• Timothy B. Terriberry's avatar
    Add runtime CPU detection support for ARM. · b71962fd
    Timothy B. Terriberry authored
    The primary goal is to allow a binary to be built which supports
     NEON, but can fall back to non-NEON routines, since some Android
     devices do not have NEON, even if they are otherwise ARMv7 (e.g.,
    The configure-generated flags HAVE_ARMV7, etc., are used to decide
     which versions of each function to build, and when
     CONFIG_RUNTIME_CPU_DETECT is enabled, the correct version is chosen
     at run time.
    In order for this to work, the CFLAGS must be set to something
     appropriate (e.g., without -mfpu=neon for ARMv7, and with
     appropriate -march and -mcpu for even earlier configurations), or
     the native C code will not be able to run.
    The ASFLAGS must remain set for the most advanced instruction set
     required at build time, since the ARM assembler will refuse to emit
     them otherwise.
    I have not attempted to make any changes to configure to do this
    Doing so will probably require the addition of new configure options.
    Many of the hooks for RTCD on A...