diff options
| author | Richard Biener <rguenther@suse.de> | 2019-05-07 13:03:19 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2019-05-07 13:03:19 +0000 |
| commit | 530ec1acebc6c7808b013ab1d7b0d8b30edeab18 (patch) | |
| tree | 4c84a9339a42c4ba577a1ea199054932d2cacb82 /gcc/tree-ssa-pre.c | |
| parent | d7b6aee8cd346328b6f22fc415ffc28b9cf8a285 (diff) | |
re PR tree-optimization/90316 (large compile time increase in opt / alias stmt walking for Go example)
2019-05-07 Richard Biener <rguenther@suse.de>
PR tree-optimization/90316
* tree-ssa-pre.c (translate_vuse_through_block): When
same_valid is NULL do not bother to search for a virtual
PHI continuation.
(phi_translate_1): When operands changed we cannot keep
the same value-number so do not bother to ask whether
that's possible from translate_vuse_through_block.
From-SVN: r270944
Diffstat (limited to 'gcc/tree-ssa-pre.c')
| -rw-r--r-- | gcc/tree-ssa-pre.c | 18 |
1 files changed, 8 insertions, 10 deletions
diff --git a/gcc/tree-ssa-pre.c b/gcc/tree-ssa-pre.c index 80227239788..09335faa6a9 100644 --- a/gcc/tree-ssa-pre.c +++ b/gcc/tree-ssa-pre.c @@ -1146,7 +1146,8 @@ translate_vuse_through_block (vec<vn_reference_op_s> operands, edge e = NULL; bool use_oracle; - *same_valid = true; + if (same_valid) + *same_valid = true; if (gimple_bb (phi) != phiblock) return vuse; @@ -1179,7 +1180,7 @@ translate_vuse_through_block (vec<vn_reference_op_s> operands, if (e) { - if (use_oracle) + if (use_oracle && same_valid) { bitmap visited = NULL; /* Try to find a vuse that dominates this phi node by skipping @@ -1191,13 +1192,9 @@ translate_vuse_through_block (vec<vn_reference_op_s> operands, } else vuse = NULL_TREE; - if (!vuse) - { - /* If we didn't find any, the value ID can't stay the same, - but return the translated vuse. */ - *same_valid = false; - vuse = PHI_ARG_DEF (phi, e->dest_idx); - } + /* If we didn't find any, the value ID can't stay the same. */ + if (!vuse && same_valid) + *same_valid = false; /* ??? We would like to return vuse here as this is the canonical upmost vdef that this reference is associated with. But during insertion of the references into the hash tables we only ever @@ -1535,7 +1532,8 @@ phi_translate_1 (bitmap_set_t dest, ? newoperands : operands, ref->set, ref->type, vuse, phiblock, pred, - &same_valid); + changed + ? NULL : &same_valid); if (newvuse == NULL_TREE) { newoperands.release (); |