From: Richard Henderson <rth@redhat.com>
Date: Thu, 24 Oct 2002 08:59:50 +0000 (-0700)
Subject: re PR rtl-optimization/7944 (gcc 3.2: Internal compiler error in find_reloads_toplev... 
X-Git-Tag: releases/gcc-3.2.1~108
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=2a3cea2b6cc11efacec89cbfc1c569079a1f88b6;p=thirdparty%2Fgcc.git

re PR rtl-optimization/7944 (gcc 3.2: Internal compiler error in find_reloads_toplev, at reload.c:4462)

        PR opt/7944
        * reload.c (find_reloads_toplev): Use simplify_gen_subreg; mode
        of X is not important when simplifying subregs of constants.
	* g++.dg/opt/reload1.C: New.

From-SVN: r58489
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 6a03ecd48500..c30bd15baec1 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2002-10-24  Richard Henderson  <rth@redhat.com>
+
+	PR opt/7944
+	* reload.c (find_reloads_toplev): Use simplify_gen_subreg; mode
+	of X is not important when simplifying subregs of constants.
+
 2002-10-23  Robert Lipe  <robertlipe@usa.net>
 
 	* config.gcc (i[34567]86-*-sco3.2v5*): Fix tm_file.
diff --git a/gcc/reload.c b/gcc/reload.c
index 166e11066205..71ed1d6771c3 100644
--- a/gcc/reload.c
+++ b/gcc/reload.c
@@ -4427,20 +4427,12 @@ find_reloads_toplev (x, opnum, type, ind_levels, is_set_dest, insn,
 					reg_equiv_constant[regno])) != 0)
 	return tem;
 
-      if (GET_MODE_BITSIZE (GET_MODE (x)) == BITS_PER_WORD
-	  && regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] < 0
-	  && reg_equiv_constant[regno] != 0
-	  && (tem = operand_subword (reg_equiv_constant[regno],
-				     SUBREG_BYTE (x) / UNITS_PER_WORD, 0,
-				     GET_MODE (SUBREG_REG (x)))) != 0)
+      if (regno >= FIRST_PSEUDO_REGISTER && reg_renumber[regno] < 0
+	  && reg_equiv_constant[regno] != 0)
 	{
-	  /* TEM is now a word sized constant for the bits from X that
-	     we wanted.  However, TEM may be the wrong representation.
-
-	     Use gen_lowpart_common to convert a CONST_INT into a
-	     CONST_DOUBLE and vice versa as needed according to by the mode
-	     of the SUBREG.  */
-	  tem = gen_lowpart_common (GET_MODE (x), tem);
+	  tem =
+	    simplify_gen_subreg (GET_MODE (x), reg_equiv_constant[regno],
+				 GET_MODE (SUBREG_REG (x)), SUBREG_BYTE (x));
 	  if (!tem)
 	    abort ();
 	  return tem;
diff --git a/gcc/testsuite/g++.dg/opt/reload1.C b/gcc/testsuite/g++.dg/opt/reload1.C
new file mode 100644
index 000000000000..0d8fb894e4e1
--- /dev/null
+++ b/gcc/testsuite/g++.dg/opt/reload1.C
@@ -0,0 +1,43 @@
+// PR 7944
+// { dg-do compile }
+// { dg-options -O2 }
+
+struct B
+{
+  B & operator << (short s)
+  {
+    int j;
+    if (j)
+        return operator << (s);
+    else
+        return operator << (s);
+  }
+};
+
+struct A
+{
+  int i;
+  static void bar ();
+  static int quux ()
+  {
+    bar ();
+    return 0;
+  }
+
+  A ():i (quux ())
+  {
+  }
+  ~A ()
+  {
+  }
+};
+
+void
+foo ()
+{
+  short s[4] = { 0, 0, 0, 1 };
+  A a[2] = { A (), A () };
+
+  B b;
+  b << s[0] << s[2];
+}