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-rw-r--r--include/llvm/Analysis/MemoryBuiltins.h4
-rw-r--r--include/llvm/Analysis/ValueTracking.h3
-rw-r--r--lib/Analysis/InstructionSimplify.cpp2
-rw-r--r--lib/Analysis/MemoryBuiltins.cpp16
-rw-r--r--lib/Analysis/ValueTracking.cpp8
-rw-r--r--test/Transforms/InstSimplify/call.ll20
6 files changed, 46 insertions, 7 deletions
diff --git a/include/llvm/Analysis/MemoryBuiltins.h b/include/llvm/Analysis/MemoryBuiltins.h
index 0d1ae8c48e..587b87f652 100644
--- a/include/llvm/Analysis/MemoryBuiltins.h
+++ b/include/llvm/Analysis/MemoryBuiltins.h
@@ -64,6 +64,10 @@ bool isAllocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
bool isReallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
bool LookThroughBitCast = false);
+/// \brief Tests if a value is a call or invoke to a library function that
+/// allocates memory and never returns null (such as operator new).
+bool isOperatorNewLikeFn(const Value *V, const TargetLibraryInfo *TLI,
+ bool LookThroughBitCast = false);
//===----------------------------------------------------------------------===//
// malloc Call Utility Functions.
diff --git a/include/llvm/Analysis/ValueTracking.h b/include/llvm/Analysis/ValueTracking.h
index 3775ec9f07..0392f98f07 100644
--- a/include/llvm/Analysis/ValueTracking.h
+++ b/include/llvm/Analysis/ValueTracking.h
@@ -25,6 +25,7 @@ namespace llvm {
class DataLayout;
class StringRef;
class MDNode;
+ class TargetLibraryInfo;
/// ComputeMaskedBits - Determine which of the bits specified in Mask are
/// known to be either zero or one and return them in the KnownZero/KnownOne
@@ -186,7 +187,7 @@ namespace llvm {
/// isKnownNonNull - Return true if this pointer couldn't possibly be null by
/// its definition. This returns true for allocas, non-extern-weak globals
/// and byval arguments.
- bool isKnownNonNull(const Value *V);
+ bool isKnownNonNull(const Value *V, const TargetLibraryInfo *TLI = 0);
} // end namespace llvm
diff --git a/lib/Analysis/InstructionSimplify.cpp b/lib/Analysis/InstructionSimplify.cpp
index af65cb7408..b867af1dc3 100644
--- a/lib/Analysis/InstructionSimplify.cpp
+++ b/lib/Analysis/InstructionSimplify.cpp
@@ -1739,7 +1739,7 @@ static Constant *computePointerICmp(const DataLayout *TD,
RHS = RHS->stripPointerCasts();
// A non-null pointer is not equal to a null pointer.
- if (llvm::isKnownNonNull(LHS) && isa<ConstantPointerNull>(RHS) &&
+ if (llvm::isKnownNonNull(LHS, TLI) && isa<ConstantPointerNull>(RHS) &&
(Pred == CmpInst::ICMP_EQ || Pred == CmpInst::ICMP_NE))
return ConstantInt::get(GetCompareTy(LHS),
!CmpInst::isTrueWhenEqual(Pred));
diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
index 0f0a1c98d0..2ec2aec4aa 100644
--- a/lib/Analysis/MemoryBuiltins.cpp
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -35,6 +35,7 @@ enum AllocType {
CallocLike = 1<<1, // allocates + bzero
ReallocLike = 1<<2, // reallocates
StrDupLike = 1<<3,
+ OpNewLike = MallocLike | (1<<4), // allocates; never returns null
AllocLike = MallocLike | CallocLike | StrDupLike,
AnyAlloc = MallocLike | CallocLike | ReallocLike | StrDupLike
};
@@ -52,13 +53,13 @@ struct AllocFnsTy {
static const AllocFnsTy AllocationFnData[] = {
{LibFunc::malloc, MallocLike, 1, 0, -1},
{LibFunc::valloc, MallocLike, 1, 0, -1},
- {LibFunc::Znwj, MallocLike, 1, 0, -1}, // new(unsigned int)
+ {LibFunc::Znwj, OpNewLike, 1, 0, -1}, // new(unsigned int)
{LibFunc::ZnwjRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned int, nothrow)
- {LibFunc::Znwm, MallocLike, 1, 0, -1}, // new(unsigned long)
+ {LibFunc::Znwm, OpNewLike, 1, 0, -1}, // new(unsigned long)
{LibFunc::ZnwmRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new(unsigned long, nothrow)
- {LibFunc::Znaj, MallocLike, 1, 0, -1}, // new[](unsigned int)
+ {LibFunc::Znaj, OpNewLike, 1, 0, -1}, // new[](unsigned int)
{LibFunc::ZnajRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new[](unsigned int, nothrow)
- {LibFunc::Znam, MallocLike, 1, 0, -1}, // new[](unsigned long)
+ {LibFunc::Znam, OpNewLike, 1, 0, -1}, // new[](unsigned long)
{LibFunc::ZnamRKSt9nothrow_t, MallocLike, 2, 0, -1}, // new[](unsigned long, nothrow)
{LibFunc::posix_memalign, MallocLike, 3, 2, -1},
{LibFunc::calloc, CallocLike, 2, 0, 1},
@@ -189,6 +190,13 @@ bool llvm::isReallocLikeFn(const Value *V, const TargetLibraryInfo *TLI,
return getAllocationData(V, ReallocLike, TLI, LookThroughBitCast);
}
+/// \brief Tests if a value is a call or invoke to a library function that
+/// allocates memory and never returns null (such as operator new).
+bool llvm::isOperatorNewLikeFn(const Value *V, const TargetLibraryInfo *TLI,
+ bool LookThroughBitCast) {
+ return getAllocationData(V, OpNewLike, TLI, LookThroughBitCast);
+}
+
/// extractMallocCall - Returns the corresponding CallInst if the instruction
/// is a malloc call. Since CallInst::CreateMalloc() only creates calls, we
/// ignore InvokeInst here.
diff --git a/lib/Analysis/ValueTracking.cpp b/lib/Analysis/ValueTracking.cpp
index c81537543f..e7a512ce0f 100644
--- a/lib/Analysis/ValueTracking.cpp
+++ b/lib/Analysis/ValueTracking.cpp
@@ -15,6 +15,7 @@
#include "llvm/Analysis/ValueTracking.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/Analysis/InstructionSimplify.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/IR/Constants.h"
#include "llvm/IR/DataLayout.h"
#include "llvm/IR/GlobalAlias.h"
@@ -2064,7 +2065,7 @@ bool llvm::isSafeToSpeculativelyExecute(const Value *V,
/// isKnownNonNull - Return true if we know that the specified value is never
/// null.
-bool llvm::isKnownNonNull(const Value *V) {
+bool llvm::isKnownNonNull(const Value *V, const TargetLibraryInfo *TLI) {
// Alloca never returns null, malloc might.
if (isa<AllocaInst>(V)) return true;
@@ -2075,5 +2076,10 @@ bool llvm::isKnownNonNull(const Value *V) {
// Global values are not null unless extern weak.
if (const GlobalValue *GV = dyn_cast<GlobalValue>(V))
return !GV->hasExternalWeakLinkage();
+
+ // operator new never returns null.
+ if (isOperatorNewLikeFn(V, TLI, /*LookThroughBitCast=*/true))
+ return true;
+
return false;
}
diff --git a/test/Transforms/InstSimplify/call.ll b/test/Transforms/InstSimplify/call.ll
index 3e1621c838..aa3b08653a 100644
--- a/test/Transforms/InstSimplify/call.ll
+++ b/test/Transforms/InstSimplify/call.ll
@@ -101,3 +101,23 @@ define float @test_idempotence(float %a) {
ret float %r4
}
+
+define i8* @operator_new() {
+entry:
+ %call = tail call noalias i8* @_Znwm(i64 8)
+ %cmp = icmp eq i8* %call, null
+ br i1 %cmp, label %cast.end, label %cast.notnull
+
+cast.notnull: ; preds = %entry
+ %add.ptr = getelementptr inbounds i8* %call, i64 4
+ br label %cast.end
+
+cast.end: ; preds = %cast.notnull, %entry
+ %cast.result = phi i8* [ %add.ptr, %cast.notnull ], [ null, %entry ]
+ ret i8* %cast.result
+
+; CHECK-LABEL: @operator_new
+; CHECK: br i1 false, label %cast.end, label %cast.notnull
+}
+
+declare noalias i8* @_Znwm(i64)
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-01 00:41:22 +0000