[LLVMdev] ARM assembly

Tim Northover t.p.northover at gmail.com
Sun Dec 9 14:17:37 PST 2012


On Sun, Dec 9, 2012 at 7:48 PM, Evan Cheng <evan.cheng at apple.com> wrote:
> Sound like you are not enabling optimization. Try with -O3.

Ah, of course! I'd forgotten about the extra allocas produced by clang.

To expand a little, the spills you're seeing are (probably)
specifically created by clang (it creates a shadow variable for each
local with alloca). "llc" on its own can't get rid of these, so you'll
either want to give clang "-O3" or run the LLVM bitcode through "opt"
before "llc".

Tim.



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