1; RUN: llc < %s | FileCheck %s
2
3; Check that the shr(shl X, 56), 48) is not mistakenly turned into
4; a shr (X, -8) that gets subsequently "optimized away" as undef
5; PR4254
6
7target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
8target triple = "x86_64-unknown-linux-gnu"
9
10define i64 @foo(i64 %b) nounwind readnone {
11entry:
12; CHECK-LABEL: foo:
13; CHECK: shlq $56, %rdi
14; CHECK: sarq $48, %rdi
15; CHECK: leaq 1(%rdi), %rax
16	%shl = shl i64 %b, 56		; <i64> [#uses=1]
17	%shr = ashr i64 %shl, 48		; <i64> [#uses=1]
18	%add5 = or i64 %shr, 1		; <i64> [#uses=1]
19	ret i64 %add5
20}
21