Fix failure in gcc.target/sve/reduc_strict_3.c

Unwanted unrolling meant that we had more single-precision FADDAs
than expected.

2019-10-25  Richard Sandiford  <richard.sandiford@arm.com>

gcc/testsuite/
	* gcc.target/aarch64/sve/reduc_strict_3.c (double_reduc1): Prevent
	the loop from being unrolled.

From-SVN: r277442

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2019-10-25  Richard Sandiford  <richard.sandiford@arm.com>
+
+	* gcc.target/aarch64/sve/reduc_strict_3.c (double_reduc1): Prevent
+	the loop from being unrolled.
+
 2019-10-25  Richard Sandiford  <richard.sandiford@arm.com>
 
 	* gcc.target/aarch64/sve/loop_add_5.c: Remove XFAILs for tests

gcc/testsuite/gcc.target/aarch64/sve/reduc_strict_3.c

@@ -82,6 +82,7 @@ double_reduc1 (float (*restrict i)[16])
 {
   float l = 0;
 
+#pragma GCC unroll 0
   for (int a = 0; a < 8; a++)
     for (int b = 0; b < 8; b++)
       l += i[b][a];