* simplify-rtx.c (mode_signbit_p): Externalize function...
* rtl.h (mode_signbit_p): ... to here.
* combine.c (simplify_shift_const): Recognize PLUS signbit as
canonical form of XOR signbit and move to outer op.
git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@89235
138bc75d-0d04-0410-961f-
82ee72b054a4
+2004-10-18 Pat Haugen <pthaugen@us.ibm.com>
+
+ * simplify-rtx.c (mode_signbit_p): Externalize function...
+ * rtl.h (mode_signbit_p): ... to here.
+ * combine.c (simplify_shift_const): Recognize PLUS signbit as
+ canonical form of XOR signbit and move to outer op.
+
2004-10-18 Diego Novillo <dnovillo@redhat.com>
* tree-cfg.c (bsi_for_stmt): Rename from stmt_for_bsi.
varop = XEXP (varop, 0);
continue;
}
+
+ /* Check for 'PLUS signbit', which is the canonical form of 'XOR
+ signbit', and attempt to change the PLUS to an XOR and move it to
+ the outer operation as is done above in the AND/IOR/XOR case
+ leg for shift(logical). See details in logical handling above
+ for reasoning in doing so. */
+ if (code == LSHIFTRT
+ && GET_CODE (XEXP (varop, 1)) == CONST_INT
+ && mode_signbit_p (result_mode, XEXP (varop, 1))
+ && (new = simplify_binary_operation (code, result_mode,
+ XEXP (varop, 1),
+ GEN_INT (count))) != 0
+ && GET_CODE (new) == CONST_INT
+ && merge_outer_ops (&outer_op, &outer_const, XOR,
+ INTVAL (new), result_mode, &complement_p))
+ {
+ varop = XEXP (varop, 0);
+ continue;
+ }
+
break;
case MINUS:
extern rtx simplify_replace_rtx (rtx, rtx, rtx);
extern rtx simplify_rtx (rtx);
extern rtx avoid_constant_pool_reference (rtx);
+extern bool mode_signbit_p (enum machine_mode, rtx);
/* In regclass.c */
extern enum machine_mode choose_hard_reg_mode (unsigned int, unsigned int,
((((HOST_WIDE_INT) low) < 0) ? ((HOST_WIDE_INT) -1) : ((HOST_WIDE_INT) 0))
static rtx neg_const_int (enum machine_mode, rtx);
-static bool mode_signbit_p (enum machine_mode, rtx);
static int simplify_plus_minus_op_data_cmp (const void *, const void *);
static rtx simplify_plus_minus (enum rtx_code, enum machine_mode, rtx,
rtx, int);
/* Test whether expression, X, is an immediate constant that represents
the most significant bit of machine mode MODE. */
-static bool
+bool
mode_signbit_p (enum machine_mode mode, rtx x)
{
unsigned HOST_WIDE_INT val;