[llvm] r256787 - [MemoryBuiltins] Remove isOperatorNewLike by consolidating non-null inference handling
Philip Reames via llvm-commits
llvm-commits at lists.llvm.org
Mon Jan 4 14:49:24 PST 2016
Author: reames
Date: Mon Jan 4 16:49:23 2016
New Revision: 256787
URL: http://llvm.org/viewvc/llvm-project?rev=256787&view=rev
Log:
[MemoryBuiltins] Remove isOperatorNewLike by consolidating non-null inference handling
This patch removes the isOperatorNewLike predicate since it was only being used to establish a non-null return value and we have attributes specifically for that purpose with generic handling. To keep approximate the same behaviour for existing frontends, I added the various operator new like (i.e. instances of operator new) to InferFunctionAttrs. It's not really clear to me why this isn't handled in Clang, but I didn't want to break existing code and any subtle assumptions it might have.
Once this patch is in, I'm going to start separating the isAllocLike family of predicates. These appear to be being used for a mixture of things which should be more clearly separated and documented. Today, they're being used to indicate (at least) aliasing facts, CSE-ability, and default values from an allocation site.
Differential Revision: http://reviews.llvm.org/D15820
Modified:
llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h
llvm/trunk/lib/Analysis/MemoryBuiltins.cpp
llvm/trunk/lib/Analysis/ValueTracking.cpp
llvm/trunk/lib/Transforms/IPO/InferFunctionAttrs.cpp
llvm/trunk/test/Transforms/InferFunctionAttrs/annotate.ll
llvm/trunk/test/Transforms/InstSimplify/call.ll
Modified: llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h?rev=256787&r1=256786&r2=256787&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h (original)
+++ llvm/trunk/include/llvm/Analysis/MemoryBuiltins.h Mon Jan 4 16:49:23 2016
@@ -59,11 +59,6 @@ bool isCallocLikeFn(const Value *V, cons
bool isAllocLikeFn(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.
//
Modified: llvm/trunk/lib/Analysis/MemoryBuiltins.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/MemoryBuiltins.cpp?rev=256787&r1=256786&r2=256787&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/MemoryBuiltins.cpp (original)
+++ llvm/trunk/lib/Analysis/MemoryBuiltins.cpp Mon Jan 4 16:49:23 2016
@@ -187,13 +187,6 @@ bool llvm::isAllocLikeFn(const Value *V,
return getAllocationData(V, AllocLike, 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.
Modified: llvm/trunk/lib/Analysis/ValueTracking.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ValueTracking.cpp?rev=256787&r1=256786&r2=256787&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ValueTracking.cpp (original)
+++ llvm/trunk/lib/Analysis/ValueTracking.cpp Mon Jan 4 16:49:23 2016
@@ -3480,10 +3480,6 @@ bool llvm::isKnownNonNull(const Value *V
if (CS.isReturnNonNull())
return true;
- // operator new never returns null.
- if (isOperatorNewLikeFn(V, TLI, /*LookThroughBitCast=*/true))
- return true;
-
return false;
}
Modified: llvm/trunk/lib/Transforms/IPO/InferFunctionAttrs.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/IPO/InferFunctionAttrs.cpp?rev=256787&r1=256786&r2=256787&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/IPO/InferFunctionAttrs.cpp (original)
+++ llvm/trunk/lib/Transforms/IPO/InferFunctionAttrs.cpp Mon Jan 4 16:49:23 2016
@@ -10,6 +10,7 @@
#include "llvm/Transforms/IPO/InferFunctionAttrs.h"
#include "llvm/ADT/Statistic.h"
#include "llvm/Analysis/TargetLibraryInfo.h"
+#include "llvm/Analysis/MemoryBuiltins.h"
#include "llvm/IR/Function.h"
#include "llvm/IR/LLVMContext.h"
#include "llvm/IR/Module.h"
@@ -25,6 +26,7 @@ STATISTIC(NumNoUnwind, "Number of functi
STATISTIC(NumNoCapture, "Number of arguments inferred as nocapture");
STATISTIC(NumReadOnlyArg, "Number of arguments inferred as readonly");
STATISTIC(NumNoAlias, "Number of function returns inferred as noalias");
+STATISTIC(NumNonNull, "Number of function returns inferred as nonnull returns");
static bool setDoesNotAccessMemory(Function &F) {
if (F.doesNotAccessMemory())
@@ -74,6 +76,17 @@ static bool setDoesNotAlias(Function &F,
return true;
}
+static bool setNonNull(Function &F, unsigned n) {
+ assert((n != AttributeSet::ReturnIndex ||
+ F.getReturnType()->isPointerTy()) &&
+ "nonnull applies only to pointers");
+ if (F.getAttributes().hasAttribute(n, Attribute::NonNull))
+ return false;
+ F.addAttribute(n, Attribute::NonNull);
+ ++NumNonNull;
+ return true;
+}
+
/// Analyze the name and prototype of the given function and set any applicable
/// attributes.
///
@@ -89,7 +102,6 @@ static bool inferPrototypeAttributes(Fun
return false;
bool Changed = false;
-
switch (TheLibFunc) {
case LibFunc::strlen:
if (FTy->getNumParams() != 1 || !FTy->getParamType(0)->isPointerTy())
@@ -873,6 +885,21 @@ static bool inferPrototypeAttributes(Fun
Changed |= setDoesNotCapture(F, 2);
return Changed;
+ case LibFunc::Znwj: // new(unsigned int)
+ case LibFunc::Znwm: // new(unsigned long)
+ case LibFunc::Znaj: // new[](unsigned int)
+ case LibFunc::Znam: // new[](unsigned long)
+ case LibFunc::msvc_new_int: // new(unsigned int)
+ case LibFunc::msvc_new_longlong: // new(unsigned long long)
+ case LibFunc::msvc_new_array_int: // new[](unsigned int)
+ case LibFunc::msvc_new_array_longlong: // new[](unsigned long long)
+ if (FTy->getNumParams() != 1)
+ return false;
+ // Operator new always returns a nonnull noalias pointer
+ Changed |= setNonNull(F, AttributeSet::ReturnIndex);
+ Changed |= setDoesNotAlias(F, AttributeSet::ReturnIndex);
+ return Changed;
+
default:
// FIXME: It'd be really nice to cover all the library functions we're
// aware of here.
Modified: llvm/trunk/test/Transforms/InferFunctionAttrs/annotate.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InferFunctionAttrs/annotate.ll?rev=256787&r1=256786&r2=256787&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InferFunctionAttrs/annotate.ll (original)
+++ llvm/trunk/test/Transforms/InferFunctionAttrs/annotate.ll Mon Jan 4 16:49:23 2016
@@ -16,6 +16,12 @@ declare i32* @realloc(i32*, i32)
declare i32 @strcpy(...)
; CHECK: declare i32 @strcpy(...)
+; operator new routines
+declare i8* @_Znwj(i64)
+; CHECK: declare noalias nonnull i8* @_Znwj(i64)
+declare i8* @_Znwm(i64)
+; CHECK: declare noalias nonnull i8* @_Znwm(i64)
+
declare i32 @gettimeofday(i8*, i8*)
; CHECK-POSIX: declare i32 @gettimeofday(i8* nocapture, i8* nocapture) [[G0:#[0-9]+]]
Modified: llvm/trunk/test/Transforms/InstSimplify/call.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/InstSimplify/call.ll?rev=256787&r1=256786&r2=256787&view=diff
==============================================================================
--- llvm/trunk/test/Transforms/InstSimplify/call.ll (original)
+++ llvm/trunk/test/Transforms/InstSimplify/call.ll Mon Jan 4 16:49:23 2016
@@ -144,7 +144,7 @@ cast.end:
; CHECK: br i1 false, label %cast.end, label %cast.notnull
}
-declare noalias i8* @_Znwm(i64)
+declare nonnull noalias i8* @_Znwm(i64)
%"struct.std::nothrow_t" = type { i8 }
@_ZSt7nothrow = external global %"struct.std::nothrow_t"
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