i386: Increase Skylake SImode pseudo register store cost

On Skylake, SImode store cost isn't less than half cost of 128-bit vector
store.  This patch increases Skylake SImode pseudo register store cost to
make it the same as QImode and HImode.

gcc/

	PR target/91446
	* config/i386/x86-tune-costs.h (skylake_cost): Increase SImode
	pseudo register store cost from 3 to 6 to make it the same as
	QImode and HImode.

gcc/testsuite/

	PR target/91446
	* gcc.target/i386/pr91446.c: New test.

From-SVN: r275905

gcc/ChangeLog

+2019-09-18  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/91446
+	* config/i386/x86-tune-costs.h (skylake_cost): Increase SImode
+	pseudo register store cost from 3 to 6 to make it the same as
+	QImode and HImode.
+
 2019-09-18  Wilco Dijkstra  <wdijkstr@arm.com>
 
 	* config/arm/arm.md (maddsidi4): Remove expander.

gcc/config/i386/x86-tune-costs.h

@@ -1638,7 +1638,7 @@ struct processor_costs skylake_cost = {
   {4, 4, 4},				/* cost of loading integer registers
 					   in QImode, HImode and SImode.
 					   Relative to reg-reg move (2).  */
-  {6, 6, 3},				/* cost of storing integer registers */
+  {6, 6, 6},				/* cost of storing integer registers */
   {6, 6, 6, 10, 20},			/* cost of loading SSE register
 					   in 32bit, 64bit, 128bit, 256bit and 512bit */
   {8, 8, 8, 12, 24},			/* cost of storing SSE register

gcc/testsuite/ChangeLog

+2019-09-18  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/91446
+	* gcc.target/i386/pr91446.c: New test.
+
 2019-09-18  Eric Botcazou  <ebotcazou@adacore.com>
 
 	* gnat.dg/warn31.adb, gnat.dg/warn31.ads: New testcase.

gcc/testsuite/gcc.target/i386/pr91446.c

+/* { dg-do compile { target { ! ia32 } } } */
+/* { dg-options "-O2 -march=skylake -ftree-slp-vectorize -mtune-ctrl=^sse_typeless_stores" } */
+
+typedef struct
+{
+  unsigned long long width, height;
+  long long x, y;
+} info;
+
+extern void bar (info *);
+
+void
+foo (unsigned long long width, unsigned long long height,
+     long long x, long long y)
+{
+  info t;
+  t.width = width;
+  t.height = height;
+  t.x = x;
+  t.y = y;
+  bar (&t);
+}
+
+/* { dg-final { scan-assembler-times "vmovdqa\[^\n\r\]*xmm\[0-9\]" 2 } } */