Clang Cross Compiling for ARM?
To cross-compile for Raspberry Pi running soft-float Linux distros add flags -ccc-host-triple arm-eabi -marm -mfpu=vfp -mcpu=arm1176jzf-s -mtune=arm1176jzf-s -mfloat-abi=softfp
To cross-compile for Raspberry Pi running hard-float Linux distros use the flags -ccc-host-triple arm-eabi -marm -mfpu=vfp -mcpu=arm1176jzf-s -mtune=arm1176jzf-s -mfloat-abi=hard
To cross-compile for Pandaboard use flags -ccc-host-triple arm-eabiv7 -mthumb -mfpu=neon-fp16 -mcpu=cortex-a9 -mtune=cortex-a9 -mfloat-abi=hard (assuming that your Pandaboard runs Ubuntu)
Note: more recent clang version use -target option instead of -ccc-host-triple
See EmbToolkit project. It gives ability to generate clang/llvmor gcc based cross compiler toolchain.