[llvm-dev] About the concept of "materialization"

[Pei Wang via llvm-dev]

Thanks for the explanation!

Pei

On 6/30/17, 8:35 AM, "dexonsmith at apple.com on behalf of Duncan P. N. Exon Smith" <dexonsmith at apple.com> wrote:

    
    > On Jun 30, 2017, at 06:14, 陳韋任 <chenwj.cs97g at g2.nctu.edu.tw> wrote:
    > 
    > 2017-06-29 2:08 GMT+08:00 Pei Wang <pxw172 at ist.psu.edu>:
    >> OK. About the error it’s a long story, so it’s probably better to pin some source code here. Below is a piece of code related to my problem, clipped from lib/Transforms/Utils/ValueMapper.cpp. I was wondering what “materialized” means here.
    >> 
    >> Value *Mapper::mapBlockAddress(const BlockAddress &BA) {
    >>   Function *F = cast<Function>(mapValue(BA.getFunction()));
    >> 
    >>   // F may not have materialized its initializer.  In that case, create a
    >>   // dummy basic block for now, and replace it once we've materialized all
    >>   // the initializers.
    >>   BasicBlock *BB;
    >>   if (F->empty()) {
    >>     DelayedBBs.push_back(DelayedBasicBlock(BA));
    >>     BB = DelayedBBs.back().TempBB.get();
    >>   } else {
    >>     BB = cast_or_null<BasicBlock>(mapValue(BA.getBasicBlock()));
    >>   }
    >> 
    >>   return getVM()[&BA] = BlockAddress::get(F, BB ? BB : BA.getBasicBlock());
    >> }
    > 
    > 
    > Hi Duncan,
    > 
    >  Could you shed light on that? I guess the code you wrote here
    > relates to JIT, but I am not sure
    > what materialize actually means. Thanks.
    
    This is for when a bitcode file has been lazy-loaded, and you're materializing global values (and related metadata) into the in-memory representation.
    
    > 
    > Regards,
    > chenwj
    > 
    > -- 
    > Wei-Ren Chen (陳韋任)
    > Homepage: https://people.cs.nctu.edu.tw/~chenwj