* [PATCH][AArch64] Use popcount_hwi instead of homebrew version
@ 2015-08-19 15:05 Kyrill Tkachov
2015-08-19 15:16 ` James Greenhalgh
0 siblings, 1 reply; 2+ messages in thread
From: Kyrill Tkachov @ 2015-08-19 15:05 UTC (permalink / raw)
To: GCC Patches; +Cc: Marcus Shawcroft, Richard Earnshaw, James Greenhalgh
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Hi all,
I noticed we have a hand-crafted "bit_count" function in the aarch64 backend that implements the popcount operation.
We already have a midend popcount_hwi function operating on HOST_WIDE_INTs which seems to be exactly what we need.
This patch removes the aarch64-specific version and updates the one callsite where it's used, the '%P' output operand,
which itself is only used by the *andim_ashift<mode>_bfiz pattern in aarch64.md.
Bootstrapped and tested on aarch64.
Ok for trunk?
Thanks,
Kyrill
2015-08-19 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
* config/aarch64/aarch64.c (bit_count): Delete prototype
and definition.
(aarch64_print_operand): Use popcount_hwi instead of the above.
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commit d52a7d4a0a4e1a8bcf11e549ded207851b6086b3
Author: Kyrylo Tkachov <kyrylo.tkachov@arm.com>
Date: Wed Aug 19 14:28:45 2015 +0100
[AArch64] Use popcount_hwi instead of homebrew version
diff --git a/gcc/config/aarch64/aarch64.c b/gcc/config/aarch64/aarch64.c
index b16e511..86eabac 100644
--- a/gcc/config/aarch64/aarch64.c
+++ b/gcc/config/aarch64/aarch64.c
@@ -150,7 +150,6 @@ static void aarch64_elf_asm_constructor (rtx, int) ATTRIBUTE_UNUSED;
static void aarch64_elf_asm_destructor (rtx, int) ATTRIBUTE_UNUSED;
static void aarch64_override_options_after_change (void);
static bool aarch64_vector_mode_supported_p (machine_mode);
-static unsigned bit_count (unsigned HOST_WIDE_INT);
static bool aarch64_vectorize_vec_perm_const_ok (machine_mode vmode,
const unsigned char *sel);
static int aarch64_address_cost (rtx, machine_mode, addr_space_t, bool);
@@ -4170,19 +4169,6 @@ aarch64_const_vec_all_same_int_p (rtx x, HOST_WIDE_INT val)
return aarch64_const_vec_all_same_in_range_p (x, val, val);
}
-static unsigned
-bit_count (unsigned HOST_WIDE_INT value)
-{
- unsigned count = 0;
-
- while (value)
- {
- count++;
- value &= value - 1;
- }
-
- return count;
-}
/* N Z C V. */
#define AARCH64_CC_V 1
@@ -4337,7 +4323,7 @@ aarch64_print_operand (FILE *f, rtx x, char code)
return;
}
- asm_fprintf (f, "%u", bit_count (INTVAL (x)));
+ asm_fprintf (f, "%u", popcount_hwi (INTVAL (x)));
break;
case 'H':
^ permalink raw reply [flat|nested] 2+ messages in thread
* Re: [PATCH][AArch64] Use popcount_hwi instead of homebrew version
2015-08-19 15:05 [PATCH][AArch64] Use popcount_hwi instead of homebrew version Kyrill Tkachov
@ 2015-08-19 15:16 ` James Greenhalgh
0 siblings, 0 replies; 2+ messages in thread
From: James Greenhalgh @ 2015-08-19 15:16 UTC (permalink / raw)
To: Kyrill Tkachov; +Cc: GCC Patches, Marcus Shawcroft, Richard Earnshaw
On Wed, Aug 19, 2015 at 04:02:41PM +0100, Kyrill Tkachov wrote:
> Hi all,
>
> I noticed we have a hand-crafted "bit_count" function in the aarch64 backend that implements the popcount operation.
> We already have a midend popcount_hwi function operating on HOST_WIDE_INTs which seems to be exactly what we need.
>
> This patch removes the aarch64-specific version and updates the one callsite where it's used, the '%P' output operand,
> which itself is only used by the *andim_ashift<mode>_bfiz pattern in aarch64.md.
>
> Bootstrapped and tested on aarch64.
>
> Ok for trunk?
OK. A change like this which performs useful cleanup is borderline
obvious.
Thanks,
James
>
> Thanks,
> Kyrill
>
> 2015-08-19 Kyrylo Tkachov <kyrylo.tkachov@arm.com>
>
> * config/aarch64/aarch64.c (bit_count): Delete prototype
> and definition.
> (aarch64_print_operand): Use popcount_hwi instead of the above.
^ permalink raw reply [flat|nested] 2+ messages in thread
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