[LazyValueInfo] Report nonnull range for nonnull pointers

Currently LazyValueInfo will report only alloca's as having nonnull range.
For loads with !nonnull metadata it will bailout with no additional information.
Same is true for calls returning nonnull pointers.

This change extends LazyValueInfo to handle additional nonnull instructions.

Differential Revision: http://reviews.llvm.org/D12932

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@247985 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/LazyValueInfo.cpp b/lib/Analysis/LazyValueInfo.cpp
index 7fc3e5a..795e398 100644 (file)
--- a/lib/Analysis/LazyValueInfo.cpp
+++ b/lib/Analysis/LazyValueInfo.cpp
@@ -531,8 +531,10 @@ bool LazyValueInfoCache::solveBlockValue(Value *Val, BasicBlock *BB) {
     return true;
   }
 
-  if (AllocaInst *AI = dyn_cast<AllocaInst>(BBI)) {
-    Res = LVILatticeVal::getNot(ConstantPointerNull::get(AI->getType()));
+  // If this value is a nonnull pointer, record it's range and bailout.
+  PointerType *PT = dyn_cast<PointerType>(BBI->getType());
+  if (PT && isKnownNonNull(BBI)) {
+    Res = LVILatticeVal::getNot(ConstantPointerNull::get(PT));
     insertResult(Val, BB, Res);
     return true;
   }

diff --git a/test/Transforms/CorrelatedValuePropagation/non-null.ll b/test/Transforms/CorrelatedValuePropagation/non-null.ll
index a24dfb6..6fb4cb6 100644 (file)
--- a/test/Transforms/CorrelatedValuePropagation/non-null.ll
+++ b/test/Transforms/CorrelatedValuePropagation/non-null.ll
@@ -140,3 +140,24 @@ merge:
   ; CHECK: call void @test11_helper(i8* nonnull %merged_arg)
   ret void
 }
+
+declare void @test12_helper(i8* %arg)
+define void @test12(i8* %arg1, i8** %arg2) {
+; CHECK-LABEL: @test12
+entry:
+  %is_null = icmp eq i8* %arg1, null
+  br i1 %is_null, label %null, label %non_null
+
+non_null:
+  br label %merge
+
+null:
+  %another_arg = load i8*, i8** %arg2, !nonnull !{}
+  br label %merge
+
+merge:
+  %merged_arg = phi i8* [%another_arg, %null], [%arg1, %non_null]
+  call void @test12_helper(i8* %merged_arg)
+  ; CHECK: call void @test12_helper(i8* nonnull %merged_arg)
+  ret void
+}