From eb0e98f885208502b82b75ed7e63a2dce252cb9b Mon Sep 17 00:00:00 2001 From: Richard Biener Date: Mon, 23 Oct 2017 09:20:14 +0000 Subject: [PATCH] re PR tree-optimization/82129 (ICE in compute_antic, at tree-ssa-pre.c:2447) 2017-10-23 Richard Biener PR tree-optimization/82129 * tree-ssa-pre.c (bitmap_set_and): Remove. (compute_antic_aux): Compute ANTIC_OUT intersection in a way canonicalizing expressions in the set to those with lowest ID rather than taking that from the first edge. * gcc.dg/torture/pr82129.c: New testcase. From-SVN: r253998 --- gcc/ChangeLog | 8 +++ gcc/testsuite/ChangeLog | 5 ++ gcc/testsuite/gcc.dg/torture/pr82129.c | 52 +++++++++++++++++++ gcc/tree-ssa-pre.c | 72 ++++++++++++++------------ 4 files changed, 104 insertions(+), 33 deletions(-) create mode 100644 gcc/testsuite/gcc.dg/torture/pr82129.c diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 6caddb801b7..28052db569f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,11 @@ +2017-10-23 Richard Biener + + PR tree-optimization/82129 + * tree-ssa-pre.c (bitmap_set_and): Remove. + (compute_antic_aux): Compute ANTIC_OUT intersection in a way + canonicalizing expressions in the set to those with lowest + ID rather than taking that from the first edge. + 2017-10-23 Richard Sandiford * combine.c (rtx_equal_for_field_assignment_p): Use diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog index f14930b6e11..9ca1131a65b 100644 --- a/gcc/testsuite/ChangeLog +++ b/gcc/testsuite/ChangeLog @@ -1,3 +1,8 @@ +2017-10-23 Richard Biener + + PR tree-optimization/82129 + * gcc.dg/torture/pr82129.c: New testcase. + 2017-10-22 Uros Bizjak PR target/52451 diff --git a/gcc/testsuite/gcc.dg/torture/pr82129.c b/gcc/testsuite/gcc.dg/torture/pr82129.c new file mode 100644 index 00000000000..b1161491fe6 --- /dev/null +++ b/gcc/testsuite/gcc.dg/torture/pr82129.c @@ -0,0 +1,52 @@ +/* { dg-do compile } */ +/* { dg-additional-options "-ftree-pre" } */ + +int pj; + +void +g4 (unsigned long int *bc, unsigned long int *h5) +{ + if (pj != 0) + { + int ib = 0; + + while (bc != 0) + { +m6: + for (pj = 0; pj < 2; ++pj) + pj = 0; + + while (pj != 0) + { + for (;;) + { + } + + while (ib != 0) + { + unsigned long int tv = *bc; + unsigned long int n7; + + *bc = 1; + while (*bc != 0) + { + } + +ut: + if (pj == 0) + n7 = *h5 > 0; + else + { + *h5 = tv; + n7 = *h5; + } + ib += n7; + } + } + } + + goto ut; + } + + goto m6; +} diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index 5eb47a9d6d5..4861a4c231f 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -537,7 +537,6 @@ static pre_expr bitmap_find_leader (bitmap_set_t, unsigned int); static void bitmap_value_insert_into_set (bitmap_set_t, pre_expr); static void bitmap_value_replace_in_set (bitmap_set_t, pre_expr); static void bitmap_set_copy (bitmap_set_t, bitmap_set_t); -static void bitmap_set_and (bitmap_set_t, bitmap_set_t); static bool bitmap_set_contains_value (bitmap_set_t, unsigned int); static void bitmap_insert_into_set (bitmap_set_t, pre_expr); static bitmap_set_t bitmap_set_new (void); @@ -800,36 +799,6 @@ sorted_array_from_bitmap_set (bitmap_set_t set) return result; } -/* Perform bitmapped set operation DEST &= ORIG. */ - -static void -bitmap_set_and (bitmap_set_t dest, bitmap_set_t orig) -{ - bitmap_iterator bi; - unsigned int i; - - if (dest != orig) - { - bitmap_and_into (&dest->values, &orig->values); - - unsigned int to_clear = -1U; - FOR_EACH_EXPR_ID_IN_SET (dest, i, bi) - { - if (to_clear != -1U) - { - bitmap_clear_bit (&dest->expressions, to_clear); - to_clear = -1U; - } - pre_expr expr = expression_for_id (i); - unsigned int value_id = get_expr_value_id (expr); - if (!bitmap_bit_p (&dest->values, value_id)) - to_clear = i; - } - if (to_clear != -1U) - bitmap_clear_bit (&dest->expressions, to_clear); - } -} - /* Subtract all expressions contained in ORIG from DEST. */ static bitmap_set_t @@ -2182,17 +2151,54 @@ compute_antic_aux (basic_block block, bool block_has_abnormal_pred_edge) phi_translate_set (ANTIC_OUT, ANTIC_IN (first), block, first); + /* If we have multiple successors we need to intersect the ANTIC_OUT + sets. For values that's a simple intersection but for + expressions it is a union. Given we want to have a single + expression per value in our sets we have to canonicalize. + Avoid randomness and running into cycles like for PR82129 and + canonicalize the expression we choose to the one with the + lowest id. This requires we actually compute the union first. */ FOR_EACH_VEC_ELT (worklist, i, bprime) { if (!gimple_seq_empty_p (phi_nodes (bprime))) { bitmap_set_t tmp = bitmap_set_new (); phi_translate_set (tmp, ANTIC_IN (bprime), block, bprime); - bitmap_set_and (ANTIC_OUT, tmp); + bitmap_and_into (&ANTIC_OUT->values, &tmp->values); + bitmap_ior_into (&ANTIC_OUT->expressions, &tmp->expressions); bitmap_set_free (tmp); } else - bitmap_set_and (ANTIC_OUT, ANTIC_IN (bprime)); + { + bitmap_and_into (&ANTIC_OUT->values, &ANTIC_IN (bprime)->values); + bitmap_ior_into (&ANTIC_OUT->expressions, + &ANTIC_IN (bprime)->expressions); + } + } + if (! worklist.is_empty ()) + { + /* Prune expressions not in the value set, canonicalizing to + expression with lowest ID. */ + bitmap_iterator bi; + unsigned int i; + unsigned int to_clear = -1U; + bitmap seen_value = BITMAP_ALLOC (NULL); + FOR_EACH_EXPR_ID_IN_SET (ANTIC_OUT, i, bi) + { + if (to_clear != -1U) + { + bitmap_clear_bit (&ANTIC_OUT->expressions, to_clear); + to_clear = -1U; + } + pre_expr expr = expression_for_id (i); + unsigned int value_id = get_expr_value_id (expr); + if (!bitmap_bit_p (&ANTIC_OUT->values, value_id) + || !bitmap_set_bit (seen_value, value_id)) + to_clear = i; + } + if (to_clear != -1U) + bitmap_clear_bit (&ANTIC_OUT->expressions, to_clear); + BITMAP_FREE (seen_value); } } -- 2.30.2