1; NOTE: Assertions have been autogenerated by utils/update_llc_test_checks.py UTC_ARGS: --version 4 2; RUN: llc < %s | FileCheck %s 3 4; Check that the shr(shl X, 56), 48) is not mistakenly turned into 5; a shr (X, -8) that gets subsequently "optimized away" as undef 6; PR4254 7 8; after fixing PR24373 9; shlq $56, %rdi 10; sarq $48, %rdi 11; folds into 12; movsbq %dil, %rax 13; shlq $8, %rax 14; which is better for x86 15 16target 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" 17target triple = "x86_64-unknown-linux-gnu" 18 19define i64 @foo(i64 %b) nounwind readnone { 20; CHECK-LABEL: foo: 21; CHECK: # %bb.0: # %entry 22; CHECK-NEXT: movsbq %dil, %rax 23; CHECK-NEXT: shlq $8, %rax 24; CHECK-NEXT: incq %rax 25; CHECK-NEXT: retq 26entry: 27 %shl = shl i64 %b, 56 ; <i64> [#uses=1] 28 %shr = ashr i64 %shl, 48 ; <i64> [#uses=1] 29 %add5 = or i64 %shr, 1 ; <i64> [#uses=1] 30 ret i64 %add5 31} 32