; RUN: opt -loop-accesses -analyze < %s | FileCheck %s ; RUN: opt -passes='require,require,loop(print-access-info)' -disable-output < %s 2>&1 | FileCheck %s ; The runtime memory check code and the access grouping ; algorithm both assume that the start and end values ; for an access range are ordered (start <= stop). ; When generating checks for accesses with negative stride ; we need to take this into account and swap the interval ; ends. ; ; for (i = 0; i < 10000; i++) { ; B[i] = A[15000 - i] * 3; ; } target datalayout = "e-m:e-i64:64-i128:128-n32:64-S128" target triple = "aarch64--linux-gnueabi" ; CHECK: function 'f': ; CHECK: (Low: (20000 + %a) High: (60000 + %a)) @B = common global i32* null, align 8 @A = common global i32* null, align 8 define void @f() { entry: %a = load i32*, i32** @A, align 8 %b = load i32*, i32** @B, align 8 br label %for.body for.body: ; preds = %for.body, %entry %idx = phi i64 [ 0, %entry ], [ %add, %for.body ] %negidx = sub i64 15000, %idx %arrayidxA0 = getelementptr inbounds i32, i32* %a, i64 %negidx %loadA0 = load i32, i32* %arrayidxA0, align 2 %res = mul i32 %loadA0, 3 %add = add nuw nsw i64 %idx, 1 %arrayidxB = getelementptr inbounds i32, i32* %b, i64 %idx store i32 %res, i32* %arrayidxB, align 2 %exitcond = icmp eq i64 %idx, 10000 br i1 %exitcond, label %for.end, label %for.body for.end: ; preds = %for.body ret void } ; CHECK: function 'g': ; When the stride is not constant, we are forced to do umin/umax to get ; the interval limits. ; for (i = 0; i < 10000; i++) { ; B[i] = A[15000 - step * i] * 3; ; } ; Here it is not obvious what the limits are, since 'step' could be negative. ; CHECK: Low: (-1 + (-1 * ((-60001 + (-1 * %a)) umax (-60001 + (40000 * %step) + (-1 * %a))))) ; CHECK: High: ((60000 + %a) umax (60000 + (-40000 * %step) + %a)) define void @g(i64 %step) { entry: %a = load i32*, i32** @A, align 8 %b = load i32*, i32** @B, align 8 br label %for.body for.body: ; preds = %for.body, %entry %idx = phi i64 [ 0, %entry ], [ %add, %for.body ] %idx_mul = mul i64 %idx, %step %negidx = sub i64 15000, %idx_mul %arrayidxA0 = getelementptr inbounds i32, i32* %a, i64 %negidx %loadA0 = load i32, i32* %arrayidxA0, align 2 %res = mul i32 %loadA0, 3 %add = add nuw nsw i64 %idx, 1 %arrayidxB = getelementptr inbounds i32, i32* %b, i64 %idx store i32 %res, i32* %arrayidxB, align 2 %exitcond = icmp eq i64 %idx, 10000 br i1 %exitcond, label %for.end, label %for.body for.end: ; preds = %for.body ret void }