PING^2 [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);
>> +}