# 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-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-gcc --version # < /opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-ld --version # < git log --format=%s --max-count=1 dc1c8034e31b14a2e5e212104ec508aec44ce1b9 # make -s -j 40 ARCH=powerpc O=/kisskb/build/linus_pseries_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- pseries_defconfig Using /kisskb/src/arch/powerpc/configs/ppc64_defconfig as base Merging /kisskb/src/arch/powerpc/configs/le.config Merging /kisskb/src/arch/powerpc/configs/guest.config Value of CONFIG_VIRTIO_BLK is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_VIRTIO_BLK=m New value: CONFIG_VIRTIO_BLK=y Value of CONFIG_SCSI_VIRTIO is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_SCSI_VIRTIO=m New value: CONFIG_SCSI_VIRTIO=y Value of CONFIG_VIRTIO_NET is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_VIRTIO_NET=m New value: CONFIG_VIRTIO_NET=y Value of CONFIG_VIRTIO_CONSOLE is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_VIRTIO_CONSOLE=m New value: CONFIG_VIRTIO_CONSOLE=y Value of CONFIG_VIRTIO_PCI is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_VIRTIO_PCI=m New value: CONFIG_VIRTIO_PCI=y Value of CONFIG_VIRTIO_BALLOON is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_VIRTIO_BALLOON=m New value: CONFIG_VIRTIO_BALLOON=y Value of CONFIG_VHOST_NET is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_VHOST_NET=m New value: CONFIG_VHOST_NET=y Value of CONFIG_IBMVETH is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_IBMVETH=m New value: CONFIG_IBMVETH=y Value of CONFIG_IBMVNIC is redefined by fragment /kisskb/src/arch/powerpc/configs/guest.config: Previous value: CONFIG_IBMVNIC=m New value: CONFIG_IBMVNIC=y Merging /kisskb/src/arch/powerpc/configs/kvm_guest.config # # merged configuration written to .config (needs make) # # < make -s -j 40 ARCH=powerpc O=/kisskb/build/linus_pseries_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- help # make -s -j 40 ARCH=powerpc O=/kisskb/build/linus_pseries_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- olddefconfig # make -s -j 40 ARCH=powerpc O=/kisskb/build/linus_pseries_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux- Completed OK # rm -rf /kisskb/build/linus_pseries_defconfig_powerpc-gcc5 # Build took: 0:01:54.083205