In the default address space, any GEP off of null results in a trap value if you...

any load in the default address space that completes implies that the base value that it GEP'd from
was not null.

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@112015 91177308-0d34-0410-b5e6-96231b3b80d8

diff --git a/lib/Analysis/LazyValueInfo.cpp b/lib/Analysis/LazyValueInfo.cpp
index e4cd867743a37731362a4df559f36103157555e1..31ca2de2836090b2fc8fcc523a780d8a40e969aa 100644 (file)
--- a/lib/Analysis/LazyValueInfo.cpp
+++ b/lib/Analysis/LazyValueInfo.cpp
@@ -457,10 +457,11 @@ LVILatticeVal LVIQuery::getBlockValue(BasicBlock *BB) {
     // then we know that the pointer can't be NULL.
     if (Val->getType()->isPointerTy()) {
       const PointerType *PTy = cast<PointerType>(Val->getType());
-      for (Value::use_iterator UI = Val->use_begin(), UE = Val->use_end();
-           UI != UE; ++UI) {
-        LoadInst *L = dyn_cast<LoadInst>(*UI);
-        if (L && L->getParent() == BB && L->getPointerAddressSpace() == 0) {
+      for (BasicBlock::iterator BI = BB->begin(), BE = BB->end();BI != BE;++BI){
+        LoadInst *L = dyn_cast<LoadInst>(BI);
+        if (L && L->getPointerAddressSpace() == 0 &&
+            L->getPointerOperand()->getUnderlyingObject() ==
+              Val->getUnderlyingObject()) {
           return LVILatticeVal::getNot(ConstantPointerNull::get(PTy));
         }
       }

diff --git a/test/Transforms/JumpThreading/lvi-load.ll b/test/Transforms/JumpThreading/lvi-load.ll
new file mode 100644 (file)
index 0000000..c6af7b5
--- /dev/null
+++ b/test/Transforms/JumpThreading/lvi-load.ll
@@ -0,0 +1,48 @@
+; RUN: opt -S -jump-threading -enable-jump-threading-lvi < %s | FileCheck %s
+target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-apple-darwin10.4"
+
+%"struct.llvm::PATypeHolder" = type { %"struct.llvm::Type"* }
+%"struct.llvm::PointerIntPair<llvm::Use**,2u,llvm::Use::PrevPtrTag,llvm::PointerLikeTypeTraits<llvm::Use**> >" = type { i64 }
+%"struct.llvm::Type" = type opaque
+%"struct.llvm::Use" = type { %"struct.llvm::Value"*, %"struct.llvm::Use"*, %"struct.llvm::PointerIntPair<llvm::Use**,2u,llvm::Use::PrevPtrTag,llvm::PointerLikeTypeTraits<llvm::Use**> >" }
+%"struct.llvm::Value" = type { i32 (...)**, i8, i8, i16, %"struct.llvm::PATypeHolder", %"struct.llvm::Use"*, %"struct.llvm::ValueName"* }
+%"struct.llvm::ValueName" = type opaque
+
+@_ZZN4llvm4castINS_11InstructionEPNS_5ValueEEENS_10cast_rettyIT_T0_E8ret_typeERKS6_E8__func__ = internal constant [5 x i8] c"cast\00", align 8 ; <[5 x i8]*> [#uses=1]
+@.str = private constant [31 x i8] c"include/llvm/Support/Casting.h\00", align 8 ; <[31 x i8]*> [#uses=1]
+@.str1 = private constant [59 x i8] c"isa<X>(Val) && \22cast<Ty>() argument of incompatible type!\22\00", align 8 ; <[59 x i8]*> [#uses=1]
+
+; CHECK: Z3fooPN4llvm5ValueE
+define zeroext i8 @_Z3fooPN4llvm5ValueE(%"struct.llvm::Value"* %V) ssp {
+entry:
+  %0 = getelementptr inbounds %"struct.llvm::Value"* %V, i64 0, i32 1 ; <i8*> [#uses=1]
+  %1 = load i8* %0, align 8                       ; <i8> [#uses=2]
+  %2 = icmp ugt i8 %1, 20                         ; <i1> [#uses=1]
+  br i1 %2, label %bb.i, label %bb2
+
+bb.i:                                             ; preds = %entry
+  %toBoolnot.i.i = icmp ult i8 %1, 21             ; <i1> [#uses=1]
+  br i1 %toBoolnot.i.i, label %bb6.i.i, label %_ZN4llvm8dyn_castINS_11InstructionEPNS_5ValueEEENS_10cast_rettyIT_T0_E8ret_typeERKS6_.exit
+
+bb6.i.i:                                          ; preds = %bb.i
+  tail call void @__assert_rtn(i8* getelementptr inbounds ([5 x i8]* @_ZZN4llvm4castINS_11InstructionEPNS_5ValueEEENS_10cast_rettyIT_T0_E8ret_typeERKS6_E8__func__, i64 0, i64 0), i8* getelementptr inbounds ([31 x i8]* @.str, i64 0, i64 0), i32 202, i8* getelementptr inbounds ([59 x i8]* @.str1, i64 0, i64 0)) noreturn
+  unreachable
+
+_ZN4llvm8dyn_castINS_11InstructionEPNS_5ValueEEENS_10cast_rettyIT_T0_E8ret_typeERKS6_.exit: ; preds = %bb.i
+; CHECK-NOT: null
+  %3 = icmp eq %"struct.llvm::Value"* %V, null    ; <i1> [#uses=1]
+  br i1 %3, label %bb2, label %bb
+
+bb:                                               ; preds = %_ZN4llvm8dyn_castINS_11InstructionEPNS_5ValueEEENS_10cast_rettyIT_T0_E8ret_typeERKS6_.exit
+  tail call void @_ZNK4llvm5Value4dumpEv(%"struct.llvm::Value"* %V)
+; CHECK: ret
+  ret i8 1
+
+bb2:                                              ; preds = %entry, %_ZN4llvm8dyn_castINS_11InstructionEPNS_5ValueEEENS_10cast_rettyIT_T0_E8ret_typeERKS6_.exit
+  ret i8 0
+}
+
+declare void @__assert_rtn(i8*, i8*, i32, i8*) noreturn
+
+declare void @_ZNK4llvm5Value4dumpEv(%"struct.llvm::Value"*)