diff mbox series

[v2,09/11] xen/bitops: Implement hweight32() in terms of hweightl()

Message ID 20240828220351.2686408-10-andrew.cooper3@citrix.com (mailing list archive)
State Superseded
Headers show
Series xen/bitops: hweight() cleanup/improvements | expand

Commit Message

Andrew Cooper Aug. 28, 2024, 10:03 p.m. UTC 
... and drop generic_hweight32().

As noted previously, the only two users of hweight32() are in __init paths.

The int-optimised form of generic_hweight() is only two instructions shorter
than the long-optimised form, and even then only on architectures which lack
fast multiplication, so there's no point providing an int-optimised form.

No functional change.

Signed-off-by: Andrew Cooper <andrew.cooper3@citrix.com>
Acked-by: Jan Beulich <jbeulich@suse.com>
---
CC: Jan Beulich <JBeulich@suse.com>
CC: Roger Pau Monné <roger.pau@citrix.com>
CC: Stefano Stabellini <sstabellini@kernel.org>
CC: Julien Grall <julien@xen.org>
CC: Volodymyr Babchuk <Volodymyr_Babchuk@epam.com>
CC: Bertrand Marquis <bertrand.marquis@arm.com>
CC: Michal Orzel <michal.orzel@amd.com>
CC: Oleksii Kurochko <oleksii.kurochko@gmail.com>
CC: Shawn Anastasio <sanastasio@raptorengineering.com>

v2:
 * Reorder with respect to the hweight64() patch
 * Rerwrite the commit message
 * s/__pure/attr_const/
---
 xen/arch/arm/include/asm/bitops.h | 1 -
 xen/arch/ppc/include/asm/bitops.h | 1 -
 xen/arch/x86/include/asm/bitops.h | 1 -
 xen/include/xen/bitops.h          | 5 +++++
 4 files changed, 5 insertions(+), 3 deletions(-)

Comments

Jan Beulich Aug. 29, 2024, 2:24 p.m. UTC | #1 
On 29.08.2024 00:03, Andrew Cooper wrote:
> --- a/xen/include/xen/bitops.h
> +++ b/xen/include/xen/bitops.h
> @@ -326,6 +326,11 @@ static always_inline attr_const unsigned int hweightl(unsigned long x)
>  #endif
>  }
>  
> +static always_inline attr_const unsigned int hweight32(uint32_t x)

See my question/remark on the earlier patch: I think we want to be consistent
with always-inline functions and const/pure attributes. Since elsewhere we
omit it, I think it should be omitted here, too.

Jan
diff mbox series

Patch

diff --git a/xen/arch/arm/include/asm/bitops.h b/xen/arch/arm/include/asm/bitops.h
index 91cd167b6bbb..b28c25b3d52d 100644
--- a/xen/arch/arm/include/asm/bitops.h
+++ b/xen/arch/arm/include/asm/bitops.h
@@ -85,7 +85,6 @@  bool clear_mask16_timeout(uint16_t mask, volatile void *p,
  * The Hamming Weight of a number is the total number of bits set in it.
  */
 #define hweight64(x) generic_hweight64(x)
-#define hweight32(x) generic_hweight32(x)
 
 #endif /* _ARM_BITOPS_H */
 /*
diff --git a/xen/arch/ppc/include/asm/bitops.h b/xen/arch/ppc/include/asm/bitops.h
index 64512e949530..f488a7c03425 100644
--- a/xen/arch/ppc/include/asm/bitops.h
+++ b/xen/arch/ppc/include/asm/bitops.h
@@ -133,6 +133,5 @@  static inline int test_and_set_bit(unsigned int nr, volatile void *addr)
  * The Hamming Weight of a number is the total number of bits set in it.
  */
 #define hweight64(x) __builtin_popcountll(x)
-#define hweight32(x) __builtin_popcount(x)
 
 #endif /* _ASM_PPC_BITOPS_H */
diff --git a/xen/arch/x86/include/asm/bitops.h b/xen/arch/x86/include/asm/bitops.h
index 4c5b21907a64..507b043b8a86 100644
--- a/xen/arch/x86/include/asm/bitops.h
+++ b/xen/arch/x86/include/asm/bitops.h
@@ -482,6 +482,5 @@  static always_inline unsigned int arch_flsl(unsigned long x)
  * The Hamming Weight of a number is the total number of bits set in it.
  */
 #define hweight64(x) generic_hweight64(x)
-#define hweight32(x) generic_hweight32(x)
 
 #endif /* _X86_BITOPS_H */
diff --git a/xen/include/xen/bitops.h b/xen/include/xen/bitops.h
index 58c600155f7e..a462c3065158 100644
--- a/xen/include/xen/bitops.h
+++ b/xen/include/xen/bitops.h
@@ -326,6 +326,11 @@  static always_inline attr_const unsigned int hweightl(unsigned long x)
 #endif
 }
 
+static always_inline attr_const unsigned int hweight32(uint32_t x)
+{
+    return hweightl(x);
+}
+
 /* --------------------- Please tidy below here --------------------- */
 
 #ifndef find_next_bit