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      1 ; RUN: llc < %s -mtriple=x86_64-darwin -mcpu=generic | FileCheck %s
      2 ; XFAIL: *
      3 ; rdar:15661073 simple example of redundant adds
      4 ;
      5 ; MachineCSE should coalesce trivial subregister copies.
      6 ;
      7 ; The extra movl+addl should be removed during MachineCSE.
      8 ; CHECK-LABEL: redundantadd
      9 ; CHECK: cmpq
     10 ; CHECK: movq
     11 ; CHECK-NOT: movl
     12 ; CHECK: addl
     13 ; CHECK-NOT: addl
     14 ; CHECK: ret
     15 
     16 define i64 @redundantadd(i64* %a0, i64* %a1) {
     17 entry:
     18   %tmp8 = load i64, i64* %a0, align 8
     19   %tmp12 = load i64, i64* %a1, align 8
     20   %tmp13 = icmp ult i64 %tmp12, -281474976710656
     21   br i1 %tmp13, label %exit1, label %body
     22 
     23 exit1:
     24   unreachable
     25 
     26 body:
     27   %tmp14 = trunc i64 %tmp8 to i32
     28   %tmp15 = trunc i64 %tmp12 to i32
     29   %tmp16 = tail call { i32, i1 } @llvm.sadd.with.overflow.i32(i32 %tmp14, i32 %tmp15)
     30   %tmp17 = extractvalue { i32, i1 } %tmp16, 1
     31   br i1 %tmp17, label %exit2, label %return
     32 
     33 exit2:
     34   unreachable
     35 
     36 return:
     37   %tmp18 = add i64 %tmp12, %tmp8
     38   %tmp19 = and i64 %tmp18, 4294967295
     39   %tmp20 = or i64 %tmp19, -281474976710656
     40   ret i64 %tmp20
     41 }
     42 
     43 declare { i32, i1 } @llvm.sadd.with.overflow.i32(i32, i32)
     44