| ; RUN: opt -disable-output < %s -disable-basic-aa -scev-aa -aa-eval -print-all-alias-modref-info \ |
| ; RUN: 2>&1 | FileCheck %s |
| ; RUN: opt -disable-output < %s -aa-pipeline=scev-aa -passes=aa-eval -print-all-alias-modref-info \ |
| ; RUN: 2>&1 | FileCheck %s |
| |
| ; At the time of this writing, -basic-aa misses the example of the form |
| ; A[i+(j+1)] != A[i+j], which can arise from multi-dimensional array references, |
| ; and the example of the form A[0] != A[i+1], where i+1 is known to be positive. |
| |
| target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64" |
| |
| ; p[i] and p[i+1] don't alias. |
| |
| ; CHECK: Function: loop: 3 pointers, 0 call sites |
| ; CHECK: NoAlias: double* %pi, double* %pi.next |
| |
| define void @loop(double* nocapture %p, i64 %n) nounwind { |
| entry: |
| %j = icmp sgt i64 %n, 0 |
| br i1 %j, label %bb, label %return |
| |
| bb: |
| %i = phi i64 [ 0, %entry ], [ %i.next, %bb ] |
| %pi = getelementptr double, double* %p, i64 %i |
| %i.next = add i64 %i, 1 |
| %pi.next = getelementptr double, double* %p, i64 %i.next |
| %x = load double, double* %pi |
| %y = load double, double* %pi.next |
| %z = fmul double %x, %y |
| store double %z, double* %pi |
| %exitcond = icmp eq i64 %i.next, %n |
| br i1 %exitcond, label %return, label %bb |
| |
| return: |
| ret void |
| } |
| |
| ; Slightly more involved: p[j][i], p[j][i+1], and p[j+1][i] don't alias. |
| |
| ; CHECK: Function: nestedloop: 4 pointers, 0 call sites |
| ; CHECK: NoAlias: double* %pi.j, double* %pi.next.j |
| ; CHECK: NoAlias: double* %pi.j, double* %pi.j.next |
| ; CHECK: NoAlias: double* %pi.j.next, double* %pi.next.j |
| |
| define void @nestedloop(double* nocapture %p, i64 %m) nounwind { |
| entry: |
| %k = icmp sgt i64 %m, 0 |
| br i1 %k, label %guard, label %return |
| |
| guard: |
| %l = icmp sgt i64 91, 0 |
| br i1 %l, label %outer.loop, label %return |
| |
| outer.loop: |
| %j = phi i64 [ 0, %guard ], [ %j.next, %outer.latch ] |
| br label %bb |
| |
| bb: |
| %i = phi i64 [ 0, %outer.loop ], [ %i.next, %bb ] |
| %i.next = add i64 %i, 1 |
| |
| %e = add i64 %i, %j |
| %pi.j = getelementptr double, double* %p, i64 %e |
| %f = add i64 %i.next, %j |
| %pi.next.j = getelementptr double, double* %p, i64 %f |
| %x = load double, double* %pi.j |
| %y = load double, double* %pi.next.j |
| %z = fmul double %x, %y |
| store double %z, double* %pi.j |
| |
| %o = add i64 %j, 91 |
| %g = add i64 %i, %o |
| %pi.j.next = getelementptr double, double* %p, i64 %g |
| %a = load double, double* %pi.j.next |
| %b = fmul double %x, %a |
| store double %b, double* %pi.j.next |
| |
| %exitcond = icmp eq i64 %i.next, 91 |
| br i1 %exitcond, label %outer.latch, label %bb |
| |
| outer.latch: |
| %j.next = add i64 %j, 91 |
| %h = icmp eq i64 %j.next, %m |
| br i1 %h, label %return, label %outer.loop |
| |
| return: |
| ret void |
| } |
| |
| ; Even more involved: same as nestedloop, but with a variable extent. |
| ; When n is 1, p[j+1][i] does alias p[j][i+1], and there's no way to |
| ; prove whether n will be greater than 1, so that relation will always |
| ; by MayAlias. The loop is guarded by a n > 0 test though, so |
| ; p[j+1][i] and p[j][i] can theoretically be determined to be NoAlias, |
| ; however the analysis currently doesn't do that. |
| ; TODO: Make the analysis smarter and turn that MayAlias into a NoAlias. |
| |
| ; CHECK: Function: nestedloop_more: 4 pointers, 0 call sites |
| ; CHECK: NoAlias: double* %pi.j, double* %pi.next.j |
| ; CHECK: MayAlias: double* %pi.j, double* %pi.j.next |
| |
| define void @nestedloop_more(double* nocapture %p, i64 %n, i64 %m) nounwind { |
| entry: |
| %k = icmp sgt i64 %m, 0 |
| br i1 %k, label %guard, label %return |
| |
| guard: |
| %l = icmp sgt i64 %n, 0 |
| br i1 %l, label %outer.loop, label %return |
| |
| outer.loop: |
| %j = phi i64 [ 0, %guard ], [ %j.next, %outer.latch ] |
| br label %bb |
| |
| bb: |
| %i = phi i64 [ 0, %outer.loop ], [ %i.next, %bb ] |
| %i.next = add i64 %i, 1 |
| |
| %e = add i64 %i, %j |
| %pi.j = getelementptr double, double* %p, i64 %e |
| %f = add i64 %i.next, %j |
| %pi.next.j = getelementptr double, double* %p, i64 %f |
| %x = load double, double* %pi.j |
| %y = load double, double* %pi.next.j |
| %z = fmul double %x, %y |
| store double %z, double* %pi.j |
| |
| %o = add i64 %j, %n |
| %g = add i64 %i, %o |
| %pi.j.next = getelementptr double, double* %p, i64 %g |
| %a = load double, double* %pi.j.next |
| %b = fmul double %x, %a |
| store double %b, double* %pi.j.next |
| |
| %exitcond = icmp eq i64 %i.next, %n |
| br i1 %exitcond, label %outer.latch, label %bb |
| |
| outer.latch: |
| %j.next = add i64 %j, %n |
| %h = icmp eq i64 %j.next, %m |
| br i1 %h, label %return, label %outer.loop |
| |
| return: |
| ret void |
| } |
| |
| ; ScalarEvolution expands field offsets into constants, which allows it to |
| ; do aggressive analysis. Contrast this with BasicAA, which works by |
| ; recognizing GEP idioms. |
| |
| %struct.A = type { %struct.B, i32, i32 } |
| %struct.B = type { double } |
| |
| ; CHECK: Function: foo: 7 pointers, 0 call sites |
| ; CHECK: NoAlias: %struct.B* %B, i32* %Z |
| ; CHECK: NoAlias: %struct.B* %B, %struct.B* %C |
| ; CHECK: MustAlias: %struct.B* %C, i32* %Z |
| ; CHECK: NoAlias: %struct.B* %B, i32* %X |
| ; CHECK: MustAlias: i32* %X, i32* %Z |
| ; CHECK: MustAlias: %struct.B* %C, i32* %Y |
| ; CHECK: MustAlias: i32* %X, i32* %Y |
| |
| define void @foo() { |
| entry: |
| %A = alloca %struct.A |
| %B = getelementptr %struct.A, %struct.A* %A, i32 0, i32 0 |
| %Q = bitcast %struct.B* %B to %struct.A* |
| %Z = getelementptr %struct.A, %struct.A* %Q, i32 0, i32 1 |
| %C = getelementptr %struct.B, %struct.B* %B, i32 1 |
| %X = bitcast %struct.B* %C to i32* |
| %Y = getelementptr %struct.A, %struct.A* %A, i32 0, i32 1 |
| ret void |
| } |
| |
| ; CHECK: Function: bar: 7 pointers, 0 call sites |
| ; CHECK: NoAlias: %struct.B* %N, i32* %P |
| ; CHECK: NoAlias: %struct.B* %N, %struct.B* %R |
| ; CHECK: MustAlias: %struct.B* %R, i32* %P |
| ; CHECK: NoAlias: %struct.B* %N, i32* %W |
| ; CHECK: MustAlias: i32* %P, i32* %W |
| ; CHECK: MustAlias: %struct.B* %R, i32* %V |
| ; CHECK: MustAlias: i32* %V, i32* %W |
| |
| define void @bar() { |
| %M = alloca %struct.A |
| %N = getelementptr %struct.A, %struct.A* %M, i32 0, i32 0 |
| %O = bitcast %struct.B* %N to %struct.A* |
| %P = getelementptr %struct.A, %struct.A* %O, i32 0, i32 1 |
| %R = getelementptr %struct.B, %struct.B* %N, i32 1 |
| %W = bitcast %struct.B* %R to i32* |
| %V = getelementptr %struct.A, %struct.A* %M, i32 0, i32 1 |
| ret void |
| } |
| |
| ; CHECK: Function: nonnegative: 2 pointers, 0 call sites |
| ; CHECK: NoAlias: i64* %arrayidx, i64* %p |
| |
| define void @nonnegative(i64* %p) nounwind { |
| entry: |
| br label %for.body |
| |
| for.body: ; preds = %entry, %for.body |
| %i = phi i64 [ %inc, %for.body ], [ 0, %entry ] ; <i64> [#uses=2] |
| %inc = add nsw i64 %i, 1 ; <i64> [#uses=2] |
| %arrayidx = getelementptr inbounds i64, i64* %p, i64 %inc |
| store i64 0, i64* %arrayidx |
| %tmp6 = load i64, i64* %p ; <i64> [#uses=1] |
| %cmp = icmp slt i64 %inc, %tmp6 ; <i1> [#uses=1] |
| br i1 %cmp, label %for.body, label %for.end |
| |
| for.end: ; preds = %for.body, %entry |
| ret void |
| } |
| |
| ; CHECK: 14 no alias responses |
| ; CHECK: 26 may alias responses |
| ; CHECK: 18 must alias responses |