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| author | Richard Biener <rguenther@suse.de> | 2018-08-01 12:03:29 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2018-08-01 12:03:29 +0000 |
| commit | e4837aa9fbb91803585f038de67b0d62d256b654 (patch) | |
| tree | deef5cb331e8d14f935a347904cbb33a90b96455 /gcc/tree-ssa-sccvn.c | |
| parent | 42c4ccce729ae19954160339aa2f20e9663408a5 (diff) | |
| download | gcc-e4837aa9fbb91803585f038de67b0d62d256b654.zip gcc-e4837aa9fbb91803585f038de67b0d62d256b654.tar.gz gcc-e4837aa9fbb91803585f038de67b0d62d256b654.tar.bz2 | |
tree-ssa-sccvn.c (visit_phi): Compare invariant addresses as base and offset.
2018-08-01 Richard Biener <rguenther@suse.de>
* tree-ssa-sccvn.c (visit_phi): Compare invariant addresses
as base and offset.
* gcc.dg/tree-ssa/ssa-fre-68.c: New testcase.
From-SVN: r263206
Diffstat (limited to 'gcc/tree-ssa-sccvn.c')
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 19 |
1 files changed, 19 insertions, 0 deletions
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index 833291a..43f3313 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -3941,6 +3941,8 @@ static bool visit_phi (gimple *phi) { tree result, sameval = VN_TOP, seen_undef = NULL_TREE; + tree sameval_base = NULL_TREE; + poly_int64 soff, doff; unsigned n_executable = 0; bool allsame = true; edge_iterator ei; @@ -3971,6 +3973,23 @@ visit_phi (gimple *phi) sameval = def; else if (!expressions_equal_p (def, sameval)) { + /* We know we're arriving only with invariant addresses here, + try harder comparing them. We can do some caching here + which we cannot do in expressions_equal_p. */ + if (TREE_CODE (def) == ADDR_EXPR + && TREE_CODE (sameval) == ADDR_EXPR + && sameval_base != (void *)-1) + { + if (!sameval_base) + sameval_base = get_addr_base_and_unit_offset + (TREE_OPERAND (sameval, 0), &soff); + if (!sameval_base) + sameval_base = (tree)(void *)-1; + else if ((get_addr_base_and_unit_offset + (TREE_OPERAND (def, 0), &doff) == sameval_base) + && known_eq (soff, doff)) + continue; + } allsame = false; break; } |