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| author | Richard Guenther <rguenther@suse.de> | 2011-10-06 08:41:44 +0000 |
|---|---|---|
| committer | Richard Biener <rguenth@gcc.gnu.org> | 2011-10-06 08:41:44 +0000 |
| commit | 0147184e2b1bbbcf506dddcde7108136fc3fe13a (patch) | |
| tree | 9aaf2ceb683800a50a7b14521c41a3b6dd79d8e8 /gcc/tree-ssa-sccvn.c | |
| parent | d1fc143dd6800922a285a57d4c3aea068f7c128d (diff) | |
| download | gcc-0147184e2b1bbbcf506dddcde7108136fc3fe13a.tar.gz | |
re PR tree-optimization/38884 (missed FRE with __real and __imag)
2011-10-06 Richard Guenther <rguenther@suse.de>
PR tree-optimization/38884
* tree-ssa-sccvn.c (vn_reference_lookup_3): Handle partial
reads from aggregate SSA names.
* gcc.dg/tree-ssa/ssa-fre-34.c: New testcase.
* gcc.dg/tree-ssa/ssa-fre-35.c: Likewise.
From-SVN: r179593
Diffstat (limited to 'gcc/tree-ssa-sccvn.c')
| -rw-r--r-- | gcc/tree-ssa-sccvn.c | 63 |
1 files changed, 61 insertions, 2 deletions
diff --git a/gcc/tree-ssa-sccvn.c b/gcc/tree-ssa-sccvn.c index 3b1ad3da269..c33b87dd7fe 100644 --- a/gcc/tree-ssa-sccvn.c +++ b/gcc/tree-ssa-sccvn.c @@ -1489,7 +1489,66 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_) } } - /* 4) For aggregate copies translate the reference through them if + /* 4) Assignment from an SSA name which definition we may be able + to access pieces from. */ + else if (ref->size == maxsize + && is_gimple_reg_type (vr->type) + && gimple_assign_single_p (def_stmt) + && TREE_CODE (gimple_assign_rhs1 (def_stmt)) == SSA_NAME) + { + tree rhs1 = gimple_assign_rhs1 (def_stmt); + gimple def_stmt2 = SSA_NAME_DEF_STMT (rhs1); + if (is_gimple_assign (def_stmt2) + && (gimple_assign_rhs_code (def_stmt2) == COMPLEX_EXPR + || gimple_assign_rhs_code (def_stmt2) == CONSTRUCTOR) + && types_compatible_p (vr->type, TREE_TYPE (TREE_TYPE (rhs1)))) + { + tree base2; + HOST_WIDE_INT offset2, size2, maxsize2, off; + base2 = get_ref_base_and_extent (gimple_assign_lhs (def_stmt), + &offset2, &size2, &maxsize2); + off = offset - offset2; + if (maxsize2 != -1 + && maxsize2 == size2 + && operand_equal_p (base, base2, 0) + && offset2 <= offset + && offset2 + size2 >= offset + maxsize) + { + tree val = NULL_TREE; + HOST_WIDE_INT elsz + = TREE_INT_CST_LOW (TYPE_SIZE (TREE_TYPE (TREE_TYPE (rhs1)))); + if (gimple_assign_rhs_code (def_stmt2) == COMPLEX_EXPR) + { + if (off == 0) + val = gimple_assign_rhs1 (def_stmt2); + else if (off == elsz) + val = gimple_assign_rhs2 (def_stmt2); + } + else if (gimple_assign_rhs_code (def_stmt2) == CONSTRUCTOR + && off % elsz == 0) + { + tree ctor = gimple_assign_rhs1 (def_stmt2); + unsigned i = off / elsz; + if (i < CONSTRUCTOR_NELTS (ctor)) + { + constructor_elt *elt = CONSTRUCTOR_ELT (ctor, i); + if (compare_tree_int (elt->index, i) == 0) + val = elt->value; + } + } + if (val) + { + unsigned int value_id = get_or_alloc_constant_value_id (val); + return vn_reference_insert_pieces + (vuse, vr->set, vr->type, + VEC_copy (vn_reference_op_s, heap, vr->operands), + val, value_id); + } + } + } + } + + /* 5) For aggregate copies translate the reference through them if the copy kills ref. */ else if (vn_walk_kind == VN_WALKREWRITE && gimple_assign_single_p (def_stmt) @@ -1587,7 +1646,7 @@ vn_reference_lookup_3 (ao_ref *ref, tree vuse, void *vr_) return NULL; } - /* 5) For memcpy copies translate the reference through them if + /* 6) For memcpy copies translate the reference through them if the copy kills ref. */ else if (vn_walk_kind == VN_WALKREWRITE && is_gimple_reg_type (vr->type) |