[Beignet] [PATCH 3/3] GBE: add basic PHINode support in legalize pass.

[Zhigang Gong]

Thanks for your testing report, just pushed.

On Wed, Oct 22, 2014 at 04:28:19AM +0000, Meng, Mengmeng wrote:
> The patch fixes VIZ-4498 [Bisect IVB/HSW/BYT-M]14 piglit cases core dumped.
> 
> 
> Thanks,
> Meng
> 
> > -----Original Message-----
> > From: Beignet [mailto:beignet-bounces at lists.freedesktop.org] On Behalf Of
> > Zhigang Gong
> > Sent: Tuesday, October 21, 2014 9:18 PM
> > To: beignet at lists.freedesktop.org
> > Cc: Gong, Zhigang
> > Subject: [Beignet] [PATCH 3/3] GBE: add basic PHINode support in legalize
> > pass.
> > 
> > Lack of the incomplete PHINode support currently.
> > After this patch, we could fix all the crash cases in piglit.
> > 
> > Signed-off-by: Zhigang Gong <zhigang.gong at intel.com>
> > ---
> >  backend/src/llvm/llvm_legalize.cpp | 66
> > ++++++++++++++++++++++++++++++++++++++
> >  1 file changed, 66 insertions(+)
> > 
> > diff --git a/backend/src/llvm/llvm_legalize.cpp
> > b/backend/src/llvm/llvm_legalize.cpp
> > index c86793b..ea0e75a 100644
> > --- a/backend/src/llvm/llvm_legalize.cpp
> > +++ b/backend/src/llvm/llvm_legalize.cpp
> > @@ -60,6 +60,9 @@ namespace gbe {
> >        if (!isKernelFunction(F)) return false;
> >        return legalizeFunction(F);
> >      }
> > +    Value *getComponent(Value *v, uint32_t i, Type *ty);
> > +    bool isIncomplete(Value *v);
> > +    void legalizePHI(IRBuilder <> Builder, Instruction *p);
> >      void legalizeSelect(IRBuilder<> &Builder, Instruction *p);
> >      void legalizeICmp(IRBuilder<> &Builder, Instruction *p);
> >      void legalizeShl(IRBuilder<> &Builder, Instruction *p); @@ -76,6 +79,7
> > @@ namespace gbe {
> >      static char ID;
> >    private:
> >      std::set<Value *> processed;
> > +    std::set<PHINode *> incompletePHIs;
> >      std::map<Value *, SmallVector<Value*, 16>> valueMap;
> >      typedef std::map<Value*, SmallVector<Value*, 16>>::iterator
> > ValueMapIter;
> >    };
> > @@ -108,6 +112,64 @@ namespace gbe {
> >      }
> >    }
> > 
> > +  bool Legalize::isIncomplete(Value *v) {
> > +    return valueMap.find(v) == valueMap.end() && !isa<ConstantInt>(v);
> > + }
> > +
> > +  Value *Legalize::getComponent(Value *v, uint32_t i, Type *ty) {
> > +    GBE_ASSERT(!isIncomplete(v));
> > +    if (isa<ConstantInt>(v)) {
> > +      GBE_ASSERT(ty);
> > +      ConstantInt *CI = dyn_cast<ConstantInt>(v);
> > +      SmallVector<APInt, 16> imm;
> > +      splitLargeInteger(CI->getValue(), ty, imm);
> > +      return ConstantInt::get(ty, imm[i]);
> > +    }
> > +    return valueMap.find(v)->second[i];  }
> > +
> > +  void Legalize::legalizePHI(IRBuilder <> Builder, Instruction *p) {
> > +    PHINode *phi = dyn_cast<PHINode>(p);
> > +    bool incomplete = false, allConst = true;
> > +    uint32_t compNum = 0;
> > +    Type *splitTy = NULL;
> > +    for (unsigned int i = 0; i < phi->getNumIncomingValues(); ++i) {
> > +      Value *val = phi->getIncomingValue(i);
> > +      if (isIncomplete(val)) {
> > +        incomplete = true;
> > +        break;
> > +      }
> > +      if (allConst && valueMap.find(val) != valueMap.end()) {
> > +        allConst = false;
> > +        splitTy = valueMap.find(val)->second[0]->getType();
> > +        compNum = valueMap.find(val)->second.size();
> > +      }
> > +    }
> > +
> > +    if (incomplete) {
> > +      // FIME, if a PHINode is totally incomplete which means
> > +      // we don't even know the base type of this instruction.
> > +      // Then it will be a little bit difficult to handle here.
> > +      // Will do it in the future.
> > +      incompletePHIs.insert(phi);
> > +      GBE_ASSERT(0 && "unsupported PHI");
> > +    }
> > +    else {
> > +      GBE_ASSERT(!allConst);
> > +      SmallVector<Value*, 16> v;
> > +      for (unsigned int i = 0; i < compNum; ++i) {
> > +        PHINode* res = Builder.CreatePHI(splitTy,
> > + phi->getNumIncomingValues());
> > +
> > +        // Loop over pairs of operands: [Value*, BasicBlock*]
> > +        for (unsigned int j = 0; j < phi->getNumIncomingValues(); j++) {
> > +          BasicBlock* bb = phi->getIncomingBlock(j);
> > +          res->addIncoming(getComponent(phi->getIncomingValue(j), i,
> > splitTy), bb);
> > +        }
> > +        v.push_back(res);
> > +      }
> > +      valueMap.insert(std::make_pair(phi, v));
> > +    }
> > +  }
> > 
> >    void Legalize::legalizeSelect(IRBuilder<> &Builder, Instruction *p) {
> >      SelectInst *sel = dyn_cast<SelectInst>(p); @@ -565,6 +627,9 @@
> > namespace gbe {
> >          Builder.SetInsertPoint(insn);
> >          switch(insn->getOpcode()) {
> >            default: { insn->dump(); GBE_ASSERT(false && "Illegal
> > instruction\n"); break;}
> > +          case Instruction::PHI:
> > +            legalizePHI(Builder, insn);
> > +            break;
> >            case Instruction::Select:
> >              legalizeSelect(Builder, insn);
> >              break;
> > @@ -621,6 +686,7 @@ namespace gbe {
> > 
> >      processed.clear();
> >      valueMap.clear();
> > +    incompletePHIs.clear();
> >      return changed;
> >    }
> > 
> > --
> > 1.8.3.2
> > 
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