re PR tree-optimization/56064 (Optimize VIEW_CONVERT_EXPR with FIXED_CST)

gcc/
	PR tree-optimization/56064
	* fixed-value.c (fixed_from_double_int): Sign/zero extend payload
	bits according to mode.
	* fixed-value.h (fixed_from_double_int)
	(const_fixed_from_double_int): Adjust comments.

gcc/testsuite/
	PR tree-optimization/56064
	* gcc.dg/fixed-point/view-convert-2.c: New test.

From-SVN: r195885

gcc/ChangeLog

@@ -1,3 +1,11 @@
+2013-02-08  Georg-Johann Lay  <avr@gjlay.de>
+
+	PR tree-optimization/56064
+	* fixed-value.c (fixed_from_double_int): Sign/zero extend payload
+	bits according to mode.
+	* fixed-value.h (fixed_from_double_int)
+	(const_fixed_from_double_int): Adjust comments.
+
 2013-02-08  Richard Biener  <rguenther@suse.de>
 
 	PR lto/56231

gcc/fixed-value.c

@@ -83,7 +83,7 @@ check_real_for_fixed_mode (REAL_VALUE_TYPE *real_value, enum machine_mode mode)
 
 
 /* Construct a CONST_FIXED from a bit payload and machine mode MODE.
-   The bits in PAYLOAD are used verbatim.  */
+   The bits in PAYLOAD are sign-extended/zero-extended according to MODE.  */
 
 FIXED_VALUE_TYPE
 fixed_from_double_int (double_int payload, enum machine_mode mode)
@@ -92,7 +92,13 @@ fixed_from_double_int (double_int payload, enum machine_mode mode)
 
   gcc_assert (GET_MODE_BITSIZE (mode) <= HOST_BITS_PER_DOUBLE_INT);
 
-  value.data = payload;
+  if (SIGNED_SCALAR_FIXED_POINT_MODE_P (mode))
+    value.data = payload.sext (1 + GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode));
+  else if (UNSIGNED_SCALAR_FIXED_POINT_MODE_P (mode))
+    value.data = payload.zext (GET_MODE_IBIT (mode) + GET_MODE_FBIT (mode));
+  else
+    gcc_unreachable();
+
   value.mode = mode;
 
   return value;

gcc/fixed-value.h

@@ -50,12 +50,12 @@ extern FIXED_VALUE_TYPE fconst1[MAX_FCONST1];
 extern rtx const_fixed_from_fixed_value (FIXED_VALUE_TYPE, enum machine_mode);
 
 /* Construct a FIXED_VALUE from a bit payload and machine mode MODE.
-   The bits in PAYLOAD are used verbatim.  */
+   The bits in PAYLOAD are sign-extended/zero-extended according to MODE.  */
 extern FIXED_VALUE_TYPE fixed_from_double_int (double_int,
 						     enum machine_mode);
 
 /* Return a CONST_FIXED from a bit payload and machine mode MODE.
-   The bits in PAYLOAD are used verbatim.  */
+   The bits in PAYLOAD are sign-extended/zero-extended according to MODE.  */
 static inline rtx
 const_fixed_from_double_int (double_int payload,
                              enum machine_mode mode)

gcc/testsuite/ChangeLog

@@ -1,3 +1,8 @@
+2013-02-08  Georg-Johann Lay  <avr@gjlay.de>
+
+	PR tree-optimization/56064
+	* gcc.dg/fixed-point/view-convert-2.c: New test.
+
 2013-02-08  Michael Matz  <matz@suse.de>
 
 	PR tree-optimization/52448

gcc/testsuite/gcc.dg/fixed-point/view-convert-2.c

@@ -0,0 +1,139 @@
+/* PR tree-optimization/56064 */
+/* { dg-do run } */
+/* { dg-options "-std=gnu99 -O2" } */
+
+extern void abort (void);
+extern void exit (int);
+
+void test_k (void)
+{
+  _Accum a;
+  __INT32_TYPE__ i = -__INT32_MAX__;
+  
+  if (sizeof (a) != sizeof (i))
+    return;
+
+  __builtin_memcpy (&a, &i, sizeof (a));
+
+  if (a >= 0k)
+    abort();
+}
+
+void test_0k (void)
+{
+  _Accum a;
+  __INT32_TYPE__ i = 0;
+  
+  if (sizeof (a) != sizeof (i))
+    return;
+
+  __builtin_memcpy (&a, &i, sizeof (a));
+
+  if (a != 0k)
+    abort();
+}
+
+
+void test_hr (void)
+{
+  short _Fract a;
+  __INT8_TYPE__ i = -__INT8_MAX__;
+
+  if (sizeof (a) != sizeof (i))
+    return;
+
+  __builtin_memcpy (&a, &i, sizeof (a));
+
+  if (a >= 0hr)
+    abort();
+}
+
+void test_0hr (void)
+{
+  short _Fract a;
+  __INT8_TYPE__ i = 0;
+
+  if (sizeof (a) != sizeof (i))
+    return;
+
+  __builtin_memcpy (&a, &i, sizeof (a));
+
+  if (a != 0hr)
+    abort();
+}
+
+
+void test_si (void)
+{
+  _Accum a = __ACCUM_MIN__;
+  __INT32_TYPE__ i;
+
+  if (sizeof (a) != sizeof (i))
+    return;
+
+  __builtin_memcpy (&i, &a, sizeof (i));
+
+  if (i >= 0)
+    abort();
+}
+
+void test_0si (void)
+{
+  _Accum a = 0;
+  __INT32_TYPE__ i;
+
+  if (sizeof (a) != sizeof (i))
+    return;
+
+  __builtin_memcpy (&i, &a, sizeof (i));
+
+  if (i != 0)
+    abort();
+}
+
+
+void test_qi (void)
+{
+  short _Fract a = __SFRACT_MIN__;
+  __INT8_TYPE__ i;
+
+  if (sizeof (a) != sizeof (i))
+    return;
+
+  __builtin_memcpy (&i, &a, sizeof (i));
+
+  if (i >= 0)
+    abort();
+}
+
+void test_0qi (void)
+{
+  short _Fract a = 0hr;
+  __INT8_TYPE__ i;
+
+  if (sizeof (a) != sizeof (i))
+    return;
+
+  __builtin_memcpy (&i, &a, sizeof (i));
+
+  if (i != 0)
+    abort();
+}
+
+
+int main (void)
+{
+  test_hr();
+  test_k();
+  test_qi();
+  test_si();
+
+  test_0hr();
+  test_0k();
+  test_0qi();
+  test_0si();
+
+  exit (0);
+
+  return 0;
+}