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| author | Eric Botcazou <ebotcazou@adacore.com> | 2015-11-03 17:19:30 +0000 |
|---|---|---|
| committer | Eric Botcazou <ebotcazou@gcc.gnu.org> | 2015-11-03 17:19:30 +0000 |
| commit | 5993d1c9a36c7b029e9ddea35f71d848d822babc (patch) | |
| tree | f3de57903796486894da59afa2a8a1d3ee7bffd1 /gcc/gimple-expr.c | |
| parent | 34148d68c7ac0bd2bb1b499b3bd8a267efbe83ad (diff) | |
| download | gcc-5993d1c9a36c7b029e9ddea35f71d848d822babc.zip gcc-5993d1c9a36c7b029e9ddea35f71d848d822babc.tar.gz gcc-5993d1c9a36c7b029e9ddea35f71d848d822babc.tar.bz2 | |
gimple-expr.c (useless_type_conversion_p): Reinstate type canonical check for aggregate types and beef up comment for mode...
* gimple-expr.c (useless_type_conversion_p): Reinstate type canonical
check for aggregate types and beef up comment for mode check.
From-SVN: r229714
Diffstat (limited to 'gcc/gimple-expr.c')
| -rw-r--r-- | gcc/gimple-expr.c | 14 |
1 files changed, 7 insertions, 7 deletions
diff --git a/gcc/gimple-expr.c b/gcc/gimple-expr.c index f5f9e87..dd2550a 100644 --- a/gcc/gimple-expr.c +++ b/gcc/gimple-expr.c @@ -86,7 +86,8 @@ useless_type_conversion_p (tree outer_type, tree inner_type) if (inner_type == outer_type) return true; - /* Changes in machine mode are never useless conversions unless. */ + /* Changes in machine mode are never useless conversions because the RTL + middle-end expects explicit conversions between modes. */ if (TYPE_MODE (inner_type) != TYPE_MODE (outer_type)) return false; @@ -262,14 +263,13 @@ useless_type_conversion_p (tree outer_type, tree inner_type) return true; } - /* For aggregates compare only the size. Accesses to fields do have - a type information by themselves and thus we only care if we can i.e. - use the types in move operations. */ + /* For aggregates we rely on TYPE_CANONICAL exclusively and require + explicit conversions for types involving to be structurally + compared types. */ else if (AGGREGATE_TYPE_P (inner_type) && TREE_CODE (inner_type) == TREE_CODE (outer_type)) - return (TYPE_MODE (outer_type) != BLKmode - || operand_equal_p (TYPE_SIZE (inner_type), - TYPE_SIZE (outer_type), 0)); + return TYPE_CANONICAL (inner_type) + && TYPE_CANONICAL (inner_type) == TYPE_CANONICAL (outer_type); else if (TREE_CODE (inner_type) == OFFSET_TYPE && TREE_CODE (outer_type) == OFFSET_TYPE) |