21 lines
648 B
LLVM
21 lines
648 B
LLVM
; RUN: llc < %s | FileCheck %s
|
|
|
|
; Check that the shr(shl X, 56), 48) is not mistakenly turned into
|
|
; a shr (X, -8) that gets subsequently "optimized away" as undef
|
|
; PR4254
|
|
|
|
target 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"
|
|
target triple = "x86_64-unknown-linux-gnu"
|
|
|
|
define i64 @foo(i64 %b) nounwind readnone {
|
|
entry:
|
|
; CHECK: foo:
|
|
; CHECK: shlq $56, %rdi
|
|
; CHECK: sarq $48, %rdi
|
|
; CHECK: leaq 1(%rdi), %rax
|
|
%shl = shl i64 %b, 56 ; <i64> [#uses=1]
|
|
%shr = ashr i64 %shl, 48 ; <i64> [#uses=1]
|
|
%add5 = or i64 %shr, 1 ; <i64> [#uses=1]
|
|
ret i64 %add5
|
|
}
|