diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 65aaca77706..ba4f7fd0dbb 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2017-03-31  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/80173
+	* expmed.c (store_bit_field_1): Don't attempt to create
+	a word subreg out of hard registers wider than word if they
+	have HARD_REGNO_NREGS of 1 for their mode.
+
 	PR middle-end/80163
 	* varasm.c (initializer_constant_valid_p_1): Disallow sign-extending
 	conversions to integer types wider than word and pointer.
diff --git a/gcc/expmed.c b/gcc/expmed.c
index bcc59225100..c0260c53853 100644
--- a/gcc/expmed.c
+++ b/gcc/expmed.c
@@ -965,8 +965,14 @@ store_bit_field_1 (rtx str_rtx, unsigned HOST_WIDE_INT bitsize,
     }
 
   /* If OP0 is a multi-word register, narrow it to the affected word.
-     If the region spans two words, defer to store_split_bit_field.  */
-  if (!MEM_P (op0) && GET_MODE_SIZE (GET_MODE (op0)) > UNITS_PER_WORD)
+     If the region spans two words, defer to store_split_bit_field.
+     Don't do this if op0 is a single hard register wider than word
+     such as a float or vector register.  */
+  if (!MEM_P (op0)
+      && GET_MODE_SIZE (GET_MODE (op0)) > UNITS_PER_WORD
+      && (!REG_P (op0)
+	  || !HARD_REGISTER_P (op0)
+	  || HARD_REGNO_NREGS (REGNO (op0), GET_MODE (op0)) != 1))
     {
       if (bitnum % BITS_PER_WORD + bitsize > BITS_PER_WORD)
 	{
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index af79d42596f..9297d533568 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,8 @@
 2017-03-31  Jakub Jelinek  <jakub@redhat.com>
 
+	PR middle-end/80173
+	* gcc.target/i386/pr80173.c: New test.
+
 	PR middle-end/80163
 	* gcc.dg/pr80163.c: New test.
 
diff --git a/gcc/testsuite/gcc.target/i386/pr80173.c b/gcc/testsuite/gcc.target/i386/pr80173.c
new file mode 100644
index 00000000000..7abd4049812
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr80173.c
@@ -0,0 +1,22 @@
+/* PR middle-end/80173 */
+/* { dg-do compile { target lp64 } } */
+/* { dg-options "-O2 -ffixed-xmm7" } */
+
+typedef int V __attribute__ ((vector_size (2 * sizeof (int))));
+
+struct U { V a; V b; };
+
+int
+foo (int i)
+{
+  register struct U u asm ("xmm7") = {{-1, 0}, {-1, 0}};
+  return u.b[i];
+}
+
+int
+bar (int i)
+{
+  register struct U u asm ("xmm7");
+  u = (struct U) {{-1, 0}, {-1, 0}};
+  return u.b[i];
+}