On Wed, May 11, 2011 at 2:15 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hi!
>
> The first testcase below ICEs, because generate_loops_for_partition
> removes phis and stmts in the get_loop_body_in_dom_order order of bbs
> and within within the bbs starting with phi nodes and then from beginning to
> end of the bb.
>
> While looking at it, I've noticed that stmts_from_loop and all the analysis
> happily considers debug stmts as any other stmts, so I fear it is
> problematic for -fcompare-debug, furthermore debug stmts should be just
> always kept and only reset when needed.
>
> The following patch implements that, debug stmts are ignored by the
> analysis, kept around unless the whole loop is transformed into memset
> and reset if they are using SSA_NAMES defined in the loop that are going to
> be removed (well, moved to another loop or done using memset).
>
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk/4.6?
Ok if you move reset_debug_uses to ... hmmm, say, tree-ssa.c near
the other debug related fns.
Thanks,
Richard.
> 2011-05-11 Jakub Jelinek <ja...@redhat.com>
>
> PR debug/48159
> * tree-data-ref.c (stmts_from_loop): Ignore debug stmts.
> * tree-loop-distribution.c (reset_debug_uses): New function.
> (generate_loops_for_partition): Call reset_debug_uses on the stmts
> that will be removed. Keep around all debug stmts, don't count them
> as bits in partition bitmap.
> (generate_builtin): Don't count debug stmts or labels as bits in
> partition bitmap.
>
> * gcc.dg/pr48159-1.c: New test.
> * gcc.dg/pr48159-2.c: New test.
>
> --- gcc/tree-data-ref.c.jj 2011-05-02 18:39:28.000000000 +0200
> +++ gcc/tree-data-ref.c 2011-05-11 10:08:15.000000000 +0200
> @@ -5017,7 +5017,7 @@ stmts_from_loop (struct loop *loop, VEC
> for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
> {
> stmt = gsi_stmt (bsi);
> - if (gimple_code (stmt) != GIMPLE_LABEL)
> + if (gimple_code (stmt) != GIMPLE_LABEL && !is_gimple_debug (stmt))
> VEC_safe_push (gimple, heap, *stmts, stmt);
> }
> }
> --- gcc/tree-loop-distribution.c.jj 2011-01-03 09:54:28.000000000 +0100
> +++ gcc/tree-loop-distribution.c 2011-05-11 10:36:27.000000000 +0200
> @@ -152,6 +152,34 @@ create_bb_after_loop (struct loop *loop)
> split_edge (exit);
> }
>
> +/* Reset all debug stmts that use SSA_NAME(s) defined in STMT. */
> +
> +static void
> +reset_debug_uses (gimple stmt)
> +{
> + ssa_op_iter op_iter;
> + def_operand_p def_p;
> + imm_use_iterator imm_iter;
> + gimple use_stmt;
> +
> + FOR_EACH_PHI_OR_STMT_DEF (def_p, stmt, op_iter, SSA_OP_DEF)
> + {
> + tree var = DEF_FROM_PTR (def_p);
> +
> + if (TREE_CODE (var) != SSA_NAME)
> + continue;
> +
> + FOR_EACH_IMM_USE_STMT (use_stmt, imm_iter, var)
> + {
> + if (!gimple_debug_bind_p (use_stmt))
> + continue;
> +
> + gimple_debug_bind_reset_value (use_stmt);
> + update_stmt (use_stmt);
> + }
> + }
> +}
> +
> /* Generate code for PARTITION from the code in LOOP. The loop is
> copied when COPY_P is true. All the statements not flagged in the
> PARTITION bitmap are removed from the loop or from its copy. The
> @@ -181,6 +209,25 @@ generate_loops_for_partition (struct loo
> stmts_from_loop. */
> bbs = get_loop_body_in_dom_order (loop);
>
> + if (MAY_HAVE_DEBUG_STMTS)
> + for (x = 0, i = 0; i < loop->num_nodes; i++)
> + {
> + basic_block bb = bbs[i];
> +
> + for (bsi = gsi_start_phis (bb); !gsi_end_p (bsi); gsi_next (&bsi))
> + if (!bitmap_bit_p (partition, x++))
> + reset_debug_uses (gsi_stmt (bsi));
> +
> + for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi); gsi_next (&bsi))
> + {
> + gimple stmt = gsi_stmt (bsi);
> + if (gimple_code (stmt) != GIMPLE_LABEL
> + && !is_gimple_debug (stmt)
> + && !bitmap_bit_p (partition, x++))
> + reset_debug_uses (stmt);
> + }
> + }
> +
> for (x = 0, i = 0; i < loop->num_nodes; i++)
> {
> basic_block bb = bbs[i];
> @@ -199,7 +246,8 @@ generate_loops_for_partition (struct loo
> for (bsi = gsi_start_bb (bb); !gsi_end_p (bsi);)
> {
> gimple stmt = gsi_stmt (bsi);
> - if (gimple_code (gsi_stmt (bsi)) != GIMPLE_LABEL
> + if (gimple_code (stmt) != GIMPLE_LABEL
> + && !is_gimple_debug (stmt)
> && !bitmap_bit_p (partition, x++))
> {
> unlink_stmt_vdef (stmt);
> @@ -312,7 +360,9 @@ generate_builtin (struct loop *loop, bit
> {
> gimple stmt = gsi_stmt (bsi);
>
> - if (bitmap_bit_p (partition, x++)
> + if (gimple_code (stmt) != GIMPLE_LABEL
> + && !is_gimple_debug (stmt)
> + && bitmap_bit_p (partition, x++)
> && is_gimple_assign (stmt)
> && !is_gimple_reg (gimple_assign_lhs (stmt)))
> {
> --- gcc/testsuite/gcc.dg/pr48159-1.c.jj 2011-05-11 10:38:03.000000000 +0200
> +++ gcc/testsuite/gcc.dg/pr48159-1.c 2011-05-11 10:37:34.000000000 +0200
> @@ -0,0 +1,10 @@
> +/* PR debug/48159 */
> +/* { dg-do compile } */
> +/* { dg-options "-O3 -fcompare-debug" } */
> +
> +void
> +foo (double x, int y, double *__restrict z, double *__restrict w)
> +{
> + while (y--)
> + *z++ = (*w++ = 0) * x;
> +}
> --- gcc/testsuite/gcc.dg/pr48159-2.c.jj 2011-05-11 11:22:54.000000000 +0200
> +++ gcc/testsuite/gcc.dg/pr48159-2.c 2011-05-11 11:21:42.000000000 +0200
> @@ -0,0 +1,22 @@
> +/* PR debug/48159 */
> +/* { dg-do compile } */
> +/* { dg-options "-O2 -ftree-loop-distribution -fcompare-debug" } */
> +
> +int foo (int * __restrict__ ia, int * __restrict__ ib,
> + int * __restrict__ oxa, int * __restrict__ oxb)
> +{
> + int i;
> + int oya[52], oyb[52];
> + for (i = 0; i < 52; i++)
> + {
> + int w1 = ia[i];
> + int w2 = oxa[i];
> + int w3 = ib[i];
> + int w4 = oxb[i];
> + int w5 = w1 + w2 + 5;
> + oya[i] = (w1 * w2) >> 10;
> + int w6 = w3 + w4 + 6;
> + oyb[i] = (w3 * w4) >> 10;
> + }
> + return oya[22] + oyb[21];
> +}
>
> Jakub
>
