On Thu, Feb 04, 2016 at 05:46:27PM +0300, Yuri Rumyantsev wrote:
> Here is a patch that cures the issues with non-correct vuse for scalar
> statements during code motion, i.e. if vuse of scalar statement is
> vdef of masked store which has been sunk to new basic block, we must
> fix it up. The patch also fixed almost all remarks pointed out by
> Jacub.
>
> Bootstrapping and regression testing on v86-64 did not show any new failures.
> Is it OK for trunk?
>
> ChangeLog:
> 2016-02-04 Yuri Rumyantsev <ysrum...@gmail.com>
>
> PR tree-optimization/69652
> * tree-vect-loop.c (optimize_mask_stores): Move declaration of STMT1
> to nested loop, introduce new SCALAR_VUSE vector to keep vuse of all
> skipped scalar statements, introduce variable LAST_VUSE that has
> vuse of LAST_STORE, add assertion that SCALAR_VUSE is empty in the
> begining of current masked store processing, did source re-formatting,
> skip parsing of debug gimples, stop processing when call or gimple
> with volatile operand habe been encountered, save scalar statement
> with vuse in SCALAR_VUSE, skip processing debug statements in IMM_USE
> iterator, change vuse of all saved scalar statements to LAST_VUSE if
> it makes sence.
>
> gcc/testsuite/ChangeLog:
> * gcc.dg/torture/pr69652.c: New test.
Your mailer breaks ChangeLog formatting, so it is hard to check the
formatting of the ChangeLog entry.
diff --git a/gcc/testsuite/gcc.dg/torture/pr69652.c
b/gcc/testsuite/gcc.dg/torture/pr69652.c
new file mode 100644
index 0000000..91f30cf
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr69652.c
@@ -0,0 +1,14 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -ffast-math -ftree-vectorize " } */
+/* { dg-additional-options "-mavx" { target { i?86-*-* x86_64-*-* } } } */
+
+void fn1(double **matrix, int column, int row, int n)
+{
+ int k;
+ for (k = 0; k < n; k++)
+ if (matrix[row][k] != matrix[column][k])
+ {
+ matrix[column][k] = -matrix[column][k];
+ matrix[row][k] = matrix[row][k] - matrix[column][k];
+ }
+}
\ No newline at end of file
Please make sure the last line of the test is a new-line.
@@ -6971,6 +6972,8 @@ optimize_mask_stores (struct loop *loop)
gsi_next (&gsi))
{
stmt = gsi_stmt (gsi);
+ if (is_gimple_debug (stmt))
+ continue;
if (is_gimple_call (stmt)
&& gimple_call_internal_p (stmt)
&& gimple_call_internal_fn (stmt) == IFN_MASK_STORE)
This is not needed, you do something only for is_gimple_call,
which is never true if is_gimple_debug, so the code used to be fine as is.
+ /* Skip debug sstatements. */
s/ss/s/
+ if (is_gimple_debug (gsi_stmt (gsi)))
+ continue;
+ stmt1 = gsi_stmt (gsi);
+ /* Do not consider writing to memory,volatile and call
Missing space after ,
+ /* Skip scalar statements. */
+ if (!VECTOR_TYPE_P (TREE_TYPE (lhs)))
+ {
+ /* If scalar statement has vuse we need to modify it
+ when another masked store will be sunk. */
+ if (gimple_vuse (stmt1))
+ scalar_vuse.safe_push (stmt1);
continue;
+ }
I don't think it is safe to take for granted that the scalar stmts are all
going to be DCEd, but I could be wrong.
+ /* Check that LHS does not have uses outside of STORE_BB. */
+ res = true;
+ FOR_EACH_IMM_USE_FAST (use_p, imm_iter, lhs)
+ {
+ gimple *use_stmt;
+ use_stmt = USE_STMT (use_p);
+ if (is_gimple_debug (use_stmt))
+ continue;
Ignoring debug stmts to make decision whether you move or not is
of course the right thing to do. But IMHO you should remember if
you saw any is_gimple_debug stmts in some bool var.
+ if (gimple_bb (use_stmt) != store_bb)
+ {
+ res = false;
+ break;
+ }
+ }
+ if (!res)
+ break;
- if (gimple_vuse (stmt1)
- && gimple_vuse (stmt1) != gimple_vuse (last_store))
- break;
+ if (gimple_vuse (stmt1)
+ && gimple_vuse (stmt1) != gimple_vuse (last_store))
+ break;
+ /* Can move STMT1 to STORE_BB. */
+ if (dump_enabled_p ())
+ {
+ dump_printf_loc (MSG_NOTE, vect_location,
+ "Move stmt to created bb\n");
+ dump_gimple_stmt (MSG_NOTE, TDF_SLIM, stmt1, 0);
+ }
And if yes, invalidate them here, because the move would otherwise
generate invalid IL.
+ gsi_move_before (&gsi_from, &gsi_to);
+ /* Shift GSI_TO for further insertion. */
+ gsi_prev (&gsi_to);
+ }
+ /* Put other masked stores with the same mask to STORE_BB. */
+ if (worklist.is_empty ()
+ || gimple_call_arg (worklist.last (), 2) != mask
+ || worklist.last () != stmt1)
+ break;
+ last = worklist.pop ();
}
add_phi_arg (phi, gimple_vuse (last_store), e, UNKNOWN_LOCATION);
+ /* Mask stores motion could crossing scalar statements with vuse
+ which should be corrected. */
s/crossing/cross/
That said, I'm not really sure if without some verification if such
reads are really dead it is safe to skip them and update this way.
Richard?
+ last_vuse = gimple_vuse (last_store);
+ while (!scalar_vuse.is_empty ())
+ {
+ stmt = scalar_vuse.pop ();
+ if (gimple_vuse (stmt) != last_vuse)
+ {
+ gimple_set_vuse (stmt, last_vuse);
+ update_stmt (stmt);
+ }
+ }
}
}
Jakub
