# git rev-parse -q --verify dc1c8034e31b14a2e5e212104ec508aec44ce1b9^{commit} dc1c8034e31b14a2e5e212104ec508aec44ce1b9 already have revision, skipping fetch # git checkout -q -f -B kisskb dc1c8034e31b14a2e5e212104ec508aec44ce1b9 # git clean -qxdf # < git log -1 # commit dc1c8034e31b14a2e5e212104ec508aec44ce1b9 # Author: Linus Torvalds # Date: Sun Jul 28 20:24:12 2024 -0700 # # minmax: simplify min()/max()/clamp() implementation # # Now that we no longer have any C constant expression contexts (ie array # size declarations or static initializers) that use min() or max(), we # can simpify the implementation by not having to worry about the result # staying as a C constant expression. # # So now we can unconditionally just use temporary variables of the right # type, and get rid of the excessive expansion that used to come from the # use of # # __builtin_choose_expr(__is_constexpr(...), .. # # to pick the specialized code for constant expressions. # # Another expansion simplification is to pass the temporary variables (in # addition to the original expression) to our __types_ok() macro. That # may superficially look like it complicates the macro, but when we only # want the type of the expression, expanding the temporary variable names # is much simpler and smaller than expanding the potentially complicated # original expression. # # As a result, on my machine, doing a # # $ time make drivers/staging/media/atomisp/pci/isp/kernels/ynr/ynr_1.0/ia_css_ynr.host.i # # goes from # # real 0m16.621s # user 0m15.360s # sys 0m1.221s # # to # # real 0m2.532s # user 0m2.091s # sys 0m0.452s # # because the token expansion goes down dramatically. # # In particular, the longest line expansion (which was line 71 of that # 'ia_css_ynr.host.c' file) shrinks from 23,338kB (yes, 23MB for one # single line) to "just" 1,444kB (now "only" 1.4MB). # # And yes, that line is still the line from hell, because it's doing # multiple levels of "min()/max()" expansion thanks to some of them being # hidden inside the uDIGIT_FITTING() macro. # # Lorenzo has a nice cleanup patch that makes that driver use inline # functions instead of macros for sDIGIT_FITTING() and uDIGIT_FITTING(), # which will fix that line once and for all, but the 16-fold reduction in # this case does show why we need to simplify these helpers. # # Cc: David Laight # Cc: Lorenzo Stoakes # Signed-off-by: Linus Torvalds # < /opt/cross/kisskb/korg/gcc-11.3.0-nolibc/m68k-linux/bin/m68k-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-11.3.0-nolibc/m68k-linux/bin/m68k-linux-ld --version # < git log --format=%s --max-count=1 dc1c8034e31b14a2e5e212104ec508aec44ce1b9 # make -s -j 160 ARCH=m68k O=/kisskb/build/linus_sun3_defconfig_m68k-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.3.0-nolibc/m68k-linux/bin/m68k-linux- sun3_defconfig # < make -s -j 160 ARCH=m68k O=/kisskb/build/linus_sun3_defconfig_m68k-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.3.0-nolibc/m68k-linux/bin/m68k-linux- help # make -s -j 160 ARCH=m68k O=/kisskb/build/linus_sun3_defconfig_m68k-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.3.0-nolibc/m68k-linux/bin/m68k-linux- olddefconfig # make -s -j 160 ARCH=m68k O=/kisskb/build/linus_sun3_defconfig_m68k-gcc11 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-11.3.0-nolibc/m68k-linux/bin/m68k-linux- Completed OK # rm -rf /kisskb/build/linus_sun3_defconfig_m68k-gcc11 # Build took: 0:00:51.934929