Commit 265fa123 authored by Bill Wendling's avatar Bill Wendling
Browse files

For PR9500. 

--- Merging r128041 into '.':
U    test/CodeGen/X86/fast-isel-gep.ll
U    lib/Target/X86/X86FastISel.cpp

llvm-svn: 128042
parent 59fe9d15

llvm/lib/Target/X86/X86FastISel.cpp

+22 −16
Original line number Diff line number Diff line
@@ -399,22 +399,27 @@ bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) { 
        Disp += SL->getElementOffset(Idx);

      } else {

        uint64_t S = TD.getTypeAllocSize(GTI.getIndexedType());

        SmallVector<const Value *, 4> Worklist;

        Worklist.push_back(Op);

        do {

          Op = Worklist.pop_back_val();

        for (;;) {

          if (const ConstantInt *CI = dyn_cast<ConstantInt>(Op)) {

            // Constant-offset addressing.

            Disp += CI->getSExtValue() * S;

          } else if (isa<AddOperator>(Op) &&

            break;

          }

          if (isa<AddOperator>(Op) &&

              (!isa<Instruction>(Op) ||

               FuncInfo.MBBMap[cast<Instruction>(Op)->getParent()]

                 == FuncInfo.MBB) &&

              isa<ConstantInt>(cast<AddOperator>(Op)->getOperand(1))) {

            // An add with a constant operand. Fold the constant.

            // An add (in the same block) with a constant operand. Fold the

            // constant.

            ConstantInt *CI =

              cast<ConstantInt>(cast<AddOperator>(Op)->getOperand(1));

            Disp += CI->getSExtValue() * S;

            // Add the other operand back to the work list.

            Worklist.push_back(cast<AddOperator>(Op)->getOperand(0));

          } else if (IndexReg == 0 &&

            // Iterate on the other operand.

            Op = cast<AddOperator>(Op)->getOperand(0);

            continue;

          }

          if (IndexReg == 0 &&

              (!AM.GV || !Subtarget->isPICStyleRIPRel()) &&

              (S == 1 || S == 2 || S == 4 || S == 8)) {

            // Scaled-index addressing.
@@ -422,10 +427,11 @@ bool X86FastISel::X86SelectAddress(const Value *V, X86AddressMode &AM) { 
            IndexReg = getRegForGEPIndex(Op).first;

            if (IndexReg == 0)

              return false;

          } else

            break;

          }

          // Unsupported.

          goto unsupported_gep;

        } while (!Worklist.empty());

        }

      }

    }

    // Check for displacement overflow.

llvm/test/CodeGen/X86/fast-isel-gep.ll

+19 −0
Original line number Diff line number Diff line
@@ -87,4 +87,23 @@ define i64 @test5(i8* %A, i32 %I, i64 %B) nounwind { 
; X64-NEXT: ret

}



; PR9500, rdar://9156159 - Don't do non-local address mode folding,

; because it may require values which wouldn't otherwise be live out

; of their blocks.

define void @test6() {

if.end:                                           ; preds = %if.then, %invoke.cont

  %tmp15 = load i64* undef

  %dec = add i64 %tmp15, 13

  store i64 %dec, i64* undef

  %call17 = invoke i8* @_ZNK18G__FastAllocString4dataEv()

          to label %invoke.cont16 unwind label %lpad



invoke.cont16:                                    ; preds = %if.then14

  %arrayidx18 = getelementptr inbounds i8* %call17, i64 %dec

  store i8 0, i8* %arrayidx18

  unreachable



lpad:                                             ; preds = %if.end19, %if.then14, %if.end, %entry

  unreachable

}

declare i8* @_ZNK18G__FastAllocString4dataEv() nounwind