On Thu, 8 Jun 2017, Jakub Jelinek wrote:
> Hi!
>
> force_gimple_operand_gsi called by update_range_test can using match.pd
> simplifications sometimes return INTEGER_CST (especially when cunroll
> unrolled code isn't really optimized by forwprop/ccp and similar passes
> before reassoc2), but that is something not acceptable to the rest of
> the optimize_range* code, because it needs to know not just the value,
> but also some gimple_stmt_iterator to insert related code etc.
>
> This patch makes sure we have a SSA_NAME even in that case.
> Bootstrapped/regtested on x86_64-linux and i686-linux, ok for trunk?
Ok.
In the end this results in a missed optimization downstream but I
guess we can't resolve this w/o major refactoring?
Thanks,
Richard.
> 2017-06-08 Jakub Jelinek <ja...@redhat.com>
>
> PR tree-optimization/81003
> * tree-ssa-reassoc.c (force_into_ssa_name): New function.
> (update_range_test): Use it instead of force_gimple_operand_gsi.
>
> * gcc.c-torture/compile/pr81003.c: New test.
>
> --- gcc/tree-ssa-reassoc.c.jj 2017-06-05 11:58:14.000000000 +0200
> +++ gcc/tree-ssa-reassoc.c 2017-06-08 12:20:47.619790903 +0200
> @@ -2282,6 +2282,26 @@ range_entry_cmp (const void *a, const vo
> }
> }
>
> +/* Helper function for update_range_test. Force EXPR into an SSA_NAME,
> + insert needed statements BEFORE or after GSI. */
> +
> +static tree
> +force_into_ssa_name (gimple_stmt_iterator *gsi, tree expr, bool before)
> +{
> + enum gsi_iterator_update m = before ? GSI_SAME_STMT : GSI_CONTINUE_LINKING;
> + tree ret = force_gimple_operand_gsi (gsi, expr, true, NULL_TREE, before,
> m);
> + if (TREE_CODE (ret) != SSA_NAME)
> + {
> + gimple *g = gimple_build_assign (make_ssa_name (TREE_TYPE (ret)), ret);
> + if (before)
> + gsi_insert_before (gsi, g, GSI_SAME_STMT);
> + else
> + gsi_insert_after (gsi, g, GSI_CONTINUE_LINKING);
> + ret = gimple_assign_lhs (g);
> + }
> + return ret;
> +}
> +
> /* Helper routine of optimize_range_test.
> [EXP, IN_P, LOW, HIGH, STRICT_OVERFLOW_P] is a merged range for
> RANGE and OTHERRANGE through OTHERRANGE + COUNT - 1 ranges,
> @@ -2393,15 +2413,13 @@ update_range_test (struct range_entry *r
> else if (op != range->exp)
> {
> gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
> - tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, true,
> - GSI_SAME_STMT);
> + tem = force_into_ssa_name (&gsi, tem, true);
> gsi_prev (&gsi);
> }
> else if (gimple_code (stmt) != GIMPLE_PHI)
> {
> gsi_insert_seq_after (&gsi, seq, GSI_CONTINUE_LINKING);
> - tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, false,
> - GSI_CONTINUE_LINKING);
> + tem = force_into_ssa_name (&gsi, tem, false);
> }
> else
> {
> @@ -2419,8 +2437,7 @@ update_range_test (struct range_entry *r
> }
> }
> gsi_insert_seq_before (&gsi, seq, GSI_SAME_STMT);
> - tem = force_gimple_operand_gsi (&gsi, tem, true, NULL_TREE, true,
> - GSI_SAME_STMT);
> + tem = force_into_ssa_name (&gsi, tem, true);
> if (gsi_end_p (gsi))
> gsi = gsi_last_bb (gimple_bb (stmt));
> else
> --- gcc/testsuite/gcc.c-torture/compile/pr81003.c.jj 2017-06-08
> 12:16:20.284127013 +0200
> +++ gcc/testsuite/gcc.c-torture/compile/pr81003.c 2017-06-08
> 12:16:07.000000000 +0200
> @@ -0,0 +1,10 @@
> +/* PR tree-optimization/81003 */
> +
> +unsigned int a, b;
> +
> +void
> +foo (void)
> +{
> + for (b = 0; b < 13; b += 2)
> + a &= !!b;
> +}
>
> Jakub
>
>
--
Richard Biener <rguent...@suse.de>
SUSE LINUX GmbH, GF: Felix Imendoerffer, Jane Smithard, Graham Norton, HRB
21284 (AG Nuernberg)
