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; This test makes sure that div instructions are properly eliminated.
; RUN: opt < %s -instcombine -S | FileCheck %s
define i32 @test1(i32 %A) {
%B = sdiv i32 %A, 1 ; <i32> [#uses=1]
ret i32 %B
; CHECK-LABEL: @test1(
; CHECK-NEXT: ret i32 %A
}
define i32 @test2(i32 %A) {
; => Shift
%B = udiv i32 %A, 8 ; <i32> [#uses=1]
ret i32 %B
; CHECK-LABEL: @test2(
; CHECK-NEXT: lshr i32 %A, 3
}
define i32 @test3(i32 %A) {
; => 0, don't need to keep traps
%B = sdiv i32 0, %A ; <i32> [#uses=1]
ret i32 %B
; CHECK-LABEL: @test3(
; CHECK-NEXT: ret i32 0
}
define i32 @test4(i32 %A) {
; 0-A
%B = sdiv i32 %A, -1 ; <i32> [#uses=1]
ret i32 %B
; CHECK-LABEL: @test4(
; CHECK-NEXT: sub i32 0, %A
}
define i32 @test5(i32 %A) {
%B = udiv i32 %A, -16 ; <i32> [#uses=1]
%C = udiv i32 %B, -4 ; <i32> [#uses=1]
ret i32 %C
; CHECK-LABEL: @test5(
; CHECK-NEXT: ret i32 0
}
define i1 @test6(i32 %A) {
%B = udiv i32 %A, 123 ; <i32> [#uses=1]
; A < 123
%C = icmp eq i32 %B, 0 ; <i1> [#uses=1]
ret i1 %C
; CHECK-LABEL: @test6(
; CHECK-NEXT: icmp ult i32 %A, 123
}
define i1 @test7(i32 %A) {
%B = udiv i32 %A, 10 ; <i32> [#uses=1]
; A >= 20 && A < 30
%C = icmp eq i32 %B, 2 ; <i1> [#uses=1]
ret i1 %C
; CHECK-LABEL: @test7(
; CHECK-NEXT: add i32 %A, -20
; CHECK-NEXT: icmp ult i32
}
define i1 @test8(i8 %A) {
%B = udiv i8 %A, 123 ; <i8> [#uses=1]
; A >= 246
%C = icmp eq i8 %B, 2 ; <i1> [#uses=1]
ret i1 %C
; CHECK-LABEL: @test8(
; CHECK-NEXT: icmp ugt i8 %A, -11
}
define i1 @test9(i8 %A) {
%B = udiv i8 %A, 123 ; <i8> [#uses=1]
; A < 246
%C = icmp ne i8 %B, 2 ; <i1> [#uses=1]
ret i1 %C
; CHECK-LABEL: @test9(
; CHECK-NEXT: icmp ult i8 %A, -10
}
define i32 @test10(i32 %X, i1 %C) {
%V = select i1 %C, i32 64, i32 8 ; <i32> [#uses=1]
%R = udiv i32 %X, %V ; <i32> [#uses=1]
ret i32 %R
; CHECK-LABEL: @test10(
; CHECK-NEXT: select i1 %C, i32 6, i32 3
; CHECK-NEXT: lshr i32 %X
}
define i32 @test11(i32 %X, i1 %C) {
%A = select i1 %C, i32 1024, i32 32 ; <i32> [#uses=1]
%B = udiv i32 %X, %A ; <i32> [#uses=1]
ret i32 %B
; CHECK-LABEL: @test11(
; CHECK-NEXT: select i1 %C, i32 10, i32 5
; CHECK-NEXT: lshr i32 %X
}
; PR2328
define i32 @test12(i32 %x) nounwind {
%tmp3 = udiv i32 %x, %x ; 1
ret i32 %tmp3
; CHECK-LABEL: @test12(
; CHECK-NEXT: ret i32 1
}
define i32 @test13(i32 %x) nounwind {
%tmp3 = sdiv i32 %x, %x ; 1
ret i32 %tmp3
; CHECK-LABEL: @test13(
; CHECK-NEXT: ret i32 1
}
define i32 @test14(i8 %x) nounwind {
%zext = zext i8 %x to i32
%div = udiv i32 %zext, 257 ; 0
ret i32 %div
; CHECK-LABEL: @test14(
; CHECK-NEXT: ret i32 0
}
; PR9814
define i32 @test15(i32 %a, i32 %b) nounwind {
%shl = shl i32 1, %b
%div = lshr i32 %shl, 2
%div2 = udiv i32 %a, %div
ret i32 %div2
; CHECK-LABEL: @test15(
; CHECK-NEXT: add i32 %b, -2
; CHECK-NEXT: lshr i32 %a,
; CHECK-NEXT: ret i32
}
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