re PR rtl-optimization/51821 (64bit > 32bit conversion produces incorrect…

re PR rtl-optimization/51821 (64bit > 32bit conversion produces incorrect results with optimizations)

	PR rtl-optimization/51821
	* recog.c (peep2_find_free_register): Determine clobbered registers
	from insn pattern.

testsuite/ChangeLog:

	PR rtl-optimization/51821
	* gcc.dg/pr51821.c: New test.

From-SVN: r183194

gcc/ChangeLog

+2012-01-15  Uros Bizjak  <ubizjak@gmail.com>
+
+	PR rtl-optimization/51821
+	* recog.c (peep2_find_free_register): Determine clobbered registers
+	from insn pattern.
+
 2012-01-14  Denis Chertykov  <chertykov@gmail.com>
 
 	PR target/50925

gcc/recog.c

@@ -3038,6 +3038,7 @@ peep2_find_free_register (int from, int to, const char *class_str,
   static int search_ofs;
   enum reg_class cl;
   HARD_REG_SET live;
+  df_ref *def_rec;
   int i;
 
   gcc_assert (from < MAX_INSNS_PER_PEEP2 + 1);
@@ -3051,12 +3052,14 @@ peep2_find_free_register (int from, int to, const char *class_str,
 
   while (from != to)
     {
-      HARD_REG_SET this_live;
+      gcc_assert (peep2_insn_data[from].insn != NULL_RTX);
+
+      /* Don't use registers set or clobbered by the insn.  */
+      for (def_rec = DF_INSN_DEFS (peep2_insn_data[from].insn);
+	   *def_rec; def_rec++)
+	SET_HARD_REG_BIT (live, DF_REF_REGNO (*def_rec));
 
       from = peep2_buf_position (from + 1);
-      gcc_assert (peep2_insn_data[from].insn != NULL_RTX);
-      REG_SET_TO_HARD_REG_SET (this_live, peep2_insn_data[from].live_before);
-      IOR_HARD_REG_SET (live, this_live);
     }
 
   cl = (class_str[0] == 'r' ? GENERAL_REGS

gcc/testsuite/ChangeLog

+2012-01-15  Uros Bizjak  <ubizjak@gmail.com>
+
+	PR rtl-optimization/51821
+	* gcc.dg/pr51821.c: New test.
+
 2012-01-15  Andreas Schwab  <schwab@linux-m68k.org>
 
 	* gcc.dg/torture/pr8081.c: Fix char signedness assumption.

gcc/testsuite/gcc.dg/pr51821.c

+/* { dg-do run } */
+/* { dg-options "-O2 -msse" { target { i?86-*-* x86_64-*-* } } } */
+/* { dg-require-effective-target sse_runtime { target { i?86-*-* x86_64-*-* } } } */
+
+extern void abort (void);
+
+unsigned int  __attribute__((noinline))
+test (int shift_size)
+{
+  unsigned long long res = ~0;
+
+  return res << shift_size;
+}
+
+int
+main ()
+{
+  int dst = 32;
+
+  if (test (dst) != 0)
+    abort ();
+
+  return 0;
+}