diff options
Diffstat (limited to 'gcc/tree.c')
| -rw-r--r-- | gcc/tree.c | 44 |
1 files changed, 44 insertions, 0 deletions
@@ -2251,6 +2251,50 @@ int_size_in_bytes (type) return TREE_INT_CST_LOW (t); } + +/* Return the strictest alignment, in bits, that T is known to have. */ + +unsigned int +expr_align (t) + tree t; +{ + unsigned int align0, align1; + + switch (TREE_CODE (t)) + { + case NOP_EXPR: case CONVERT_EXPR: case NON_LVALUE_EXPR: + /* If we have conversions, we know that the alignment of the + object must meet each of the alignments of the types. */ + align0 = expr_align (TREE_OPERAND (t, 0)); + align1 = TYPE_ALIGN (TREE_TYPE (t)); + return MAX (align0, align1); + + case SAVE_EXPR: case COMPOUND_EXPR: case MODIFY_EXPR: + case INIT_EXPR: case TARGET_EXPR: case WITH_CLEANUP_EXPR: + case WITH_RECORD_EXPR: case CLEANUP_POINT_EXPR: case UNSAVE_EXPR: + /* These don't change the alignment of an object. */ + return expr_align (TREE_OPERAND (t, 0)); + + case COND_EXPR: + /* The best we can do is say that the alignment is the least aligned + of the two arms. */ + align0 = expr_align (TREE_OPERAND (t, 1)); + align1 = expr_align (TREE_OPERAND (t, 2)); + return MIN (align0, align1); + + case FUNCTION_DECL: case LABEL_DECL: case CONST_DECL: + case VAR_DECL: case PARM_DECL: case RESULT_DECL: + if (DECL_ALIGN (t) != 0) + return DECL_ALIGN (t); + break; + + default: + break; + } + + /* Otherwise take the alignment from that of the type. */ + return TYPE_ALIGN (TREE_TYPE (t)); +} /* Return, as a tree node, the number of elements for TYPE (which is an ARRAY_TYPE) minus one. This counts only elements of the top array. */ |