llvm-project/llvm/test/Transforms/InstCombine/bitreverse-known-bits.ll

35 lines
786 B
LLVM

; RUN: opt < %s -S -instcombine | FileCheck %s
declare i32 @llvm.bitreverse.i32(i32)
; CHECK-LABEL: @test1
; CHECK: ret i1 true
define i1 @test1(i32 %arg) {
%a = or i32 %arg, 4294901760
%b = call i32 @llvm.bitreverse.i32(i32 %a)
%and = and i32 %b, 65535
%res = icmp eq i32 %and, 65535
ret i1 %res
}
; CHECK-LABEL: @test2
; CHECK: ret i1 true
define i1 @test2(i32 %arg) {
%a = or i32 %arg, 1
%b = call i32 @llvm.bitreverse.i32(i32 %a)
%c = and i32 %b, 2147483648
%d = call i32 @llvm.bitreverse.i32(i32 %c)
%res = icmp eq i32 %d, 1
ret i1 %res
}
; CHECK-LABEL: @test3
; CHECK: ret i1 false
define i1 @test3(i32 %arg) {
%a = or i32 %arg, 65536
%b = call i32 @llvm.bitreverse.i32(i32 %a)
%and = and i32 %b, 32768
%res = icmp eq i32 %and, 0
ret i1 %res
}