From: Eric Botcazou <ebotca...@adacore.com>
This prevents the expression from being tweaked by the match.pd machinery
in the process, which can damage the readability of the -gnatR3 output.
gcc/ada/ChangeLog:
* gcc-interface/decl.cc (elaborate_expression_2): Do not divide and
multiply back if the alignment factor is already explicit.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/gcc-interface/decl.cc | 33 ++++++++++++++++++++++++---------
1 file changed, 24 insertions(+), 9 deletions(-)
diff --git a/gcc/ada/gcc-interface/decl.cc b/gcc/ada/gcc-interface/decl.cc
index 32e476c6993..024bf456bc9 100644
--- a/gcc/ada/gcc-interface/decl.cc
+++ b/gcc/ada/gcc-interface/decl.cc
@@ -7355,15 +7355,30 @@ static tree
elaborate_expression_2 (tree gnu_expr, Entity_Id gnat_entity, const char *s,
bool definition, bool need_for_debug, unsigned int
align)
{
- tree unit_align = size_int (align / BITS_PER_UNIT);
- return
- size_binop (MULT_EXPR,
- elaborate_expression_1 (size_binop (EXACT_DIV_EXPR,
- gnu_expr,
- unit_align),
- gnat_entity, s, definition,
- need_for_debug),
- unit_align);
+ /* Nothing more to do if the factor is already explicit in the tree. */
+ if (TREE_CODE (gnu_expr) == MULT_EXPR
+ && TREE_CONSTANT (TREE_OPERAND (gnu_expr, 1))
+ && value_factor_p (TREE_OPERAND (gnu_expr, 1), align / BITS_PER_UNIT))
+ return
+ size_binop (MULT_EXPR,
+ elaborate_expression_1 (TREE_OPERAND (gnu_expr, 0),
+ gnat_entity, s, definition,
+ need_for_debug),
+ TREE_OPERAND (gnu_expr, 1));
+
+ /* Otherwise divide by the factor, elaborate the result and multiply back.
*/
+ else
+ {
+ tree unit_align = size_int (align / BITS_PER_UNIT);
+ return
+ size_binop (MULT_EXPR,
+ elaborate_expression_1 (size_binop (EXACT_DIV_EXPR,
+ gnu_expr,
+ unit_align),
+ gnat_entity, s, definition,
+ need_for_debug),
+ unit_align);
+ }
}
/* Structure to hold internal data for elaborate_reference. */
--
2.43.0
