From patchwork Tue Jul 20 16:21:31 2010
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Subject: Further sign_extend/zero_extend VTA fixes (PR debug/45003)
Date: Tue, 20 Jul 2010 06:21:31 -0000
From: Jakub Jelinek <jakub@redhat.com>
X-Patchwork-Id: 59341
Message-Id: <20100720162131.GE19172@tyan-ft48-01.lab.bos.redhat.com>
To: Richard Guenther <rguenther@suse.de>
Cc: gcc-patches@gcc.gnu.org, Alexandre Oliva <aoliva@redhat.com>

Hi!

This patch handles reg = sign_extend (mem) and
reg = zero_extend (mem) as reversible like if the sign/zero extension
operand is a reg, which cures the attached testcase.  The dwarf2out.c
hunk removes wrong handling of SIGN_EXTEND/ZERO_EXTEND, we can't ignore
them, as can be seen on the -3.c testcase.  mem_loc_descriptor from
default: will handle it correctly.

Bootstrapped/regtested on x86_64-linux and i686-linux.  Ok for trunk?

2010-07-20  Jakub Jelinek  <jakub@redhat.com>

	PR debug/45003
	* var-tracking.c (reverse_op): Also handle {SIGN,ZERO}_EXTEND of
	a MEM.
	* dwarf2out.c (loc_descriptor): Don't handle SIGN_EXTEND nor
	ZERO_EXTEND here.

	* gcc.dg/guality/pr45003-2.c: New test.
	* gcc.dg/guality/pr45003-3.c: New test.


	Jakub


--- gcc/dwarf2out.c.jj	2010-07-16 17:55:08.000000000 +0200
+++ gcc/dwarf2out.c	2010-07-20 15:43:37.000000000 +0200
@@ -14254,11 +14254,6 @@ loc_descriptor (rtx rtl, enum machine_mo
       loc_result = reg_loc_descriptor (rtl, initialized);
       break;
 
-    case SIGN_EXTEND:
-    case ZERO_EXTEND:
-      loc_result = loc_descriptor (XEXP (rtl, 0), mode, initialized);
-      break;
-
     case MEM:
       loc_result = mem_loc_descriptor (XEXP (rtl, 0), GET_MODE (rtl),
 				       initialized);
--- gcc/var-tracking.c.jj	2010-07-16 17:55:08.000000000 +0200
+++ gcc/var-tracking.c	2010-07-20 15:02:47.000000000 +0200
@@ -5187,16 +5187,19 @@ reverse_op (rtx val, const_rtx expr)
     case XOR:
     case NOT:
     case NEG:
+      if (!REG_P (XEXP (src, 0)))
+	return NULL_RTX;
+      break;
     case SIGN_EXTEND:
     case ZERO_EXTEND:
+      if (!REG_P (XEXP (src, 0)) && !MEM_P (XEXP (src, 0)))
+	return NULL_RTX;
       break;
     default:
       return NULL_RTX;
     }
 
-  if (!REG_P (XEXP (src, 0))
-      || !SCALAR_INT_MODE_P (GET_MODE (src))
-      || XEXP (src, 0) == cfa_base_rtx)
+  if (!SCALAR_INT_MODE_P (GET_MODE (src)) || XEXP (src, 0) == cfa_base_rtx)
     return NULL_RTX;
 
   v = cselib_lookup (XEXP (src, 0), GET_MODE (XEXP (src, 0)), 0);
--- gcc/testsuite/gcc.dg/guality/pr45003-2.c.jj	2010-07-20 15:07:21.000000000 +0200
+++ gcc/testsuite/gcc.dg/guality/pr45003-2.c	2010-07-20 15:07:50.000000000 +0200
@@ -0,0 +1,31 @@
+/* PR debug/45003 */
+/* { dg-do run { target { x86_64-*-* && lp64 } } } */
+/* { dg-options "-g" } */
+
+int __attribute__((noinline))
+foo (unsigned short *p)
+{
+  int a = *p;
+  asm volatile ("nop" : : "D" ((int) *p));
+  asm volatile ("nop" : : "D" ((int) *p));	/* { dg-final { gdb-test 10 "a" "0x8078" } } */
+  return 0;
+}
+
+int __attribute__((noinline))
+bar (short *p)
+{
+  unsigned int a = *p;
+  asm volatile ("nop" : : "D" ((unsigned int) *p));
+  asm volatile ("nop" : : "D" ((unsigned int) *p));	/* { dg-final { gdb-test 19 "a" "0xffff8078" } } */
+  return 0;
+}
+
+int
+main ()
+{
+  unsigned short us = 0x8078;
+  foo (&us);
+  short s = -32648;
+  bar (&s);
+  return 0;
+}
--- gcc/testsuite/gcc.dg/guality/pr45003-3.c.jj	2010-07-20 15:43:58.000000000 +0200
+++ gcc/testsuite/gcc.dg/guality/pr45003-3.c	2010-07-20 15:45:39.000000000 +0200
@@ -0,0 +1,31 @@
+/* PR debug/45003 */
+/* { dg-do run { target { x86_64-*-* && lp64 } } } */
+/* { dg-options "-g" } */
+
+int __attribute__((noinline))
+foo (unsigned short *p)
+{
+  int a = (short) *p;
+  asm volatile ("nop" : : "D" ((int) *p));
+  asm volatile ("nop" : : "D" ((int) *p));	/* { dg-final { gdb-test 10 "a" "-32648" } } */
+  return 0;
+}
+
+int __attribute__((noinline))
+bar (short *p)
+{
+  unsigned int a = (unsigned short) *p;
+  asm volatile ("nop" : : "D" ((unsigned int) *p));
+  asm volatile ("nop" : : "D" ((unsigned int) *p));	/* { dg-final { gdb-test 19 "a" "0x8078" } } */
+  return 0;
+}
+
+int
+main ()
+{
+  unsigned short us = 0x8078;
+  foo (&us);
+  short s = -32648;
+  bar (&s);
+  return 0;
+}