From: "Kewen.Lin" <linkw@linux.ibm.com>
To: GCC Patches <gcc-patches@gcc.gnu.org>
Cc: David Edelsohn <dje.gcc@gmail.com>,
Segher Boessenkool <segher@kernel.crashing.org>
Subject: PING^3 [PATCH v3] rs6000: Fix the check of bif argument number [PR104482]
Date: Thu, 28 Jul 2022 16:46:45 +0800 [thread overview]
Message-ID: <fb8d20a7-c397-c9a5-f7f5-fff8b04243cd@linux.ibm.com> (raw)
In-Reply-To: <10f2af43-d178-5416-fdd8-e93e7cbf4df7@linux.ibm.com>
Hi,
Gentle ping https://gcc.gnu.org/pipermail/gcc-patches/2022-May/595208.html
BR,
Kewen
>>> Hi,
>>>
>>> As PR104482 shown, it's one regression about the handlings when
>>> the argument number is more than the one of built-in function
>>> prototype. The new bif support only catches the case that the
>>> argument number is less than the one of function prototype, but
>>> it misses the case that the argument number is more than the one
>>> of function prototype. Because it uses "n != expected_args",
>>> n is updated in
>>>
>>> for (n = 0; !VOID_TYPE_P (TREE_VALUE (fnargs)) && n < nargs;
>>> fnargs = TREE_CHAIN (fnargs), n++)
>>>
>>> , it's restricted to be less than or equal to expected_args with
>>> the guard !VOID_TYPE_P (TREE_VALUE (fnargs)), so it's wrong.
>>>
>>> The fix is to use nargs instead, also move the checking hunk's
>>> location ahead to avoid useless further scanning when the counts
>>> mismatch.
>>>
>>> Bootstrapped and regtested on powerpc64-linux-gnu P8 and
>>> powerpc64le-linux-gnu P9 and P10.
>>>
>>> v3: Update test case with dg-excess-errors.
>>>
>>> v2: Add one test case and refine commit logs.
>>> https://gcc.gnu.org/pipermail/gcc-patches/2022-April/593155.html
>>>
>>> v1: https://gcc.gnu.org/pipermail/gcc-patches/2022-March/591768.html
>>>
>>> Is it ok for trunk?
>>>
>>> BR,
>>> Kewen
>>> -----
>>> PR target/104482
>>>
>>> gcc/ChangeLog:
>>>
>>> * config/rs6000/rs6000-c.cc (altivec_resolve_overloaded_builtin): Fix
>>> the equality check for argument number, and move this hunk ahead.
>>>
>>> gcc/testsuite/ChangeLog:
>>>
>>> * gcc.target/powerpc/pr104482.c: New test.
>>> ---
>>> gcc/config/rs6000/rs6000-c.cc | 60 ++++++++++-----------
>>> gcc/testsuite/gcc.target/powerpc/pr104482.c | 16 ++++++
>>> 2 files changed, 46 insertions(+), 30 deletions(-)
>>> create mode 100644 gcc/testsuite/gcc.target/powerpc/pr104482.c
>>>
>>> diff --git a/gcc/config/rs6000/rs6000-c.cc b/gcc/config/rs6000/rs6000-c.cc
>>> index 9c8cbd7a66e..61881f29230 100644
>>> --- a/gcc/config/rs6000/rs6000-c.cc
>>> +++ b/gcc/config/rs6000/rs6000-c.cc
>>> @@ -1756,6 +1756,36 @@ altivec_resolve_overloaded_builtin (location_t loc, tree fndecl,
>>> vec<tree, va_gc> *arglist = static_cast<vec<tree, va_gc> *> (passed_arglist);
>>> unsigned int nargs = vec_safe_length (arglist);
>>>
>>> + /* If the number of arguments did not match the prototype, return NULL
>>> + and the generic code will issue the appropriate error message. Skip
>>> + this test for functions where we don't fully describe all the possible
>>> + overload signatures in rs6000-overload.def (because they aren't relevant
>>> + to the expansion here). If we don't, we get confusing error messages. */
>>> + /* As an example, for vec_splats we have:
>>> +
>>> +; There are no actual builtins for vec_splats. There is special handling for
>>> +; this in altivec_resolve_overloaded_builtin in rs6000-c.cc, where the call
>>> +; is replaced by a constructor. The single overload here causes
>>> +; __builtin_vec_splats to be registered with the front end so that can happen.
>>> +[VEC_SPLATS, vec_splats, __builtin_vec_splats]
>>> + vsi __builtin_vec_splats (vsi);
>>> + ABS_V4SI SPLATS_FAKERY
>>> +
>>> + So even though __builtin_vec_splats accepts all vector types, the
>>> + infrastructure cheats and just records one prototype. We end up getting
>>> + an error message that refers to this specific prototype even when we
>>> + are handling a different argument type. That is completely confusing
>>> + to the user, so it's best to let these cases be handled individually
>>> + in the resolve_vec_splats, etc., helper functions. */
>>> +
>>> + if (expected_args != nargs
>>> + && !(fcode == RS6000_OVLD_VEC_PROMOTE
>>> + || fcode == RS6000_OVLD_VEC_SPLATS
>>> + || fcode == RS6000_OVLD_VEC_EXTRACT
>>> + || fcode == RS6000_OVLD_VEC_INSERT
>>> + || fcode == RS6000_OVLD_VEC_STEP))
>>> + return NULL;
>>> +
>>> for (n = 0;
>>> !VOID_TYPE_P (TREE_VALUE (fnargs)) && n < nargs;
>>> fnargs = TREE_CHAIN (fnargs), n++)
>>> @@ -1816,36 +1846,6 @@ altivec_resolve_overloaded_builtin (location_t loc, tree fndecl,
>>> types[n] = type;
>>> }
>>>
>>> - /* If the number of arguments did not match the prototype, return NULL
>>> - and the generic code will issue the appropriate error message. Skip
>>> - this test for functions where we don't fully describe all the possible
>>> - overload signatures in rs6000-overload.def (because they aren't relevant
>>> - to the expansion here). If we don't, we get confusing error messages. */
>>> - /* As an example, for vec_splats we have:
>>> -
>>> -; There are no actual builtins for vec_splats. There is special handling for
>>> -; this in altivec_resolve_overloaded_builtin in rs6000-c.cc, where the call
>>> -; is replaced by a constructor. The single overload here causes
>>> -; __builtin_vec_splats to be registered with the front end so that can happen.
>>> -[VEC_SPLATS, vec_splats, __builtin_vec_splats]
>>> - vsi __builtin_vec_splats (vsi);
>>> - ABS_V4SI SPLATS_FAKERY
>>> -
>>> - So even though __builtin_vec_splats accepts all vector types, the
>>> - infrastructure cheats and just records one prototype. We end up getting
>>> - an error message that refers to this specific prototype even when we
>>> - are handling a different argument type. That is completely confusing
>>> - to the user, so it's best to let these cases be handled individually
>>> - in the resolve_vec_splats, etc., helper functions. */
>>> -
>>> - if (n != expected_args
>>> - && !(fcode == RS6000_OVLD_VEC_PROMOTE
>>> - || fcode == RS6000_OVLD_VEC_SPLATS
>>> - || fcode == RS6000_OVLD_VEC_EXTRACT
>>> - || fcode == RS6000_OVLD_VEC_INSERT
>>> - || fcode == RS6000_OVLD_VEC_STEP))
>>> - return NULL;
>>> -
>>> /* Some overloads require special handling. */
>>> tree returned_expr = NULL;
>>> resolution res = unresolved;
>>> diff --git a/gcc/testsuite/gcc.target/powerpc/pr104482.c b/gcc/testsuite/gcc.target/powerpc/pr104482.c
>>> new file mode 100644
>>> index 00000000000..92191265e4c
>>> --- /dev/null
>>> +++ b/gcc/testsuite/gcc.target/powerpc/pr104482.c
>>> @@ -0,0 +1,16 @@
>>> +/* { dg-require-effective-target powerpc_vsx_ok } */
>>> +/* { dg-options "-mvsx" } */
>>> +
>>> +/* It's to verify no ICE here, ignore error messages about
>>> + mismatch argument number since they are not test points
>>> + here. */
>>> +/* { dg-excess-errors "pr104482" } */
>>> +
>>> +__attribute__ ((altivec (vector__))) int vsi;
>>> +
>>> +double
>>> +testXXPERMDI (void)
>>> +{
>>> + return __builtin_vsx_xxpermdi (vsi, vsi, 2, 4);
>>> +}
>>> +
>>
next prev parent reply other threads:[~2022-07-28 8:46 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-05-18 14:07 Kewen.Lin
2022-06-06 8:52 ` PING^1 " Kewen.Lin
2022-06-23 2:02 ` PING^2 " Kewen.Lin
2022-07-28 8:46 ` Kewen.Lin [this message]
2022-08-15 8:07 ` PING^4 " Kewen.Lin
2022-08-29 6:29 ` PING^5 " Kewen.Lin
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