On Sat, Sep 22, 2012 at 11:17 PM, Marc Glisse <marc.gli...@inria.fr> wrote:
> Hello,
>
> this patch lets forwprop fold bit_field_refs of constructors. It is
> particularly useful in forwprop4, which happens after the pass that lowers
> unsupported vector operations. Indeed, that pass keeps breaking vectors into
> pieces and reconstructing them for each operation, which is a waste when
> there are several operations in a row. This happens fairly late though, and
> dead constructors are left lying around (no dead code elimination after
> forwprop4) for the rtl layer to remove, so we are probably missing possible
> optimizations.
>
> Bootstrap+testsuite ok (well, still about a thousand FAILs, but it doesn't
> increase with my patch).
Ok.
Thanks,
Richard.
> 2012-09-24 Marc Glisse <marc.gli...@inria.fr>
>
> gcc/
> * tree-ssa-forwprop.c: Include tree-ssa-propagate.h.
> (simplify_bitfield_ref): Handle constructors.
> * Makefile.in (tree-ssa-forwprop.o): Depend on tree-ssa-propagate.h.
>
> gcc/testsuite/
> * gcc.dg/tree-ssa/forwprop-23.c: New testcase.
>
> --
> Marc Glisse
> Index: Makefile.in
> ===================================================================
> --- Makefile.in (revision 191644)
> +++ Makefile.in (working copy)
> @@ -2239,21 +2239,21 @@ tree-outof-ssa.o : tree-outof-ssa.c $(TR
> $(TREE_SSA_LIVE_H) $(BASIC_BLOCK_H) $(BITMAP_H) $(GGC_H) \
> $(EXPR_H) $(SSAEXPAND_H) $(GIMPLE_PRETTY_PRINT_H)
> tree-ssa-dse.o : tree-ssa-dse.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
> $(TM_H) $(GGC_H) $(TREE_H) $(TM_P_H) $(BASIC_BLOCK_H) \
> $(TREE_FLOW_H) $(TREE_PASS_H) domwalk.h $(FLAGS_H) \
> $(GIMPLE_PRETTY_PRINT_H) langhooks.h
> tree-ssa-forwprop.o : tree-ssa-forwprop.c $(CONFIG_H) $(SYSTEM_H)
> coretypes.h \
> $(TM_H) $(TREE_H) $(TM_P_H) $(BASIC_BLOCK_H) $(CFGLOOP_H) \
> $(TREE_FLOW_H) $(TREE_PASS_H) $(DIAGNOSTIC_H) \
> langhooks.h $(FLAGS_H) $(GIMPLE_H) $(GIMPLE_PRETTY_PRINT_H) $(EXPR_H) \
> - $(OPTABS_H)
> + $(OPTABS_H) tree-ssa-propagate.h
> tree-ssa-phiprop.o : tree-ssa-phiprop.c $(CONFIG_H) $(SYSTEM_H) coretypes.h
> \
> $(TM_H) $(TREE_H) $(TM_P_H) $(BASIC_BLOCK_H) \
> $(TREE_FLOW_H) $(TREE_PASS_H) $(DIAGNOSTIC_H) \
> langhooks.h $(FLAGS_H) $(GIMPLE_PRETTY_PRINT_H)
> tree-ssa-ifcombine.o : tree-ssa-ifcombine.c $(CONFIG_H) $(SYSTEM_H) \
> coretypes.h $(TM_H) $(TREE_H) $(BASIC_BLOCK_H) \
> $(TREE_FLOW_H) $(TREE_PASS_H) $(DIAGNOSTIC_H) \
> $(TREE_PRETTY_PRINT_H)
> tree-ssa-phiopt.o : tree-ssa-phiopt.c $(CONFIG_H) $(SYSTEM_H) coretypes.h \
> $(TM_H) $(GGC_H) $(TREE_H) $(TM_P_H) $(BASIC_BLOCK_H) \
> Index: tree-ssa-forwprop.c
> ===================================================================
> --- tree-ssa-forwprop.c (revision 191644)
> +++ tree-ssa-forwprop.c (working copy)
> @@ -27,20 +27,21 @@ along with GCC; see the file COPYING3.
> #include "basic-block.h"
> #include "gimple-pretty-print.h"
> #include "tree-flow.h"
> #include "tree-pass.h"
> #include "langhooks.h"
> #include "flags.h"
> #include "gimple.h"
> #include "expr.h"
> #include "cfgloop.h"
> #include "optabs.h"
> +#include "tree-ssa-propagate.h"
>
> /* This pass propagates the RHS of assignment statements into use
> sites of the LHS of the assignment. It's basically a specialized
> form of tree combination. It is hoped all of this can disappear
> when we have a generalized tree combiner.
>
> One class of common cases we handle is forward propagating a single use
> variable into a COND_EXPR.
>
> bb0:
> @@ -2575,39 +2576,49 @@ simplify_bitfield_ref (gimple_stmt_itera
> enum tree_code code;
>
> op = gimple_assign_rhs1 (stmt);
> gcc_checking_assert (TREE_CODE (op) == BIT_FIELD_REF);
>
> op0 = TREE_OPERAND (op, 0);
> if (TREE_CODE (op0) != SSA_NAME
> || TREE_CODE (TREE_TYPE (op0)) != VECTOR_TYPE)
> return false;
>
> + def_stmt = get_prop_source_stmt (op0, false, NULL);
> + if (!def_stmt || !can_propagate_from (def_stmt))
> + return false;
> +
> + op1 = TREE_OPERAND (op, 1);
> + op2 = TREE_OPERAND (op, 2);
> + code = gimple_assign_rhs_code (def_stmt);
> +
> + if (code == CONSTRUCTOR)
> + {
> + tree tem = fold_ternary (BIT_FIELD_REF, TREE_TYPE (op),
> + gimple_assign_rhs1 (def_stmt), op1, op2);
> + if (!tem || !valid_gimple_rhs_p (tem))
> + return false;
> + gimple_assign_set_rhs_from_tree (gsi, tem);
> + update_stmt (gsi_stmt (*gsi));
> + return true;
> + }
> +
> elem_type = TREE_TYPE (TREE_TYPE (op0));
> if (TREE_TYPE (op) != elem_type)
> return false;
>
> size = TREE_INT_CST_LOW (TYPE_SIZE (elem_type));
> - op1 = TREE_OPERAND (op, 1);
> n = TREE_INT_CST_LOW (op1) / size;
> if (n != 1)
> return false;
> -
> - def_stmt = get_prop_source_stmt (op0, false, NULL);
> - if (!def_stmt || !can_propagate_from (def_stmt))
> - return false;
> -
> - op2 = TREE_OPERAND (op, 2);
> idx = TREE_INT_CST_LOW (op2) / size;
>
> - code = gimple_assign_rhs_code (def_stmt);
> -
> if (code == VEC_PERM_EXPR)
> {
> tree p, m, index, tem;
> unsigned nelts;
> m = gimple_assign_rhs3 (def_stmt);
> if (TREE_CODE (m) != VECTOR_CST)
> return false;
> nelts = VECTOR_CST_NELTS (m);
> idx = TREE_INT_CST_LOW (VECTOR_CST_ELT (m, idx));
> idx %= 2 * nelts;
> Index: testsuite/gcc.dg/tree-ssa/forwprop-23.c
> ===================================================================
> --- testsuite/gcc.dg/tree-ssa/forwprop-23.c (revision 0)
> +++ testsuite/gcc.dg/tree-ssa/forwprop-23.c (revision 0)
> @@ -0,0 +1,15 @@
> +/* { dg-do compile } */
> +/* { dg-options "-O -fdump-tree-forwprop1" } */
> +
> +typedef long vec __attribute__ ((vector_size (2 * sizeof (long))));
> +
> +long f (long d, long e)
> +{
> + vec x = { d, e };
> + vec m = { 1, 0 };
> + return __builtin_shuffle (x, m) [1];
> +}
> +
> +
> +/* { dg-final { scan-tree-dump-not "BIT_FIELD_REF" "forwprop1" } } */
> +/* { dg-final { cleanup-tree-dump "forwprop1" } } */
>
> Property changes on: testsuite/gcc.dg/tree-ssa/forwprop-23.c
> ___________________________________________________________________
> Added: svn:keywords
> + Author Date Id Revision URL
> Added: svn:eol-style
> + native
>
>
