1 ; RUN: opt %s -instcombine -S | FileCheck %s 2 ; PR5438 3 4 ; TODO: This should also optimize down. 5 ;define i32 @test1(i32 %a, i32 %b) nounwind readnone { 6 ;entry: 7 ; %0 = icmp sgt i32 %a, -1 ; <i1> [#uses=1] 8 ; %1 = icmp slt i32 %b, 0 ; <i1> [#uses=1] 9 ; %2 = xor i1 %1, %0 ; <i1> [#uses=1] 10 ; %3 = zext i1 %2 to i32 ; <i32> [#uses=1] 11 ; ret i32 %3 12 ;} 13 14 ; TODO: This optimizes partially but not all the way. 15 ;define i32 @test2(i32 %a, i32 %b) nounwind readnone { 16 ;entry: 17 ; %0 = and i32 %a, 8 ;<i32> [#uses=1] 18 ; %1 = and i32 %b, 8 ;<i32> [#uses=1] 19 ; %2 = icmp eq i32 %0, %1 ;<i1> [#uses=1] 20 ; %3 = zext i1 %2 to i32 ;<i32> [#uses=1] 21 ; ret i32 %3 22 ;} 23 24 define i32 @test3(i32 %a, i32 %b) nounwind readnone { 25 ; CHECK: @test3 26 entry: 27 ; CHECK: xor i32 %a, %b 28 ; CHECK: lshr i32 %0, 31 29 ; CHECK: xor i32 %1, 1 30 %0 = lshr i32 %a, 31 ; <i32> [#uses=1] 31 %1 = lshr i32 %b, 31 ; <i32> [#uses=1] 32 %2 = icmp eq i32 %0, %1 ; <i1> [#uses=1] 33 %3 = zext i1 %2 to i32 ; <i32> [#uses=1] 34 ret i32 %3 35 ; CHECK-NOT: icmp 36 ; CHECK-NOT: zext 37 ; CHECK: ret i32 %2 38 } 39 40 ; Variation on @test3: checking the 2nd bit in a situation where the 5th bit 41 ; is one, not zero. 42 define i32 @test3i(i32 %a, i32 %b) nounwind readnone { 43 ; CHECK: @test3i 44 entry: 45 ; CHECK: xor i32 %a, %b 46 ; CHECK: lshr i32 %0, 31 47 ; CHECK: xor i32 %1, 1 48 %0 = lshr i32 %a, 29 ; <i32> [#uses=1] 49 %1 = lshr i32 %b, 29 ; <i32> [#uses=1] 50 %2 = or i32 %0, 35 51 %3 = or i32 %1, 35 52 %4 = icmp eq i32 %2, %3 ; <i1> [#uses=1] 53 %5 = zext i1 %4 to i32 ; <i32> [#uses=1] 54 ret i32 %5 55 ; CHECK-NOT: icmp 56 ; CHECK-NOT: zext 57 ; CHECK: ret i32 %2 58 } 59
