On Fri, Jun 24, 2011 at 7:07 AM, Eric Botcazou <ebotca...@adacore.com> wrote:
>> I compared x32 glibc built with the old x32 gcc against x32 glibc built
>> with this patch and
>>
>> http://gcc.gnu.org/ml/gcc-patches/2011-06/msg00913.html
>>
>> reverted, the new glibc is little smaller:
>>
>> New:
>>
>> [hjl@gnu-33 build-x86_64-linux]$ size libc.so
>> text data bss dec hex filename
>> 1537648 10076 12944 1560668 17d05c libc.so
>> [hjl@gnu-33 build-x86_64-linux]$
>>
>> Old:
>>
>> [hjl@gnu-33 build-x86_64-linux.old]$ size libc.so
>> text data bss dec hex filename
>> 1538968 10076 12944 1561988 17d584 libc.so
>> [hjl@gnu-33 build-x86_64-linux.old]$
>>
>> I looked at assembly codes. The new one is better.
>> I will check it in.
>
> OK, but remove the equivalent code in num_sign_bit_copies1 then, otherwise
> someone in a couple of years from now will adapt it to nonzero_bits1 and we
> will be back to square one.
>
I am testing this patch on x32 branch. I will compare glibc binaries before and
after.
Thanks.
--
H.J.
---
diff --git a/gcc/rtlanal.c b/gcc/rtlanal.c
index e5c045d..0be6504 100644
--- a/gcc/rtlanal.c
+++ b/gcc/rtlanal.c
@@ -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);
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;
case MULT:
