The Nest
Explore
0
Compiler projects using llvm 
; RUN: opt < %s -passes=newgvn -S | FileCheck %s

%struct.A = type { i32 (...)** }
@_ZTV1A = available_externally unnamed_addr constant [3 x i8*] [i8* null, i8* bitcast (i8** @_ZTI1A to i8*), i8* bitcast (void (%struct.A*)* @_ZN1A3fooEv to i8*)], align 8
@_ZTI1A = external constant i8*

@unknownPtr = external global i8

; CHECK-LABEL: define i8 @simple() {
define i8 @simple() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr, !invariant.group !0
    call void @foo(i8* %ptr)

    %a = load i8, i8* %ptr, !invariant.group !0
    %b = load i8, i8* %ptr, !invariant.group !0
    %c = load i8, i8* %ptr, !invariant.group !0
; CHECK: ret i8 42
    ret i8 %a
}

; CHECK-LABEL: define i8 @optimizable1() {
define i8 @optimizable1() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr, !invariant.group !0
    %ptr2 = call i8* @llvm.launder.invariant.group.p0i8(i8* %ptr)
    %a = load i8, i8* %ptr, !invariant.group !0
    
    call void @foo(i8* %ptr2); call to use %ptr2
; CHECK: ret i8 42
    ret i8 %a
}

; CHECK-LABEL: define i8 @optimizable2() {
define i8 @optimizable2() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr, !invariant.group !0
    call void @foo(i8* %ptr)
    
    store i8 13, i8* %ptr ; can't use this store with invariant.group
    %a = load i8, i8* %ptr 
    call void @bar(i8 %a) ; call to use %a
    
    call void @foo(i8* %ptr)
    %b = load i8, i8* %ptr, !invariant.group !0
    
; CHECK: ret i8 42
    ret i8 %b
}

; CHECK-LABEL: define i1 @proveEqualityForStrip(
define i1 @proveEqualityForStrip(i8* %a) {
  %b1 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
; CHECK-NOT: llvm.strip.invariant.group
  %b2 = call i8* @llvm.strip.invariant.group.p0i8(i8* %a)
  %r = icmp eq i8* %b1, %b2
; CHECK: ret i1 true
  ret i1 %r
}

; CHECK-LABEL: define i8 @unoptimizable1() {
define i8 @unoptimizable1() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr
    call void @foo(i8* %ptr)
    %a = load i8, i8* %ptr, !invariant.group !0
; CHECK: ret i8 %a
    ret i8 %a
}

; NewGVN doesn't support assumes.
; CHECK-LABEL: define void @indirectLoads() {
define void @indirectLoads() {
entry:
  %a = alloca %struct.A*, align 8
  %0 = bitcast %struct.A** %a to i8*
  
  %call = call i8* @getPointer(i8* null) 
  %1 = bitcast i8* %call to %struct.A*
  call void @_ZN1AC1Ev(%struct.A* %1)
  %2 = bitcast %struct.A* %1 to i8***
  
; CHECK: %vtable = load {{.*}} !invariant.group
  %vtable = load i8**, i8*** %2, align 8, !invariant.group !0
  %cmp.vtables = icmp eq i8** %vtable, getelementptr inbounds ([3 x i8*], [3 x i8*]* @_ZTV1A, i64 0, i64 2)
  call void @llvm.assume(i1 %cmp.vtables)
  
  store %struct.A* %1, %struct.A** %a, align 8
  %3 = load %struct.A*, %struct.A** %a, align 8
  %4 = bitcast %struct.A* %3 to void (%struct.A*)***

; FIXME: call void @_ZN1A3fooEv(
  %vtable1 = load void (%struct.A*)**, void (%struct.A*)*** %4, align 8, !invariant.group !0
  %vfn = getelementptr inbounds void (%struct.A*)*, void (%struct.A*)** %vtable1, i64 0
  %5 = load void (%struct.A*)*, void (%struct.A*)** %vfn, align 8
  call void %5(%struct.A* %3)
  %6 = load %struct.A*, %struct.A** %a, align 8
  %7 = bitcast %struct.A* %6 to void (%struct.A*)***

; FIXME: call void @_ZN1A3fooEv(
  %vtable2 = load void (%struct.A*)**, void (%struct.A*)*** %7, align 8, !invariant.group !0
  %vfn3 = getelementptr inbounds void (%struct.A*)*, void (%struct.A*)** %vtable2, i64 0
  %8 = load void (%struct.A*)*, void (%struct.A*)** %vfn3, align 8
  
  call void %8(%struct.A* %6)
  %9 = load %struct.A*, %struct.A** %a, align 8
  %10 = bitcast %struct.A* %9 to void (%struct.A*)***
  
  %vtable4 = load void (%struct.A*)**, void (%struct.A*)*** %10, align 8, !invariant.group !0
  %vfn5 = getelementptr inbounds void (%struct.A*)*, void (%struct.A*)** %vtable4, i64 0
  %11 = load void (%struct.A*)*, void (%struct.A*)** %vfn5, align 8
; FIXME: call void @_ZN1A3fooEv(
  call void %11(%struct.A* %9)
 
  %vtable5 = load i8**, i8*** %2, align 8, !invariant.group !0
  %vfn6 = getelementptr inbounds i8*, i8** %vtable5, i64 0
  %12 = bitcast i8** %vfn6 to void (%struct.A*)**
  %13 = load void (%struct.A*)*, void (%struct.A*)** %12, align 8
; FIXME: call void @_ZN1A3fooEv(
  call void %13(%struct.A* %9)
  
  ret void
}

; NewGVN won't CSE loads with different pointee types.
; CHECK-LABEL: define void @combiningBitCastWithLoad() {
define void @combiningBitCastWithLoad() {
entry:
  %a = alloca %struct.A*, align 8
  %0 = bitcast %struct.A** %a to i8*
  
  %call = call i8* @getPointer(i8* null) 
  %1 = bitcast i8* %call to %struct.A*
  call void @_ZN1AC1Ev(%struct.A* %1)
  %2 = bitcast %struct.A* %1 to i8***
  
; CHECK: %vtable = load {{.*}} !invariant.group
  %vtable = load i8**, i8*** %2, align 8, !invariant.group !0
  %cmp.vtables = icmp eq i8** %vtable, getelementptr inbounds ([3 x i8*], [3 x i8*]* @_ZTV1A, i64 0, i64 2)
  
  store %struct.A* %1, %struct.A** %a, align 8
; FIXME-NOT: !invariant.group
  %3 = load %struct.A*, %struct.A** %a, align 8
  %4 = bitcast %struct.A* %3 to void (%struct.A*)***

  %vtable1 = load void (%struct.A*)**, void (%struct.A*)*** %4, align 8, !invariant.group !0
  %vfn = getelementptr inbounds void (%struct.A*)*, void (%struct.A*)** %vtable1, i64 0
  %5 = load void (%struct.A*)*, void (%struct.A*)** %vfn, align 8
  call void %5(%struct.A* %3)

  ret void
}

; CHECK-LABEL:define void @loadCombine() {
define void @loadCombine() {
enter:
  %ptr = alloca i8
  store i8 42, i8* %ptr
  call void @foo(i8* %ptr)
; CHECK: %[[A:.*]] = load i8, i8* %ptr, align 1, !invariant.group
  %a = load i8, i8* %ptr, !invariant.group !0
; CHECK-NOT: load
  %b = load i8, i8* %ptr, !invariant.group !0
; CHECK: call void @bar(i8 %[[A]])
  call void @bar(i8 %a)
; CHECK: call void @bar(i8 %[[A]])
  call void @bar(i8 %b)
  ret void
}

; CHECK-LABEL: define void @loadCombine1() {
define void @loadCombine1() {
enter:
  %ptr = alloca i8
  store i8 42, i8* %ptr
  call void @foo(i8* %ptr)
; CHECK: %[[D:.*]] = load i8, i8* %ptr, align 1, !invariant.group
  %c = load i8, i8* %ptr
; CHECK-NOT: load
  %d = load i8, i8* %ptr, !invariant.group !0
; CHECK: call void @bar(i8 %[[D]])
  call void @bar(i8 %c)
; CHECK: call void @bar(i8 %[[D]])
  call void @bar(i8 %d)
  ret void
}

; CHECK-LABEL: define void @loadCombine2() {    
define void @loadCombine2() {
enter:
  %ptr = alloca i8
  store i8 42, i8* %ptr
  call void @foo(i8* %ptr)
; CHECK: %[[E:.*]] = load i8, i8* %ptr, align 1, !invariant.group
  %e = load i8, i8* %ptr, !invariant.group !0
; CHECK-NOT: load
  %f = load i8, i8* %ptr
; CHECK: call void @bar(i8 %[[E]])
  call void @bar(i8 %e)
; CHECK: call void @bar(i8 %[[E]])
  call void @bar(i8 %f)
  ret void
}

; CHECK-LABEL: define void @loadCombine3() {
define void @loadCombine3() {
enter:
  %ptr = alloca i8
  store i8 42, i8* %ptr
  call void @foo(i8* %ptr)
; CHECK: %[[E:.*]] = load i8, i8* %ptr, align 1, !invariant.group
  %e = load i8, i8* %ptr, !invariant.group !0
; CHECK-NOT: load
  %f = load i8, i8* %ptr, !invariant.group !0
; CHECK: call void @bar(i8 %[[E]])
  call void @bar(i8 %e)
; CHECK: call void @bar(i8 %[[E]])
  call void @bar(i8 %f)
  ret void
}

; CHECK-LABEL: define i8 @unoptimizable2() {
define i8 @unoptimizable2() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr
    call void @foo(i8* %ptr)
    %a = load i8, i8* %ptr
    call void @foo(i8* %ptr)
    %b = load i8, i8* %ptr, !invariant.group !0
    
; CHECK: ret i8 %a
    ret i8 %a
}

; CHECK-LABEL: define i8 @unoptimizable3() {
define i8 @unoptimizable3() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr, !invariant.group !0
    %ptr2 = call i8* @getPointer(i8* %ptr)
    %a = load i8, i8* %ptr2, !invariant.group !0
    
; CHECK: ret i8 %a
    ret i8 %a
}

; NewGVN cares about the launder for some reason.
; CHECK-LABEL: define i8 @optimizable4() {
define i8 @optimizable4() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr
    %ptr2 = call i8* @llvm.launder.invariant.group.p0i8(i8* %ptr)
; FIXME-NOT: load
    %a = load i8, i8* %ptr2
    
; FIXME: ret i8 42
    ret i8 %a
}

; CHECK-LABEL: define i8 @volatile1() {
define i8 @volatile1() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr, !invariant.group !0
    call void @foo(i8* %ptr)
    %a = load i8, i8* %ptr, !invariant.group !0
    %b = load volatile i8, i8* %ptr
; CHECK: call void @bar(i8 %b)
    call void @bar(i8 %b)

    %c = load volatile i8, i8* %ptr, !invariant.group !0
; We might be able to optimize this, but nobody cares
; CHECK: call void @bar(i8 %c)
    call void @bar(i8 %c)
; CHECK: ret i8 42
    ret i8 %a
}

; CHECK-LABEL: define i8 @volatile2() {
define i8 @volatile2() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr, !invariant.group !0
    call void @foo(i8* %ptr)
    %a = load i8, i8* %ptr, !invariant.group !0
    %b = load volatile i8, i8* %ptr
; CHECK: call void @bar(i8 %b)
    call void @bar(i8 %b)

    %c = load volatile i8, i8* %ptr, !invariant.group !0
; We might be able to optimize this, but nobody cares
; CHECK: call void @bar(i8 %c)
    call void @bar(i8 %c)
; CHECK: ret i8 42
    ret i8 %a
}

; CHECK-LABEL: define void @fun() {
define void @fun() {
entry:
    %ptr = alloca i8
    store i8 42, i8* %ptr, !invariant.group !0
    call void @foo(i8* %ptr)

    %a = load i8, i8* %ptr, !invariant.group !0 ; Can assume that value under %ptr didn't change
; CHECK: call void @bar(i8 42)
    call void @bar(i8 %a)

    ret void
}

; FIXME: NewGVN doesn't run instsimplify on a load from a vtable definition?
; This test checks if invariant.group understands gep with zeros
; CHECK-LABEL: define void @testGEP0() {
define void @testGEP0() {
  %a = alloca %struct.A, align 8
  %1 = bitcast %struct.A* %a to i8*
  %2 = getelementptr inbounds %struct.A, %struct.A* %a, i64 0, i32 0
  store i32 (...)** bitcast (i8** getelementptr inbounds ([3 x i8*], [3 x i8*]* @_ZTV1A, i64 0, i64 2) to i32 (...)**), i32 (...)*** %2, align 8, !invariant.group !0
; CHECK: call void @_ZN1A3fooEv(%struct.A* nonnull dereferenceable(8) %a)
  call void @_ZN1A3fooEv(%struct.A* nonnull dereferenceable(8) %a) ; This call may change vptr
  %3 = load i8, i8* @unknownPtr, align 4
  %4 = icmp eq i8 %3, 0
  br i1 %4, label %_Z1gR1A.exit, label %5

; This should be devirtualized by invariant.group
  %6 = bitcast %struct.A* %a to void (%struct.A*)***
  %7 = load void (%struct.A*)**, void (%struct.A*)*** %6, align 8, !invariant.group !0
  %8 = load void (%struct.A*)*, void (%struct.A*)** %7, align 8
; FIXME: call void @_ZN1A3fooEv(%struct.A* nonnull %a)
  call void %8(%struct.A* nonnull %a)
  br label %_Z1gR1A.exit

_Z1gR1A.exit:                                     ; preds = %0, %5
  ret void
}

; Check if no optimizations are performed with global pointers.
; FIXME: we could do the optimizations if we would check if dependency comes
; from the same function.
; CHECK-LABEL: define void @testGlobal() {
define void @testGlobal() {
; CHECK:  %a = load i8, i8* @unknownPtr, align 1, !invariant.group !0
   %a = load i8, i8* @unknownPtr, !invariant.group !0
   call void @foo2(i8* @unknownPtr, i8 %a)
; CHECK:  %1 = load i8, i8* @unknownPtr, align 1, !invariant.group !0
   %1 = load i8, i8* @unknownPtr, !invariant.group !0
   call void @bar(i8 %1)

   %b0 = bitcast i8* @unknownPtr to i1*
   call void @fooBit(i1* %b0, i1 1)
; Adding regex because of canonicalization of bitcasts
; CHECK: %2 = load i1, i1* {{.*}}, !invariant.group !0
   %2 = load i1, i1* %b0, !invariant.group !0
   call void @fooBit(i1* %b0, i1 %2)
; CHECK:  %3 = load i1, i1* {{.*}}, !invariant.group !0
   %3 = load i1, i1* %b0, !invariant.group !0
   call void @fooBit(i1* %b0, i1 %3)
   ret void
}

; Might be similar to above where NewGVN doesn't handle loads of different types from the same location.
; Not super important anyway.
; CHECK-LABEL: define void @testTrunc() {
define void @testTrunc() {
   %a = alloca i8
   call void @foo(i8* %a)
; CHECK:  %b = load i8, i8* %a, align 1, !invariant.group !0
   %b = load i8, i8* %a, !invariant.group !0
   call void @foo2(i8* %a, i8 %b)

   %1 = load i8, i8* %a, !invariant.group !0
; CHECK: call void @bar(i8 %b)
   call void @bar(i8 %1)

   %b0 = bitcast i8* %a to i1*
   call void @fooBit(i1* %b0, i1 1)
; FIXME: %1 = trunc i8 %b to i1
   %2 = load i1, i1* %b0, !invariant.group !0
; FIXME-NEXT: call void @fooBit(i1* %b0, i1 %1)
   call void @fooBit(i1* %b0, i1 %2)
   %3 = load i1, i1* %b0, !invariant.group !0
; FIXME-NEXT: call void @fooBit(i1* %b0, i1 %1)
   call void @fooBit(i1* %b0, i1 %3)
   ret void
}

; See comment in @testGEP0 on what NewGVN is lacking.
; CHECK-LABEL: define void @handling_loops()
define void @handling_loops() {
  %a = alloca %struct.A, align 8
  %1 = bitcast %struct.A* %a to i8*
  %2 = getelementptr inbounds %struct.A, %struct.A* %a, i64 0, i32 0
  store i32 (...)** bitcast (i8** getelementptr inbounds ([3 x i8*], [3 x i8*]* @_ZTV1A, i64 0, i64 2) to i32 (...)**), i32 (...)*** %2, align 8, !invariant.group !0
  %3 = load i8, i8* @unknownPtr, align 4
  %4 = icmp sgt i8 %3, 0
  br i1 %4, label %.lr.ph.i, label %_Z2g2R1A.exit

.lr.ph.i:                                         ; preds = %0
  %5 = bitcast %struct.A* %a to void (%struct.A*)***
  %6 = load i8, i8* @unknownPtr, align 4
  %7 = icmp sgt i8 %6, 1
  br i1 %7, label %._crit_edge.preheader, label %_Z2g2R1A.exit

._crit_edge.preheader:                            ; preds = %.lr.ph.i
  br label %._crit_edge

._crit_edge:                                      ; preds = %._crit_edge.preheader, %._crit_edge
  %8 = phi i8 [ %10, %._crit_edge ], [ 1, %._crit_edge.preheader ]
  %.pre = load void (%struct.A*)**, void (%struct.A*)*** %5, align 8, !invariant.group !0
  %9 = load void (%struct.A*)*, void (%struct.A*)** %.pre, align 8
  ; FIXME: call void @_ZN1A3fooEv(%struct.A* nonnull %a)
  call void %9(%struct.A* nonnull %a) #3
  ; FIXME-NOT: call void %
  %10 = add nuw nsw i8 %8, 1
  %11 = load i8, i8* @unknownPtr, align 4
  %12 = icmp slt i8 %10, %11
  br i1 %12, label %._crit_edge, label %_Z2g2R1A.exit.loopexit

_Z2g2R1A.exit.loopexit:                           ; preds = %._crit_edge
  br label %_Z2g2R1A.exit

_Z2g2R1A.exit:                                    ; preds = %_Z2g2R1A.exit.loopexit, %.lr.ph.i, %0
  ret void
}


declare void @foo(i8*)
declare void @foo2(i8*, i8)
declare void @bar(i8)
declare i8* @getPointer(i8*)
declare void @_ZN1A3fooEv(%struct.A*)
declare void @_ZN1AC1Ev(%struct.A*)
declare void @fooBit(i1*, i1)

declare i8* @llvm.launder.invariant.group.p0i8(i8*)
declare i8* @llvm.strip.invariant.group.p0i8(i8*)

; Function Attrs: nounwind
declare void @llvm.assume(i1 %cmp.vtables) #0


attributes #0 = { nounwind }
!0 = !{}