From: Eric Botcazou <ebotca...@adacore.com>
The optimized form generated in this case turns out to be problematic.
gcc/ada/
* gcc-interface/trans.cc (Loop_Statement_to_gnu): Always use the
simpler form for a loop with a boolean iteration variable.
Tested on x86_64-pc-linux-gnu, committed on master.
---
gcc/ada/gcc-interface/trans.cc | 8 ++++++--
1 file changed, 6 insertions(+), 2 deletions(-)
diff --git a/gcc/ada/gcc-interface/trans.cc b/gcc/ada/gcc-interface/trans.cc
index c7d91628f80..9c418beda96 100644
--- a/gcc/ada/gcc-interface/trans.cc
+++ b/gcc/ada/gcc-interface/trans.cc
@@ -3021,7 +3021,9 @@ Loop_Statement_to_gnu (Node_Id gnat_node)
}
/* We use two different strategies to translate the loop, depending on
- whether optimization is enabled.
+ whether optimization is enabled, except for the very peculiar case
+ of a loop running over a boolean type where we use the simpler form
+ in order to avoid manipulating negative values in a boolean context.
If it is, we generate the canonical loop form expected by the loop
optimizer and the loop vectorizer, which is the do-while form:
@@ -3067,7 +3069,9 @@ Loop_Statement_to_gnu (Node_Id gnat_node)
which works in all cases. */
- if (optimize && !optimize_debug)
+ if (optimize
+ && !optimize_debug
+ && TREE_CODE (gnu_base_type) != BOOLEAN_TYPE)
{
/* We can use the do-while form directly if GNU_FIRST-1 doesn't
overflow. */
--
2.42.0
