| ; 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 |
| } |
| |