[ARC] Rework delegitimate_address hook

Delegitimize address is used to undo the obfuscating effect of PIC
addresses, returning the address in a way which is understood by the
compiler.  The old version of the hook was outdated, not beeing able
to recognize the current addresses generated by the ARC backend.

gcc/
2018-01-26  Claudiu Zissulescu  <claziss@synopsys.com>

	* config/arc/arc.c (arc_delegitimize_address_0): Refactored to
	recognize new pic like addresses.
	(arc_delegitimize_address): Clean up.

testsuite/
2018-01-26  Claudiu Zissulescu  <claziss@synopsys.com>

	* testsuite/gcc.target/arc/tdelegitimize_addr.c: New test.

From-SVN: r257084

4 files changed, 72 insertions, 52 deletions

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index f4f61fe..751226d 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,5 +1,11 @@
 2018-01-26  Claudiu Zissulescu  <claziss@synopsys.com>
 
+	* config/arc/arc.c (arc_delegitimize_address_0): Refactored to
+	recognize new pic like addresses.
+	(arc_delegitimize_address): Clean up.
+
+2018-01-26  Claudiu Zissulescu  <claziss@synopsys.com>
+
 	* config/arc/arc-arches.def: Option mrf16 valid for all
 	architectures.
 	* config/arc/arc-c.def (__ARC_RF16__): New predefined macro.
diff --git a/gcc/config/arc/arc.c b/gcc/config/arc/arc.c
index fd10d01..fc18f65 100644
--- a/gcc/config/arc/arc.c
+++ b/gcc/config/arc/arc.c
@@ -9567,68 +9567,55 @@ arc_legitimize_address (rtx orig_x, rtx oldx, machine_mode mode)
 }
 
 static rtx
-arc_delegitimize_address_0 (rtx x)
+arc_delegitimize_address_0 (rtx op)
 {
-  rtx u, gp, p;
-
-  if (GET_CODE (x) == CONST && GET_CODE (u = XEXP (x, 0)) == UNSPEC)
+  switch (GET_CODE (op))
     {
-      if (XINT (u, 1) == ARC_UNSPEC_GOT
-	  || XINT (u, 1) == ARC_UNSPEC_GOTOFFPC)
-	return XVECEXP (u, 0, 0);
+    case CONST:
+      return arc_delegitimize_address_0 (XEXP (op, 0));
+
+    case UNSPEC:
+      switch (XINT (op, 1))
+	{
+	case ARC_UNSPEC_GOT:
+	case ARC_UNSPEC_GOTOFFPC:
+	  return XVECEXP (op, 0, 0);
+	default:
+	  break;
+	}
+      break;
+
+    case PLUS:
+      {
+	rtx t1 = arc_delegitimize_address_0 (XEXP (op, 0));
+	rtx t2 = XEXP (op, 1);
+
+	if (t1 && t2)
+	  return gen_rtx_PLUS (GET_MODE (op), t1, t2);
+	break;
+      }
+
+    default:
+      break;
     }
-  else if (GET_CODE (x) == CONST && GET_CODE (p = XEXP (x, 0)) == PLUS
-	   && GET_CODE (u = XEXP (p, 0)) == UNSPEC
-	   && (XINT (u, 1) == ARC_UNSPEC_GOT
-	       || XINT (u, 1) == ARC_UNSPEC_GOTOFFPC))
-    return gen_rtx_CONST
-	    (GET_MODE (x),
-	     gen_rtx_PLUS (GET_MODE (p), XVECEXP (u, 0, 0), XEXP (p, 1)));
-  else if (GET_CODE (x) == PLUS
-	   && ((REG_P (gp = XEXP (x, 0))
-		&& REGNO (gp) == PIC_OFFSET_TABLE_REGNUM)
-	       || (GET_CODE (gp) == CONST
-		   && GET_CODE (u = XEXP (gp, 0)) == UNSPEC
-		   && XINT (u, 1) == ARC_UNSPEC_GOT
-		   && GET_CODE (XVECEXP (u, 0, 0)) == SYMBOL_REF
-		   && !strcmp (XSTR (XVECEXP (u, 0, 0), 0), "_DYNAMIC")))
-	   && GET_CODE (XEXP (x, 1)) == CONST
-	   && GET_CODE (u = XEXP (XEXP (x, 1), 0)) == UNSPEC
-	   && XINT (u, 1) == ARC_UNSPEC_GOTOFF)
-    return XVECEXP (u, 0, 0);
-  else if (GET_CODE (x) == PLUS && GET_CODE (XEXP (x, 0)) == PLUS
-	   && ((REG_P (gp = XEXP (XEXP (x, 0), 1))
-		&& REGNO (gp) == PIC_OFFSET_TABLE_REGNUM)
-	       || (GET_CODE (gp) == CONST
-		   && GET_CODE (u = XEXP (gp, 0)) == UNSPEC
-		   && XINT (u, 1) == ARC_UNSPEC_GOT
-		   && GET_CODE (XVECEXP (u, 0, 0)) == SYMBOL_REF
-		   && !strcmp (XSTR (XVECEXP (u, 0, 0), 0), "_DYNAMIC")))
-	   && GET_CODE (XEXP (x, 1)) == CONST
-	   && GET_CODE (u = XEXP (XEXP (x, 1), 0)) == UNSPEC
-	   && XINT (u, 1) == ARC_UNSPEC_GOTOFF)
-    return gen_rtx_PLUS (GET_MODE (x), XEXP (XEXP (x, 0), 0),
-			 XVECEXP (u, 0, 0));
-  else if (GET_CODE (x) == PLUS
-	   && (u = arc_delegitimize_address_0 (XEXP (x, 1))))
-    return gen_rtx_PLUS (GET_MODE (x), XEXP (x, 0), u);
   return NULL_RTX;
 }
 
 static rtx
-arc_delegitimize_address (rtx x)
+arc_delegitimize_address (rtx orig_x)
 {
-  rtx orig_x = x = delegitimize_mem_from_attrs (x);
-  if (GET_CODE (x) == MEM)
+  rtx x = orig_x;
+
+  if (MEM_P (x))
     x = XEXP (x, 0);
+
   x = arc_delegitimize_address_0 (x);
-  if (x)
-    {
-      if (MEM_P (orig_x))
-	x = replace_equiv_address_nv (orig_x, x);
-      return x;
-    }
-  return orig_x;
+  if (!x)
+    return orig_x;
+
+  if (MEM_P (orig_x))
+    x = replace_equiv_address_nv (orig_x, x);
+  return x;
 }
 
 /* Return a REG rtx for acc1.  N.B. the gcc-internal representation may
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 4e02b1e..741e538 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,5 +1,9 @@
 2018-01-26  Claudiu Zissulescu  <claziss@synopsys.com>
 
+	* testsuite/gcc.target/arc/tdelegitimize_addr.c: New test.
+
+2018-01-26  Claudiu Zissulescu  <claziss@synopsys.com>
+
 	* gcc.target/arc/jli-1.c: New file.
 	* gcc.target/arc/jli-2.c: Likewise.
 
diff --git a/gcc/testsuite/gcc.target/arc/tdelegitimize_addr.c b/gcc/testsuite/gcc.target/arc/tdelegitimize_addr.c
new file mode 100755
index 0000000..0d010ff
--- /dev/null
+++ b/gcc/testsuite/gcc.target/arc/tdelegitimize_addr.c
@@ -0,0 +1,23 @@
+/* { dg-do compile } */
+/* { dg-skip-if "" { ! { clmcpu } } } */
+/* { dg-options "-mcpu=archs -g -O1 -fpic -mlra" } */
+
+/* Check if delegitimize address returns correctly the un-obfuscated
+   address.  */
+
+typedef struct {
+  long long tv_usec;
+} t_a;
+
+static t_a a;
+
+int b;
+extern void fn2 (t_a);
+
+void fn1 (void)
+{
+ again:
+  fn2(a);
+  if (b)
+    goto again;
+}