store-merging: ICE in find_bswap_or_nop_1 PR95854.

The patch add a judgement in find_bswap_or_nop_1 to make sure both
operand1 and operand2 cannot be converted to unsigned HOST_WIDE_INT.
If not, return NULL.

gcc/ChangeLog:

2020-06-24  Kaipeng Zhou  <zhoukaipeng3@huawei.com>

	PR tree-optimization/95854
	* gimple-ssa-store-merging.c (find_bswap_or_nop_1): Return NULL
	if operand 1 or 2 of a BIT_FIELD_REF cannot be converted to
	unsigned HOST_WIDE_INT.

gcc/testsuite/ChangeLog:

2020-06-24  Kaipeng Zhou  <zhoukaipeng3@huawei.com>

	PR tree-optimization/95854
	* gcc.dg/pr95854.c: New test.

diff --git a/gcc/gimple-ssa-store-merging.c b/gcc/gimple-ssa-store-merging.c
index 3ab614148a742ff6558bd25b679595ddd4f48c24..5cb71019d65eff68b307778376378a55353707de 100644 (file)
--- a/gcc/gimple-ssa-store-merging.c
+++ b/gcc/gimple-ssa-store-merging.c
@@ -598,6 +598,10 @@ find_bswap_or_nop_1 (gimple *stmt, struct symbolic_number *n, int limit)
   if (TREE_CODE (rhs1) == BIT_FIELD_REF
       && TREE_CODE (TREE_OPERAND (rhs1, 0)) == SSA_NAME)
     {
+      if (!tree_fits_uhwi_p (TREE_OPERAND (rhs1, 1))
+         || !tree_fits_uhwi_p (TREE_OPERAND (rhs1, 2)))
+       return NULL;
+
       unsigned HOST_WIDE_INT bitsize = tree_to_uhwi (TREE_OPERAND (rhs1, 1));
       unsigned HOST_WIDE_INT bitpos = tree_to_uhwi (TREE_OPERAND (rhs1, 2));
       if (bitpos % BITS_PER_UNIT == 0

diff --git a/gcc/testsuite/gcc.dg/pr95854.c b/gcc/testsuite/gcc.dg/pr95854.c
new file mode 100644 (file)
index 0000000..db45d6a
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/pr95854.c
@@ -0,0 +1,20 @@
+/* { dg-do compile } */
+/* { dg-options "-O3 -fno-vect-cost-model -fno-tree-scev-cprop -ftracer" } */
+/* { dg-additional-options "-march=armv8.5-a+sve2" { target aarch64*-*-* } } */
+
+extern void abort (void);
+int c, d;
+int main()
+{
+  int e[] = {4, 4, 4, 4, 4, 4, 4, 4, 4};
+  d = 8;
+  for (; d; d--)
+    for (int a = 0; a <= 8; a++)
+      {
+       c = e[1];
+       e[d] = 0;
+      }
+  if (c != 0)
+    abort ();
+  return 0;
+}