Align ix86_{move_max,store_max} with vectorizer.

When none of mprefer-vector-width, avx256_optimal/avx128_optimal,
avx256_store_by_pieces/avx512_store_by_pieces is specified, GCC will
set ix86_{move_max,store_max} as max available vector length except
for AVX part.

	      if (TARGET_AVX512F_P (opts->x_ix86_isa_flags)
		  && TARGET_EVEX512_P (opts->x_ix86_isa_flags2))
		opts->x_ix86_move_max = PVW_AVX512;
	      else
		opts->x_ix86_move_max = PVW_AVX128;

So for -mavx2, vectorizer will choose 256-bit for vectorization, but
128-bit is used for struct copy, there could be a potential STLF issue
due to this "misalign".

The patch fixes that.

gcc/ChangeLog:

	* config/i386/i386-options.cc (ix86_option_override_internal):
	set ix86_{move_max,store_max} to PVW_AVX256 when TARGET_AVX
	instead of PVW_AVX128.

gcc/testsuite/ChangeLog:
	* gcc.target/i386/pieces-memcpy-10.c: Add -mprefer-vector-width=128.
	* gcc.target/i386/pieces-memcpy-6.c: Ditto.
	* gcc.target/i386/pieces-memset-38.c: Ditto.
	* gcc.target/i386/pieces-memset-40.c: Ditto.
	* gcc.target/i386/pieces-memset-41.c: Ditto.
	* gcc.target/i386/pieces-memset-42.c: Ditto.
	* gcc.target/i386/pieces-memset-43.c: Ditto.
	* gcc.target/i386/pieces-strcpy-2.c: Ditto.
	* gcc.target/i386/pieces-memcpy-22.c: New test.
	* gcc.target/i386/pieces-memset-51.c: New test.
	* gcc.target/i386/pieces-strcpy-3.c: New test.

gcc/config/i386/i386-options.cc

@@ -3023,6 +3023,9 @@ ix86_option_override_internal (bool main_args_p,
 	      if (TARGET_AVX512F_P (opts->x_ix86_isa_flags)
 		  && TARGET_EVEX512_P (opts->x_ix86_isa_flags2))
 		opts->x_ix86_move_max = PVW_AVX512;
+	      /* Align with vectorizer to avoid potential STLF issue.  */
+	      else if (TARGET_AVX_P (opts->x_ix86_isa_flags))
+		opts->x_ix86_move_max = PVW_AVX256;
 	      else
 		opts->x_ix86_move_max = PVW_AVX128;
 	    }
@@ -3047,6 +3050,9 @@ ix86_option_override_internal (bool main_args_p,
 	      if (TARGET_AVX512F_P (opts->x_ix86_isa_flags)
 		  && TARGET_EVEX512_P (opts->x_ix86_isa_flags2))
 		opts->x_ix86_store_max = PVW_AVX512;
+	      /* Align with vectorizer to avoid potential STLF issue.  */
+	      else if (TARGET_AVX_P (opts->x_ix86_isa_flags))
+		opts->x_ix86_store_max = PVW_AVX256;
 	      else
 		opts->x_ix86_store_max = PVW_AVX128;
 	    }

gcc/testsuite/gcc.target/i386/pieces-memcpy-10.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-avx2 -mavx -mtune=sandybridge" } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mprefer-vector-width=128 -mtune=sandybridge" } */
 
 extern char *dst, *src;
 

gcc/testsuite/gcc.target/i386/pieces-memcpy-22.c

@@ -0,0 +1,12 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mtune=generic" } */
+
+extern char *dst, *src;
+
+void
+foo (void)
+{
+  __builtin_memcpy (dst, src, 33);
+}
+
+/* { dg-final { scan-assembler-times "vmovdqu\[ \\t\]+\[^\n\]*%ymm" 2 } } */

gcc/testsuite/gcc.target/i386/pieces-memcpy-6.c

@@ -1,5 +1,5 @@
 /* { dg-do compile { target { ! ia32 } } } */
-/* { dg-options "-O2 -mno-avx2 -mavx -mtune=sandybridge" } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mprefer-vector-width=128 -mtune=sandybridge" } */
 
 extern char *dst, *src;
 

gcc/testsuite/gcc.target/i386/pieces-memset-38.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-avx512f -mavx2 -mtune=sandybridge" } */
+/* { dg-options "-O2 -mno-avx512f -mavx2 -mprefer-vector-width=128 -mtune=sandybridge" } */
 
 extern char *dst;
 

gcc/testsuite/gcc.target/i386/pieces-memset-40.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-avx512f -mavx2 -mtune=sandybridge" } */
+/* { dg-options "-O2 -mno-avx512f -mavx2 -mprefer-vector-width=128 -mtune=sandybridge" } */
 /* Cope with --enable-frame-pointer, Solaris/x86 -mstackrealign default.  */
 /* { dg-additional-options "-fomit-frame-pointer -mno-stackrealign" } */
 

gcc/testsuite/gcc.target/i386/pieces-memset-41.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-avx2 -mavx -mtune=sandybridge -mno-stackrealign" } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mprefer-vector-width=128 -mtune=sandybridge -mno-stackrealign" } */
 /* Cope with --enable-frame-pointer.  */
 /* { dg-additional-options "-fomit-frame-pointer" } */
 

gcc/testsuite/gcc.target/i386/pieces-memset-42.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-avx2 -mavx -mtune=sandybridge" } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mprefer-vector-width=128 -mtune=sandybridge" } */
 
 extern char *dst;
 

gcc/testsuite/gcc.target/i386/pieces-memset-43.c

@@ -1,5 +1,5 @@
 /* { dg-do compile } */
-/* { dg-options "-O2 -mno-avx2 -mavx -mtune=sandybridge" } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mprefer-vector-width=128 -mtune=sandybridge" } */
 
 extern char *dst;
 

gcc/testsuite/gcc.target/i386/pieces-memset-51.c

@@ -0,0 +1,12 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mtune=generic" } */
+
+extern char *dst;
+
+void
+foo (int x)
+{
+  __builtin_memset (dst, x, 64);
+}
+
+/* { dg-final { scan-assembler-times "vmovdqu\[ \\t\]+\[^\n\]*%ymm" 2 } } */

gcc/testsuite/gcc.target/i386/pieces-strcpy-2.c

@@ -1,5 +1,5 @@
 /* { dg-do compile { target { ! ia32 } } } */
-/* { dg-options "-O2 -mno-avx2 -mavx -mtune=sandybridge" } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mprefer-vector-width=128 -mtune=sandybridge" } */
 
 extern char *strcpy (char *, const char *);
 

gcc/testsuite/gcc.target/i386/pieces-strcpy-3.c

@@ -0,0 +1,15 @@
+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2 -mno-avx2 -mavx -mtune=generic" } */
+
+extern char *strcpy (char *, const char *);
+
+void
+foo (char *s)
+{
+  strcpy (s,
+	  "1234567890abcdef123456abcdef5678123456abcdef567abcdef678"
+	  "1234567");
+}
+
+/* { dg-final { scan-assembler-times "vmovdqa\[ \\t\]+\[^\n\]*%ymm" 2 } } */
+/* { dg-final { scan-assembler-times "vmovdqu\[ \\t\]+\[^\n\]*%ymm" 2 } } */