Avoid unnecessary nested min()/max() which results in egregious macro expansion. Use clamp_t() as this introduces the least possible expansion.
Not doing so results in an impact on build times.
This resolves an issue with slackware 15.0 32-bit compilation as reported by Richard Narron.
Presumably the min/max fixups would be difficult to backport, this patch should be easier and fix's Richard's problem in 5.15.
Reported-by: Richard Narron richard@aaazen.com Closes: https://lore.kernel.org/all/4a5321bd-b1f-1832-f0c-cea8694dc5aa@aaazen.com/ Fixes: 867046cc7027 ("minmax: relax check to allow comparison between unsigned arguments and signed constants") Cc: stable@vger.kernel.org Signed-off-by: Lorenzo Stoakes lorenzo.stoakes@oracle.com --- .../staging/media/atomisp/pci/sh_css_frac.h | 26 ++++++++++++++----- 1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/drivers/staging/media/atomisp/pci/sh_css_frac.h b/drivers/staging/media/atomisp/pci/sh_css_frac.h index b90b5b330dfa..8ba65161f7a9 100644 --- a/drivers/staging/media/atomisp/pci/sh_css_frac.h +++ b/drivers/staging/media/atomisp/pci/sh_css_frac.h @@ -32,12 +32,24 @@ #define uISP_VAL_MAX ((unsigned int)((1 << uISP_REG_BIT) - 1))
/* a:fraction bits for 16bit precision, b:fraction bits for ISP precision */ -#define sDIGIT_FITTING(v, a, b) \ - min_t(int, max_t(int, (((v) >> sSHIFT) >> max(sFRACTION_BITS_FITTING(a) - (b), 0)), \ - sISP_VAL_MIN), sISP_VAL_MAX) -#define uDIGIT_FITTING(v, a, b) \ - min((unsigned int)max((unsigned)(((v) >> uSHIFT) \ - >> max((int)(uFRACTION_BITS_FITTING(a) - (b)), 0)), \ - uISP_VAL_MIN), uISP_VAL_MAX) +static inline int sDIGIT_FITTING(int v, int a, int b) +{ + int fit_shift = sFRACTION_BITS_FITTING(a) - b; + + v >>= sSHIFT; + v >>= fit_shift > 0 ? fit_shift : 0; + + return clamp_t(int, v, sISP_VAL_MIN, sISP_VAL_MAX); +} + +static inline unsigned int uDIGIT_FITTING(unsigned int v, int a, int b) +{ + int fit_shift = uFRACTION_BITS_FITTING(a) - b; + + v >>= uSHIFT; + v >>= fit_shift > 0 ? fit_shift : 0; + + return clamp_t(unsigned int, v, uISP_VAL_MIN, uISP_VAL_MAX); +}
#endif /* __SH_CSS_FRAC_H */ -- 2.46.0
Hi,
On 9/11/24 7:51 PM, Lorenzo Stoakes wrote:
Avoid unnecessary nested min()/max() which results in egregious macro expansion. Use clamp_t() as this introduces the least possible expansion.
Not doing so results in an impact on build times.
This resolves an issue with slackware 15.0 32-bit compilation as reported by Richard Narron.
Presumably the min/max fixups would be difficult to backport, this patch should be easier and fix's Richard's problem in 5.15.
Reported-by: Richard Narron richard@aaazen.com Closes: https://lore.kernel.org/all/4a5321bd-b1f-1832-f0c-cea8694dc5aa@aaazen.com/ Fixes: 867046cc7027 ("minmax: relax check to allow comparison between unsigned arguments and signed constants") Cc: stable@vger.kernel.org Signed-off-by: Lorenzo Stoakes lorenzo.stoakes@oracle.com
Thanks, patch looks good to me:
Reviewed-by: Hans de Goede hdegoede@redhat.com
Regards,
Hans
.../staging/media/atomisp/pci/sh_css_frac.h | 26 ++++++++++++++----- 1 file changed, 19 insertions(+), 7 deletions(-)
diff --git a/drivers/staging/media/atomisp/pci/sh_css_frac.h b/drivers/staging/media/atomisp/pci/sh_css_frac.h index b90b5b330dfa..8ba65161f7a9 100644 --- a/drivers/staging/media/atomisp/pci/sh_css_frac.h +++ b/drivers/staging/media/atomisp/pci/sh_css_frac.h @@ -32,12 +32,24 @@ #define uISP_VAL_MAX ((unsigned int)((1 << uISP_REG_BIT) - 1))
/* a:fraction bits for 16bit precision, b:fraction bits for ISP precision */ -#define sDIGIT_FITTING(v, a, b) \
- min_t(int, max_t(int, (((v) >> sSHIFT) >> max(sFRACTION_BITS_FITTING(a) - (b), 0)), \
sISP_VAL_MIN), sISP_VAL_MAX)-#define uDIGIT_FITTING(v, a, b) \
- min((unsigned int)max((unsigned)(((v) >> uSHIFT) \
uISP_VAL_MIN), uISP_VAL_MAX)+static inline int sDIGIT_FITTING(int v, int a, int b) +{
- int fit_shift = sFRACTION_BITS_FITTING(a) - b;
- v >>= sSHIFT;
- v >>= fit_shift > 0 ? fit_shift : 0;
- return clamp_t(int, v, sISP_VAL_MIN, sISP_VAL_MAX);
+}
+static inline unsigned int uDIGIT_FITTING(unsigned int v, int a, int b) +{
- int fit_shift = uFRACTION_BITS_FITTING(a) - b;
- v >>= uSHIFT;
- v >>= fit_shift > 0 ? fit_shift : 0;
- return clamp_t(unsigned int, v, uISP_VAL_MIN, uISP_VAL_MAX);
+}
#endif /* __SH_CSS_FRAC_H */
2.46.0
On Wed, 11 Sept 2024 at 10:51, Lorenzo Stoakes lorenzo.stoakes@oracle.com wrote:
Avoid unnecessary nested min()/max() which results in egregious macro expansion. Use clamp_t() as this introduces the least possible expansion.
I took this (single) patch directly, since that's the one that actually causes build problems in limited environments (admittedly not in current git with the more invasive min/max cleanups, but in order to be back-ported).
Plus it cleans up the code with more legible inline functions, rather than just doing some minimal syntactic changes. I expanded on the commit message to say that.
The two others I'll leave for now and see what maintainers of their respective areas think.
Linus
linux-stable-mirror@lists.linaro.org
-
Hans de Goede -
Linus Torvalds -
Lorenzo Stoakes