[llvm-dev] GSoC Idea Project (original) (raw)

Cheng, Xiang via llvm-dev llvm-dev at lists.llvm.org
Wed May 27 12:57:59 PDT 2020

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Hi all,

I'm Xiang Cheng in Gatech and I'm interested in this project: http://llvm.org/OpenProjects.html#llvm_dbg_invariant

I noticed that this project is not in the GSoC selected projects list, so I think nobody is working on this.

Now I try to reproduce this issue on aarch64 Ubuntu-18.04 using the latest LLVM-10 release with following code (http://lists.llvm.org/pipermail/llvm-dev/2019-September/135433.html):

void b(void* d){}

void c(char* cc, void* d){}

void a() { b(a); for (;;) c("", b); } int main(){ a(); return 0; }

I compile it using "-O0 -g" or only "-O0". However, I failed to reproduce the issue since all the outputs have the same instructions in their .text regions (attached below).

Could you please give a sample to reproduce this issue? Or is this bug has been fixed(https://bugs.llvm.org/show_bug.cgi?id=37240)?

Best, Xiang

00000000004004f4 : 4004f4: d10043ff sub sp, sp, #0x10 4004f8: f90007e0 str x0, [sp, #8] 4004fc: 910043ff add sp, sp, #0x10 400500: d65f03c0 ret

0000000000400504 : 400504: d10043ff sub sp, sp, #0x10 400508: f90007e0 str x0, [sp, #8] 40050c: f90003e1 str x1, [sp] 400510: 910043ff add sp, sp, #0x10 400514: d65f03c0 ret

0000000000400518 : 400518: a9bf7bfd stp x29, x30, [sp, #-16]! 40051c: 910003fd mov x29, sp 400520: 90000000 adrp x0, 400000 <_init-0x388> 400524: 91146000 add x0, x0, #0x518 400528: 97fffff3 bl 4004f4 40052c: 90000000 adrp x0, 400000 <_init-0x388> 400530: 91188000 add x0, x0, #0x620 400534: 90000001 adrp x1, 400000 <_init-0x388> 400538: 9113d021 add x1, x1, #0x4f4 40053c: 97fffff2 bl 400504 400540: 17fffffb b 40052c <a+0x14>

0000000000400544