PING^3 [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

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);
>>> +}