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| author | Bill Schmidt <wschmidt@linux.vnet.ibm.com> | 2017-03-20 20:04:25 +0000 |
|---|---|---|
| committer | William Schmidt <wschmidt@gcc.gnu.org> | 2017-03-20 20:04:25 +0000 |
| commit | c34923c44c49a18014b49bf33d180619a9fa0ac9 (patch) | |
| tree | ccbcf5648b7808b2c65e066ad61a0d0c2d5c120c /gcc/gimple-ssa-strength-reduction.c | |
| parent | 8afd9c45b6e84193b2fc12a2332191e28cdbdd70 (diff) | |
| download | gcc-c34923c44c49a18014b49bf33d180619a9fa0ac9.zip gcc-c34923c44c49a18014b49bf33d180619a9fa0ac9.tar.gz gcc-c34923c44c49a18014b49bf33d180619a9fa0ac9.tar.bz2 | |
re PR tree-optimization/80054 (ICE in verify_ssa with -O3 -march=broadwell/skylake-avx512)
[gcc]
2017-03-20 Bill Schmidt <wschmidt@linux.vnet.ibm.com>
PR tree-optimization/80054
* gimple-ssa-strength-reduction.c (all_phi_incrs_profitable): Fail
the optimization if a PHI or any of its arguments is not dominated
by the candidate's basis. Use gphi* rather than gimple* as
appropriate.
(replace_profitable_candidates): Clean up a gimple* variable that
should be a gphi* variable.
[gcc/testsuite]
2017-03-20 Bill Schmidt <wschmidt@linux.vnet.ibm.com>
PR tree-optimization/80054
* g++.dg/torture/pr80054.C: New file.
From-SVN: r246290
Diffstat (limited to 'gcc/gimple-ssa-strength-reduction.c')
| -rw-r--r-- | gcc/gimple-ssa-strength-reduction.c | 25 |
1 files changed, 21 insertions, 4 deletions
diff --git a/gcc/gimple-ssa-strength-reduction.c b/gcc/gimple-ssa-strength-reduction.c index 9ebe198..ca154c5 100644 --- a/gcc/gimple-ssa-strength-reduction.c +++ b/gcc/gimple-ssa-strength-reduction.c @@ -3279,17 +3279,34 @@ insert_initializers (slsr_cand_t c) } /* Return TRUE iff all required increments for candidates feeding PHI - are profitable to replace on behalf of candidate C. */ + are profitable (and legal!) to replace on behalf of candidate C. */ static bool -all_phi_incrs_profitable (slsr_cand_t c, gimple *phi) +all_phi_incrs_profitable (slsr_cand_t c, gphi *phi) { unsigned i; slsr_cand_t basis = lookup_cand (c->basis); slsr_cand_t phi_cand = *stmt_cand_map->get (phi); + /* If the basis doesn't dominate the PHI (including when the PHI is + in the same block as the basis), we won't be able to create a PHI + using the basis here. */ + basic_block basis_bb = gimple_bb (basis->cand_stmt); + basic_block phi_bb = gimple_bb (phi); + + if (phi_bb == basis_bb + || !dominated_by_p (CDI_DOMINATORS, phi_bb, basis_bb)) + return false; + for (i = 0; i < gimple_phi_num_args (phi); i++) { + /* If the PHI arg resides in a block not dominated by the basis, + we won't be able to create a PHI using the basis here. */ + basic_block pred_bb = gimple_phi_arg_edge (phi, i)->src; + + if (!dominated_by_p (CDI_DOMINATORS, pred_bb, basis_bb)) + return false; + tree arg = gimple_phi_arg_def (phi, i); if (!operand_equal_p (arg, phi_cand->base_expr, 0)) @@ -3298,7 +3315,7 @@ all_phi_incrs_profitable (slsr_cand_t c, gimple *phi) if (gimple_code (arg_def) == GIMPLE_PHI) { - if (!all_phi_incrs_profitable (c, arg_def)) + if (!all_phi_incrs_profitable (c, as_a <gphi *> (arg_def))) return false; } else @@ -3565,7 +3582,7 @@ replace_profitable_candidates (slsr_cand_t c) { if (phi_dependent_cand_p (c)) { - gimple *phi = lookup_cand (c->def_phi)->cand_stmt; + gphi *phi = as_a <gphi *> (lookup_cand (c->def_phi)->cand_stmt); if (all_phi_incrs_profitable (c, phi)) { |