1
; This test makes sure that div instructions are properly eliminated.
3
; RUN: opt < %s -instcombine -S | FileCheck %s
5
define i32 @test1(i32 %A) {
6
%B = sdiv i32 %A, 1 ; <i32> [#uses=1]
9
; CHECK-NEXT: ret i32 %A
12
define i32 @test2(i32 %A) {
14
%B = udiv i32 %A, 8 ; <i32> [#uses=1]
17
; CHECK-NEXT: lshr i32 %A, 3
20
define i32 @test3(i32 %A) {
21
; => 0, don't need to keep traps
22
%B = sdiv i32 0, %A ; <i32> [#uses=1]
25
; CHECK-NEXT: ret i32 0
28
define i32 @test4(i32 %A) {
30
%B = sdiv i32 %A, -1 ; <i32> [#uses=1]
33
; CHECK-NEXT: sub i32 0, %A
36
define i32 @test5(i32 %A) {
37
%B = udiv i32 %A, -16 ; <i32> [#uses=1]
38
%C = udiv i32 %B, -4 ; <i32> [#uses=1]
41
; CHECK-NEXT: ret i32 0
44
define i1 @test6(i32 %A) {
45
%B = udiv i32 %A, 123 ; <i32> [#uses=1]
47
%C = icmp eq i32 %B, 0 ; <i1> [#uses=1]
50
; CHECK-NEXT: icmp ult i32 %A, 123
53
define i1 @test7(i32 %A) {
54
%B = udiv i32 %A, 10 ; <i32> [#uses=1]
56
%C = icmp eq i32 %B, 2 ; <i1> [#uses=1]
59
; CHECK-NEXT: add i32 %A, -20
60
; CHECK-NEXT: icmp ult i32
63
define i1 @test8(i8 %A) {
64
%B = udiv i8 %A, 123 ; <i8> [#uses=1]
66
%C = icmp eq i8 %B, 2 ; <i1> [#uses=1]
69
; CHECK-NEXT: icmp ugt i8 %A, -11
72
define i1 @test9(i8 %A) {
73
%B = udiv i8 %A, 123 ; <i8> [#uses=1]
75
%C = icmp ne i8 %B, 2 ; <i1> [#uses=1]
78
; CHECK-NEXT: icmp ult i8 %A, -10
81
define i32 @test10(i32 %X, i1 %C) {
82
%V = select i1 %C, i32 64, i32 8 ; <i32> [#uses=1]
83
%R = udiv i32 %X, %V ; <i32> [#uses=1]
86
; CHECK-NEXT: select i1 %C, i32 6, i32 3
87
; CHECK-NEXT: lshr i32 %X
90
define i32 @test11(i32 %X, i1 %C) {
91
%A = select i1 %C, i32 1024, i32 32 ; <i32> [#uses=1]
92
%B = udiv i32 %X, %A ; <i32> [#uses=1]
95
; CHECK-NEXT: select i1 %C, i32 10, i32 5
96
; CHECK-NEXT: lshr i32 %X
100
define i32 @test12(i32 %x) nounwind {
101
%tmp3 = udiv i32 %x, %x ; 1
104
; CHECK-NEXT: ret i32 1
107
define i32 @test13(i32 %x) nounwind {
108
%tmp3 = sdiv i32 %x, %x ; 1
111
; CHECK-NEXT: ret i32 1
114
define i32 @test14(i8 %x) nounwind {
115
%zext = zext i8 %x to i32
116
%div = udiv i32 %zext, 257 ; 0
119
; CHECK-NEXT: ret i32 0
123
define i32 @test15(i32 %a, i32 %b) nounwind {
125
%div = lshr i32 %shl, 2
126
%div2 = udiv i32 %a, %div
129
; CHECK-NEXT: add i32 %b, -2
130
; CHECK-NEXT: lshr i32 %a,
131
; CHECK-NEXT: ret i32