[llvm-dev] [LLVMdev] Cc llvmdev: Re: llvm bpf debug info. Re: [RFC PATCH v4 3/3] bpf: Introduce function for outputing data to perf event
ast at plumgrid.com
Wed Aug 5 00:11:19 PDT 2015
On 8/4/15 11:51 PM, Wangnan (F) wrote:
> void bpf_store_half(void *skb, int off, int val)
> int func()
> bpf_store_half(0, 0, 0);
> return 0;
> Compiled with:
> $ clang -g -target bpf -O2 -S -c test.c
> And get this:
> .globl func
> .align 8
> func: # @func
> # BB#0: # %entry
> mov r1, 0
> mov r2, 0
> mov r3, 0
> call llvm.bpf.store.half
it didn't work because number and types of args were incompatible.
Every samples/bpf/sockex[0-9]_kern.c is using llvm.bpf.load.* intrinsics.
the typeid changing ids with order is surprising.
I think the assertion in ExtractTypeInfo() is not hard.
Just there were no such use cases. May be we can do something
similar to what LowerIntrinsicCall() does and lower it differently
in the backend.
More information about the llvm-dev