re PR rtl-optimization/77919 (ICE converting DC to V2DF mode)

	PR rtl-optimization/77919
	* expr.c (expand_expr_real_1) <normal_inner_ref>: Only avoid forcing
	into memory if both modes are complex and their inner modes have the
	same precision.  If the two modes are different complex modes, convert
	each part separately and generate a new CONCAT.

	* g++.dg/torture/pr77919-2.C: New test.

From-SVN: r241681

gcc/ChangeLog

+2016-10-29  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/77919
+	* expr.c (expand_expr_real_1) <normal_inner_ref>: Only avoid forcing
+	into memory if both modes are complex and their inner modes have the
+	same precision.  If the two modes are different complex modes, convert
+	each part separately and generate a new CONCAT.
+
 2016-10-29  John David Anglin  <danglin@gcc.gnu.org>
 
 	* config/pa/pa64-hpux.h (FINI_SECTION_ASM_OP): Define to null string.

gcc/expr.c

@@ -10422,10 +10422,35 @@ expand_expr_real_1 (tree exp, rtx target, machine_mode tmode,
 	  {
 	    if (bitpos == 0
 		&& bitsize == GET_MODE_BITSIZE (GET_MODE (op0))
-		&& COMPLEX_MODE_P (mode1))
+		&& COMPLEX_MODE_P (mode1)
+		&& COMPLEX_MODE_P (GET_MODE (op0))
+		&& (GET_MODE_PRECISION (GET_MODE_INNER (mode1))
+		    == GET_MODE_PRECISION (GET_MODE_INNER (GET_MODE (op0)))))
 	      {
 		if (reversep)
 		  op0 = flip_storage_order (GET_MODE (op0), op0);
+		if (mode1 != GET_MODE (op0))
+		  {
+		    rtx parts[2];
+		    for (int i = 0; i < 2; i++)
+		      {
+			rtx op = read_complex_part (op0, i != 0);
+			if (GET_CODE (op) == SUBREG)
+			  op = force_reg (GET_MODE (op), op);
+			rtx temp = gen_lowpart_common (GET_MODE_INNER (mode1),
+						       op);
+			if (temp)
+			  op = temp;
+			else
+			  {
+			    if (!REG_P (op) && !MEM_P (op))
+			      op = force_reg (GET_MODE (op), op);
+			    op = gen_lowpart (GET_MODE_INNER (mode1), op);
+			  }
+			parts[i] = op;
+		      }
+		    op0 = gen_rtx_CONCAT (mode1, parts[0], parts[1]);
+		  }
 		return op0;
 	      }
 	    if (bitpos == 0

gcc/testsuite/ChangeLog

 2016-10-29  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/77919
+	* g++.dg/torture/pr77919-2.C: New test.
+
 	PR target/78148
 	* gcc.dg/pr78148.c: New test.
 

gcc/testsuite/g++.dg/torture/pr77919-2.C

+// PR rtl-optimization/77919
+// { dg-do compile }
+
+typedef _Complex long long B;
+struct A { A (double) {} _Complex double i; };
+typedef struct { B b; } C;
+struct D { D (const B &x) : b (x) {} B b; };
+static inline B foo (const double *x) { C *a; a = (C *) x; return a->b; }
+static inline D baz (const A &x) { return foo ((double *) &x); }
+D b = baz (0);