# 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 <torvalds@linux-foundation.org>
# 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 <David.Laight@aculab.com>
#     Cc: Lorenzo Stoakes <lorenzo.stoakes@oracle.com>
#     Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
# < /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_ppc64_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  ppc64_defconfig
# < make -s -j 40 ARCH=powerpc O=/kisskb/build/linus_ppc64_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_ppc64_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_ppc64_defconfig_powerpc-gcc5 CROSS_COMPILE=/opt/cross/kisskb/korg/gcc-5.5.0-nolibc/powerpc64-linux/bin/powerpc64-linux-  
/kisskb/src/fs/btrfs/inode.c: In function 'btrfs_lookup_dentry':
/kisskb/src/fs/btrfs/inode.c:5603:9: warning: 'location.objectid' may be used uninitialized in this function [-Wmaybe-uninitialized]
  return btrfs_iget_path(ino, root, NULL);
         ^
/kisskb/src/fs/btrfs/inode.c:5663:19: note: 'location.objectid' was declared here
  struct btrfs_key location;
                   ^
/kisskb/src/fs/btrfs/inode.c:5674:5: warning: 'location.type' may be used uninitialized in this function [-Wmaybe-uninitialized]
  if (location.type == BTRFS_INODE_ITEM_KEY) {
     ^
/kisskb/src/fs/btrfs/inode.c: At top level:
cc1: warning: unrecognized command line option '-Wno-shift-negative-value'
cc1: warning: unrecognized command line option '-Wno-shift-negative-value'
cc1: warning: unrecognized command line option '-Wno-stringop-overflow'
Completed OK
# rm -rf /kisskb/build/linus_ppc64_defconfig_powerpc-gcc5
# Build took: 0:02:03.223343