[MemDep] NFC walk invariant.group graph only down

Summary:
By using stripPointerCasts we can get to the root
value and then walk down the bitcast graph

Reviewers: reames

Subscribers: llvm-commits

Differential Revision: https://reviews.llvm.org/D28181

llvm-svn: 291405

2 files changed, 104 insertions, 0 deletions

diff --git a/llvm/test/Transforms/GVN/invariant.group.ll b/llvm/test/Transforms/GVN/invariant.group.ll
index 026671a5bdf..d0b32d7f3dd 100644
--- a/llvm/test/Transforms/GVN/invariant.group.ll
+++ b/llvm/test/Transforms/GVN/invariant.group.ll
@@ -344,11 +344,63 @@ _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, !invariant.group !0
+   %a = load i8, i8* @unknownPtr, !invariant.group !0
+   call void @foo2(i8* @unknownPtr, i8 %a)
+; CHECK:  %1 = load i8, i8* @unknownPtr, !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
+}
+; And in the case it is not global
+; CHECK-LABEL: define void @testNotGlobal() {
+define void @testNotGlobal() {
+   %a = alloca i8
+   call void @foo(i8* %a)
+; CHECK:  %b = load i8, i8* %a, !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)
+; CHECK: %trunc = trunc i8 %b to i1
+   %2 = load i1, i1* %b0, !invariant.group !0
+; CHECK-NEXT: call void @fooBit(i1* %b0, i1 %trunc)
+   call void @fooBit(i1* %b0, i1 %2)
+   %3 = load i1, i1* %b0, !invariant.group !0
+; CHECK-NEXT: call void @fooBit(i1* %b0, i1 %trunc)
+   call void @fooBit(i1* %b0, i1 %3)
+   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.invariant.group.barrier(i8*)
 
 ; Function Attrs: nounwind
diff --git a/llvm/test/Transforms/NewGVN/invariant.group.ll b/llvm/test/Transforms/NewGVN/invariant.group.ll
index 2bddc99c8b8..80c6e05a8e2 100644
--- a/llvm/test/Transforms/NewGVN/invariant.group.ll
+++ b/llvm/test/Transforms/NewGVN/invariant.group.ll
@@ -345,11 +345,63 @@ _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, !invariant.group !0
+   %a = load i8, i8* @unknownPtr, !invariant.group !0
+   call void @foo2(i8* @unknownPtr, i8 %a)
+; CHECK:  %1 = load i8, i8* @unknownPtr, !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
+}
+; And in the case it is not global
+; CHECK-LABEL: define void @testNotGlobal() {
+define void @testNotGlobal() {
+   %a = alloca i8
+   call void @foo(i8* %a)
+; CHECK:  %b = load i8, i8* %a, !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)
+; CHECK: %trunc = trunc i8 %b to i1
+   %2 = load i1, i1* %b0, !invariant.group !0
+; CHECK-NEXT: call void @fooBit(i1* %b0, i1 %trunc)
+   call void @fooBit(i1* %b0, i1 %2)
+   %3 = load i1, i1* %b0, !invariant.group !0
+; CHECK-NEXT: call void @fooBit(i1* %b0, i1 %trunc)
+   call void @fooBit(i1* %b0, i1 %3)
+   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.invariant.group.barrier(i8*)
 
 ; Function Attrs: nounwind