gcse.c (struct bb_data): Add new fields, old_pressure, live_in and backup.

	* gcse.c (struct bb_data): Add new fields, old_pressure, live_in
	and backup.
	(get_regno_pressure_class): Add prototype.
	(update_bb_reg_pressure): New.
	(should_hoist_expr_to_dom): Add new parameter from.
	Monitor the change of reg pressure and use it to drive hoisting.
	(hoist_code): Update LIVE and reg pressure information.
	(calculate_bb_reg_pressure): Initialize live_in and backup.

	* gcc.dg/hoist-register-pressure-3.c: New test.

From-SVN: r193425

gcc/ChangeLog

+2012-11-12  Bin Cheng  <bin.cheng@arm.com>
+
+	* gcse.c (struct bb_data): Add new fields, old_pressure, live_in
+	and backup.
+	(get_regno_pressure_class): Add prototype.
+	(update_bb_reg_pressure): New.
+	(should_hoist_expr_to_dom): Add new parameter from.
+	Monitor the change of reg pressure and use it to drive hoisting.
+	(hoist_code): Update LIVE and reg pressure information.
+	(calculate_bb_reg_pressure): Initialize live_in and backup.
+
 2012-11-12  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	* doc/md.texi (Standard Pattern Names For Generation): Fix swapped

gcc/testsuite/ChangeLog

+2012-11-12  Bin Cheng  <bin.cheng@arm.com>
+
+	* gcc.dg/hoist-register-pressure-3.c: New test.
+
 2012-11-11  Oleg Endo  <olegendo@gcc.gnu.org>
 
 	* gcc.target/sh/sh4a-fprun.c: Add test_sinf and test_cosf noinline

gcc/testsuite/gcc.dg/hoist-register-pressure-3.c

+/* { dg-options "-Os -fdump-rtl-hoist" }  */
+/* { dg-final { scan-rtl-dump "PRE/HOIST: end of bb .* copying expression" "hoist" } } */
+
+#define BUF 100
+int a[BUF];
+
+void com (int);
+void bar (int);
+
+int foo (int x, int y, int z)
+{
+  /* "x+y" won't be hoisted if "-fira-hoist-pressure" is disabled,
+     because its rtx_cost is too small.  */
+  if (z)
+    {
+      a[1] = a[0] + a[2] + a[3] + a[4] + a[5] + a[6];
+      a[2] = a[1] + a[3] + a[5] + a[5] + a[6] + a[7];
+      a[3] = a[2] + a[5] + a[7] + a[6] + a[7] + a[8];
+      a[4] = a[3] + a[7] + a[11] + a[7] + a[8] + a[9];
+      a[5] = a[5] + a[11] + a[13] + a[8] + a[9] + a[10];
+      a[6] = a[7] + a[13] + a[17] + a[9] + a[10] + a[11];
+      a[7] = a[11] + a[17] + a[19] + a[10] + a[11] + a[12];
+      com (x+y);
+    }
+  else
+    {
+      bar (x+y);
+    }
+
+  return 0;
+}
+