commit 068224c568d6f06f68512f12ecebea8bfc873fe9
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date:   Tue Nov 15 14:52:33 2016 +0000

    [AArch64] PR target/78362: Make sure to only take REGNO of a register

diff --git a/gcc/config/aarch64/aarch64.md b/gcc/config/aarch64/aarch64.md
index 9e5eee9..1dcb6b2 100644
--- a/gcc/config/aarch64/aarch64.md
+++ b/gcc/config/aarch64/aarch64.md
@@ -1611,11 +1611,15 @@ (define_expand "add<mode>3"
 	      (match_operand:GPI 2 "aarch64_pluslong_operand" "")))]
   ""
 {
+  /* If operands[1] is a subreg extract the inner RTX.  */
+  rtx op1 = REG_P (operands[1]) ? operands[1] : SUBREG_REG (operands[1]);
+
   /* If the constant is too large for a single instruction and isn't frame
      based, split off the immediate so it is available for CSE.  */
   if (!aarch64_plus_immediate (operands[2], <MODE>mode)
       && can_create_pseudo_p ()
-      && !REGNO_PTR_FRAME_P (REGNO (operands[1])))
+      && (!REG_P (op1)
+	 || !REGNO_PTR_FRAME_P (REGNO (op1))))
     operands[2] = force_reg (<MODE>mode, operands[2]);
 })
 
diff --git a/gcc/testsuite/gcc.c-torture/compile/pr78362.c b/gcc/testsuite/gcc.c-torture/compile/pr78362.c
new file mode 100644
index 0000000..66eea7d
--- /dev/null
+++ b/gcc/testsuite/gcc.c-torture/compile/pr78362.c
@@ -0,0 +1,11 @@
+/* PR target/78362.  */
+
+long a;
+
+void
+foo (void)
+{
+  for (;; a--)
+    if ((int) a)
+      break;
+}