Note: this is the dual of the preceding patch, only for stores
instead of loads.
find_dominating_stores() call find_dominating_parents() which can
add an OP_PHISRC in each BB it visits and the corresponding
%phi are collected in a list. Then, depending on the returned
value, an OP_PHI is created with this list as phi_list.
However, it could that because of the returned value, no such
OP_PHI is created and thus the newly created OP_PHISRC stay
there but are of no use.
It seems also (but I can't strictly confirm this) that this can
sometimes happen at each CSE-simplification cycle, creating one
more such OP_PHISRC at each cycle, into each concerned BB.
Not good.
Change this by not creating these OP_PHISRC but instead just
collecting their source pseudo. And then only created them
together with the corresponding OP_PHI, or simply discarding
the list, depending on the returned value.
The situation can clearly be seen with the following code:
extern void abort(void);
extern int bar;
int foo(void)
{
if (bar)
abort();
return bar;
}
which was linearized as:
foo:
load.32 %r1 <- 0[bar]
> phisrc.32 %phi2(bar) <- %r1
cbr %r1, .L1, .L2
.L1:
call abort
br .L2
.L2:
load.32 %r2 <- 0[bar]
ret.32 %r2
and is now linearized as:
foo:
load.32 %r1 <- 0[bar]
cbr %r1, .L1, .L2
.L1:
call abort
br .L2
.L2:
load.32 %r2 <- 0[bar]
ret.32 %r2
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
flow.c | 20 +++++++++++---------
validation/linear/phisrc-orphan-st.c | 17 +++++++++++++++++
2 files changed, 28 insertions(+), 9 deletions(-)
create mode 100644 validation/linear/phisrc-orphan-st.c
diff --git a/flow.c b/flow.c
index aa7a6586f..678f9ba86 100644
--- a/flow.c
+++ b/flow.c
@@ -352,19 +352,19 @@ int dominates(pseudo_t pseudo, struct instruction *insn, struct instruction *dom
return 1;
}
-static int phisrc_in_bb(struct pseudo_list *list, struct basic_block *bb)
+static int phisrc_in_bb(struct instruction_list *list, struct basic_block *bb)
{
- pseudo_t p;
- FOR_EACH_PTR(list, p) {
- if (p->def->bb == bb)
+ struct instruction *def;
+ FOR_EACH_PTR(list, def) {
+ if (def->bb == bb)
return 1;
- } END_FOR_EACH_PTR(p);
+ } END_FOR_EACH_PTR(def);
return 0;
}
static int find_dominating_parents(pseudo_t pseudo, struct instruction *insn,
- struct basic_block *bb, unsigned long generation, struct pseudo_list **dominators,
+ struct basic_block *bb, unsigned long generation, struct instruction_list **dominators,
int local)
{
struct basic_block *parent;
@@ -401,7 +401,7 @@ no_dominance:
found_dominator:
if (dominators && phisrc_in_bb(*dominators, parent))
continue;
- add_dominator(dominators, insn, one, pseudo->ident);
+ add_instruction(dominators, one);
} END_FOR_EACH_PTR(parent);
return 1;
}
@@ -472,7 +472,8 @@ static int find_dominating_stores(pseudo_t pseudo, struct instruction *insn,
{
struct basic_block *bb = insn->bb;
struct instruction *one, *dom = NULL;
- struct pseudo_list *dominators;
+ struct instruction_list *dominators;
+ struct pseudo_list *phi_list;
int partial;
/* Unreachable load? Undo it */
@@ -534,7 +535,8 @@ found:
* have to turn the load into a phi-node of the
* dominators.
*/
- rewrite_load_instruction(insn, dominators);
+ phi_list = add_load_dominators(insn, dominators, pseudo->ident);
+ rewrite_load_instruction(insn, phi_list);
return 1;
}
diff --git a/validation/linear/phisrc-orphan-st.c b/validation/linear/phisrc-orphan-st.c
new file mode 100644
index 000000000..e5b3a3a46
--- /dev/null
+++ b/validation/linear/phisrc-orphan-st.c
@@ -0,0 +1,17 @@
+extern void abort(void);
+extern int bar;
+
+int foo(void)
+{
+ if (bar)
+ abort();
+ return bar;
+}
+
+/*
+ * check-name: phisrc orphaned (stores)
+ * check-command: test-linearize -Wno-decl $file
+ *
+ * check-output-ignore
+ * check-output-excludes: phisrc
+ */
--
2.12.0
--
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