc-patches wrote:
>>>>> Hi,
>>>>>
>>>>> PR105485 exposes that new builtin function framework doesn't handle
>>>>> unresolved overloaded builtin function well.  With new builtin
>>>>> function support, we don't have builtin info for any overloaded
>>>>> rs6000_gen_builtins enum, since they are expected to be resolved to
>>>>> one specific instance.  So when function rs6000_gimple_fold_builtin
>>>>> faces one unresolved overloaded builtin, the access for builtin info
>>>>> becomes out of bound and gets ICE then.
>>>>>
>>>>> We should not try to fold one unresolved overloaded builtin there
>>>>> and as the previous support we should emit one error message during
>>>>> expansion phase like "unresolved overload for builtin ...".
>>>>>
>>>>> Bootstrapped and regtested on powerpc64-linux-gnu P8 and
>>>>> powerpc64le-linux-gnu P9 and P10.
>>>>>
>>>>> Is it ok for trunk?
>>>>>
>>>>> BR,
>>>>> Kewen
>>>>> -----
>>>>> 	PR target/105485
>>>>>
>>>>> gcc/ChangeLog:
>>>>>
>>>>> 	* config/rs6000/rs6000-builtin.cc (rs6000_gimple_fold_builtin): Add
>>>>> 	the handling for unresolved overloaded builtin function.
>>>>> 	(rs6000_expand_builtin): Likewise.
>>>>>
>>>>> gcc/testsuite/ChangeLog:
>>>>>
>>>>> 	* g++.target/powerpc/pr105485.C: New test.
>>>>>
>>>>> ---
>>>>>  gcc/config/rs6000/rs6000-builtin.cc         | 13 +++++++++++++
>>>>>  gcc/testsuite/g++.target/powerpc/pr105485.C |  9 +++++++++
>>>>>  2 files changed, 22 insertions(+)
>>>>>  create mode 100644 gcc/testsuite/g++.target/powerpc/pr105485.C
>>>>>
>>>>> diff --git a/gcc/config/rs6000/rs6000-builtin.cc b/gcc/config/rs6000/rs6000-builtin.cc
>>>>> index e925ba9fad9..e102305c90c 100644
>>>>> --- a/gcc/config/rs6000/rs6000-builtin.cc
>>>>> +++ b/gcc/config/rs6000/rs6000-builtin.cc
>>>>> @@ -1294,6 +1294,11 @@ rs6000_gimple_fold_builtin (gimple_stmt_iterator *gsi)
>>>>>    enum tree_code bcode;
>>>>>    gimple *g;
>>>>>
>>>>> +  /* For an unresolved overloaded builtin, return early here since there
>>>>> +     is no builtin info for it and we are unable to fold it.  */
>>>>> +  if (fn_code > RS6000_OVLD_NONE)
>>>>> +    return false;
>>>>> +
>>>>>    size_t uns_fncode = (size_t) fn_code;
>>>>>    enum insn_code icode = rs6000_builtin_info[uns_fncode].icode;
>>>>>    const char *fn_name1 = rs6000_builtin_info[uns_fncode].bifname;
>>>>> @@ -3295,6 +3300,14 @@ rs6000_expand_builtin (tree exp, rtx target, rtx /* subtarget */,
>>>>>    tree fndecl = TREE_OPERAND (CALL_EXPR_FN (exp), 0);
>>>>>    enum rs6000_gen_builtins fcode
>>>>>      = (enum rs6000_gen_builtins) DECL_MD_FUNCTION_CODE (fndecl);
>>>>> +
>>>>> +  /* Emit error message if it's an unresolved overloaded builtin.  */
>>>>> +  if (fcode > RS6000_OVLD_NONE)
>>>>> +    {
>>>>> +      error ("unresolved overload for builtin %qF", fndecl);
>>>>> +      return const0_rtx;
>>>>> +    }
>>>>> +
>>>>>    size_t uns_fcode = (size_t)fcode;
>>>>>    enum insn_code icode = rs6000_builtin_info[uns_fcode].icode;
>>>>>
>>>>> diff --git a/gcc/testsuite/g++.target/powerpc/pr105485.C b/gcc/testsuite/g++.target/powerpc/pr105485.C
>>>>> new file mode 100644
>>>>> index 00000000000..a3b8290df8c
>>>>> --- /dev/null
>>>>> +++ b/gcc/testsuite/g++.target/powerpc/pr105485.C
>>>>> @@ -0,0 +1,9 @@
>>>>> +/* It's to verify no ICE here, ignore error/warning messages since
>>>>> +   they are not test points here.  */
>>>>> +/* { dg-excess-errors "pr105485" } */
>>>>> +
>>>>> +template <class> void __builtin_vec_vslv();
>>>>> +typedef  __attribute__((altivec(vector__))) char T;
>>>>> +T b (T c, T d) {
>>>>> +    return __builtin_vec_vslv(c, d);
>>>>> +}