On Mon, 28 Sep 2020, Jan Hubicka wrote:

> > On Mon, 28 Sep 2020, Jan Hubicka wrote:
> > 
> > > Hi,
> > > ipa-reference, ipa-pure-const and ipa-modref could use the knowledge
> > > about bulitins which is currently harwired into
> > > ref_maybe_used_by_call_p_1, call_may_clobber_ref_p_1 and the PTA
> > > computation.  This patch breaks out logic implemented in the first two
> > > into a form of a simple descriptor that can be used by the IPA passes
> > > (and other code).
> > > 
> > > I was considering an option of putting this into def file but I do not 
> > > think
> > > it is feasible without cluttering it quite a lot.
> > > 
> > > For ipa-modref I implemented dump informing about missing builtins. 
> > > strlen,
> > > sqrt and exp seems common offenders, but that can be handled incrementally
> > > if the approach looks reasonable.
> > > I would also look adding the description for PTA (perhaps with some
> > > special cases remainig since it is more ad-hoc)
> > > 
> > > Bootstrapped/regtested x86_64-linux, OK?
> > 
> > Hmm, this looks awfully similar to fn-spec handling done in
> > process_args via gimple_call_arg_flags ()?
> 
> Kind of similar (I was also looking into this, since with modref we
> could detect noescape attribute rather easily).
> 
> I am not quite sure the attribute machinery overlaps that well with what
> we do with builtins.  tree-ssa-alias only use gimple_call_arg_flags to
> detect that pure/const fuction does not use its argument.

Hmm, no - it expects the gimple_call_use/clobber_set to include
actions of the called function itself (const functions none here)
but for passed-by-value the loads may be in the call itself
which is where it uses gimple_call_arg_flags to skip unused ones.

But note that PTA uses gimple_call_arg_flags to compute
the gimple_call_use/clobber_set (but only in IPA mode) and the individual 
BUILT_IN_* handlings in tree-ssa-alias.c do what PTA would do
here, just directly as alias queries.  Originally I tried adding
"fn spec"s to BUILT_IN_* decls but that got out-of-hands ...

For example

        /* All the following functions read memory pointed to by
           their second argument.  strcat/strncat additionally
           reads memory pointed to by the first argument.  */
        case BUILT_IN_STRCAT:
        case BUILT_IN_STRNCAT:
          {
            ao_ref dref;
            ao_ref_init_from_ptr_and_size (&dref,
                                           gimple_call_arg (call, 0),
                                           NULL_TREE);
            if (refs_may_alias_p_1 (&dref, ref, false))
              return true;
          }

would be covered by "1WR" (W also implies read).  So the question
would be whether at least parts of your patch could be implemented
by making gimple_call_fnspec () return pre-determined fn-specs
for BUILT_IN_* (like we do with internal_fn_fnspec).

>  We would need
> to invent how to add info that non pure/const function only access the
> argument according to fn spec, add way to represent sizes of accesses
> and how to handle errno.

True - fn-spec lacks an ability to specify access size - fortunately
it's internal and we could change it ;)  Whether or not sth can clobber
errno is sth we eventually need to move to the stmt level anyway
(-f[no-]math-errno crossing inline boundary) - bit sad to waste a
bit in a gimple call for this though.  OTOH we waste a ton of space
in the call_used/call_clobbered members due to bad packing
(unsigned int bitfield followed by a pointer to a bitmap).  Eventually
we could offload this kind of info from the main stmt.  We could
also allocate a fake UID to represent errno (but then the rest of
the bits in call_used/call_clobbered have to be precise) - but note
call_used/call_clobbered does not transfer during inlining.

So for the access size issue we could blow up fnspec by factor of two,
reserving two chars per argument/return value and do

 1.W3R.

for strncat plus add gimple_call_arg_size to access it.  The 2nd
slot in return value could host the errno thing (eh).

 .e

for sqrt for example.

Just to repeat again - the info looks too similar to warrant an
extra mechanism to record it.

Richard.

> Honza
> > 
> > > gcc/ChangeLog:
> > > 
> > > 2020-09-28  Jan Hubicka  <hubi...@ucw.cz>
> > > 
> > >   * tree-ssa-alias.c (ao_classify_builtin): New function commonizing
> > >   logic from ...
> > >   (ref_maybe_used_by_call_p_1): ... here.
> > >   (call_may_clobber_ref_p_1): ... and here.
> > >   * tree-ssa-alias.h (enum ao_function_flags): New enum.
> > >   (struct ao_function_info): New structure.
> > >   (ao_classify_builtin): Declare.
> > > 
> > > diff --git a/gcc/tree-ssa-alias.h b/gcc/tree-ssa-alias.h
> > > index 1dd02c0ea62..eecb8da6dd7 100644
> > > --- a/gcc/tree-ssa-alias.h
> > > +++ b/gcc/tree-ssa-alias.h
> > > @@ -108,6 +108,33 @@ ao_ref::max_size_known_p () const
> > >    return known_size_p (max_size);
> > >  }
> > >  
> > > +/* Flags used in ao_function_info.  */
> > > +
> > > +enum ao_function_flags
> > > +{
> > > +  AO_FUNCTION_BARRIER = 1,
> > > +  AO_FUNCTION_ERRNO = 2,
> > > +};
> > > +
> > > +/* Describe side effects relevant for alias analysis of function call to
> > > +   DECL.  */
> > > +
> > > +struct ao_function_info
> > > +{
> > > +  int num_param_reads;  /* Number of parameters function reads from,
> > > +                    -1 if reads are unknown.  */
> > > +  struct ao_access_info
> > > +    {
> > > +      char param;        /* Index of parameter read/written from.  */
> > > +      char size_param;   /* Index of parameter specifying size of the 
> > > access,
> > > +                    -1 if unknown.  */
> > > +      char size; /* Size of access if known, 0 if unknown.  */
> > > +    } reads[2];
> > > +  int num_param_writes;
> > > +  struct ao_access_info writes[2];
> > > +  enum ao_function_flags flags;
> > > +};
> > > +
> > >  /* In tree-ssa-alias.c  */
> > >  extern void ao_ref_init (ao_ref *, tree);
> > >  extern void ao_ref_init_from_ptr_and_size (ao_ref *, tree, tree);
> > > @@ -158,6 +185,7 @@ extern void debug (pt_solution *ptr);
> > >  extern void dump_points_to_info_for (FILE *, tree);
> > >  extern void debug_points_to_info_for (tree);
> > >  extern void dump_alias_stats (FILE *);
> > > +extern bool ao_classify_builtin (tree callee, ao_function_info *info);
> > >  
> > >  
> > >  /* In tree-ssa-structalias.c  */
> > > diff --git a/gcc/tree-ssa-alias.c b/gcc/tree-ssa-alias.c
> > > index fe390d4ffbe..c182e7bb39c 100644
> > > --- a/gcc/tree-ssa-alias.c
> > > +++ b/gcc/tree-ssa-alias.c
> > > @@ -2503,6 +2503,507 @@ modref_may_conflict (const gimple *stmt,
> > >    return false;
> > >  }
> > >  
> > > +/* If CALLEE has known side effects, fill in INFO and return true.
> > > +   See tree-ssa-structalias.c:find_func_aliases
> > > +   for the list of builtins we might need to handle here.  */
> > > +
> > > +bool
> > > +ao_classify_builtin (tree callee, ao_function_info *info)
> > > +{
> > > +  built_in_function code = DECL_FUNCTION_CODE (callee);
> > > +
> > > +  switch (code)
> > > +    {
> > > +      /* All the following functions read memory pointed to by
> > > +  their second argument and write memory pointed to by first
> > > +  argument.
> > > +  strcat/strncat additionally reads memory pointed to by the first
> > > +  argument.  */
> > > +      case BUILT_IN_STRCAT:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             2,                          /* num_param_reads.  */
> > > +
> > > +             /* Reads and write descriptors are triples containing:
> > > +                - index of parameter read
> > > +                - index of parameter specifying access size
> > > +                  (-1 if unknown)
> > > +                - access size in bytes (0 if unkown).  */
> > > +
> > > +             {{0, -1, 0}, {1, -1, 0}},   /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STRNCAT:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             2,                          /* num_param_reads.  */
> > > +             {{0, -1, 0}, {1, 2, 0}},    /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STRCPY:
> > > +      case BUILT_IN_STPCPY:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{1, -1, 0}},               /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STRNCPY:
> > > +      case BUILT_IN_MEMCPY:
> > > +      case BUILT_IN_MEMMOVE:
> > > +      case BUILT_IN_MEMPCPY:
> > > +      case BUILT_IN_STPNCPY:
> > > +      case BUILT_IN_TM_MEMCPY:
> > > +      case BUILT_IN_TM_MEMMOVE:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{1, 2, 0}},                /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, 2, 0}},                /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STRCAT_CHK:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             2,                          /* num_param_reads.  */
> > > +             {{0, -1, 0}, {1, -1, 0}},   /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STRNCAT_CHK:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             2,                          /* num_param_reads.  */
> > > +             {{0, -1, 0}, {1, 2, 0}},    /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STRCPY_CHK:
> > > +      case BUILT_IN_STPCPY_CHK:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{1, -1, 0}},               /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STRNCPY_CHK:
> > > +      case BUILT_IN_MEMCPY_CHK:
> > > +      case BUILT_IN_MEMMOVE_CHK:
> > > +      case BUILT_IN_MEMPCPY_CHK:
> > > +      case BUILT_IN_STPNCPY_CHK:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{1, 2, 0}},                /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, 2, 0}},                /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_BCOPY:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{0, 2, 0}},                /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{1, 2, 0}},                /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +
> > > +      /* The following functions read memory pointed to by their
> > > +  first argument.  */
> > > +      CASE_BUILT_IN_TM_LOAD (1):
> > > +      CASE_BUILT_IN_TM_LOAD (2):
> > > +      CASE_BUILT_IN_TM_LOAD (4):
> > > +      CASE_BUILT_IN_TM_LOAD (8):
> > > +      CASE_BUILT_IN_TM_LOAD (FLOAT):
> > > +      CASE_BUILT_IN_TM_LOAD (DOUBLE):
> > > +      CASE_BUILT_IN_TM_LOAD (LDOUBLE):
> > > +      CASE_BUILT_IN_TM_LOAD (M64):
> > > +      CASE_BUILT_IN_TM_LOAD (M128):
> > > +      CASE_BUILT_IN_TM_LOAD (M256):
> > > +      case BUILT_IN_TM_LOG:
> > > +      case BUILT_IN_TM_LOG_1:
> > > +      case BUILT_IN_TM_LOG_2:
> > > +      case BUILT_IN_TM_LOG_4:
> > > +      case BUILT_IN_TM_LOG_8:
> > > +      case BUILT_IN_TM_LOG_FLOAT:
> > > +      case BUILT_IN_TM_LOG_DOUBLE:
> > > +      case BUILT_IN_TM_LOG_LDOUBLE:
> > > +      case BUILT_IN_TM_LOG_M64:
> > > +      case BUILT_IN_TM_LOG_M128:
> > > +      case BUILT_IN_TM_LOG_M256:
> > > +
> > > +      case BUILT_IN_INDEX:
> > > +      case BUILT_IN_STRCHR:
> > > +      case BUILT_IN_STRRCHR:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             /* TODO: For TM builtins size is known.  */
> > > +             {{0, -1, 0}},               /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +
> > > +      /* These read memory pointed to by the first argument.
> > > +  Allocating memory does not have any side-effects apart from
> > > +  being the definition point for the pointer.
> > > +  Unix98 specifies that errno is set on allocation failure.  */
> > > +      case BUILT_IN_STRDUP:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{0, -1, 0}},               /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             AO_FUNCTION_ERRNO,          /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STRNDUP:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{0, 1, 0}},                /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             AO_FUNCTION_ERRNO,          /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      /* Allocating memory does not have any side-effects apart from
> > > +  being the definition point for the pointer.  */
> > > +      case BUILT_IN_MALLOC:
> > > +      case BUILT_IN_ALIGNED_ALLOC:
> > > +      case BUILT_IN_CALLOC:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             AO_FUNCTION_ERRNO,          /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      /* These read memory pointed to by the first argument with size
> > > +  in the third argument.  */
> > > +      case BUILT_IN_MEMCHR:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{0, 2, 0}},                /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      /* These read memory pointed to by the first and second arguments. 
> > >  */
> > > +      case BUILT_IN_STRSTR:
> > > +      case BUILT_IN_STRPBRK:
> > > + {
> > > +   static struct ao_function_info ret_info
> > > +        = {
> > > +             2,                          /* num_param_reads.  */
> > > +             {{0, -1, 0}, {1, -1, 0}},   /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      /* Freeing memory kills the pointed-to memory.  More importantly
> > > +  the call has to serve as a barrier for moving loads and stores
> > > +  across it.  */
> > > +      case BUILT_IN_FREE:
> > > +      case BUILT_IN_VA_END:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      /* Realloc serves both as allocation point and deallocation point. 
> > >  */
> > > +      case BUILT_IN_REALLOC:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             1,                          /* num_param_reads.  */
> > > +             {{0, 1, 0}},                /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             AO_FUNCTION_ERRNO,          /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_GAMMA_R:
> > > +      case BUILT_IN_GAMMAF_R:
> > > +      case BUILT_IN_GAMMAL_R:
> > > +      case BUILT_IN_LGAMMA_R:
> > > +      case BUILT_IN_LGAMMAF_R:
> > > +      case BUILT_IN_LGAMMAL_R:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{1, -1, 0}},               /* Param written.  */
> > > +             AO_FUNCTION_ERRNO,          /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_FREXP:
> > > +      case BUILT_IN_FREXPF:
> > > +      case BUILT_IN_FREXPL:
> > > +      case BUILT_IN_MODF:
> > > +      case BUILT_IN_MODFF:
> > > +      case BUILT_IN_MODFL:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{1, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_REMQUO:
> > > +      case BUILT_IN_REMQUOF:
> > > +      case BUILT_IN_REMQUOL:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{2, -1, 0}},               /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_SINCOS:
> > > +      case BUILT_IN_SINCOSF:
> > > +      case BUILT_IN_SINCOSL:
> > > + {
> > > +   static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {{1, -1, 0}, {2, -1, 0}},   /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   tree type = float_ptr_type_node;
> > > +   if (code == BUILT_IN_SINCOS)
> > > +     type = double_ptr_type_node;
> > > +   else
> > > +     type = long_double_ptr_type_node;
> > > +   ret_info.writes[0].size = ret_info.writes[1].size
> > > +          = tree_to_uhwi (TYPE_SIZE_UNIT (type));
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_MEMSET:
> > > +      case BUILT_IN_MEMSET_CHK:
> > > +      case BUILT_IN_TM_MEMSET:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             {0, 2, 0},                  /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      CASE_BUILT_IN_TM_STORE (1):
> > > +      CASE_BUILT_IN_TM_STORE (2):
> > > +      CASE_BUILT_IN_TM_STORE (4):
> > > +      CASE_BUILT_IN_TM_STORE (8):
> > > +      CASE_BUILT_IN_TM_STORE (FLOAT):
> > > +      CASE_BUILT_IN_TM_STORE (DOUBLE):
> > > +      CASE_BUILT_IN_TM_STORE (LDOUBLE):
> > > +      CASE_BUILT_IN_TM_STORE (M64):
> > > +      CASE_BUILT_IN_TM_STORE (M128):
> > > +      CASE_BUILT_IN_TM_STORE (M256):
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             1,                          /* num_param_writes.  */
> > > +             /* TODO: Size is known.  */
> > > +             {0, -1, 0},                 /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      case BUILT_IN_STACK_SAVE:
> > > +      CASE_BUILT_IN_ALLOCA:
> > > +      case BUILT_IN_ASSUME_ALIGNED:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      /* But posix_memalign stores a pointer into the memory pointed to
> > > +  by its first argument.  */
> > > +      case BUILT_IN_POSIX_MEMALIGN:
> > > + {
> > > +   static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {{0, -1, 0}},               /* Param written.  */
> > > +             AO_FUNCTION_ERRNO,          /* flags.  */
> > > +          };
> > > +   ret_info.writes[0].size
> > > +          = tree_to_uhwi (TYPE_SIZE_UNIT (ptr_type_node));
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      /* The following builtins do not read from memory.  */
> > > +      case BUILT_IN_STACK_RESTORE:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             0,                          /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             0,                          /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             (ao_function_flags)0,       /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +      /* __sync_* builtins and some OpenMP builtins act as threading
> > > +  barriers.  */
> > > +#undef DEF_SYNC_BUILTIN
> > > +#define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
> > > +#include "sync-builtins.def"
> > > +#undef DEF_SYNC_BUILTIN
> > > +      case BUILT_IN_GOMP_ATOMIC_START:
> > > +      case BUILT_IN_GOMP_ATOMIC_END:
> > > +      case BUILT_IN_GOMP_BARRIER:
> > > +      case BUILT_IN_GOMP_BARRIER_CANCEL:
> > > +      case BUILT_IN_GOMP_TASKWAIT:
> > > +      case BUILT_IN_GOMP_TASKGROUP_END:
> > > +      case BUILT_IN_GOMP_CRITICAL_START:
> > > +      case BUILT_IN_GOMP_CRITICAL_END:
> > > +      case BUILT_IN_GOMP_CRITICAL_NAME_START:
> > > +      case BUILT_IN_GOMP_CRITICAL_NAME_END:
> > > +      case BUILT_IN_GOMP_LOOP_END:
> > > +      case BUILT_IN_GOMP_LOOP_END_CANCEL:
> > > +      case BUILT_IN_GOMP_ORDERED_START:
> > > +      case BUILT_IN_GOMP_ORDERED_END:
> > > +      case BUILT_IN_GOMP_SECTIONS_END:
> > > +      case BUILT_IN_GOMP_SECTIONS_END_CANCEL:
> > > +      case BUILT_IN_GOMP_SINGLE_COPY_START:
> > > +      case BUILT_IN_GOMP_SINGLE_COPY_END:
> > > + {
> > > +   const static struct ao_function_info ret_info
> > > +        = {
> > > +             -1,                         /* num_param_reads.  */
> > > +             {},                         /* Param read.  */
> > > +             -1,                         /* num_param_writes.  */
> > > +             {},                         /* Param written.  */
> > > +             AO_FUNCTION_BARRIER,        /* flags.  */
> > > +          };
> > > +   *info = ret_info;
> > > +   return true;
> > > + }
> > > +
> > > +      default:
> > > + return false;
> > > +    }
> > > +}
> > > +
> > >  /* If the call CALL may use the memory reference REF return true,
> > >     otherwise return false.  */
> > >  
> > > @@ -2574,219 +3075,37 @@ ref_maybe_used_by_call_p_1 (gcall *call, ao_ref 
> > > *ref, bool tbaa_p)
> > >    /* Handle those builtin functions explicitly that do not act as
> > >       escape points.  See tree-ssa-structalias.c:find_func_aliases
> > >       for the list of builtins we might need to handle here.  */
> > > +  struct ao_function_info info;
> > >    if (callee != NULL_TREE
> > > -      && gimple_call_builtin_p (call, BUILT_IN_NORMAL))
> > > -    switch (DECL_FUNCTION_CODE (callee))
> > > -      {
> > > - /* All the following functions read memory pointed to by
> > > -    their second argument.  strcat/strncat additionally
> > > -    reads memory pointed to by the first argument.  */
> > > - case BUILT_IN_STRCAT:
> > > - case BUILT_IN_STRNCAT:
> > > -   {
> > > -     ao_ref dref;
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    NULL_TREE);
> > > -     if (refs_may_alias_p_1 (&dref, ref, false))
> > > -       return true;
> > > -   }
> > > -   /* FALLTHRU */
> > > - case BUILT_IN_STRCPY:
> > > - case BUILT_IN_STRNCPY:
> > > - case BUILT_IN_MEMCPY:
> > > - case BUILT_IN_MEMMOVE:
> > > - case BUILT_IN_MEMPCPY:
> > > - case BUILT_IN_STPCPY:
> > > - case BUILT_IN_STPNCPY:
> > > - case BUILT_IN_TM_MEMCPY:
> > > - case BUILT_IN_TM_MEMMOVE:
> > > -   {
> > > -     ao_ref dref;
> > > -     tree size = NULL_TREE;
> > > -     if (gimple_call_num_args (call) == 3)
> > > -       size = gimple_call_arg (call, 2);
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 1),
> > > -                                    size);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > - case BUILT_IN_STRCAT_CHK:
> > > - case BUILT_IN_STRNCAT_CHK:
> > > -   {
> > > -     ao_ref dref;
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    NULL_TREE);
> > > -     if (refs_may_alias_p_1 (&dref, ref, false))
> > > -       return true;
> > > -   }
> > > -   /* FALLTHRU */
> > > - case BUILT_IN_STRCPY_CHK:
> > > - case BUILT_IN_STRNCPY_CHK:
> > > - case BUILT_IN_MEMCPY_CHK:
> > > - case BUILT_IN_MEMMOVE_CHK:
> > > - case BUILT_IN_MEMPCPY_CHK:
> > > - case BUILT_IN_STPCPY_CHK:
> > > - case BUILT_IN_STPNCPY_CHK:
> > > -   {
> > > -     ao_ref dref;
> > > -     tree size = NULL_TREE;
> > > -     if (gimple_call_num_args (call) == 4)
> > > -       size = gimple_call_arg (call, 2);
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 1),
> > > -                                    size);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > - case BUILT_IN_BCOPY:
> > > -   {
> > > -     ao_ref dref;
> > > -     tree size = gimple_call_arg (call, 2);
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    size);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > -
> > > - /* The following functions read memory pointed to by their
> > > -    first argument.  */
> > > - CASE_BUILT_IN_TM_LOAD (1):
> > > - CASE_BUILT_IN_TM_LOAD (2):
> > > - CASE_BUILT_IN_TM_LOAD (4):
> > > - CASE_BUILT_IN_TM_LOAD (8):
> > > - CASE_BUILT_IN_TM_LOAD (FLOAT):
> > > - CASE_BUILT_IN_TM_LOAD (DOUBLE):
> > > - CASE_BUILT_IN_TM_LOAD (LDOUBLE):
> > > - CASE_BUILT_IN_TM_LOAD (M64):
> > > - CASE_BUILT_IN_TM_LOAD (M128):
> > > - CASE_BUILT_IN_TM_LOAD (M256):
> > > - case BUILT_IN_TM_LOG:
> > > - case BUILT_IN_TM_LOG_1:
> > > - case BUILT_IN_TM_LOG_2:
> > > - case BUILT_IN_TM_LOG_4:
> > > - case BUILT_IN_TM_LOG_8:
> > > - case BUILT_IN_TM_LOG_FLOAT:
> > > - case BUILT_IN_TM_LOG_DOUBLE:
> > > - case BUILT_IN_TM_LOG_LDOUBLE:
> > > - case BUILT_IN_TM_LOG_M64:
> > > - case BUILT_IN_TM_LOG_M128:
> > > - case BUILT_IN_TM_LOG_M256:
> > > -   return ptr_deref_may_alias_ref_p_1 (gimple_call_arg (call, 0), ref);
> > > -
> > > - /* These read memory pointed to by the first argument.  */
> > > - case BUILT_IN_STRDUP:
> > > - case BUILT_IN_STRNDUP:
> > > - case BUILT_IN_REALLOC:
> > > -   {
> > > -     ao_ref dref;
> > > -     tree size = NULL_TREE;
> > > -     if (gimple_call_num_args (call) == 2)
> > > -       size = gimple_call_arg (call, 1);
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    size);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > - /* These read memory pointed to by the first argument.  */
> > > - case BUILT_IN_INDEX:
> > > - case BUILT_IN_STRCHR:
> > > - case BUILT_IN_STRRCHR:
> > > -   {
> > > -     ao_ref dref;
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    NULL_TREE);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > - /* These read memory pointed to by the first argument with size
> > > -    in the third argument.  */
> > > - case BUILT_IN_MEMCHR:
> > > -   {
> > > -     ao_ref dref;
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    gimple_call_arg (call, 2));
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > - /* These read memory pointed to by the first and second arguments.  */
> > > - case BUILT_IN_STRSTR:
> > > - case BUILT_IN_STRPBRK:
> > > -   {
> > > -     ao_ref dref;
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    NULL_TREE);
> > > -     if (refs_may_alias_p_1 (&dref, ref, false))
> > > -       return true;
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 1),
> > > -                                    NULL_TREE);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > -
> > > - /* The following builtins do not read from memory.  */
> > > - case BUILT_IN_FREE:
> > > - case BUILT_IN_MALLOC:
> > > - case BUILT_IN_POSIX_MEMALIGN:
> > > - case BUILT_IN_ALIGNED_ALLOC:
> > > - case BUILT_IN_CALLOC:
> > > - CASE_BUILT_IN_ALLOCA:
> > > - case BUILT_IN_STACK_SAVE:
> > > - case BUILT_IN_STACK_RESTORE:
> > > - case BUILT_IN_MEMSET:
> > > - case BUILT_IN_TM_MEMSET:
> > > - case BUILT_IN_MEMSET_CHK:
> > > - case BUILT_IN_FREXP:
> > > - case BUILT_IN_FREXPF:
> > > - case BUILT_IN_FREXPL:
> > > - case BUILT_IN_GAMMA_R:
> > > - case BUILT_IN_GAMMAF_R:
> > > - case BUILT_IN_GAMMAL_R:
> > > - case BUILT_IN_LGAMMA_R:
> > > - case BUILT_IN_LGAMMAF_R:
> > > - case BUILT_IN_LGAMMAL_R:
> > > - case BUILT_IN_MODF:
> > > - case BUILT_IN_MODFF:
> > > - case BUILT_IN_MODFL:
> > > - case BUILT_IN_REMQUO:
> > > - case BUILT_IN_REMQUOF:
> > > - case BUILT_IN_REMQUOL:
> > > - case BUILT_IN_SINCOS:
> > > - case BUILT_IN_SINCOSF:
> > > - case BUILT_IN_SINCOSL:
> > > - case BUILT_IN_ASSUME_ALIGNED:
> > > - case BUILT_IN_VA_END:
> > > +      && gimple_call_builtin_p (call, BUILT_IN_NORMAL)
> > > +      && (ao_classify_builtin (callee, &info)))
> > > +    {
> > > +      if (info.flags & AO_FUNCTION_BARRIER)
> > > + return true;
> > > +      if (info.num_param_reads >= 0)
> > > + {
> > > +   for (int i = 0; i < info.num_param_reads; i++)
> > > +     {
> > > +       ao_ref dref;
> > > +       tree size = NULL_TREE;
> > > +
> > > +       gcc_checking_assert (info.reads[i].size_param
> > > +                            != info.reads[i].param);
> > > +       if (info.reads[i].size_param != -1)
> > > +         size = gimple_call_arg (call, info.reads[i].size);
> > > +       else if (info.reads[i].size)
> > > +         size = build_int_cst (size_type_node, info.reads[i].size);
> > > +       ao_ref_init_from_ptr_and_size (&dref,
> > > +                                      gimple_call_arg
> > > +                                          (call,
> > > +                                           info.reads[i].param),
> > > +                                      size);
> > > +       if (refs_may_alias_p_1 (&dref, ref, tbaa_p))
> > > +         return true;
> > > +     }
> > >     return false;
> > > - /* __sync_* builtins and some OpenMP builtins act as threading
> > > -    barriers.  */
> > > -#undef DEF_SYNC_BUILTIN
> > > -#define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
> > > -#include "sync-builtins.def"
> > > -#undef DEF_SYNC_BUILTIN
> > > - case BUILT_IN_GOMP_ATOMIC_START:
> > > - case BUILT_IN_GOMP_ATOMIC_END:
> > > - case BUILT_IN_GOMP_BARRIER:
> > > - case BUILT_IN_GOMP_BARRIER_CANCEL:
> > > - case BUILT_IN_GOMP_TASKWAIT:
> > > - case BUILT_IN_GOMP_TASKGROUP_END:
> > > - case BUILT_IN_GOMP_CRITICAL_START:
> > > - case BUILT_IN_GOMP_CRITICAL_END:
> > > - case BUILT_IN_GOMP_CRITICAL_NAME_START:
> > > - case BUILT_IN_GOMP_CRITICAL_NAME_END:
> > > - case BUILT_IN_GOMP_LOOP_END:
> > > - case BUILT_IN_GOMP_LOOP_END_CANCEL:
> > > - case BUILT_IN_GOMP_ORDERED_START:
> > > - case BUILT_IN_GOMP_ORDERED_END:
> > > - case BUILT_IN_GOMP_SECTIONS_END:
> > > - case BUILT_IN_GOMP_SECTIONS_END_CANCEL:
> > > - case BUILT_IN_GOMP_SINGLE_COPY_START:
> > > - case BUILT_IN_GOMP_SINGLE_COPY_END:
> > > -   return true;
> > > -
> > > - default:
> > > -   /* Fallthru to general call handling.  */;
> > > -      }
> > > + }
> > > +    }
> > >  
> > >    /* Check if base is a global static variable that is not read
> > >       by the function.  */
> > > @@ -2961,7 +3280,9 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref *ref, 
> > > bool tbaa_p)
> > >     modref_summary *summary = get_modref_function_summary (node);
> > >     if (summary)
> > >       {
> > > -       if (!modref_may_conflict (call, summary->stores, ref, tbaa_p))
> > > +       if (!modref_may_conflict (call, summary->stores, ref, tbaa_p)
> > > +           && (!summary->writes_errno
> > > +               || !targetm.ref_may_alias_errno (ref)))
> > >           {
> > >             alias_stats.modref_clobber_no_alias++;
> > >             if (dump_file && (dump_flags & TDF_DETAILS))
> > > @@ -3016,205 +3337,43 @@ call_may_clobber_ref_p_1 (gcall *call, ao_ref 
> > > *ref, bool tbaa_p)
> > >        && SSA_NAME_POINTS_TO_READONLY_MEMORY (TREE_OPERAND (base, 0)))
> > >      return false;
> > >  
> > > +  struct ao_function_info info;
> > >    /* Handle those builtin functions explicitly that do not act as
> > > -     escape points.  See tree-ssa-structalias.c:find_func_aliases
> > > -     for the list of builtins we might need to handle here.  */
> > > +     escape points.  */
> > >    if (callee != NULL_TREE
> > > -      && gimple_call_builtin_p (call, BUILT_IN_NORMAL))
> > > -    switch (DECL_FUNCTION_CODE (callee))
> > > -      {
> > > - /* All the following functions clobber memory pointed to by
> > > -    their first argument.  */
> > > - case BUILT_IN_STRCPY:
> > > - case BUILT_IN_STRNCPY:
> > > - case BUILT_IN_MEMCPY:
> > > - case BUILT_IN_MEMMOVE:
> > > - case BUILT_IN_MEMPCPY:
> > > - case BUILT_IN_STPCPY:
> > > - case BUILT_IN_STPNCPY:
> > > - case BUILT_IN_STRCAT:
> > > - case BUILT_IN_STRNCAT:
> > > - case BUILT_IN_MEMSET:
> > > - case BUILT_IN_TM_MEMSET:
> > > - CASE_BUILT_IN_TM_STORE (1):
> > > - CASE_BUILT_IN_TM_STORE (2):
> > > - CASE_BUILT_IN_TM_STORE (4):
> > > - CASE_BUILT_IN_TM_STORE (8):
> > > - CASE_BUILT_IN_TM_STORE (FLOAT):
> > > - CASE_BUILT_IN_TM_STORE (DOUBLE):
> > > - CASE_BUILT_IN_TM_STORE (LDOUBLE):
> > > - CASE_BUILT_IN_TM_STORE (M64):
> > > - CASE_BUILT_IN_TM_STORE (M128):
> > > - CASE_BUILT_IN_TM_STORE (M256):
> > > - case BUILT_IN_TM_MEMCPY:
> > > - case BUILT_IN_TM_MEMMOVE:
> > > -   {
> > > -     ao_ref dref;
> > > -     tree size = NULL_TREE;
> > > -     /* Don't pass in size for strncat, as the maximum size
> > > -        is strlen (dest) + n + 1 instead of n, resp.
> > > -        n + 1 at dest + strlen (dest), but strlen (dest) isn't
> > > -        known.  */
> > > -     if (gimple_call_num_args (call) == 3
> > > -         && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT)
> > > -       size = gimple_call_arg (call, 2);
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    size);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > - case BUILT_IN_STRCPY_CHK:
> > > - case BUILT_IN_STRNCPY_CHK:
> > > - case BUILT_IN_MEMCPY_CHK:
> > > - case BUILT_IN_MEMMOVE_CHK:
> > > - case BUILT_IN_MEMPCPY_CHK:
> > > - case BUILT_IN_STPCPY_CHK:
> > > - case BUILT_IN_STPNCPY_CHK:
> > > - case BUILT_IN_STRCAT_CHK:
> > > - case BUILT_IN_STRNCAT_CHK:
> > > - case BUILT_IN_MEMSET_CHK:
> > > -   {
> > > -     ao_ref dref;
> > > -     tree size = NULL_TREE;
> > > -     /* Don't pass in size for __strncat_chk, as the maximum size
> > > -        is strlen (dest) + n + 1 instead of n, resp.
> > > -        n + 1 at dest + strlen (dest), but strlen (dest) isn't
> > > -        known.  */
> > > -     if (gimple_call_num_args (call) == 4
> > > -         && DECL_FUNCTION_CODE (callee) != BUILT_IN_STRNCAT_CHK)
> > > -       size = gimple_call_arg (call, 2);
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 0),
> > > -                                    size);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > - case BUILT_IN_BCOPY:
> > > -   {
> > > -     ao_ref dref;
> > > -     tree size = gimple_call_arg (call, 2);
> > > -     ao_ref_init_from_ptr_and_size (&dref,
> > > -                                    gimple_call_arg (call, 1),
> > > -                                    size);
> > > -     return refs_may_alias_p_1 (&dref, ref, false);
> > > -   }
> > > - /* Allocating memory does not have any side-effects apart from
> > > -    being the definition point for the pointer.  */
> > > - case BUILT_IN_MALLOC:
> > > - case BUILT_IN_ALIGNED_ALLOC:
> > > - case BUILT_IN_CALLOC:
> > > - case BUILT_IN_STRDUP:
> > > - case BUILT_IN_STRNDUP:
> > > -   /* Unix98 specifies that errno is set on allocation failure.  */
> > > -   if (flag_errno_math
> > > -       && targetm.ref_may_alias_errno (ref))
> > > -     return true;
> > > -   return false;
> > > - case BUILT_IN_STACK_SAVE:
> > > - CASE_BUILT_IN_ALLOCA:
> > > - case BUILT_IN_ASSUME_ALIGNED:
> > > +      && gimple_call_builtin_p (call, BUILT_IN_NORMAL)
> > > +      && (ao_classify_builtin (callee, &info)))
> > > +    {
> > > +      if (info.flags & AO_FUNCTION_BARRIER)
> > > + return true;
> > > +      if ((info.flags & AO_FUNCTION_ERRNO)
> > > +   && flag_errno_math
> > > +   && targetm.ref_may_alias_errno (ref))
> > > + return true;
> > > +      if (info.num_param_writes >= 0)
> > > + {
> > > +   for (int i = 0; i < info.num_param_writes; i++)
> > > +     {
> > > +       ao_ref dref;
> > > +       tree size = NULL_TREE;
> > > +
> > > +       gcc_checking_assert (info.writes[i].size_param
> > > +                            != info.writes[i].param);
> > > +       if (info.writes[i].size_param != -1)
> > > +         size = gimple_call_arg (call, info.writes[i].size_param);
> > > +       else if (info.writes[i].size)
> > > +         size = build_int_cst (size_type_node, info.writes[i].size);
> > > +       ao_ref_init_from_ptr_and_size (&dref,
> > > +                                      gimple_call_arg
> > > +                                          (call,
> > > +                                           info.writes[i].param),
> > > +                                      size);
> > > +       if (refs_may_alias_p_1 (&dref, ref, tbaa_p))
> > > +         return true;
> > > +     }
> > >     return false;
> > > - /* But posix_memalign stores a pointer into the memory pointed to
> > > -    by its first argument.  */
> > > - case BUILT_IN_POSIX_MEMALIGN:
> > > -   {
> > > -     tree ptrptr = gimple_call_arg (call, 0);
> > > -     ao_ref dref;
> > > -     ao_ref_init_from_ptr_and_size (&dref, ptrptr,
> > > -                                    TYPE_SIZE_UNIT (ptr_type_node));
> > > -     return (refs_may_alias_p_1 (&dref, ref, false)
> > > -             || (flag_errno_math
> > > -                 && targetm.ref_may_alias_errno (ref)));
> > > -   }
> > > - /* Freeing memory kills the pointed-to memory.  More importantly
> > > -    the call has to serve as a barrier for moving loads and stores
> > > -    across it.  */
> > > - case BUILT_IN_FREE:
> > > - case BUILT_IN_VA_END:
> > > -   {
> > > -     tree ptr = gimple_call_arg (call, 0);
> > > -     return ptr_deref_may_alias_ref_p_1 (ptr, ref);
> > > -   }
> > > - /* Realloc serves both as allocation point and deallocation point.  */
> > > - case BUILT_IN_REALLOC:
> > > -   {
> > > -     tree ptr = gimple_call_arg (call, 0);
> > > -     /* Unix98 specifies that errno is set on allocation failure.  */
> > > -     return ((flag_errno_math
> > > -              && targetm.ref_may_alias_errno (ref))
> > > -             || ptr_deref_may_alias_ref_p_1 (ptr, ref));
> > > -   }
> > > - case BUILT_IN_GAMMA_R:
> > > - case BUILT_IN_GAMMAF_R:
> > > - case BUILT_IN_GAMMAL_R:
> > > - case BUILT_IN_LGAMMA_R:
> > > - case BUILT_IN_LGAMMAF_R:
> > > - case BUILT_IN_LGAMMAL_R:
> > > -   {
> > > -     tree out = gimple_call_arg (call, 1);
> > > -     if (ptr_deref_may_alias_ref_p_1 (out, ref))
> > > -       return true;
> > > -     if (flag_errno_math)
> > > -       break;
> > > -     return false;
> > > -   }
> > > - case BUILT_IN_FREXP:
> > > - case BUILT_IN_FREXPF:
> > > - case BUILT_IN_FREXPL:
> > > - case BUILT_IN_MODF:
> > > - case BUILT_IN_MODFF:
> > > - case BUILT_IN_MODFL:
> > > -   {
> > > -     tree out = gimple_call_arg (call, 1);
> > > -     return ptr_deref_may_alias_ref_p_1 (out, ref);
> > > -   }
> > > - case BUILT_IN_REMQUO:
> > > - case BUILT_IN_REMQUOF:
> > > - case BUILT_IN_REMQUOL:
> > > -   {
> > > -     tree out = gimple_call_arg (call, 2);
> > > -     if (ptr_deref_may_alias_ref_p_1 (out, ref))
> > > -       return true;
> > > -     if (flag_errno_math)
> > > -       break;
> > > -     return false;
> > > -   }
> > > - case BUILT_IN_SINCOS:
> > > - case BUILT_IN_SINCOSF:
> > > - case BUILT_IN_SINCOSL:
> > > -   {
> > > -     tree sin = gimple_call_arg (call, 1);
> > > -     tree cos = gimple_call_arg (call, 2);
> > > -     return (ptr_deref_may_alias_ref_p_1 (sin, ref)
> > > -             || ptr_deref_may_alias_ref_p_1 (cos, ref));
> > > -   }
> > > - /* __sync_* builtins and some OpenMP builtins act as threading
> > > -    barriers.  */
> > > -#undef DEF_SYNC_BUILTIN
> > > -#define DEF_SYNC_BUILTIN(ENUM, NAME, TYPE, ATTRS) case ENUM:
> > > -#include "sync-builtins.def"
> > > -#undef DEF_SYNC_BUILTIN
> > > - case BUILT_IN_GOMP_ATOMIC_START:
> > > - case BUILT_IN_GOMP_ATOMIC_END:
> > > - case BUILT_IN_GOMP_BARRIER:
> > > - case BUILT_IN_GOMP_BARRIER_CANCEL:
> > > - case BUILT_IN_GOMP_TASKWAIT:
> > > - case BUILT_IN_GOMP_TASKGROUP_END:
> > > - case BUILT_IN_GOMP_CRITICAL_START:
> > > - case BUILT_IN_GOMP_CRITICAL_END:
> > > - case BUILT_IN_GOMP_CRITICAL_NAME_START:
> > > - case BUILT_IN_GOMP_CRITICAL_NAME_END:
> > > - case BUILT_IN_GOMP_LOOP_END:
> > > - case BUILT_IN_GOMP_LOOP_END_CANCEL:
> > > - case BUILT_IN_GOMP_ORDERED_START:
> > > - case BUILT_IN_GOMP_ORDERED_END:
> > > - case BUILT_IN_GOMP_SECTIONS_END:
> > > - case BUILT_IN_GOMP_SECTIONS_END_CANCEL:
> > > - case BUILT_IN_GOMP_SINGLE_COPY_START:
> > > - case BUILT_IN_GOMP_SINGLE_COPY_END:
> > > -   return true;
> > > - default:
> > > -   /* Fallthru to general call handling.  */;
> > > -      }
> > > + }
> > > +    }
> > >  
> > >    /* Check if base is a global static variable that is not written
> > >       by the function.  */
> > > 
> > 
> > -- 
> > Richard Biener <rguent...@suse.de>
> > SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
> > Germany; GF: Felix Imend
> 
> 

-- 
Richard Biener <rguent...@suse.de>
SUSE Software Solutions Germany GmbH, Maxfeldstrasse 5, 90409 Nuernberg,
Germany; GF: Felix Imend

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