1 ; RUN: llc < %s -march=x86 | FileCheck %s 2 3 define i32 @t1(i8* %X, i32 %i) { 4 ; CHECK-LABEL: t1: 5 ; CHECK-NOT: and 6 ; CHECK: movzbl 7 ; CHECK: movl (%{{...}},%{{...}},4), 8 ; CHECK: ret 9 10 entry: 11 %tmp2 = shl i32 %i, 2 12 %tmp4 = and i32 %tmp2, 1020 13 %tmp7 = getelementptr i8* %X, i32 %tmp4 14 %tmp78 = bitcast i8* %tmp7 to i32* 15 %tmp9 = load i32* %tmp78 16 ret i32 %tmp9 17 } 18 19 define i32 @t2(i16* %X, i32 %i) { 20 ; CHECK-LABEL: t2: 21 ; CHECK-NOT: and 22 ; CHECK: movzwl 23 ; CHECK: movl (%{{...}},%{{...}},4), 24 ; CHECK: ret 25 26 entry: 27 %tmp2 = shl i32 %i, 1 28 %tmp4 = and i32 %tmp2, 131070 29 %tmp7 = getelementptr i16* %X, i32 %tmp4 30 %tmp78 = bitcast i16* %tmp7 to i32* 31 %tmp9 = load i32* %tmp78 32 ret i32 %tmp9 33 } 34 35 define i32 @t3(i16* %i.ptr, i32* %arr) { 36 ; This case is tricky. The lshr followed by a gep will produce a lshr followed 37 ; by an and to remove the low bits. This can be simplified by doing the lshr by 38 ; a greater constant and using the addressing mode to scale the result back up. 39 ; To make matters worse, because of the two-phase zext of %i and their reuse in 40 ; the function, the DAG can get confusing trying to re-use both of them and 41 ; prevent easy analysis of the mask in order to match this. 42 ; CHECK-LABEL: t3: 43 ; CHECK-NOT: and 44 ; CHECK: shrl 45 ; CHECK: addl (%{{...}},%{{...}},4), 46 ; CHECK: ret 47 48 entry: 49 %i = load i16* %i.ptr 50 %i.zext = zext i16 %i to i32 51 %index = lshr i32 %i.zext, 11 52 %val.ptr = getelementptr inbounds i32* %arr, i32 %index 53 %val = load i32* %val.ptr 54 %sum = add i32 %val, %i.zext 55 ret i32 %sum 56 } 57 58 define i32 @t4(i16* %i.ptr, i32* %arr) { 59 ; A version of @t3 that has more zero extends and more re-use of intermediate 60 ; values. This exercise slightly different bits of canonicalization. 61 ; CHECK-LABEL: t4: 62 ; CHECK-NOT: and 63 ; CHECK: shrl 64 ; CHECK: addl (%{{...}},%{{...}},4), 65 ; CHECK: ret 66 67 entry: 68 %i = load i16* %i.ptr 69 %i.zext = zext i16 %i to i32 70 %index = lshr i32 %i.zext, 11 71 %index.zext = zext i32 %index to i64 72 %val.ptr = getelementptr inbounds i32* %arr, i64 %index.zext 73 %val = load i32* %val.ptr 74 %sum.1 = add i32 %val, %i.zext 75 %sum.2 = add i32 %sum.1, %index 76 ret i32 %sum.2 77 } 78
