[LLVMdev] i64 OR instruction elimination

[Mark Schimmel]

for.body:                                         ; preds = %for.body.lr.ph, %for.body
  %ACC.sroa.0.013 = phi i64 [ 0, %for.body.lr.ph ], [ %phitmp9, %for.body ]
  %ACC.sroa.4.012 = phi i64 [ 0, %for.body.lr.ph ], [ %tmp.sroa.2.0.extract.shift, %for.body ]
  %i.011 = phi i32 [ 0, %for.body.lr.ph ], [ %inc, %for.body ]
  %arrayidx = getelementptr inbounds i16* %ary, i32 %i.011
  %0 = load i16* %arrayidx, align 2, !tbaa !1
  %add = add i32 %i.011, 8
  %arrayidx1 = getelementptr inbounds i16* %ary, i32 %add
  %1 = load i16* %arrayidx1, align 2, !tbaa !1
  %2 = tail call i64 @llvm.arc.ACC40.GUARD.MUL.SQ15.SQ15(i16 %0, i16 %1) #1
  %L.sroa.0.0.insert.insert.i = or i64 %ACC.sroa.0.013, %ACC.sroa.4.012
  %3 = tail call i64 @llvm.arc.ADD.ACC40(i64 %L.sroa.0.0.insert.insert.i, i64 %2) #1
  %tmp.sroa.2.0.extract.shift = and i64 %3, -4294967296
  %inc = add i32 %i.011, 1
  %phitmp9 = and i64 %3, 4294967295
  %cmp = icmp ult i32 %inc, %limit
  br i1 %cmp, label %for.body, label %for.cond.for.end_crit_edge

The value of the OR is simply the PHI of %3 and 0.  Nobody detects this and it generates pretty ugly code in a loop.  Can you tell me what phase should handle this simple transform?  That is, what phase does this kind of transformation belong in?
Thanks

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