|  | ; RUN: llc -mtriple=arm64-apple-darwin < %s | FileCheck %s | 
|  | ; Check that the peephole optimizer knows about sext and zext instructions. | 
|  | ; CHECK: test1sext | 
|  | define i32 @test1sext(i64 %A, i64 %B, i32* %P, i64 *%P2) nounwind { | 
|  | %C = add i64 %A, %B | 
|  | ; CHECK: add x[[SUM:[0-9]+]], x0, x1 | 
|  | %D = trunc i64 %C to i32 | 
|  | %E = shl i64 %C, 32 | 
|  | %F = ashr i64 %E, 32 | 
|  | ; CHECK: sxtw x[[EXT:[0-9]+]], w[[SUM]] | 
|  | store volatile i64 %F, i64 *%P2 | 
|  | ; CHECK: str x[[EXT]] | 
|  | store volatile i32 %D, i32* %P | 
|  | ; Reuse low bits of extended register, don't extend live range of SUM. | 
|  | ; CHECK: str w[[SUM]] | 
|  | ret i32 %D | 
|  | } |