In sparse-llvm the field 'struct pseudo:priv' is used to store
the LLVMValueRef corresponding to this pseudo. This field is
normaly assigned when processing the instruction that produce
the speudo.
In output_op_store(), the field insn->target->priv is overwritten
by the LLVMValueRef returned by LLVMBuildStore().
I have no idea to what this return value can be but:
- this corrupts the pseudo, making it unusable in subsequent
instructions.
- there is no reason to change this field anyway.
Fix this by removing the assignment to insn->target->priv
in output_op_store().
Reported-by: Dibyendu Majumdar <mobile@xxxxxxxxxxxxxxx>
Signed-off-by: Luc Van Oostenryck <luc.vanoostenryck@xxxxxxxxx>
---
sparse-llvm.c | 6 ++----
validation/backend/store-x2.c | 16 ++++++++++++++++
2 files changed, 18 insertions(+), 4 deletions(-)
create mode 100644 validation/backend/store-x2.c
diff --git a/sparse-llvm.c b/sparse-llvm.c
index 9f362b3ed..edd0615ec 100644
--- a/sparse-llvm.c
+++ b/sparse-llvm.c
@@ -622,16 +622,14 @@ static void output_op_load(struct function *fn, struct instruction *insn)
static void output_op_store(struct function *fn, struct instruction *insn)
{
- LLVMValueRef addr, target, target_in;
+ LLVMValueRef addr, target_in;
addr = calc_memop_addr(fn, insn);
target_in = pseudo_to_value(fn, insn, insn->target);
/* perform store */
- target = LLVMBuildStore(fn->builder, target_in, addr);
-
- insn->target->priv = target;
+ LLVMBuildStore(fn->builder, target_in, addr);
}
static LLVMValueRef bool_value(struct function *fn, LLVMValueRef value)
diff --git a/validation/backend/store-x2.c b/validation/backend/store-x2.c
new file mode 100644
index 000000000..5ccc9b43a
--- /dev/null
+++ b/validation/backend/store-x2.c
@@ -0,0 +1,16 @@
+void foo(int *p, int a, int b);
+void foo(int *p, int a, int b)
+{
+ int c = a + b;
+
+ p[0] = c;
+ p[1] = c;
+}
+
+/*
+ * check-name: store-x2
+ * check-command: sparsec -c $file -o tmp.o
+ * check-description: Verify in output_op_store() that
+ * the first store doesn't mess anymore with the
+ * 'target' and thus making the second store unusable.
+ */
--
2.11.1
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