[PATCH] [Gimple] Fix ICE. [PR103682]

[liuhongt via Gcc-patches]

Check is_gimple_assign before gimple_assign_rhs_code.

Bootstrapped and regtested on x86_64-pc-linux-gnu{-m32,}.
Ok for trunk?

gcc/ChangeLog:

        PR target/103682
        * tree-ssa-ccp.c (optimize_atomic_bit_test_and): Check
        is_gimple_assign before gimple_assign_rhs_code.

gcc/testsuite/ChangeLog:

        * gcc.target/i386/pr103682.c: New test.
---
 gcc/testsuite/gcc.target/i386/pr103682.c | 6 ++++++
 gcc/tree-ssa-ccp.c                       | 4 ++--
 2 files changed, 8 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.target/i386/pr103682.c

diff --git a/gcc/testsuite/gcc.target/i386/pr103682.c 
b/gcc/testsuite/gcc.target/i386/pr103682.c
new file mode 100644
index 00000000000..52371879a69
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr103682.c
@@ -0,0 +1,6 @@
+/* { dg-do compile } */
+/* { dg-options "-O2" } */
+
+int bug(unsigned *ready, unsigned u) {
+  return __atomic_fetch_and (ready, ~u, 0) & u;
+}
diff --git a/gcc/tree-ssa-ccp.c b/gcc/tree-ssa-ccp.c
index 9e12da8f011..a5b1f60f979 100644
--- a/gcc/tree-ssa-ccp.c
+++ b/gcc/tree-ssa-ccp.c
@@ -3703,8 +3703,8 @@ optimize_atomic_bit_test_and (gimple_stmt_iterator *gsip,
              g = SSA_NAME_DEF_STMT (mask);
            }
 
-         rhs_code = gimple_assign_rhs_code (g);
-         if (rhs_code != LSHIFT_EXPR
+         if (!is_gimple_assign (g)
+             || gimple_assign_rhs_code (g) != LSHIFT_EXPR
              || !integer_onep (gimple_assign_rhs1 (g)))
            return;
          bit = gimple_assign_rhs2 (g);
-- 
2.18.1