LLVM Backend for the VideoCore4, Raspberry Pi 2 VPU

Re:LLVM Backend for the VideoCore4, Raspberry Pi 2 VPU by puppeh on Tuesday May 03, 2016 @03:45AM (#11618686)

I did GCC too, https://github.com/puppeh/vc4-toolchain.

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Re:LLVM Backend for the VideoCore4, Raspberry Pi 2 VPU by christina_b on Tuesday May 03, 2016 @03:49AM (#11618708)

Yeah, I saw, I haven't looked at it in detail but I think yours probably works better than mine since you did comprehensive testing. My only tests involved compiling my own firmware code, but from what I can tell, it works well, I haven't ran into any bugs yet aside from what I outlined in the README.

The assembler/linker I'm using is not ideal, I want to get MC code emission working eventually. I saw that you mentioned limitations on ld/st, why not use lea for data?

For example:

  BB1_12:                                 # %sdram_clkman_update_end.exit2
	mov r0, 2114982312 # long
	ld r2, (r0)
	lea r0, .str8(pc) # PCrel load
	lea r1, __FUNCTION__.sdram_init_late(pc) # PCrel load
	bl xprintf

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Re:LLVM Backend for the VideoCore4, Raspberry Pi 2 VPU by puppeh on Tuesday May 03, 2016 @04:04AM (#11618768)

No reason I guess, except it means an extra instruction. I thought about adding a flag for "large model" compilation, but it's not been a priority so far.

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