Re: [PATCH v2 7/8] qemu/bswap: Use compiler __builtin_bswap() on NetBSD

[Kamil Rytarowski]

On 28.09.2020 15:19, Philippe Mathieu-Daudé wrote:
> Since commit efc6c070aca ("configure: Add a test for the minimum
> compiler version") the minimum compiler version required for GCC
> is 4.8, which supports __builtin_bswap().
> Remove the NetBSD specific ifdef'ry.
> 
> This reverts commit 1360677cfe3ca8f945fa1de77823df21a77e4500
> ("makes NetBSD use the native bswap functions").
> 

Personally, I prefer using the system headers. but if you want to use
the GCC builtins, please go for it.

> Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
> ---
>  configure            | 15 ---------------
>  include/qemu/bswap.h |  5 -----
>  2 files changed, 20 deletions(-)
> 
> diff --git a/configure b/configure
> index bff787daea7..1b0a02a0af8 100755
> --- a/configure
> +++ b/configure
> @@ -4886,18 +4886,6 @@ if test "$docs" != "no" ; then
>    fi
>  fi
>  
> -# Search for bswap32 function
> -bswap_h=no
> -cat > $TMPC << EOF
> -#include <sys/endian.h>
> -#include <sys/types.h>
> -#include <machine/bswap.h>
> -int main(void) { return bswap32(0); }
> -EOF
> -if compile_prog "" "" ; then
> -  bswap_h=yes
> -fi
> -
>  ##########################################
>  # Do we have libiscsi >= 1.9.0
>  if test "$libiscsi" != "no" ; then
> @@ -6779,9 +6767,6 @@ fi
>  if test "$st_atim" = "yes" ; then
>    echo "HAVE_STRUCT_STAT_ST_ATIM=y" >> $config_host_mak
>  fi
> -if test "$bswap_h" = "yes" ; then
> -  echo "CONFIG_MACHINE_BSWAP_H=y" >> $config_host_mak
> -fi
>  if test "$curl" = "yes" ; then
>    echo "CONFIG_CURL=y" >> $config_host_mak
>    echo "CURL_CFLAGS=$curl_cflags" >> $config_host_mak
> diff --git a/include/qemu/bswap.h b/include/qemu/bswap.h
> index 1a297bfec22..7e586531c09 100644
> --- a/include/qemu/bswap.h
> +++ b/include/qemu/bswap.h
> @@ -3,17 +3,12 @@
>  
>  #include "fpu/softfloat-types.h"
>  
> -#ifdef CONFIG_MACHINE_BSWAP_H
> -# include <sys/endian.h>
> -# include <machine/bswap.h>
> -#else
>  #undef  bswap16
>  #define bswap16(_x) __builtin_bswap16(_x)
>  #undef  bswap32
>  #define bswap32(_x) __builtin_bswap32(_x)
>  #undef  bswap64
>  #define bswap64(_x) __builtin_bswap64(_x)
> -#endif /* ! CONFIG_MACHINE_BSWAP_H */
>  
>  static inline void bswap16s(uint16_t *s)
>  {
>