re PR target/71103 (avr-gcc crashes with unrecognizable insn error)

gcc/
	PR target/71103
	* config/avr/avr.md (movqi): Handle loading subreg:qi (const).

gcc/testsuite/
	PR target/71103
	* gcc.target/avr/torture/pr71103-2.c: New test.

From-SVN: r237589

gcc/ChangeLog

 2016-06-20  Georg-Johann Lay  <avr@gjlay.de>
 
+	PR target/71103
+	* config/avr/avr.md (movqi): Handle loading subreg:qi (const).
+
+2016-06-20  Georg-Johann Lay  <avr@gjlay.de>
+
 	* config/avr/avr.c (avr_print_operand): Fix "format not a string
 	literal" build warnings.
 	(avr_print_operand_address): Dito.

gcc/config/avr/avr.md

@@ -638,16 +638,24 @@
     rtx dest = operands[0];
     rtx src  = avr_eval_addr_attrib (operands[1]);
 
-    if (SUBREG_P(src) && (GET_CODE(XEXP(src,0)) == SYMBOL_REF) &&
-        can_create_pseudo_p())
-      {
-        rtx symbol_ref = XEXP(src, 0);
-        XEXP (src, 0) = copy_to_mode_reg (GET_MODE(symbol_ref), symbol_ref);
-      }
-
     if (avr_mem_flash_p (dest))
       DONE;
 
+    if (QImode == <MODE>mode
+        && SUBREG_P (src)
+        && CONSTANT_ADDRESS_P (SUBREG_REG (src)))
+    {
+        // store_bitfield may want to store a SYMBOL_REF or CONST in a
+        // structure that's represented as PSImode.  As the upper 16 bits
+        // of PSImode cannot be expressed as an HImode subreg, the rhs is
+        // decomposed into QImode (word_mode) subregs of SYMBOL_REF,
+        // CONST or LABEL_REF; cf. PR71103.
+
+        rtx const_addr = SUBREG_REG (src);
+        operands[1] = src = copy_rtx (src);
+        SUBREG_REG (src) = copy_to_mode_reg (GET_MODE (const_addr), const_addr);
+      }
+
     /* One of the operands has to be in a register.  */
     if (!register_operand (dest, <MODE>mode)
         && !reg_or_0_operand (src, <MODE>mode))

gcc/testsuite/ChangeLog

+2016-06-20  Georg-Johann Lay  <avr@gjlay.de>
+
+	PR target/71103
+	* gcc.target/avr/torture/pr71103-2.c: New test.
+
 2016-06-19 Martin Sebor  <msebor@redhat.com>
 
 	PR c/69507

gcc/testsuite/gcc.target/avr/torture/pr71103-2.c

+/* Use -g0 so that this test case doesn't just fail because
+   of PR52472.  */
+
+/* { dg-do compile } */
+/* { dg-options "-std=gnu99 -g0" } */
+
+struct S12
+{
+  char c;
+  const char *p;
+};
+
+struct S12f
+{
+  char c;
+  struct S12f (*f)(void);
+};
+
+struct S12labl
+{
+  char c;
+  void **labl;
+};
+
+struct S121
+{
+  char c;
+  const char *p;
+  char d;
+};
+
+const char str[5] = "abcd";
+
+struct S12 test_S12_0 (void)
+{
+  struct S12 s;
+  s.c = 'A';
+  s.p = str;
+  return s;
+}
+
+struct S12 test_S12_4 (void)
+{
+  struct S12 s;
+  s.c = 'A';
+  s.p = str + 4;
+  return s;
+}
+
+struct S12f test_S12f (void)
+{
+  struct S12f s;
+  s.c = 'A';
+  s.f = test_S12f;
+  return s;
+}
+
+struct S121 test_S121 (void)
+{
+  struct S121 s;
+  s.c = 'c';
+  s.p = str + 4;
+  s.d = 'd';
+  return s;
+}
+
+extern void use_S12lab (struct S12labl*);
+
+struct S12labl test_S12lab (void)
+{
+  struct S12labl s;
+labl:;
+  s.c = 'A';
+  s.labl = &&labl;
+  return s;
+}
+
+#ifdef __MEMX
+
+struct S13
+{
+  char c;
+  const __memx char *p;
+};
+
+const __memx char str_x[] = "abcd";
+
+struct S13 test_S13_0 (void)
+{
+  struct S13 s;
+  s.c = 'A';
+  s.p = str_x;
+  return s;
+}
+
+struct S13 test_S13_4a (void)
+{
+  struct S13 s;
+  s.c = 'A';
+  s.p = str_x + 4;
+  return s;
+}
+
+#ifdef __FLASH1
+
+const __flash1 char str_1[] = "abcd";
+
+struct S13 test_13_4b (void)
+{
+  struct S13 s;
+  s.c = 'A';
+  s.p = str_1 + 4;
+  return s;
+}
+
+#endif /* have __flash1 */
+#endif /* have __memx */
+