[linux-yocto] [yocto-4.12][PATCH] Mips kernel warining:resolve some warning when compiling arch/mips/math-emu/cp1emu.c

[Bruce Ashfield]

I had already merged this, when I realized that the patch headers
are wrong on this.

I'm not sure how you prepared and sent this, but make sure to not
modify the shortlog, and put the "commit <> upstream", after the
upstream shortlog.

Bruce

n 01/18/2018 01:04 AM, Hongzhi.Song wrote:
> From: Manuel Lauss <manuel.lauss at gmail.com>
> 
> commit 8535f2ba0a9b971df62a5890699b9dfe2e0d5580 upstream
> 
> MIPS: math-emu: do not use bools for arithmetic
> 
> GCC-7 complains about a boolean value being used with an arithmetic
> AND:
> 
> arch/mips/math-emu/cp1emu.c: In function 'cop1Emulate':
> arch/mips/math-emu/cp1emu.c:838:14: warning: '~' on a boolean expression [-Wbool-operation]
>    fpr = (x) & ~(cop1_64bit(xcp) == 0);    \
>                ^
> arch/mips/math-emu/cp1emu.c:1068:3: note: in expansion of macro 'DITOREG'
>     DITOREG(dval, MIPSInst_RT(ir));
>     ^~~~~~~
> arch/mips/math-emu/cp1emu.c:838:14: note: did you mean to use logical not?
>    fpr = (x) & ~(cop1_64bit(xcp) == 0);    \
> 
> Since cop1_64bit() returns and int, just flip the LSB.
> 
> Suggested-by: Maciej W. Rozycki <macro at imgtec.com>
> Signed-off-by: Manuel Lauss <manuel.lauss at gmail.com>
> Reviewed-by: Maciej W. Rozycki <macro at imgtec.com>
> Cc: linux-mips at linux-mips.org
> Patchwork: https://patchwork.linux-mips.org/patch/17058/
> Signed-off-by: Ralf Baechle <ralf at linux-mips.org>
> 
> Signed-off-by: Hongzhi Song <hongzhi.song at windriver.com>
> ---
>   arch/mips/math-emu/cp1emu.c | 4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c
> index add2320..ad20b69 100644
> --- a/arch/mips/math-emu/cp1emu.c
> +++ b/arch/mips/math-emu/cp1emu.c
> @@ -830,12 +830,12 @@ do {									\
>   } while (0)
>   
>   #define DIFROMREG(di, x)						\
> -	((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) == 0)], 0))
> +	((di) = get_fpr64(&ctx->fpr[(x) & ~(cop1_64bit(xcp) ^ 1)], 0))
>   
>   #define DITOREG(di, x)							\
>   do {									\
>   	unsigned fpr, i;						\
> -	fpr = (x) & ~(cop1_64bit(xcp) == 0);				\
> +	fpr = (x) & ~(cop1_64bit(xcp) ^ 1);				\
>   	set_fpr64(&ctx->fpr[fpr], 0, di);				\
>   	for (i = 1; i < ARRAY_SIZE(ctx->fpr[x].val64); i++)		\
>   		set_fpr64(&ctx->fpr[fpr], i, 0);			\
>