The following fixes vectorization of loops with CLOBBER statements
in the way of ignoring them during analysis and removing them during
vectorization (because we ignored them for store/load placement
and do not handle them in case we need to unroll the loop body).
Bootstrap / regtest pending on x86_64-unknown-linux-gnu.
Do you see a better way of handling the CLOBBERs that is worthwhile?
Thanks,
Richard.
2013-05-28 Richard Biener <rguent...@suse.de>
PR tree-optimization/56787
* tree-vect-data-refs.c (vect_analyze_data_refs): Drop clobbers
from the list of data references.
* tree-vect-loop.c (vect_determine_vectorization_factor): Skip
clobbers.
(vect_analyze_loop_operations): Likewise.
(vect_transform_loop): Remove clobbers.
* gcc.dg/vect/pr56787.c: New testcase.
Index: gcc/tree-vect-data-refs.c
===================================================================
*** gcc/tree-vect-data-refs.c (revision 199374)
--- gcc/tree-vect-data-refs.c (working copy)
*************** vect_analyze_data_refs (loop_vec_info lo
*** 2861,2866 ****
--- 2861,2867 ----
bool gather = false;
int vf;
+ again:
if (!dr || !DR_REF (dr))
{
if (dump_enabled_p ())
*************** vect_analyze_data_refs (loop_vec_info lo
*** 2872,2877 ****
--- 2873,2891 ----
stmt = DR_STMT (dr);
stmt_info = vinfo_for_stmt (stmt);
+ /* Discard clobbers from the dataref vector. We will remove
+ clobber stmts during vectorization. */
+ if (gimple_clobber_p (stmt))
+ {
+ if (i == datarefs.length () - 1)
+ {
+ datarefs.pop ();
+ break;
+ }
+ datarefs[i] = datarefs.pop ();
+ goto again;
+ }
+
/* Check that analysis of the data-ref succeeded. */
if (!DR_BASE_ADDRESS (dr) || !DR_OFFSET (dr) || !DR_INIT (dr)
|| !DR_STEP (dr))
Index: gcc/tree-vect-loop.c
===================================================================
*** gcc/tree-vect-loop.c (revision 199374)
--- gcc/tree-vect-loop.c (working copy)
*************** vect_determine_vectorization_factor (loo
*** 270,277 ****
gcc_assert (stmt_info);
/* Skip stmts which do not need to be vectorized. */
! if (!STMT_VINFO_RELEVANT_P (stmt_info)
! && !STMT_VINFO_LIVE_P (stmt_info))
{
if (STMT_VINFO_IN_PATTERN_P (stmt_info)
&& (pattern_stmt = STMT_VINFO_RELATED_STMT (stmt_info))
--- 270,278 ----
gcc_assert (stmt_info);
/* Skip stmts which do not need to be vectorized. */
! if ((!STMT_VINFO_RELEVANT_P (stmt_info)
! && !STMT_VINFO_LIVE_P (stmt_info))
! || gimple_clobber_p (stmt))
{
if (STMT_VINFO_IN_PATTERN_P (stmt_info)
&& (pattern_stmt = STMT_VINFO_RELATED_STMT (stmt_info))
*************** vect_analyze_loop_operations (loop_vec_i
*** 1431,1437 ****
for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
{
gimple stmt = gsi_stmt (si);
! if (!vect_analyze_stmt (stmt, &need_to_vectorize, NULL))
return false;
}
} /* bbs */
--- 1432,1439 ----
for (si = gsi_start_bb (bb); !gsi_end_p (si); gsi_next (&si))
{
gimple stmt = gsi_stmt (si);
! if (!gimple_clobber_p (stmt)
! && !vect_analyze_stmt (stmt, &need_to_vectorize, NULL))
return false;
}
} /* bbs */
*************** vect_transform_loop (loop_vec_info loop_
*** 5595,5601 ****
if (transform_pattern_stmt)
stmt = pattern_stmt;
else
! stmt = gsi_stmt (si);
if (dump_enabled_p ())
{
--- 5597,5613 ----
if (transform_pattern_stmt)
stmt = pattern_stmt;
else
! {
! stmt = gsi_stmt (si);
! /* During vectorization remove existing clobber stmts. */
! if (gimple_clobber_p (stmt))
! {
! unlink_stmt_vdef (stmt);
! gsi_remove (&si, true);
! release_defs (stmt);
! continue;
! }
! }
if (dump_enabled_p ())
{
Index: gcc/testsuite/gcc.dg/vect/pr56787.c
===================================================================
*** gcc/testsuite/gcc.dg/vect/pr56787.c (revision 0)
--- gcc/testsuite/gcc.dg/vect/pr56787.c (working copy)
***************
*** 0 ****
--- 1,35 ----
+ /* { dg-do compile } */
+ /* { dg-require-effective-target vect_float } */
+
+ inline void
+ bar (const float s[5], float z[3][5])
+ {
+ float a = s[0], b = s[1], c = s[2], d = s[3], e = s[4];
+ float f = 1.0f / a;
+ float u = f * b, v = f * c, w = f * d;
+ float p = 0.4f * (e - 0.5f * (b * u + c * v + d * w));
+ z[0][3] = b * w;
+ z[1][3] = c * w;
+ z[2][3] = d * w + p;
+ }
+
+ void
+ foo (unsigned long n, const float *__restrict u0,
+ const float *__restrict u1, const float *__restrict u2,
+ const float *__restrict u3, const float *__restrict u4,
+ const float *__restrict s0, const float *__restrict s1,
+ const float *__restrict s2, float *__restrict t3,
+ float *__restrict t4)
+ {
+ unsigned long i;
+ for (i = 0; i < n; i++)
+ {
+ float u[5], f[3][5];
+ u[0] = u0[i]; u[1] = u1[i]; u[2] = u2[i]; u[3] = u3[i]; u[4] = u4[i];
+ bar (u, f);
+ t3[i] = s0[i] * f[0][3] + s1[i] * f[1][3] + s2[i] * f[2][3];
+ }
+ }
+
+ /* { dg-final { scan-tree-dump "vectorized 1 loops" "vect" } } */
+ /* { dg-final { cleanup-tree-dump "vect" } } */
