[llvm] r240039 - [CallGraph] Teach the CallGraph about non-leaf intrinsics.
Sanjoy Das
sanjoy at playingwithpointers.com
Thu Jun 18 12:28:26 PDT 2015
Author: sanjoy
Date: Thu Jun 18 14:28:26 2015
New Revision: 240039
URL: http://llvm.org/viewvc/llvm-project?rev=240039&view=rev
Log:
[CallGraph] Teach the CallGraph about non-leaf intrinsics.
Summary:
Currently intrinsics don't affect the creation of the call graph.
This is not accurate with respect to statepoint and patchpoint
intrinsics -- these do call (or invoke) LLVM level functions.
This change fixes this inconsistency by adding a call to the external
node for call sites that call these non-leaf intrinsics. This coupled
with the fact that these intrinsics also escape the function pointer
they call gives us a conservatively correct call graph.
Reviewers: reames, chandlerc, atrick, pgavlin
Subscribers: llvm-commits
Differential Revision: http://reviews.llvm.org/D10526
Added:
llvm/trunk/test/Analysis/CallGraph/non-leaf-intrinsics.ll
Modified:
llvm/trunk/include/llvm/Analysis/CallGraph.h
llvm/trunk/include/llvm/IR/Intrinsics.h
llvm/trunk/lib/Analysis/IPA/CallGraph.cpp
llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp
llvm/trunk/lib/IR/Function.cpp
Modified: llvm/trunk/include/llvm/Analysis/CallGraph.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/CallGraph.h?rev=240039&r1=240038&r2=240039&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/CallGraph.h (original)
+++ llvm/trunk/include/llvm/Analysis/CallGraph.h Thu Jun 18 14:28:26 2015
@@ -56,6 +56,7 @@
#include "llvm/ADT/STLExtras.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Function.h"
+#include "llvm/IR/Intrinsics.h"
#include "llvm/IR/ValueHandle.h"
#include "llvm/Pass.h"
#include <map>
@@ -229,7 +230,8 @@ public:
/// \brief Adds a function to the list of functions called by this one.
void addCalledFunction(CallSite CS, CallGraphNode *M) {
assert(!CS.getInstruction() || !CS.getCalledFunction() ||
- !CS.getCalledFunction()->isIntrinsic());
+ !CS.getCalledFunction()->isIntrinsic() ||
+ !Intrinsic::isLeaf(CS.getCalledFunction()->getIntrinsicID()));
CalledFunctions.emplace_back(CS.getInstruction(), M);
M->AddRef();
}
Modified: llvm/trunk/include/llvm/IR/Intrinsics.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/IR/Intrinsics.h?rev=240039&r1=240038&r2=240039&view=diff
==============================================================================
--- llvm/trunk/include/llvm/IR/Intrinsics.h (original)
+++ llvm/trunk/include/llvm/IR/Intrinsics.h Thu Jun 18 14:28:26 2015
@@ -52,6 +52,11 @@ namespace Intrinsic {
/// Returns true if the intrinsic can be overloaded.
bool isOverloaded(ID id);
+ /// Returns true if the intrinsic is a leaf, i.e. it does not make any calls
+ /// itself. Most intrinsics are leafs, the exceptions being the patchpoint
+ /// and statepoint intrinsics. These call (or invoke) their "target" argument.
+ bool isLeaf(ID id);
+
/// Return the attributes for an intrinsic.
AttributeSet getAttributes(LLVMContext &C, ID id);
Modified: llvm/trunk/lib/Analysis/IPA/CallGraph.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/IPA/CallGraph.cpp?rev=240039&r1=240038&r2=240039&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/IPA/CallGraph.cpp (original)
+++ llvm/trunk/lib/Analysis/IPA/CallGraph.cpp Thu Jun 18 14:28:26 2015
@@ -79,8 +79,10 @@ void CallGraph::addToCallGraph(Function
CallSite CS(cast<Value>(II));
if (CS) {
const Function *Callee = CS.getCalledFunction();
- if (!Callee)
+ if (!Callee || !Intrinsic::isLeaf(Callee->getIntrinsicID()))
// Indirect calls of intrinsics are not allowed so no need to check.
+ // We can be more precise here by using TargetArg returned by
+ // Intrinsic::isLeaf.
Node->addCalledFunction(CS, CallsExternalNode);
else if (!Callee->isIntrinsic())
Node->addCalledFunction(CS, getOrInsertFunction(Callee));
Modified: llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp?rev=240039&r1=240038&r2=240039&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp (original)
+++ llvm/trunk/lib/Analysis/IPA/CallGraphSCCPass.cpp Thu Jun 18 14:28:26 2015
@@ -217,8 +217,10 @@ bool CGPassManager::RefreshCallGraph(Cal
// another value. This can happen when constant folding happens
// of well known functions etc.
!CallSite(I->first) ||
- (CallSite(I->first).getCalledFunction() &&
- CallSite(I->first).getCalledFunction()->isIntrinsic())) {
+ (CallSite(I->first).getCalledFunction() &&
+ CallSite(I->first).getCalledFunction()->isIntrinsic() &&
+ Intrinsic::isLeaf(
+ CallSite(I->first).getCalledFunction()->getIntrinsicID()))) {
assert(!CheckingMode &&
"CallGraphSCCPass did not update the CallGraph correctly!");
Modified: llvm/trunk/lib/IR/Function.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/IR/Function.cpp?rev=240039&r1=240038&r2=240039&view=diff
==============================================================================
--- llvm/trunk/lib/IR/Function.cpp (original)
+++ llvm/trunk/lib/IR/Function.cpp Thu Jun 18 14:28:26 2015
@@ -846,6 +846,18 @@ bool Intrinsic::isOverloaded(ID id) {
#undef GET_INTRINSIC_OVERLOAD_TABLE
}
+bool Intrinsic::isLeaf(ID id) {
+ switch (id) {
+ default:
+ return true;
+
+ case Intrinsic::experimental_gc_statepoint:
+ case Intrinsic::experimental_patchpoint_void:
+ case Intrinsic::experimental_patchpoint_i64:
+ return false;
+ }
+}
+
/// This defines the "Intrinsic::getAttributes(ID id)" method.
#define GET_INTRINSIC_ATTRIBUTES
#include "llvm/IR/Intrinsics.gen"
Added: llvm/trunk/test/Analysis/CallGraph/non-leaf-intrinsics.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Analysis/CallGraph/non-leaf-intrinsics.ll?rev=240039&view=auto
==============================================================================
--- llvm/trunk/test/Analysis/CallGraph/non-leaf-intrinsics.ll (added)
+++ llvm/trunk/test/Analysis/CallGraph/non-leaf-intrinsics.ll Thu Jun 18 14:28:26 2015
@@ -0,0 +1,32 @@
+; RUN: opt -S -print-callgraph -disable-output < %s 2>&1 | FileCheck %s
+
+declare void @llvm.experimental.patchpoint.void(i64, i32, i8*, i32, ...)
+declare i32 @llvm.experimental.gc.statepoint.p0f_isVoidf(i64, i32, void ()*, i32, i32, ...)
+
+define private void @f() {
+ ret void
+}
+
+define void @calls_statepoint(i8 addrspace(1)* %arg) gc "statepoint-example" {
+entry:
+ %cast = bitcast i8 addrspace(1)* %arg to i64 addrspace(1)*
+ %safepoint_token = call i32 (i64, i32, void ()*, i32, i32, ...) @llvm.experimental.gc.statepoint.p0f_isVoidf(i64 0, i32 0, void ()* @f, i32 0, i32 0, i32 0, i32 5, i32 0, i32 0, i32 0, i32 10, i32 0, i8 addrspace(1)* %arg, i64 addrspace(1)* %cast, i8 addrspace(1)* %arg, i8 addrspace(1)* %arg)
+ ret void
+}
+
+define void @calls_patchpoint() {
+entry:
+ %c = bitcast void()* @f to i8*
+ tail call void (i64, i32, i8*, i32, ...) @llvm.experimental.patchpoint.void(i64 1, i32 15, i8* %c, i32 0, i16 65535, i16 -1, i32 65536, i32 2000000000, i32 2147483647, i32 -1, i32 4294967295, i32 4294967296, i64 2147483648, i64 4294967295, i64 4294967296, i64 -1)
+ ret void
+}
+
+
+; CHECK: Call graph node <<null function>>
+; CHECK: CS<0x0> calls function 'f'
+
+; CHECK: Call graph node for function: 'calls_statepoint'
+; CHECK-NEXT: CS<[[addr_0:[^>]+]]> calls external node
+
+; CHECK: Call graph node for function: 'calls_patchpoint'
+; CHECK-NEXT: CS<[[addr_1:[^>]+]]> calls external node
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