From 832b4117d4068670cc9ed496a7ab06104a12dc00 Mon Sep 17 00:00:00 2001 From: Richard Sandiford Date: Mon, 3 Jul 2017 13:36:45 +0000 Subject: [PATCH] Add DR_STEP_ALIGNMENT A later patch adds base alignment information to innermost_loop_behavior. After that, the only remaining piece of alignment information that wasn't immediately obvious was the step alignment. Adding that allows a minor simplification to vect_compute_data_ref_alignment, and also potentially improves the handling of variable strides for outer loop vectorisation. A later patch will also use it to give the alignment of the DR as a whole. 2017-07-03 Richard Sandiford gcc/ * tree-data-ref.h (innermost_loop_behavior): Add a step_alignment field. (DR_STEP_ALIGNMENT): New macro. * tree-vectorizer.h (STMT_VINFO_DR_STEP_ALIGNMENT): Likewise. * tree-data-ref.c (dr_analyze_innermost): Initalize step_alignment. (create_data_ref): Print it. * tree-vect-stmts.c (vectorizable_load): Use the step alignment to tell whether the step preserves vector (mis)alignment. * tree-vect-data-refs.c (vect_compute_data_ref_alignment): Likewise. Move the check for an integer step and generalise to all INTEGER_CST. (vect_analyze_data_refs): Set DR_STEP_ALIGNMENT when setting DR_STEP. Print the outer step alignment. From-SVN: r249915 --- gcc/ChangeLog | 15 +++++++++++++++ gcc/tree-data-ref.c | 2 ++ gcc/tree-data-ref.h | 4 ++++ gcc/tree-vect-data-refs.c | 20 ++++++++++++-------- gcc/tree-vect-stmts.c | 3 +-- gcc/tree-vectorizer.h | 2 ++ 6 files changed, 36 insertions(+), 10 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index b063bb49ebe..42a8bc0bf90 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,18 @@ +2017-07-03 Richard Sandiford + + * tree-data-ref.h (innermost_loop_behavior): Add a step_alignment + field. + (DR_STEP_ALIGNMENT): New macro. + * tree-vectorizer.h (STMT_VINFO_DR_STEP_ALIGNMENT): Likewise. + * tree-data-ref.c (dr_analyze_innermost): Initalize step_alignment. + (create_data_ref): Print it. + * tree-vect-stmts.c (vectorizable_load): Use the step alignment + to tell whether the step preserves vector (mis)alignment. + * tree-vect-data-refs.c (vect_compute_data_ref_alignment): Likewise. + Move the check for an integer step and generalise to all INTEGER_CST. + (vect_analyze_data_refs): Set DR_STEP_ALIGNMENT when setting DR_STEP. + Print the outer step alignment. + 2017-07-03 Richard Sandiford * tree-data-ref.h (innermost_loop_behavior): Replace aligned_to diff --git a/gcc/tree-data-ref.c b/gcc/tree-data-ref.c index c5cf0acabae..03dfb204685 100644 --- a/gcc/tree-data-ref.c +++ b/gcc/tree-data-ref.c @@ -870,6 +870,7 @@ dr_analyze_innermost (innermost_loop_behavior *drb, tree ref, drb->init = init; drb->step = step; drb->offset_alignment = highest_pow2_factor (offset_iv.base); + drb->step_alignment = highest_pow2_factor (step); if (dump_file && (dump_flags & TDF_DETAILS)) fprintf (dump_file, "success.\n"); @@ -1086,6 +1087,7 @@ create_data_ref (loop_p nest, loop_p loop, tree memref, gimple *stmt, print_generic_expr (dump_file, DR_STEP (dr), TDF_SLIM); fprintf (dump_file, "\n\toffset alignment: %d", DR_OFFSET_ALIGNMENT (dr)); + fprintf (dump_file, "\n\tstep alignment: %d", DR_STEP_ALIGNMENT (dr)); fprintf (dump_file, "\n\tbase_object: "); print_generic_expr (dump_file, DR_BASE_OBJECT (dr), TDF_SLIM); fprintf (dump_file, "\n"); diff --git a/gcc/tree-data-ref.h b/gcc/tree-data-ref.h index 45ecf9bc172..3a5068d3a1f 100644 --- a/gcc/tree-data-ref.h +++ b/gcc/tree-data-ref.h @@ -56,6 +56,9 @@ struct innermost_loop_behavior high value if the offset is zero. This is a byte rather than a bit quantity. */ unsigned int offset_alignment; + + /* Likewise for STEP. */ + unsigned int step_alignment; }; /* Describes the evolutions of indices of the memory reference. The indices @@ -145,6 +148,7 @@ struct data_reference #define DR_STEP(DR) (DR)->innermost.step #define DR_PTR_INFO(DR) (DR)->alias.ptr_info #define DR_OFFSET_ALIGNMENT(DR) (DR)->innermost.offset_alignment +#define DR_STEP_ALIGNMENT(DR) (DR)->innermost.step_alignment #define DR_INNERMOST(DR) (DR)->innermost typedef struct data_reference *data_reference_p; diff --git a/gcc/tree-vect-data-refs.c b/gcc/tree-vect-data-refs.c index 091771cedbc..9ee53ec9879 100644 --- a/gcc/tree-vect-data-refs.c +++ b/gcc/tree-vect-data-refs.c @@ -698,10 +698,9 @@ vect_compute_data_ref_alignment (struct data_reference *dr) divides by the vector size. */ else if (nested_in_vect_loop_p (loop, stmt)) { - tree step = DR_STEP (dr); step_preserves_misalignment_p - = (tree_fits_shwi_p (step) - && tree_to_shwi (step) % GET_MODE_SIZE (TYPE_MODE (vectype)) == 0); + = (DR_STEP_ALIGNMENT (dr) + % GET_MODE_SIZE (TYPE_MODE (vectype))) == 0; if (dump_enabled_p ()) { @@ -720,12 +719,10 @@ vect_compute_data_ref_alignment (struct data_reference *dr) the dataref evenly divides by the vector size. */ else { - tree step = DR_STEP (dr); unsigned vf = LOOP_VINFO_VECT_FACTOR (loop_vinfo); step_preserves_misalignment_p - = (tree_fits_shwi_p (step) - && ((tree_to_shwi (step) * vf) - % GET_MODE_SIZE (TYPE_MODE (vectype)) == 0)); + = ((DR_STEP_ALIGNMENT (dr) * vf) + % GET_MODE_SIZE (TYPE_MODE (vectype))) == 0; if (!step_preserves_misalignment_p && dump_enabled_p ()) dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, @@ -773,7 +770,10 @@ vect_compute_data_ref_alignment (struct data_reference *dr) alignment = TYPE_ALIGN_UNIT (vectype); if (drb->offset_alignment < alignment - || !step_preserves_misalignment_p) + || !step_preserves_misalignment_p + /* We need to know whether the step wrt the vectorized loop is + negative when computing the starting misalignment below. */ + || TREE_CODE (drb->step) != INTEGER_CST) { if (dump_enabled_p ()) { @@ -3414,6 +3414,8 @@ again: DR_STEP (newdr) = step; DR_OFFSET_ALIGNMENT (newdr) = BIGGEST_ALIGNMENT; + DR_STEP_ALIGNMENT (newdr) + = highest_pow2_factor (step); dr = newdr; simd_lane_access = true; } @@ -3665,6 +3667,8 @@ again: STMT_VINFO_DR_STEP (stmt_info)); dump_printf (MSG_NOTE, "\n\touter offset alignment: %d\n", STMT_VINFO_DR_OFFSET_ALIGNMENT (stmt_info)); + dump_printf (MSG_NOTE, "\n\touter step alignment: %d\n", + STMT_VINFO_DR_STEP_ALIGNMENT (stmt_info)); } } diff --git a/gcc/tree-vect-stmts.c b/gcc/tree-vect-stmts.c index 1067421d575..f01f297eaeb 100644 --- a/gcc/tree-vect-stmts.c +++ b/gcc/tree-vect-stmts.c @@ -7288,8 +7288,7 @@ vectorizable_load (gimple *stmt, gimple_stmt_iterator *gsi, gimple **vec_stmt, nested within an outer-loop that is being vectorized. */ if (nested_in_vect_loop - && (TREE_INT_CST_LOW (DR_STEP (dr)) - % GET_MODE_SIZE (TYPE_MODE (vectype)) != 0)) + && (DR_STEP_ALIGNMENT (dr) % GET_MODE_SIZE (TYPE_MODE (vectype))) != 0) { gcc_assert (alignment_support_scheme != dr_explicit_realign_optimized); compute_in_loop = true; diff --git a/gcc/tree-vectorizer.h b/gcc/tree-vectorizer.h index 15f5dc3a925..fba5151654d 100644 --- a/gcc/tree-vectorizer.h +++ b/gcc/tree-vectorizer.h @@ -711,6 +711,8 @@ STMT_VINFO_BB_VINFO (stmt_vec_info stmt_vinfo) #define STMT_VINFO_DR_STEP(S) (S)->dr_wrt_vec_loop.step #define STMT_VINFO_DR_OFFSET_ALIGNMENT(S) \ (S)->dr_wrt_vec_loop.offset_alignment +#define STMT_VINFO_DR_STEP_ALIGNMENT(S) \ + (S)->dr_wrt_vec_loop.step_alignment #define STMT_VINFO_IN_PATTERN_P(S) (S)->in_pattern_p #define STMT_VINFO_RELATED_STMT(S) (S)->related_stmt -- 2.30.2