From 5ef30aea284c2a61df00aef66e08ffa578ff774c Mon Sep 17 00:00:00 2001
From: jakub <jakub@138bc75d-0d04-0410-961f-82ee72b054a4>
Date: Fri, 8 Feb 2013 15:19:02 +0000
Subject: [PATCH] 	PR rtl-optimization/56195 	* lra-constraints.c
 (get_reload_reg): Don't reuse regs 	if they have smaller mode than
 requested, if they have 	wider mode than requested, try to return a
 SUBREG.

	* gcc.dg/torture/pr56195.c: New test.


git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@195891 138bc75d-0d04-0410-961f-82ee72b054a4
---
 gcc/ChangeLog                          |  5 +++++
 gcc/lra-constraints.c                  | 16 ++++++++++++++--
 gcc/testsuite/ChangeLog                |  5 +++++
 gcc/testsuite/gcc.dg/torture/pr56195.c | 31 +++++++++++++++++++++++++++++++
 4 files changed, 55 insertions(+), 2 deletions(-)
 create mode 100644 gcc/testsuite/gcc.dg/torture/pr56195.c

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 4c6bfba..420f95d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,10 @@
 2013-02-08  Jakub Jelinek  <jakub@redhat.com>
 
+	PR rtl-optimization/56195
+	* lra-constraints.c (get_reload_reg): Don't reuse regs
+	if they have smaller mode than requested, if they have
+	wider mode than requested, try to return a SUBREG.
+
 	PR tree-optimization/56250
 	* fold-const.c (extract_muldiv_1) <case NEGATE_EXPR>: Don't optimize
 	if type is unsigned and code isn't MULT_EXPR.
diff --git a/gcc/lra-constraints.c b/gcc/lra-constraints.c
index af68c3a..13420eb 100644
--- a/gcc/lra-constraints.c
+++ b/gcc/lra-constraints.c
@@ -421,8 +421,20 @@ get_reload_reg (enum op_type type, enum machine_mode mode, rtx original,
       if (rtx_equal_p (curr_insn_input_reloads[i].input, original)
 	  && in_class_p (curr_insn_input_reloads[i].reg, rclass, &new_class))
 	{
-	  *result_reg = curr_insn_input_reloads[i].reg;
-	  regno = REGNO (*result_reg);
+	  rtx reg = curr_insn_input_reloads[i].reg;
+	  regno = REGNO (reg);
+	  /* If input is equal to original and both are VOIDmode,
+	     GET_MODE (reg) might be still different from mode.
+	     Ensure we don't return *result_reg with wrong mode.  */
+	  if (GET_MODE (reg) != mode)
+	    {
+	      if (GET_MODE_SIZE (GET_MODE (reg)) < GET_MODE_SIZE (mode))
+		continue;
+	      reg = lowpart_subreg (mode, reg, GET_MODE (reg));
+	      if (reg == NULL_RTX || GET_CODE (reg) != SUBREG)
+		continue;
+	    }
+	  *result_reg = reg;
 	  if (lra_dump_file != NULL)
 	    {
 	      fprintf (lra_dump_file, "	 Reuse r%d for reload ", regno);
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 60fc928..5872f36 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2013-02-08  Jakub Jelinek  <jakub@redhat.com>
+
+	PR rtl-optimization/56195
+	* gcc.dg/torture/pr56195.c: New test.
+
 2013-02-08  Mikael Morin  <mikael@gcc.gnu.org>
 
 	PR fortran/54107
diff --git a/gcc/testsuite/gcc.dg/torture/pr56195.c b/gcc/testsuite/gcc.dg/torture/pr56195.c
new file mode 100644
index 0000000..d1949fd
--- /dev/null
+++ b/gcc/testsuite/gcc.dg/torture/pr56195.c
@@ -0,0 +1,31 @@
+/* PR rtl-optimization/56195 */
+/* { dg-do assemble } */
+
+int i, a, t, b, c, d, e, f, j, *h;
+
+void
+fn (void)
+{
+  if (b)
+    {
+      int *p, *q;
+      char g;
+
+      if (f++)
+	for (;; e++);
+    lbl:
+      for (b = 0; b < 2; b++)
+	t /= d + 1 ? : i || a < c < (d = f) ? : 1 | (j = 2);
+
+      *p = g >= *q ^ c != a ^ *p;
+
+      if (!e)
+	{
+	  q = p;
+	  goto lbl;
+	}
+    }
+
+  if (h++)
+    goto lbl;
+}
-- 
2.7.4