peter green via llvm-dev
2016-May-17 20:36 UTC
[llvm-dev] llvm-toolchain-3.8 on lower arm targets, specifically Debian armel and Raspbian.
On 17/05/16 18:07, Tim Northover wrote:> Yes, it looks like we'd need to conditionally compile these functions > in ARM mode and use the v6 barrier instead of dmb ("mcr p15, #0, r0, > c7, c10, #5" I believe) to support the ARM1176JZF-S in RPi. You'd > probably also want the build system to use an explicit -march=armv6 or > something so you're not at the mercy of how the host compiler was > configured. > > I suspect you're the first person to try and get compiler-rt going for > pre-v7 hardware, which most of us prefer to pretend never happened > most of the time. >Thank you very much for your reply. Can you clarify what exactly compiler-rt is and how important it is to the stack as a whole. It seems that llvm-toolchain-3.7 built successfully on raspbian without building compiler-rt while llvm-toolchain-3.8 built an armv7 compiler-rt (and hence got blocked from entering the raspbian repos).
Tim Northover via llvm-dev
2016-May-17 21:38 UTC
[llvm-dev] llvm-toolchain-3.8 on lower arm targets, specifically Debian armel and Raspbian.
> Can you clarify what exactly compiler-rt is and how important it is to the > stack as a whole. It seems that llvm-toolchain-3.7 built successfully on > raspbian without building compiler-rt while llvm-toolchain-3.8 built an > armv7 compiler-rt (and hence got blocked from entering the raspbian repos).Compiler-rt is the equivalent of libgcc, and Clang can use the existing host's libgcc quite happily so it's really not that important unless you're trying to build a GNU-free environment for whatever reason. Cheers. Tim.
peter green via llvm-dev
2016-May-17 22:15 UTC
[llvm-dev] llvm-toolchain-3.8 on lower arm targets, specifically Debian armel and Raspbian.
On 17/05/16 22:38, Tim Northover wrote:> Compiler-rt is the equivalent of libgcc, and Clang can use the > existing host's libgcc quite happily so it's really not that important > unless you're trying to build a GNU-free environment for whatever > reason. >Thanks Can you tell me how I would go about telling the cmake buildsystem (which is what the Debian packaging currently seems to use) that I want it to build without compiler-rt?