| Message ID | 20240301091735.8BBBD13A39@imap2.dmz-prg2.suse.org |
|---|---|
| State | New |
| Headers | show |
| Series | Allow patterns in SLP reductions | expand |
On Fri, Mar 1, 2024 at 10:21 AM Richard Biener <rguenther@suse.de> wrote: > > The following removes the over-broad rejection of patterns for SLP > reductions which is done by removing them from LOOP_VINFO_REDUCTIONS > during pattern detection. That's also insufficient in case the > pattern only appears on the reduction path. Instead this implements > the proper correctness check in vectorizable_reduction and guides > SLP discovery to heuristically avoid forming later invalid groups. > > I also couldn't find any testcase that FAILs when allowing the SLP > reductions to form so I've added one. > > I came across this for single-lane SLP reductions with the all-SLP > work where we rely on patterns to properly vectorize COND_EXPR > reductions. > > Bootstrapped and tested on x86_64-unknown-linux-gnu, queued for stage1. Re-bootstrapped/tested, r15-361-g52d4691294c847 Richard. > Richard. > > * tree-vect-patterns.cc (vect_pattern_recog_1): Do not > remove reductions involving patterns. > * tree-vect-loop.cc (vectorizable_reduction): Reject SLP > reduction groups with multiple lane-reducing reductions. > * tree-vect-slp.cc (vect_analyze_slp_instance): When discovering > SLP reduction groups avoid including lane-reducing ones. > > * gcc.dg/vect/vect-reduc-sad-9.c: New testcase. > --- > gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c | 68 ++++++++++++++++++++ > gcc/tree-vect-loop.cc | 15 +++++ > gcc/tree-vect-patterns.cc | 13 ---- > gcc/tree-vect-slp.cc | 26 +++++--- > 4 files changed, 101 insertions(+), 21 deletions(-) > create mode 100644 gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > > diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > new file mode 100644 > index 00000000000..3c6af4510f4 > --- /dev/null > +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > @@ -0,0 +1,68 @@ > +/* Disabling epilogues until we find a better way to deal with scans. */ > +/* { dg-additional-options "--param vect-epilogues-nomask=0" } */ > +/* { dg-additional-options "-msse4.2" { target { x86_64-*-* i?86-*-* } } } */ > +/* { dg-require-effective-target vect_usad_char } */ > + > +#include <stdarg.h> > +#include "tree-vect.h" > + > +#define N 64 > + > +unsigned char X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))); > +unsigned char Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))); > +int abs (int); > + > +/* Sum of absolute differences between arrays of unsigned char types. > + Detected as a sad pattern. > + Vectorized on targets that support sad for unsigned chars. */ > + > +__attribute__ ((noinline)) int > +foo (int len, int *res2) > +{ > + int i; > + int result = 0; > + int result2 = 0; > + > + for (i = 0; i < len; i++) > + { > + /* Make sure we are not using an SLP reduction for this. */ > + result += abs (X[2*i] - Y[2*i]); > + result2 += abs (X[2*i + 1] - Y[2*i + 1]); > + } > + > + *res2 = result2; > + return result; > +} > + > + > +int > +main (void) > +{ > + int i; > + int sad; > + > + check_vect (); > + > + for (i = 0; i < N/2; i++) > + { > + X[2*i] = i; > + Y[2*i] = N/2 - i; > + X[2*i+1] = i; > + Y[2*i+1] = 0; > + __asm__ volatile (""); > + } > + > + > + int sad2; > + sad = foo (N/2, &sad2); > + if (sad != (N/2)*(N/4)) > + abort (); > + if (sad2 != (N/2-1)*(N/2)/2) > + abort (); > + > + return 0; > +} > + > +/* { dg-final { scan-tree-dump "vect_recog_sad_pattern: detected" "vect" } } */ > +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */ > + > diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc > index 35f1f8c7d42..13dcdba403a 100644 > --- a/gcc/tree-vect-loop.cc > +++ b/gcc/tree-vect-loop.cc > @@ -7703,6 +7703,21 @@ vectorizable_reduction (loop_vec_info loop_vinfo, > return false; > } > > + /* Lane-reducing ops also never can be used in a SLP reduction group > + since we'll mix lanes belonging to different reductions. But it's > + OK to use them in a reduction chain or when the reduction group > + has just one element. */ > + if (lane_reduc_code_p > + && slp_node > + && !REDUC_GROUP_FIRST_ELEMENT (stmt_info) > + && SLP_TREE_LANES (slp_node) > 1) > + { > + if (dump_enabled_p ()) > + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, > + "lane-reducing reduction in reduction group.\n"); > + return false; > + } > + > /* All uses but the last are expected to be defined in the loop. > The last use is the reduction variable. In case of nested cycle this > assumption is not true: we use reduc_index to record the index of the > diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc > index d562f57920f..fe1ffba8688 100644 > --- a/gcc/tree-vect-patterns.cc > +++ b/gcc/tree-vect-patterns.cc > @@ -7172,7 +7172,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > vect_recog_func *recog_func, stmt_vec_info stmt_info) > { > gimple *pattern_stmt; > - loop_vec_info loop_vinfo; > tree pattern_vectype; > > /* If this statement has already been replaced with pattern statements, > @@ -7198,8 +7197,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > return; > } > > - loop_vinfo = dyn_cast <loop_vec_info> (vinfo); > - > /* Found a vectorizable pattern. */ > if (dump_enabled_p ()) > dump_printf_loc (MSG_NOTE, vect_location, > @@ -7208,16 +7205,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > > /* Mark the stmts that are involved in the pattern. */ > vect_mark_pattern_stmts (vinfo, stmt_info, pattern_stmt, pattern_vectype); > - > - /* Patterns cannot be vectorized using SLP, because they change the order of > - computation. */ > - if (loop_vinfo) > - { > - unsigned ix, ix2; > - stmt_vec_info *elem_ptr; > - VEC_ORDERED_REMOVE_IF (LOOP_VINFO_REDUCTIONS (loop_vinfo), ix, ix2, > - elem_ptr, *elem_ptr == stmt_info); > - } > } > > > diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc > index dabd8407aaf..d9961945c1c 100644 > --- a/gcc/tree-vect-slp.cc > +++ b/gcc/tree-vect-slp.cc > @@ -3597,14 +3597,24 @@ vect_analyze_slp_instance (vec_info *vinfo, > = as_a <loop_vec_info> (vinfo)->reductions; > scalar_stmts.create (reductions.length ()); > for (i = 0; reductions.iterate (i, &next_info); i++) > - if ((STMT_VINFO_RELEVANT_P (next_info) > - || STMT_VINFO_LIVE_P (next_info)) > - /* ??? Make sure we didn't skip a conversion around a reduction > - path. In that case we'd have to reverse engineer that conversion > - stmt following the chain using reduc_idx and from the PHI > - using reduc_def. */ > - && STMT_VINFO_DEF_TYPE (next_info) == vect_reduction_def) > - scalar_stmts.quick_push (next_info); > + { > + gassign *g; > + next_info = vect_stmt_to_vectorize (next_info); > + if ((STMT_VINFO_RELEVANT_P (next_info) > + || STMT_VINFO_LIVE_P (next_info)) > + /* ??? Make sure we didn't skip a conversion around a reduction > + path. In that case we'd have to reverse engineer that > + conversion stmt following the chain using reduc_idx and from > + the PHI using reduc_def. */ > + && STMT_VINFO_DEF_TYPE (next_info) == vect_reduction_def > + /* Do not discover SLP reductions for lane-reducing ops, that > + will fail later. */ > + && (!(g = dyn_cast <gassign *> (STMT_VINFO_STMT (next_info))) > + || (gimple_assign_rhs_code (g) != DOT_PROD_EXPR > + && gimple_assign_rhs_code (g) != WIDEN_SUM_EXPR > + && gimple_assign_rhs_code (g) != SAD_EXPR))) > + scalar_stmts.quick_push (next_info); > + } > /* If less than two were relevant/live there's nothing to SLP. */ > if (scalar_stmts.length () < 2) > return false; > -- > 2.35.3
> -----Original Message----- > From: Richard Biener <richard.guenther@gmail.com> > Sent: Friday, May 10, 2024 2:07 PM > To: Richard Biener <rguenther@suse.de> > Cc: gcc-patches@gcc.gnu.org > Subject: Re: [PATCH] Allow patterns in SLP reductions > > On Fri, Mar 1, 2024 at 10:21 AM Richard Biener <rguenther@suse.de> wrote: > > > > The following removes the over-broad rejection of patterns for SLP > > reductions which is done by removing them from LOOP_VINFO_REDUCTIONS > > during pattern detection. That's also insufficient in case the > > pattern only appears on the reduction path. Instead this implements > > the proper correctness check in vectorizable_reduction and guides > > SLP discovery to heuristically avoid forming later invalid groups. > > > > I also couldn't find any testcase that FAILs when allowing the SLP > > reductions to form so I've added one. > > > > I came across this for single-lane SLP reductions with the all-SLP > > work where we rely on patterns to properly vectorize COND_EXPR > > reductions. > > > > Bootstrapped and tested on x86_64-unknown-linux-gnu, queued for stage1. > > Re-bootstrapped/tested, r15-361-g52d4691294c847 Awesome! Does this now allow us to write new reductions using patterns? i.e. widening reductions? Cheers, Tamar > > Richard. > > > Richard. > > > > * tree-vect-patterns.cc (vect_pattern_recog_1): Do not > > remove reductions involving patterns. > > * tree-vect-loop.cc (vectorizable_reduction): Reject SLP > > reduction groups with multiple lane-reducing reductions. > > * tree-vect-slp.cc (vect_analyze_slp_instance): When discovering > > SLP reduction groups avoid including lane-reducing ones. > > > > * gcc.dg/vect/vect-reduc-sad-9.c: New testcase. > > --- > > gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c | 68 ++++++++++++++++++++ > > gcc/tree-vect-loop.cc | 15 +++++ > > gcc/tree-vect-patterns.cc | 13 ---- > > gcc/tree-vect-slp.cc | 26 +++++--- > > 4 files changed, 101 insertions(+), 21 deletions(-) > > create mode 100644 gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > > > > diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > b/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > > new file mode 100644 > > index 00000000000..3c6af4510f4 > > --- /dev/null > > +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > > @@ -0,0 +1,68 @@ > > +/* Disabling epilogues until we find a better way to deal with scans. */ > > +/* { dg-additional-options "--param vect-epilogues-nomask=0" } */ > > +/* { dg-additional-options "-msse4.2" { target { x86_64-*-* i?86-*-* } } } */ > > +/* { dg-require-effective-target vect_usad_char } */ > > + > > +#include <stdarg.h> > > +#include "tree-vect.h" > > + > > +#define N 64 > > + > > +unsigned char X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))); > > +unsigned char Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))); > > +int abs (int); > > + > > +/* Sum of absolute differences between arrays of unsigned char types. > > + Detected as a sad pattern. > > + Vectorized on targets that support sad for unsigned chars. */ > > + > > +__attribute__ ((noinline)) int > > +foo (int len, int *res2) > > +{ > > + int i; > > + int result = 0; > > + int result2 = 0; > > + > > + for (i = 0; i < len; i++) > > + { > > + /* Make sure we are not using an SLP reduction for this. */ > > + result += abs (X[2*i] - Y[2*i]); > > + result2 += abs (X[2*i + 1] - Y[2*i + 1]); > > + } > > + > > + *res2 = result2; > > + return result; > > +} > > + > > + > > +int > > +main (void) > > +{ > > + int i; > > + int sad; > > + > > + check_vect (); > > + > > + for (i = 0; i < N/2; i++) > > + { > > + X[2*i] = i; > > + Y[2*i] = N/2 - i; > > + X[2*i+1] = i; > > + Y[2*i+1] = 0; > > + __asm__ volatile (""); > > + } > > + > > + > > + int sad2; > > + sad = foo (N/2, &sad2); > > + if (sad != (N/2)*(N/4)) > > + abort (); > > + if (sad2 != (N/2-1)*(N/2)/2) > > + abort (); > > + > > + return 0; > > +} > > + > > +/* { dg-final { scan-tree-dump "vect_recog_sad_pattern: detected" "vect" } } */ > > +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */ > > + > > diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc > > index 35f1f8c7d42..13dcdba403a 100644 > > --- a/gcc/tree-vect-loop.cc > > +++ b/gcc/tree-vect-loop.cc > > @@ -7703,6 +7703,21 @@ vectorizable_reduction (loop_vec_info loop_vinfo, > > return false; > > } > > > > + /* Lane-reducing ops also never can be used in a SLP reduction group > > + since we'll mix lanes belonging to different reductions. But it's > > + OK to use them in a reduction chain or when the reduction group > > + has just one element. */ > > + if (lane_reduc_code_p > > + && slp_node > > + && !REDUC_GROUP_FIRST_ELEMENT (stmt_info) > > + && SLP_TREE_LANES (slp_node) > 1) > > + { > > + if (dump_enabled_p ()) > > + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, > > + "lane-reducing reduction in reduction group.\n"); > > + return false; > > + } > > + > > /* All uses but the last are expected to be defined in the loop. > > The last use is the reduction variable. In case of nested cycle this > > assumption is not true: we use reduc_index to record the index of the > > diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc > > index d562f57920f..fe1ffba8688 100644 > > --- a/gcc/tree-vect-patterns.cc > > +++ b/gcc/tree-vect-patterns.cc > > @@ -7172,7 +7172,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > > vect_recog_func *recog_func, stmt_vec_info stmt_info) > > { > > gimple *pattern_stmt; > > - loop_vec_info loop_vinfo; > > tree pattern_vectype; > > > > /* If this statement has already been replaced with pattern statements, > > @@ -7198,8 +7197,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > > return; > > } > > > > - loop_vinfo = dyn_cast <loop_vec_info> (vinfo); > > - > > /* Found a vectorizable pattern. */ > > if (dump_enabled_p ()) > > dump_printf_loc (MSG_NOTE, vect_location, > > @@ -7208,16 +7205,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > > > > /* Mark the stmts that are involved in the pattern. */ > > vect_mark_pattern_stmts (vinfo, stmt_info, pattern_stmt, pattern_vectype); > > - > > - /* Patterns cannot be vectorized using SLP, because they change the order of > > - computation. */ > > - if (loop_vinfo) > > - { > > - unsigned ix, ix2; > > - stmt_vec_info *elem_ptr; > > - VEC_ORDERED_REMOVE_IF (LOOP_VINFO_REDUCTIONS (loop_vinfo), ix, > ix2, > > - elem_ptr, *elem_ptr == stmt_info); > > - } > > } > > > > > > diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc > > index dabd8407aaf..d9961945c1c 100644 > > --- a/gcc/tree-vect-slp.cc > > +++ b/gcc/tree-vect-slp.cc > > @@ -3597,14 +3597,24 @@ vect_analyze_slp_instance (vec_info *vinfo, > > = as_a <loop_vec_info> (vinfo)->reductions; > > scalar_stmts.create (reductions.length ()); > > for (i = 0; reductions.iterate (i, &next_info); i++) > > - if ((STMT_VINFO_RELEVANT_P (next_info) > > - || STMT_VINFO_LIVE_P (next_info)) > > - /* ??? Make sure we didn't skip a conversion around a reduction > > - path. In that case we'd have to reverse engineer that conversion > > - stmt following the chain using reduc_idx and from the PHI > > - using reduc_def. */ > > - && STMT_VINFO_DEF_TYPE (next_info) == vect_reduction_def) > > - scalar_stmts.quick_push (next_info); > > + { > > + gassign *g; > > + next_info = vect_stmt_to_vectorize (next_info); > > + if ((STMT_VINFO_RELEVANT_P (next_info) > > + || STMT_VINFO_LIVE_P (next_info)) > > + /* ??? Make sure we didn't skip a conversion around a reduction > > + path. In that case we'd have to reverse engineer that > > + conversion stmt following the chain using reduc_idx and from > > + the PHI using reduc_def. */ > > + && STMT_VINFO_DEF_TYPE (next_info) == vect_reduction_def > > + /* Do not discover SLP reductions for lane-reducing ops, that > > + will fail later. */ > > + && (!(g = dyn_cast <gassign *> (STMT_VINFO_STMT (next_info))) > > + || (gimple_assign_rhs_code (g) != DOT_PROD_EXPR > > + && gimple_assign_rhs_code (g) != WIDEN_SUM_EXPR > > + && gimple_assign_rhs_code (g) != SAD_EXPR))) > > + scalar_stmts.quick_push (next_info); > > + } > > /* If less than two were relevant/live there's nothing to SLP. */ > > if (scalar_stmts.length () < 2) > > return false; > > -- > > 2.35.3
On Mon, 13 May 2024, Tamar Christina wrote: > > -----Original Message----- > > From: Richard Biener <richard.guenther@gmail.com> > > Sent: Friday, May 10, 2024 2:07 PM > > To: Richard Biener <rguenther@suse.de> > > Cc: gcc-patches@gcc.gnu.org > > Subject: Re: [PATCH] Allow patterns in SLP reductions > > > > On Fri, Mar 1, 2024 at 10:21 AM Richard Biener <rguenther@suse.de> wrote: > > > > > > The following removes the over-broad rejection of patterns for SLP > > > reductions which is done by removing them from LOOP_VINFO_REDUCTIONS > > > during pattern detection. That's also insufficient in case the > > > pattern only appears on the reduction path. Instead this implements > > > the proper correctness check in vectorizable_reduction and guides > > > SLP discovery to heuristically avoid forming later invalid groups. > > > > > > I also couldn't find any testcase that FAILs when allowing the SLP > > > reductions to form so I've added one. > > > > > > I came across this for single-lane SLP reductions with the all-SLP > > > work where we rely on patterns to properly vectorize COND_EXPR > > > reductions. > > > > > > Bootstrapped and tested on x86_64-unknown-linux-gnu, queued for stage1. > > > > Re-bootstrapped/tested, r15-361-g52d4691294c847 > > Awesome! > > Does this now allow us to write new reductions using patterns? i.e. > widening reductions? Yes (SLP reductions, that is). This is really only for SLP reductions (not SLP reduction chains, not non-SLP reductions). So it's just a corner-case but since with SLP-only non-SLP reductions become SLP reductions with a single lane that was important to fix ;) Richard. > Cheers, > Tamar > > > > Richard. > > > > > Richard. > > > > > > * tree-vect-patterns.cc (vect_pattern_recog_1): Do not > > > remove reductions involving patterns. > > > * tree-vect-loop.cc (vectorizable_reduction): Reject SLP > > > reduction groups with multiple lane-reducing reductions. > > > * tree-vect-slp.cc (vect_analyze_slp_instance): When discovering > > > SLP reduction groups avoid including lane-reducing ones. > > > > > > * gcc.dg/vect/vect-reduc-sad-9.c: New testcase. > > > --- > > > gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c | 68 ++++++++++++++++++++ > > > gcc/tree-vect-loop.cc | 15 +++++ > > > gcc/tree-vect-patterns.cc | 13 ---- > > > gcc/tree-vect-slp.cc | 26 +++++--- > > > 4 files changed, 101 insertions(+), 21 deletions(-) > > > create mode 100644 gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > > > > > > diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > > b/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > > > new file mode 100644 > > > index 00000000000..3c6af4510f4 > > > --- /dev/null > > > +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c > > > @@ -0,0 +1,68 @@ > > > +/* Disabling epilogues until we find a better way to deal with scans. */ > > > +/* { dg-additional-options "--param vect-epilogues-nomask=0" } */ > > > +/* { dg-additional-options "-msse4.2" { target { x86_64-*-* i?86-*-* } } } */ > > > +/* { dg-require-effective-target vect_usad_char } */ > > > + > > > +#include <stdarg.h> > > > +#include "tree-vect.h" > > > + > > > +#define N 64 > > > + > > > +unsigned char X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))); > > > +unsigned char Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))); > > > +int abs (int); > > > + > > > +/* Sum of absolute differences between arrays of unsigned char types. > > > + Detected as a sad pattern. > > > + Vectorized on targets that support sad for unsigned chars. */ > > > + > > > +__attribute__ ((noinline)) int > > > +foo (int len, int *res2) > > > +{ > > > + int i; > > > + int result = 0; > > > + int result2 = 0; > > > + > > > + for (i = 0; i < len; i++) > > > + { > > > + /* Make sure we are not using an SLP reduction for this. */ > > > + result += abs (X[2*i] - Y[2*i]); > > > + result2 += abs (X[2*i + 1] - Y[2*i + 1]); > > > + } > > > + > > > + *res2 = result2; > > > + return result; > > > +} > > > + > > > + > > > +int > > > +main (void) > > > +{ > > > + int i; > > > + int sad; > > > + > > > + check_vect (); > > > + > > > + for (i = 0; i < N/2; i++) > > > + { > > > + X[2*i] = i; > > > + Y[2*i] = N/2 - i; > > > + X[2*i+1] = i; > > > + Y[2*i+1] = 0; > > > + __asm__ volatile (""); > > > + } > > > + > > > + > > > + int sad2; > > > + sad = foo (N/2, &sad2); > > > + if (sad != (N/2)*(N/4)) > > > + abort (); > > > + if (sad2 != (N/2-1)*(N/2)/2) > > > + abort (); > > > + > > > + return 0; > > > +} > > > + > > > +/* { dg-final { scan-tree-dump "vect_recog_sad_pattern: detected" "vect" } } */ > > > +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */ > > > + > > > diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc > > > index 35f1f8c7d42..13dcdba403a 100644 > > > --- a/gcc/tree-vect-loop.cc > > > +++ b/gcc/tree-vect-loop.cc > > > @@ -7703,6 +7703,21 @@ vectorizable_reduction (loop_vec_info loop_vinfo, > > > return false; > > > } > > > > > > + /* Lane-reducing ops also never can be used in a SLP reduction group > > > + since we'll mix lanes belonging to different reductions. But it's > > > + OK to use them in a reduction chain or when the reduction group > > > + has just one element. */ > > > + if (lane_reduc_code_p > > > + && slp_node > > > + && !REDUC_GROUP_FIRST_ELEMENT (stmt_info) > > > + && SLP_TREE_LANES (slp_node) > 1) > > > + { > > > + if (dump_enabled_p ()) > > > + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, > > > + "lane-reducing reduction in reduction group.\n"); > > > + return false; > > > + } > > > + > > > /* All uses but the last are expected to be defined in the loop. > > > The last use is the reduction variable. In case of nested cycle this > > > assumption is not true: we use reduc_index to record the index of the > > > diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc > > > index d562f57920f..fe1ffba8688 100644 > > > --- a/gcc/tree-vect-patterns.cc > > > +++ b/gcc/tree-vect-patterns.cc > > > @@ -7172,7 +7172,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > > > vect_recog_func *recog_func, stmt_vec_info stmt_info) > > > { > > > gimple *pattern_stmt; > > > - loop_vec_info loop_vinfo; > > > tree pattern_vectype; > > > > > > /* If this statement has already been replaced with pattern statements, > > > @@ -7198,8 +7197,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > > > return; > > > } > > > > > > - loop_vinfo = dyn_cast <loop_vec_info> (vinfo); > > > - > > > /* Found a vectorizable pattern. */ > > > if (dump_enabled_p ()) > > > dump_printf_loc (MSG_NOTE, vect_location, > > > @@ -7208,16 +7205,6 @@ vect_pattern_recog_1 (vec_info *vinfo, > > > > > > /* Mark the stmts that are involved in the pattern. */ > > > vect_mark_pattern_stmts (vinfo, stmt_info, pattern_stmt, pattern_vectype); > > > - > > > - /* Patterns cannot be vectorized using SLP, because they change the order of > > > - computation. */ > > > - if (loop_vinfo) > > > - { > > > - unsigned ix, ix2; > > > - stmt_vec_info *elem_ptr; > > > - VEC_ORDERED_REMOVE_IF (LOOP_VINFO_REDUCTIONS (loop_vinfo), ix, > > ix2, > > > - elem_ptr, *elem_ptr == stmt_info); > > > - } > > > } > > > > > > > > > diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc > > > index dabd8407aaf..d9961945c1c 100644 > > > --- a/gcc/tree-vect-slp.cc > > > +++ b/gcc/tree-vect-slp.cc > > > @@ -3597,14 +3597,24 @@ vect_analyze_slp_instance (vec_info *vinfo, > > > = as_a <loop_vec_info> (vinfo)->reductions; > > > scalar_stmts.create (reductions.length ()); > > > for (i = 0; reductions.iterate (i, &next_info); i++) > > > - if ((STMT_VINFO_RELEVANT_P (next_info) > > > - || STMT_VINFO_LIVE_P (next_info)) > > > - /* ??? Make sure we didn't skip a conversion around a reduction > > > - path. In that case we'd have to reverse engineer that conversion > > > - stmt following the chain using reduc_idx and from the PHI > > > - using reduc_def. */ > > > - && STMT_VINFO_DEF_TYPE (next_info) == vect_reduction_def) > > > - scalar_stmts.quick_push (next_info); > > > + { > > > + gassign *g; > > > + next_info = vect_stmt_to_vectorize (next_info); > > > + if ((STMT_VINFO_RELEVANT_P (next_info) > > > + || STMT_VINFO_LIVE_P (next_info)) > > > + /* ??? Make sure we didn't skip a conversion around a reduction > > > + path. In that case we'd have to reverse engineer that > > > + conversion stmt following the chain using reduc_idx and from > > > + the PHI using reduc_def. */ > > > + && STMT_VINFO_DEF_TYPE (next_info) == vect_reduction_def > > > + /* Do not discover SLP reductions for lane-reducing ops, that > > > + will fail later. */ > > > + && (!(g = dyn_cast <gassign *> (STMT_VINFO_STMT (next_info))) > > > + || (gimple_assign_rhs_code (g) != DOT_PROD_EXPR > > > + && gimple_assign_rhs_code (g) != WIDEN_SUM_EXPR > > > + && gimple_assign_rhs_code (g) != SAD_EXPR))) > > > + scalar_stmts.quick_push (next_info); > > > + } > > > /* If less than two were relevant/live there's nothing to SLP. */ > > > if (scalar_stmts.length () < 2) > > > return false; > > > -- > > > 2.35.3 >
diff --git a/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c b/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c new file mode 100644 index 00000000000..3c6af4510f4 --- /dev/null +++ b/gcc/testsuite/gcc.dg/vect/vect-reduc-sad-9.c @@ -0,0 +1,68 @@ +/* Disabling epilogues until we find a better way to deal with scans. */ +/* { dg-additional-options "--param vect-epilogues-nomask=0" } */ +/* { dg-additional-options "-msse4.2" { target { x86_64-*-* i?86-*-* } } } */ +/* { dg-require-effective-target vect_usad_char } */ + +#include <stdarg.h> +#include "tree-vect.h" + +#define N 64 + +unsigned char X[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))); +unsigned char Y[N] __attribute__ ((__aligned__(__BIGGEST_ALIGNMENT__))); +int abs (int); + +/* Sum of absolute differences between arrays of unsigned char types. + Detected as a sad pattern. + Vectorized on targets that support sad for unsigned chars. */ + +__attribute__ ((noinline)) int +foo (int len, int *res2) +{ + int i; + int result = 0; + int result2 = 0; + + for (i = 0; i < len; i++) + { + /* Make sure we are not using an SLP reduction for this. */ + result += abs (X[2*i] - Y[2*i]); + result2 += abs (X[2*i + 1] - Y[2*i + 1]); + } + + *res2 = result2; + return result; +} + + +int +main (void) +{ + int i; + int sad; + + check_vect (); + + for (i = 0; i < N/2; i++) + { + X[2*i] = i; + Y[2*i] = N/2 - i; + X[2*i+1] = i; + Y[2*i+1] = 0; + __asm__ volatile (""); + } + + + int sad2; + sad = foo (N/2, &sad2); + if (sad != (N/2)*(N/4)) + abort (); + if (sad2 != (N/2-1)*(N/2)/2) + abort (); + + return 0; +} + +/* { dg-final { scan-tree-dump "vect_recog_sad_pattern: detected" "vect" } } */ +/* { dg-final { scan-tree-dump-times "vectorized 1 loops" 1 "vect" } } */ + diff --git a/gcc/tree-vect-loop.cc b/gcc/tree-vect-loop.cc index 35f1f8c7d42..13dcdba403a 100644 --- a/gcc/tree-vect-loop.cc +++ b/gcc/tree-vect-loop.cc @@ -7703,6 +7703,21 @@ vectorizable_reduction (loop_vec_info loop_vinfo, return false; } + /* Lane-reducing ops also never can be used in a SLP reduction group + since we'll mix lanes belonging to different reductions. But it's + OK to use them in a reduction chain or when the reduction group + has just one element. */ + if (lane_reduc_code_p + && slp_node + && !REDUC_GROUP_FIRST_ELEMENT (stmt_info) + && SLP_TREE_LANES (slp_node) > 1) + { + if (dump_enabled_p ()) + dump_printf_loc (MSG_MISSED_OPTIMIZATION, vect_location, + "lane-reducing reduction in reduction group.\n"); + return false; + } + /* All uses but the last are expected to be defined in the loop. The last use is the reduction variable. In case of nested cycle this assumption is not true: we use reduc_index to record the index of the diff --git a/gcc/tree-vect-patterns.cc b/gcc/tree-vect-patterns.cc index d562f57920f..fe1ffba8688 100644 --- a/gcc/tree-vect-patterns.cc +++ b/gcc/tree-vect-patterns.cc @@ -7172,7 +7172,6 @@ vect_pattern_recog_1 (vec_info *vinfo, vect_recog_func *recog_func, stmt_vec_info stmt_info) { gimple *pattern_stmt; - loop_vec_info loop_vinfo; tree pattern_vectype; /* If this statement has already been replaced with pattern statements, @@ -7198,8 +7197,6 @@ vect_pattern_recog_1 (vec_info *vinfo, return; } - loop_vinfo = dyn_cast <loop_vec_info> (vinfo); - /* Found a vectorizable pattern. */ if (dump_enabled_p ()) dump_printf_loc (MSG_NOTE, vect_location, @@ -7208,16 +7205,6 @@ vect_pattern_recog_1 (vec_info *vinfo, /* Mark the stmts that are involved in the pattern. */ vect_mark_pattern_stmts (vinfo, stmt_info, pattern_stmt, pattern_vectype); - - /* Patterns cannot be vectorized using SLP, because they change the order of - computation. */ - if (loop_vinfo) - { - unsigned ix, ix2; - stmt_vec_info *elem_ptr; - VEC_ORDERED_REMOVE_IF (LOOP_VINFO_REDUCTIONS (loop_vinfo), ix, ix2, - elem_ptr, *elem_ptr == stmt_info); - } } diff --git a/gcc/tree-vect-slp.cc b/gcc/tree-vect-slp.cc index dabd8407aaf..d9961945c1c 100644 --- a/gcc/tree-vect-slp.cc +++ b/gcc/tree-vect-slp.cc @@ -3597,14 +3597,24 @@ vect_analyze_slp_instance (vec_info *vinfo, = as_a <loop_vec_info> (vinfo)->reductions; scalar_stmts.create (reductions.length ()); for (i = 0; reductions.iterate (i, &next_info); i++) - if ((STMT_VINFO_RELEVANT_P (next_info) - || STMT_VINFO_LIVE_P (next_info)) - /* ??? Make sure we didn't skip a conversion around a reduction - path. In that case we'd have to reverse engineer that conversion - stmt following the chain using reduc_idx and from the PHI - using reduc_def. */ - && STMT_VINFO_DEF_TYPE (next_info) == vect_reduction_def) - scalar_stmts.quick_push (next_info); + { + gassign *g; + next_info = vect_stmt_to_vectorize (next_info); + if ((STMT_VINFO_RELEVANT_P (next_info) + || STMT_VINFO_LIVE_P (next_info)) + /* ??? Make sure we didn't skip a conversion around a reduction + path. In that case we'd have to reverse engineer that + conversion stmt following the chain using reduc_idx and from + the PHI using reduc_def. */ + && STMT_VINFO_DEF_TYPE (next_info) == vect_reduction_def + /* Do not discover SLP reductions for lane-reducing ops, that + will fail later. */ + && (!(g = dyn_cast <gassign *> (STMT_VINFO_STMT (next_info))) + || (gimple_assign_rhs_code (g) != DOT_PROD_EXPR + && gimple_assign_rhs_code (g) != WIDEN_SUM_EXPR + && gimple_assign_rhs_code (g) != SAD_EXPR))) + scalar_stmts.quick_push (next_info); + } /* If less than two were relevant/live there's nothing to SLP. */ if (scalar_stmts.length () < 2) return false;