UpdateValueMap(Call, ResultReg);
return true;
}
+ case Intrinsic::expect: {
+ unsigned ResultReg = getRegForValue(Call->getArgOperand(0));
+ if (ResultReg == 0)
+ return false;
+ UpdateValueMap(Call, ResultReg);
+ return true;
+ }
}
// Usually, it does not make sense to initialize a value,
// all the values which have already been materialized,
// appear after the call. It also makes sense to skip intrinsics
// since they tend to be inlined.
- if (!isa<IntrinsicInst>(F))
+ if (!isa<IntrinsicInst>(Call))
flushLocalValueMap();
// An arbitrary call. Bail.
IntegerType *ITy = IntegerType::get(FuncInfo.Fn->getContext(),
VT.getSizeInBits());
MaterialReg = getRegForValue(ConstantInt::get(ITy, Imm));
+ assert (MaterialReg != 0 && "Unable to materialize imm.");
+ if (MaterialReg == 0) return 0;
}
return FastEmit_rr(VT, VT, Opcode,
Op0, Op0IsKill,
return true;
}
+
+bool FastISel::tryToFoldLoad(const LoadInst *LI, const Instruction *FoldInst) {
+ assert(LI->hasOneUse() &&
+ "tryToFoldLoad expected a LoadInst with a single use");
+ // We know that the load has a single use, but don't know what it is. If it
+ // isn't one of the folded instructions, then we can't succeed here. Handle
+ // this by scanning the single-use users of the load until we get to FoldInst.
+ unsigned MaxUsers = 6; // Don't scan down huge single-use chains of instrs.
+
+ const Instruction *TheUser = LI->use_back();
+ while (TheUser != FoldInst && // Scan up until we find FoldInst.
+ // Stay in the right block.
+ TheUser->getParent() == FoldInst->getParent() &&
+ --MaxUsers) { // Don't scan too far.
+ // If there are multiple or no uses of this instruction, then bail out.
+ if (!TheUser->hasOneUse())
+ return false;
+
+ TheUser = TheUser->use_back();
+ }
+
+ // If we didn't find the fold instruction, then we failed to collapse the
+ // sequence.
+ if (TheUser != FoldInst)
+ return false;
+
+ // Don't try to fold volatile loads. Target has to deal with alignment
+ // constraints.
+ if (LI->isVolatile())
+ return false;
+
+ // Figure out which vreg this is going into. If there is no assigned vreg yet
+ // then there actually was no reference to it. Perhaps the load is referenced
+ // by a dead instruction.
+ unsigned LoadReg = getRegForValue(LI);
+ if (LoadReg == 0)
+ return false;
+
+ // We can't fold if this vreg has no uses or more than one use. Multiple uses
+ // may mean that the instruction got lowered to multiple MIs, or the use of
+ // the loaded value ended up being multiple operands of the result.
+ if (!MRI.hasOneUse(LoadReg))
+ return false;
+
+ MachineRegisterInfo::reg_iterator RI = MRI.reg_begin(LoadReg);
+ MachineInstr *User = &*RI;
+
+ // Set the insertion point properly. Folding the load can cause generation of
+ // other random instructions (like sign extends) for addressing modes; make
+ // sure they get inserted in a logical place before the new instruction.
+ FuncInfo.InsertPt = User;
+ FuncInfo.MBB = User->getParent();
+
+ // Ask the target to try folding the load.
+ return tryToFoldLoadIntoMI(User, RI.getOperandNo(), LI);
+}
+
+