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|
; This test makes sure that these instructions are properly eliminated.
;
; RUN: llvm-as < %s | opt -instcombine | llvm-dis | not grep sh
; END.
define i32 @test1(i32 %A) {
%B = shl i32 %A, 0 ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test2(i8 %A) {
%shift.upgrd.1 = zext i8 %A to i32 ; <i32> [#uses=1]
%B = shl i32 0, %shift.upgrd.1 ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test3(i32 %A) {
%B = ashr i32 %A, 0 ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test4(i8 %A) {
%shift.upgrd.2 = zext i8 %A to i32 ; <i32> [#uses=1]
%B = ashr i32 0, %shift.upgrd.2 ; <i32> [#uses=1]
ret i32 %B
}
define i32 @test5(i32 %A) {
%B = lshr i32 %A, 32 ;; shift all bits out
ret i32 %B
}
define i32 @test5a(i32 %A) {
%B = shl i32 %A, 32 ;; shift all bits out
ret i32 %B
}
define i32 @test6(i32 %A) {
%B = shl i32 %A, 1 ;; convert to an mul instruction
%C = mul i32 %B, 3
ret i32 %C
}
define i32 @test7(i8 %A) {
%shift.upgrd.3 = zext i8 %A to i32
%B = ashr i32 -1, %shift.upgrd.3 ;; Always equal to -1
ret i32 %B
}
;; (A << 5) << 3 === A << 8 == 0
define i8 @test8(i8 %A) {
%B = shl i8 %A, 5 ; <i8> [#uses=1]
%C = shl i8 %B, 3 ; <i8> [#uses=1]
ret i8 %C
}
;; (A << 7) >> 7 === A & 1
define i8 @test9(i8 %A) {
%B = shl i8 %A, 7 ; <i8> [#uses=1]
%C = lshr i8 %B, 7 ; <i8> [#uses=1]
ret i8 %C
}
;; (A >> 7) << 7 === A & 128
define i8 @test10(i8 %A) {
%B = lshr i8 %A, 7 ; <i8> [#uses=1]
%C = shl i8 %B, 7 ; <i8> [#uses=1]
ret i8 %C
}
;; (A >> 3) << 4 === (A & 0x1F) << 1
define i8 @test11(i8 %A) {
%a = mul i8 %A, 3 ; <i8> [#uses=1]
%B = lshr i8 %a, 3 ; <i8> [#uses=1]
%C = shl i8 %B, 4 ; <i8> [#uses=1]
ret i8 %C
}
;; (A >> 8) << 8 === A & -256
define i32 @test12(i32 %A) {
%B = ashr i32 %A, 8 ; <i32> [#uses=1]
%C = shl i32 %B, 8 ; <i32> [#uses=1]
ret i32 %C
}
;; (A >> 3) << 4 === (A & -8) * 2
define i8 @test13(i8 %A) {
%a = mul i8 %A, 3 ; <i8> [#uses=1]
%B = ashr i8 %a, 3 ; <i8> [#uses=1]
%C = shl i8 %B, 4 ; <i8> [#uses=1]
ret i8 %C
}
;; D = ((B | 1234) << 4) === ((B << 4)|(1234 << 4)
define i32 @test14(i32 %A) {
%B = lshr i32 %A, 4 ; <i32> [#uses=1]
%C = or i32 %B, 1234 ; <i32> [#uses=1]
%D = shl i32 %C, 4 ; <i32> [#uses=1]
ret i32 %D
}
;; D = ((B | 1234) << 4) === ((B << 4)|(1234 << 4)
define i32 @test14a(i32 %A) {
%B = shl i32 %A, 4 ; <i32> [#uses=1]
%C = and i32 %B, 1234 ; <i32> [#uses=1]
%D = lshr i32 %C, 4 ; <i32> [#uses=1]
ret i32 %D
}
define i32 @test15(i1 %C) {
%A = select i1 %C, i32 3, i32 1 ; <i32> [#uses=1]
%V = shl i32 %A, 2 ; <i32> [#uses=1]
ret i32 %V
}
define i32 @test15a(i1 %C) {
%A = select i1 %C, i8 3, i8 1 ; <i8> [#uses=1]
%shift.upgrd.4 = zext i8 %A to i32 ; <i32> [#uses=1]
%V = shl i32 64, %shift.upgrd.4 ; <i32> [#uses=1]
ret i32 %V
}
define i1 @test16(i32 %X) {
%tmp.3 = ashr i32 %X, 4 ; <i32> [#uses=1]
%tmp.6 = and i32 %tmp.3, 1 ; <i32> [#uses=1]
%tmp.7 = icmp ne i32 %tmp.6, 0 ; <i1> [#uses=1]
ret i1 %tmp.7
}
define i1 @test17(i32 %A) {
%B = lshr i32 %A, 3 ; <i32> [#uses=1]
%C = icmp eq i32 %B, 1234 ; <i1> [#uses=1]
ret i1 %C
}
define i1 @test18(i8 %A) {
%B = lshr i8 %A, 7 ; <i8> [#uses=1]
;; false
%C = icmp eq i8 %B, 123 ; <i1> [#uses=1]
ret i1 %C
}
define i1 @test19(i32 %A) {
%B = ashr i32 %A, 2 ; <i32> [#uses=1]
;; (X & -4) == 0
%C = icmp eq i32 %B, 0 ; <i1> [#uses=1]
ret i1 %C
}
define i1 @test19a(i32 %A) {
%B = ashr i32 %A, 2 ; <i32> [#uses=1]
;; (X & -4) == -4
%C = icmp eq i32 %B, -1 ; <i1> [#uses=1]
ret i1 %C
}
define i1 @test20(i8 %A) {
%B = ashr i8 %A, 7 ; <i8> [#uses=1]
;; false
%C = icmp eq i8 %B, 123 ; <i1> [#uses=1]
ret i1 %C
}
define i1 @test21(i8 %A) {
%B = shl i8 %A, 4 ; <i8> [#uses=1]
%C = icmp eq i8 %B, -128 ; <i1> [#uses=1]
ret i1 %C
}
define i1 @test22(i8 %A) {
%B = shl i8 %A, 4 ; <i8> [#uses=1]
%C = icmp eq i8 %B, 0 ; <i1> [#uses=1]
ret i1 %C
}
define i8 @test23(i32 %A) {
;; casts not needed
%B = shl i32 %A, 24 ; <i32> [#uses=1]
%C = ashr i32 %B, 24 ; <i32> [#uses=1]
%D = trunc i32 %C to i8 ; <i8> [#uses=1]
ret i8 %D
}
define i8 @test24(i8 %X) {
%Y = and i8 %X, -5 ; <i8> [#uses=1]
%Z = shl i8 %Y, 5 ; <i8> [#uses=1]
%Q = ashr i8 %Z, 5 ; <i8> [#uses=1]
ret i8 %Q
}
define i32 @test25(i32 %tmp.2, i32 %AA) {
%x = lshr i32 %AA, 17 ; <i32> [#uses=1]
%tmp.3 = lshr i32 %tmp.2, 17 ; <i32> [#uses=1]
%tmp.5 = add i32 %tmp.3, %x ; <i32> [#uses=1]
%tmp.6 = shl i32 %tmp.5, 17 ; <i32> [#uses=1]
ret i32 %tmp.6
}
;; handle casts between shifts.
define i32 @test26(i32 %A) {
%B = lshr i32 %A, 1 ; <i32> [#uses=1]
%C = bitcast i32 %B to i32 ; <i32> [#uses=1]
%D = shl i32 %C, 1 ; <i32> [#uses=1]
ret i32 %D
}
define i1 @test27(i32 %x) nounwind {
%y = lshr i32 %x, 3
%z = trunc i32 %y to i1
ret i1 %z
}
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