Some branch simplifications are only valid if the branch is free
of side-effects. The check is done in flow.c:bb_has_side_effects()
but currently deosn't take in account the fact that a volatile load
is also a side-effect.
Fix this by adding the appropriate check.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
flow.c | 7 +++++++
validation/optim/volatile-side-effect.c | 13 +++++++++++++
2 files changed, 20 insertions(+)
create mode 100644 validation/optim/volatile-side-effect.c
diff --git a/flow.c b/flow.c
index 6b2c879a8..1144bff4e 100644
--- a/flow.c
+++ b/flow.c
@@ -169,6 +169,13 @@ static int bb_has_side_effects(struct basic_block *bb)
/* FIXME! This should take "const" etc into account */
return 1;
+ case OP_LOAD:
+ if (!insn->type)
+ return 1;
+ if (insn->type->ctype.modifiers & MOD_VOLATILE)
+ return 1;
+ continue;
+
case OP_STORE:
case OP_CONTEXT:
return 1;
diff --git a/validation/optim/volatile-side-effect.c b/validation/optim/volatile-side-effect.c
new file mode 100644
index 000000000..842b72282
--- /dev/null
+++ b/validation/optim/volatile-side-effect.c
@@ -0,0 +1,13 @@
+void foo(int p, volatile int *ptr)
+{
+ p ? : *ptr;
+ p ? : *ptr;
+}
+
+/*
+ * check-name: volatile-side-effect
+ * check-command: test-linearize -Wno-decl $file
+ * check-output-ignore
+ *
+ * check-output-pattern(2): load
+ */
--
2.14.0
--
To unsubscribe from this list: send the line "unsubscribe linux-sparse" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
