Jakub Jelinek <ja...@redhat.com> wrote:
>On Thu, Jan 16, 2014 at 09:40:24AM +0100, Richard Biener wrote:
>> That should be enough I think (we can't hoist PHIs anyway).
>
>Ok, here is what I've finally successfully bootstrapped/regtested
>on x86_64-linux and i686-linux, ok for trunk?
Ok.
Thanks,
Richard.
>2014-01-16 Jakub Jelinek <ja...@redhat.com>
>
> * tree-vectorizer.h (struct _loop_vec_info): Add no_data_dependencies
> field.
> (LOOP_VINFO_NO_DATA_DEPENDENCIES): Define.
> * tree-vect-data-refs.c (vect_analyze_data_ref_dependence): Clear it
> when not giving up or versioning for alias only because of
> loop->safelen.
> (vect_analyze_data_ref_dependences): Set to true.
> * tree-vect-stmts.c (hoist_defs_of_uses): Return false if def_stmt
> is a GIMPLE_PHI.
> (vectorizable_load): Use LOOP_VINFO_NO_DATA_DEPENDENCIES instead of
> LOOP_REQUIRES_VERSIONING_FOR_ALIAS, add && !nested_in_vect_loop
> to the condition.
>
>--- gcc/tree-vectorizer.h.jj 2014-01-15 08:11:18.903449194 +0100
>+++ gcc/tree-vectorizer.h 2014-01-16 16:01:48.892476417 +0100
>@@ -347,6 +347,25 @@ typedef struct _loop_vec_info {
> fix it up. */
> bool operands_swapped;
>
>+ /* True if there are no loop carried data dependencies in the loop.
>+ If loop->safelen <= 1, then this is always true, either the loop
>+ didn't have any loop carried data dependencies, or the loop is
>being
>+ vectorized guarded with some runtime alias checks, or couldn't
>+ be vectorized at all, but then this field shouldn't be used.
>+ For loop->safelen >= 2, the user has asserted that there are no
>+ backward dependencies, but there still could be loop carried
>forward
>+ dependencies in such loops. This flag will be false if normal
>+ vectorizer data dependency analysis would fail or require
>versioning
>+ for alias, but because of loop->safelen >= 2 it has been
>vectorized
>+ even without versioning for alias. E.g. in:
>+ #pragma omp simd
>+ for (int i = 0; i < m; i++)
>+ a[i] = a[i + k] * c;
>+ (or #pragma simd or #pragma ivdep) we can vectorize this and it
>will
>+ DTRT even for k > 0 && k < m, but without safelen we would not
>+ vectorize this, so this field would be false. */
>+ bool no_data_dependencies;
>+
> /* If if-conversion versioned this loop before conversion, this is the
> loop version without if-conversion. */
> struct loop *scalar_loop;
>@@ -385,6 +404,7 @@ typedef struct _loop_vec_info {
> #define LOOP_VINFO_PEELING_FOR_GAPS(L) (L)->peeling_for_gaps
> #define LOOP_VINFO_OPERANDS_SWAPPED(L) (L)->operands_swapped
> #define LOOP_VINFO_PEELING_FOR_NITER(L) (L)->peeling_for_niter
>+#define LOOP_VINFO_NO_DATA_DEPENDENCIES(L) (L)->no_data_dependencies
> #define LOOP_VINFO_SCALAR_LOOP(L) (L)->scalar_loop
>
> #define LOOP_REQUIRES_VERSIONING_FOR_ALIGNMENT(L) \
>--- gcc/tree-vect-data-refs.c.jj 2014-01-15 08:11:22.593430265 +0100
>+++ gcc/tree-vect-data-refs.c 2014-01-16 16:01:48.916476273 +0100
>@@ -244,6 +244,7 @@ vect_analyze_data_ref_dependence (struct
> {
> if (loop->safelen < *max_vf)
> *max_vf = loop->safelen;
>+ LOOP_VINFO_NO_DATA_DEPENDENCIES (loop_vinfo) = false;
> return false;
> }
>
>@@ -291,6 +292,7 @@ vect_analyze_data_ref_dependence (struct
> {
> if (loop->safelen < *max_vf)
> *max_vf = loop->safelen;
>+ LOOP_VINFO_NO_DATA_DEPENDENCIES (loop_vinfo) = false;
> return false;
> }
>
>@@ -447,6 +449,7 @@ vect_analyze_data_ref_dependences (loop_
> dump_printf_loc (MSG_NOTE, vect_location,
> "=== vect_analyze_data_ref_dependences ===\n");
>
>+ LOOP_VINFO_NO_DATA_DEPENDENCIES (loop_vinfo) = true;
> if (!compute_all_dependences (LOOP_VINFO_DATAREFS (loop_vinfo),
> &LOOP_VINFO_DDRS (loop_vinfo),
> LOOP_VINFO_LOOP_NEST (loop_vinfo), true))
>--- gcc/tree-vect-stmts.c.jj 2014-01-16 09:41:19.534630044 +0100
>+++ gcc/tree-vect-stmts.c 2014-01-16 16:03:50.948856799 +0100
>@@ -5504,6 +5504,8 @@ hoist_defs_of_uses (gimple stmt, struct
> dependencies within them. */
> tree op2;
> ssa_op_iter i2;
>+ if (gimple_code (def_stmt) == GIMPLE_PHI)
>+ return false;
> FOR_EACH_SSA_TREE_OPERAND (op2, def_stmt, i2, SSA_OP_USE)
> {
> gimple def_stmt2 = SSA_NAME_DEF_STMT (op2);
>@@ -6434,10 +6436,12 @@ vectorizable_load (gimple stmt, gimple_s
> if (inv_p && !bb_vinfo)
> {
> gcc_assert (!grouped_load);
>- /* If we have versioned for aliasing then we are sure
>- this is a loop invariant load and thus we can insert
>- it on the preheader edge. */
>- if (LOOP_REQUIRES_VERSIONING_FOR_ALIAS (loop_vinfo)
>+ /* If we have versioned for aliasing or the loop doesn't
>+ have any data dependencies that would preclude this,
>+ then we are sure this is a loop invariant load and
>+ thus we can insert it on the preheader edge. */
>+ if (LOOP_VINFO_NO_DATA_DEPENDENCIES (loop_vinfo)
>+ && !nested_in_vect_loop
> && hoist_defs_of_uses (stmt, loop))
> {
> if (dump_enabled_p ())
>
>
> Jakub
