1 ; RUN: opt -basicaa -loop-load-elim -S < %s | FileCheck %s 2 3 ; When optimizing for size don't eliminate in this loop because the loop would 4 ; have to be versioned first because A and C may alias. 5 ; 6 ; for (unsigned i = 0; i < 100; i++) { 7 ; A[i+1] = B[i] + 2; 8 ; C[i] = A[i] * 2; 9 ; } 10 11 target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128" 12 13 ; CHECK-LABEL: @f( 14 define void @f(i32* %A, i32* %B, i32* %C, i64 %N) optsize { 15 16 entry: 17 br label %for.body 18 19 for.body: ; preds = %for.body, %entry 20 %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] 21 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 22 23 %Aidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next 24 %Bidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv 25 %Cidx = getelementptr inbounds i32, i32* %C, i64 %indvars.iv 26 %Aidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv 27 28 %b = load i32, i32* %Bidx, align 4 29 %a_p1 = add i32 %b, 2 30 store i32 %a_p1, i32* %Aidx_next, align 4 31 32 %a = load i32, i32* %Aidx, align 4 33 ; CHECK: %c = mul i32 %a, 2 34 %c = mul i32 %a, 2 35 store i32 %c, i32* %Cidx, align 4 36 37 %exitcond = icmp eq i64 %indvars.iv.next, %N 38 br i1 %exitcond, label %for.end, label %for.body 39 40 for.end: ; preds = %for.body 41 ret void 42 } 43 44 ; Same loop but with noalias on %A and %C. In this case load-eliminate even 45 ; with -Os. 46 47 ; CHECK-LABEL: @g( 48 define void @g(i32* noalias %A, i32* %B, i32* noalias %C, i64 %N) optsize { 49 50 entry: 51 br label %for.body 52 53 for.body: ; preds = %for.body, %entry 54 %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %for.body ] 55 %indvars.iv.next = add nuw nsw i64 %indvars.iv, 1 56 57 %Aidx_next = getelementptr inbounds i32, i32* %A, i64 %indvars.iv.next 58 %Bidx = getelementptr inbounds i32, i32* %B, i64 %indvars.iv 59 %Cidx = getelementptr inbounds i32, i32* %C, i64 %indvars.iv 60 %Aidx = getelementptr inbounds i32, i32* %A, i64 %indvars.iv 61 62 %b = load i32, i32* %Bidx, align 4 63 %a_p1 = add i32 %b, 2 64 store i32 %a_p1, i32* %Aidx_next, align 4 65 66 %a = load i32, i32* %Aidx, align 4 67 ; CHECK: %c = mul i32 %store_forwarded, 2 68 %c = mul i32 %a, 2 69 store i32 %c, i32* %Cidx, align 4 70 71 %exitcond = icmp eq i64 %indvars.iv.next, %N 72 br i1 %exitcond, label %for.end, label %for.body 73 74 for.end: ; preds = %for.body 75 ret void 76 } 77
