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Properly handle pointer addition/subtraction in num_sign_bit_copies1. 

From-SVN: r175383
This commit is contained in:
H.J. Lu 2011-06-24 15:26:33 +00:00 committed by H.J. Lu
parent 89f920259c
commit 1f134bd6d6
2 changed files with 2 additions and 16 deletions
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3
gcc/ChangeLog
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@ -2,7 +2,8 @@
PR rtl-optimization/49504 PR rtl-optimization/49504
* rtlanal.c (nonzero_bits1): Properly handle addition or * rtlanal.c (nonzero_bits1): Properly handle addition or
subtraction a pointer in Pmode if pointers extend unsigned. subtraction of a pointer in Pmode if pointers extend unsigned.
(num_sign_bit_copies1): Likewise.
2011-06-24 Martin Jambor <mjambor@suse.cz> 2011-06-24 Martin Jambor <mjambor@suse.cz>

15
gcc/rtlanal.c
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@ -4605,21 +4605,6 @@ num_sign_bit_copies1 (const_rtx x, enum machine_mode mode, const_rtx known_x,
known_x, known_mode, known_ret); known_x, known_mode, known_ret);
result = MAX (1, MIN (num0, num1) - 1); result = MAX (1, MIN (num0, num1) - 1);
#ifdef POINTERS_EXTEND_UNSIGNED
/* If pointers extend signed and this is an addition or subtraction
to a pointer in Pmode, all the bits above ptr_mode are known to be
sign bit copies. */
/* As we do not know which address space the pointer is refering to,
we can do this only if the target does not support different pointer
or address modes depending on the address space. */
if (target_default_pointer_address_modes_p ()
&& ! POINTERS_EXTEND_UNSIGNED && GET_MODE (x) == Pmode
&& (code == PLUS || code == MINUS)
&& REG_P (XEXP (x, 0)) && REG_POINTER (XEXP (x, 0)))
result = MAX ((int) (GET_MODE_BITSIZE (Pmode)
- GET_MODE_BITSIZE (ptr_mode) + 1),
result);
#endif
return result; return result;
case MULT: case MULT: