On Wed, 16 May 2012, William J. Schmidt wrote:
> On Wed, 2012-05-16 at 11:45 +0200, Richard Guenther wrote:
> > On Tue, 15 May 2012, William J. Schmidt wrote:
> >
> > > Ping.
> >
> > I don't like it too much - but pondering a bit over it I can't find
> > a nicer solution.
> >
> > So, ok.
> >
> > Thanks,
> > Richard.
> >
> Agreed. I'm not fond of it either, and I feel it's a bit fragile.
>
> An alternative would be to go back to handling the exponentiation
> expressions outside of the ops list (generating an explicit multiply to
> hook them up with the results of normal linear/parallel expansion). In
> hindsight, placing the exponentiation results in the ops list and
> letting the rank order handle things introduces some complexity as well
> as saving some. The DAG'd nature of the exponentiation expressions
> isn't a perfect fit for the pure tree form of the reassociated
> multiplies.
True.
> Let me know if you'd like me to pursue that instead.
You can try - if the result looks better I'm all for it ;)
Thanks,
Richard.
> Thanks,
> Bill
>
> > > Thanks,
> > > Bill
> > >
> > > On Tue, 2012-05-08 at 22:04 -0500, William J. Schmidt wrote:
> > > > This fixes another statement-placement issue when reassociating
> > > > expressions with repeated factors. Multiplies feeding into
> > > > __builtin_powi calls were not getting placed properly ahead of them in
> > > > some cases.
> > > >
> > > > Bootstrapped and tested on powerpc64-unknown-linux-gnu with no new
> > > > regressions. I've also run SPEC cpu2006 with no build or correctness
> > > > issues. OK for trunk?
> > > >
> > > > Thanks,
> > > > Bill
> > > >
> > > >
> > > > gcc:
> > > >
> > > > 2012-05-08 Bill Schmidt <wschm...@linux.vnet.ibm.com>
> > > >
> > > > PR tree-optimization/53217
> > > > * tree-ssa-reassoc.c (bip_map): New static variable.
> > > > (possibly_move_powi): Move feeding multiplies with
> > > > __builtin_powi call.
> > > > (attempt_builtin_powi): Save feeding multiplies on a stack.
> > > > (reassociate_bb): Create and destroy bip_map.
> > > >
> > > > gcc/testsuite:
> > > >
> > > > 2012-05-08 Bill Schmidt <wschm...@linux.vnet.ibm.com>
> > > >
> > > > PR tree-optimization/53217
> > > > * gfortran.dg/pr53217.f90: New test.
> > > >
> > > >
> > > > Index: gcc/testsuite/gfortran.dg/pr53217.f90
> > > > ===================================================================
> > > > --- gcc/testsuite/gfortran.dg/pr53217.f90 (revision 0)
> > > > +++ gcc/testsuite/gfortran.dg/pr53217.f90 (revision 0)
> > > > @@ -0,0 +1,28 @@
> > > > +! { dg-do compile }
> > > > +! { dg-options "-O1 -ffast-math" }
> > > > +
> > > > +! This tests only for compile-time failure, which formerly occurred
> > > > +! when statements were emitted out of order, failing verify_ssa.
> > > > +
> > > > +MODULE xc_cs1
> > > > + INTEGER, PARAMETER :: dp=KIND(0.0D0)
> > > > + REAL(KIND=dp), PARAMETER :: a = 0.04918_dp, &
> > > > + c = 0.2533_dp, &
> > > > + d = 0.349_dp
> > > > +CONTAINS
> > > > + SUBROUTINE cs1_u_2 ( rho, grho, r13, e_rho_rho, e_rho_ndrho,
> > > > e_ndrho_ndrho,&
> > > > + npoints, error)
> > > > + REAL(KIND=dp), DIMENSION(*), &
> > > > + INTENT(INOUT) :: e_rho_rho,
> > > > e_rho_ndrho, &
> > > > + e_ndrho_ndrho
> > > > + DO ip = 1, npoints
> > > > + IF ( rho(ip) > eps_rho ) THEN
> > > > + oc = 1.0_dp/(r*r*r3*r3 + c*g*g)
> > > > + d2rF4 = c4p*f13*f23*g**4*r3/r *
> > > > (193*d*r**5*r3*r3+90*d*d*r**5*r3 &
> > > > + -88*g*g*c*r**3*r3-100*d*d*c*g*g*r*r*r3*r3 &
> > > > + +104*r**6)*od**3*oc**4
> > > > + e_rho_rho(ip) = e_rho_rho(ip) + d2F1 + d2rF2 + d2F3 + d2rF4
> > > > + END IF
> > > > + END DO
> > > > + END SUBROUTINE cs1_u_2
> > > > +END MODULE xc_cs1
> > > > Index: gcc/tree-ssa-reassoc.c
> > > > ===================================================================
> > > > --- gcc/tree-ssa-reassoc.c (revision 187117)
> > > > +++ gcc/tree-ssa-reassoc.c (working copy)
> > > > @@ -200,6 +200,10 @@ static long *bb_rank;
> > > > /* Operand->rank hashtable. */
> > > > static struct pointer_map_t *operand_rank;
> > > >
> > > > +/* Map from inserted __builtin_powi calls to multiply chains that
> > > > + feed them. */
> > > > +static struct pointer_map_t *bip_map;
> > > > +
> > > > /* Forward decls. */
> > > > static long get_rank (tree);
> > > >
> > > > @@ -2249,7 +2253,7 @@ remove_visited_stmt_chain (tree var)
> > > > static void
> > > > possibly_move_powi (gimple stmt, tree op)
> > > > {
> > > > - gimple stmt2;
> > > > + gimple stmt2, *mpy;
> > > > tree fndecl;
> > > > gimple_stmt_iterator gsi1, gsi2;
> > > >
> > > > @@ -2278,9 +2282,39 @@ possibly_move_powi (gimple stmt, tree op)
> > > > return;
> > > > }
> > > >
> > > > + /* Move the __builtin_powi. */
> > > > gsi1 = gsi_for_stmt (stmt);
> > > > gsi2 = gsi_for_stmt (stmt2);
> > > > gsi_move_before (&gsi2, &gsi1);
> > > > +
> > > > + /* See if there are multiplies feeding the __builtin_powi base
> > > > + argument that must also be moved. */
> > > > + while ((mpy = (gimple *) pointer_map_contains (bip_map, stmt2)) !=
> > > > NULL)
> > > > + {
> > > > + /* If we've already moved this statement, we're done. This is
> > > > + identified by a NULL entry for the statement in bip_map. */
> > > > + gimple *next = (gimple *) pointer_map_contains (bip_map, *mpy);
> > > > + if (next && !*next)
> > > > + return;
> > > > +
> > > > + stmt = stmt2;
> > > > + stmt2 = *mpy;
> > > > + gsi1 = gsi_for_stmt (stmt);
> > > > + gsi2 = gsi_for_stmt (stmt2);
> > > > + gsi_move_before (&gsi2, &gsi1);
> > > > +
> > > > + /* The moved multiply may be DAG'd from multiple calls if it
> > > > + was the result of a cached multiply. Only move it once.
> > > > + Rank order ensures we move it to the right place the first
> > > > + time. */
> > > > + if (next)
> > > > + *next = NULL;
> > > > + else
> > > > + {
> > > > + next = (gimple *) pointer_map_insert (bip_map, *mpy);
> > > > + *next = NULL;
> > > > + }
> > > > + }
> > > > }
> > > >
> > > > /* This function checks three consequtive operands in
> > > > @@ -3281,6 +3315,7 @@ attempt_builtin_powi (gimple stmt, VEC(operand_ent
> > > > while (true)
> > > > {
> > > > HOST_WIDE_INT power;
> > > > + gimple last_mul = NULL;
> > > >
> > > > /* First look for the largest cached product of factors from
> > > > preceding iterations. If found, create a builtin_powi for
> > > > @@ -3318,16 +3353,25 @@ attempt_builtin_powi (gimple stmt,
> > > > VEC(operand_ent
> > > > }
> > > > else
> > > > {
> > > > + gimple *value;
> > > > +
> > > > iter_result = get_reassoc_pow_ssa_name (target, type);
> > > > pow_stmt = gimple_build_call (powi_fndecl, 2, rf1->repr,
> > > > build_int_cst
> > > > (integer_type_node,
> > > > power));
> > > > gimple_call_set_lhs (pow_stmt, iter_result);
> > > > gimple_set_location (pow_stmt, gimple_location (stmt));
> > > > - /* Temporarily place the call; we will move it to the
> > > > - correct place during rewrite_expr. */
> > > > + /* Temporarily place the call; we will move it and its
> > > > + feeding multiplies to the correct place during
> > > > + rewrite_expr. */
> > > > gsi_insert_before (&gsi, pow_stmt, GSI_SAME_STMT);
> > > >
> > > > + if (!operand_equal_p (rf1->repr, rf1->factor, 0))
> > > > + {
> > > > + value = (gimple *) pointer_map_insert (bip_map,
> > > > pow_stmt);
> > > > + *value = SSA_NAME_DEF_STMT (rf1->repr);
> > > > + }
> > > > +
> > > > if (dump_file && (dump_flags & TDF_DETAILS))
> > > > {
> > > > unsigned elt;
> > > > @@ -3413,6 +3457,15 @@ attempt_builtin_powi (gimple stmt,
> > > > VEC(operand_ent
> > > > gsi_insert_before (&gsi, mul_stmt, GSI_SAME_STMT);
> > > > rf1->repr = target_ssa;
> > > >
> > > > + /* Chain multiplies together for later movement. */
> > > > + if (last_mul)
> > > > + {
> > > > + gimple *value
> > > > + = (gimple *) pointer_map_insert (bip_map,
> > > > mul_stmt);
> > > > + *value = last_mul;
> > > > + }
> > > > + last_mul = mul_stmt;
> > > > +
> > > > /* Don't reprocess the multiply we just introduced.
> > > > */
> > > > gimple_set_visited (mul_stmt, true);
> > > > }
> > > > @@ -3428,6 +3481,15 @@ attempt_builtin_powi (gimple stmt,
> > > > VEC(operand_ent
> > > > gimple_call_set_lhs (pow_stmt, iter_result);
> > > > gimple_set_location (pow_stmt, gimple_location (stmt));
> > > > gsi_insert_before (&gsi, pow_stmt, GSI_SAME_STMT);
> > > > +
> > > > + /* If we inserted a chain of multiplies before the pow_stmt,
> > > > + record that fact so we can move it later when we move the
> > > > + pow_stmt. */
> > > > + if (last_mul)
> > > > + {
> > > > + gimple *value = (gimple *) pointer_map_insert (bip_map,
> > > > pow_stmt);
> > > > + *value = last_mul;
> > > > + }
> > > > }
> > > >
> > > > /* Append the result of this iteration to the ops vector. */
> > > > @@ -3544,6 +3606,7 @@ reassociate_bb (basic_block bb)
> > > > if (associative_tree_code (rhs_code))
> > > > {
> > > > VEC(operand_entry_t, heap) *ops = NULL;
> > > > + bip_map = pointer_map_create ();
> > > >
> > > > /* There may be no immediate uses left by the time we
> > > > get here because we may have eliminated them all. */
> > > > @@ -3608,6 +3671,7 @@ reassociate_bb (basic_block bb)
> > > > }
> > > >
> > > > VEC_free (operand_entry_t, heap, ops);
> > > > + pointer_map_destroy (bip_map);
> > > > }
> > > > }
> > > > }
> > > >
> > > >
> > >
> > >
> >
>
>
--
Richard Guenther <rguent...@suse.de>
SUSE / SUSE Labs
SUSE LINUX Products GmbH - Nuernberg - AG Nuernberg - HRB 16746
GF: Jeff Hawn, Jennifer Guild, Felix Imendörffer
