llvm-project/llvm/test/Analysis/ValueTracking/knownzero-shift.ll

15 lines
437 B
LLVM

; RUN: opt -instsimplify -S < %s | FileCheck %s
; CHECK-LABEL: @test
define i1 @test(i8 %p, i8* %pq) {
%q = load i8, i8* %pq, !range !0 ; %q is known nonzero; no known bits
%1 = or i8 %p, 2 ; %1[1] = 1
%2 = and i8 %1, 254 ; %2[0] = 0, %2[1] = 1
%A = lshr i8 %2, 1 ; We should know that %A is nonzero.
%x = icmp eq i8 %A, 0
; CHECK: ret i1 false
ret i1 %x
}
!0 = !{ i8 1, i8 5 }