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| author | Zdenek Dvorak <dvorakz@suse.cz> | 2005-01-12 01:05:55 +0100 |
|---|---|---|
| committer | Zdenek Dvorak <rakdver@gcc.gnu.org> | 2005-01-12 00:05:55 +0000 |
| commit | 0a915e3d7a94aae8a572f3f7a631269980250050 (patch) | |
| tree | b73b45d4e9db23918f55c23b3446e4237574ffd5 /gcc | |
| parent | 78593d78f1800fcdf5d274e7eef51ed6ca379716 (diff) | |
| download | gcc-0a915e3d7a94aae8a572f3f7a631269980250050.zip gcc-0a915e3d7a94aae8a572f3f7a631269980250050.tar.gz gcc-0a915e3d7a94aae8a572f3f7a631269980250050.tar.bz2 | |
re PR tree-optimization/17949 (Tree loop optimization generates unaligned access (STRICT_ALIGNMENT is set))
PR tree-optimization/17949
* tree-ssa-loop-ivopts.c (may_be_unaligned_p): New function.
(find_interesting_uses_address): Use it.
From-SVN: r93209
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 6 | ||||
| -rw-r--r-- | gcc/tree-ssa-loop-ivopts.c | 35 |
2 files changed, 41 insertions, 0 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 1ce0395..20f5d2f 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,9 @@ +2005-01-11 Zdenek Dvorak <dvorakz@suse.cz> + + PR tree-optimization/17949 + * tree-ssa-loop-ivopts.c (may_be_unaligned_p): New function. + (find_interesting_uses_address): Use it. + 2005-01-11 Aldy Hernandez <aldyh@redhat.com> * regrename.c (kill_value): Handle subreg's that won't simplify. diff --git a/gcc/tree-ssa-loop-ivopts.c b/gcc/tree-ssa-loop-ivopts.c index 7303412..475f45e 100644 --- a/gcc/tree-ssa-loop-ivopts.c +++ b/gcc/tree-ssa-loop-ivopts.c @@ -1400,6 +1400,37 @@ idx_record_use (tree base, tree *idx, return true; } +/* Returns true if memory reference REF may be unaligned. */ + +static bool +may_be_unaligned_p (tree ref) +{ + tree base; + tree base_type; + HOST_WIDE_INT bitsize; + HOST_WIDE_INT bitpos; + tree toffset; + enum machine_mode mode; + int unsignedp, volatilep; + unsigned base_align; + + /* The test below is basically copy of what expr.c:normal_inner_ref + does to check whether the object must be loaded by parts when + STRICT_ALIGNMENT is true. */ + base = get_inner_reference (ref, &bitsize, &bitpos, &toffset, &mode, + &unsignedp, &volatilep, true); + base_type = TREE_TYPE (base); + base_align = TYPE_ALIGN (base_type); + + if (mode != BLKmode + && (base_align < GET_MODE_ALIGNMENT (mode) + || bitpos % GET_MODE_ALIGNMENT (mode) != 0 + || bitpos % BITS_PER_UNIT != 0)) + return true; + + return false; +} + /* Finds addresses in *OP_P inside STMT. */ static void @@ -1415,6 +1446,10 @@ find_interesting_uses_address (struct ivopts_data *data, tree stmt, tree *op_p) && DECL_NONADDRESSABLE_P (TREE_OPERAND (base, 1))) goto fail; + if (STRICT_ALIGNMENT + && may_be_unaligned_p (base)) + goto fail; + ifs_ivopts_data.ivopts_data = data; ifs_ivopts_data.stmt = stmt; ifs_ivopts_data.step_p = &step; |