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; REQUIRES: asserts
; RUN: opt -passes='print<access-info>' -debug-only=loop-accesses -disable-output < %s 2>&1 | FileCheck %s
; void negative_step(int *A) {
; for (int i = 1022; i >= 0; i--)
; A[i+1] = A[i] + 1;
; }
; CHECK-LABEL: 'negative_step'
; CHECK: LAA: Found an analyzable loop: loop
; CHECK: LAA: Checking memory dependencies
; CHECK-NEXT: LAA: Src Scev: {(4092 + %A),+,-4}<nw><%loop>Sink Scev: {(4088 + %A)<nuw>,+,-4}<nw><%loop>
; CHECK-NEXT: LAA: Distance for store i32 %add, ptr %gep.A.plus.1, align 4 to %l = load i32, ptr %gep.A, align 4: -4
; CHECK-NEXT: LAA: Src induction step: -1 Sink induction step: -1
; CHECK-NEXT: LAA: Dependence is negative
define void @negative_step(ptr nocapture %A) {
entry:
%A.plus.1 = getelementptr i32, ptr %A, i64 1
br label %loop
loop:
%iv = phi i64 [ 1022, %entry ], [ %iv.next, %loop ]
%gep.A = getelementptr inbounds i32, ptr %A, i64 %iv
%l = load i32, ptr %gep.A, align 4
%add = add nsw i32 %l, 1
%gep.A.plus.1 = getelementptr i32, ptr %A.plus.1, i64 %iv
store i32 %add, ptr %gep.A.plus.1, align 4
%iv.next = add nsw i64 %iv, -1
%cmp.not = icmp eq i64 %iv, 0
br i1 %cmp.not, label %exit, label %loop
exit:
ret void
}
; void positive_step(int *A) {
; for (int i = 1; i < 1024; i++)
; A[i-1] = A[i] + 1;
; }
; CHECK-LABEL: 'positive_step'
; CHECK: LAA: Found an analyzable loop: loop
; CHECK: LAA: Checking memory dependencies
; CHECK-NEXT: LAA: Src Scev: {(4 + %A)<nuw>,+,4}<nuw><%loop>Sink Scev: {%A,+,4}<nw><%loop>
; CHECK-NEXT: LAA: Distance for %l = load i32, ptr %gep.A, align 4 to store i32 %add, ptr %gep.A.minus.1, align 4: -4
; CHECK-NEXT: LAA: Src induction step: 1 Sink induction step: 1
; CHECK-NEXT: LAA: Dependence is negative
define void @positive_step(ptr nocapture %A) {
entry:
%A.minus.1 = getelementptr i32, ptr %A, i64 -1
br label %loop
loop:
%iv = phi i64 [ 1, %entry ], [ %iv.next, %loop ]
%gep.A = getelementptr inbounds i32, ptr %A, i64 %iv
%l = load i32, ptr %gep.A, align 4
%add = add nsw i32 %l, 1
%gep.A.minus.1 = getelementptr i32, ptr %A.minus.1, i64 %iv
store i32 %add, ptr %gep.A.minus.1, align 4
%iv.next = add nsw i64 %iv, 1
%cmp.not = icmp eq i64 %iv, 1024
br i1 %cmp.not, label %exit, label %loop
exit:
ret void
}
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