During load simplification it may happen that a load is unused
but if this fact is ignored and the usual conversion to a phi-node
is node, then this value may seem to be needed and can't be anymore
be simplified away.
Fix this by removing dead loads during load simplification.
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
memops.c | 5 +++++
validation/memops/kill-dead-loads00.c | 22 ++++++++++++++++++++++
2 files changed, 27 insertions(+)
create mode 100644 validation/memops/kill-dead-loads00.c
diff --git a/memops.c b/memops.c
index badcdbbb9378..6baf4d163b00 100644
--- a/memops.c
+++ b/memops.c
@@ -111,6 +111,11 @@ static void simplify_loads(struct basic_block *bb)
if (insn->is_volatile)
continue;
+ if (!has_users(insn->target)) {
+ kill_instruction(insn);
+ continue;
+ }
+
RECURSE_PTR_REVERSE(insn, dom) {
int dominance;
if (!dom->bb)
diff --git a/validation/memops/kill-dead-loads00.c b/validation/memops/kill-dead-loads00.c
new file mode 100644
index 000000000000..df7ec037e2f2
--- /dev/null
+++ b/validation/memops/kill-dead-loads00.c
@@ -0,0 +1,22 @@
+void fun(void);
+
+void foo(int *p)
+{
+ for (*p; *p; *p) {
+l:
+ fun();
+ }
+
+ if (0)
+ goto l;
+}
+
+/*
+ * check-name: kill-dead-loads00
+ * check-command: test-linearize -Wno-decl $file
+ *
+ * check-output-ignore
+ * check-output-excludes: phi\\.
+ * check-output-pattern(1): load\\.
+ * check-output-end
+ */
--
2.29.2
