[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
wangnan0 at huawei.com
Wed Aug 5 01:28:13 PDT 2015
On 2015/8/5 15:11, Alexei Starovoitov wrote:
> 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.
Make it work. Thank you.
It doesn't work for me at first since in my llvm there's only
I think llvm.bpf.store.* belone to some patches you haven't posted yet?
> 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.
But in backend can we still get type information? I thought type is
meaningful in frontend only, and backend behaviors is unable to affect
DWARF generation, right?
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