Use address-taken to disambiguate global variable and indirect memops.
Major steps include:
1). introduces a not-addr-taken bit-field in GlobalVariable
2). GlobalOpt pass sets "not-address-taken" if it proves a global varirable
dosen't have its address taken.
3). AA use this info for disambiguation.
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@193251 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/docs/LangRef.rst b/docs/LangRef.rst
index b75c6b1..1e2016b 100644
--- a/docs/LangRef.rst
+++ b/docs/LangRef.rst
@@ -511,6 +511,9 @@
``@llvm.used``. This assumption may be suppressed by marking the
variable with ``externally_initialized``.
+If a global variable dose not have its address taken, it will be optionally
+flagged ``notaddrtaken``.
+
An explicit alignment may be specified for a global, which must be a
power of 2. If not present, or if the alignment is set to zero, the
alignment of the global is set by the target to whatever it feels
diff --git a/include/llvm/IR/GlobalVariable.h b/include/llvm/IR/GlobalVariable.h
index bfed507..a5ab97d 100644
--- a/include/llvm/IR/GlobalVariable.h
+++ b/include/llvm/IR/GlobalVariable.h
@@ -48,6 +48,7 @@
// can change from its initial
// value before global
// initializers are run?
+ bool notAddrTaken : 1; // Dose not have address taken.
public:
// allocate space for exactly one operand
@@ -174,6 +175,9 @@
isExternallyInitializedConstant = Val;
}
+ void setAddressMaybeTaken(bool Val) { notAddrTaken = !Val; }
+ bool AddressMaybeTaken(void) const { return !notAddrTaken; }
+
/// copyAttributesFrom - copy all additional attributes (those not needed to
/// create a GlobalVariable) from the GlobalVariable Src to this one.
void copyAttributesFrom(const GlobalValue *Src);
diff --git a/lib/Analysis/BasicAliasAnalysis.cpp b/lib/Analysis/BasicAliasAnalysis.cpp
index bf92969..4e423a7 100644
--- a/lib/Analysis/BasicAliasAnalysis.cpp
+++ b/lib/Analysis/BasicAliasAnalysis.cpp
@@ -1238,6 +1238,17 @@
return NoAlias;
if (isEscapeSource(O2) && isNonEscapingLocalObject(O1))
return NoAlias;
+
+ // If one object is a global variable without address taken, the other one
+ // is a different object, they will not alias because the global variable
+ // in question cannot be indirectly accessed.
+ if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(O1))
+ if (!GV->AddressMaybeTaken())
+ return NoAlias;
+
+ if (const GlobalVariable *GV = dyn_cast<GlobalVariable>(O2))
+ if (!GV->AddressMaybeTaken())
+ return NoAlias;
}
// If the size of one access is larger than the entire object on the other
diff --git a/lib/AsmParser/LLLexer.cpp b/lib/AsmParser/LLLexer.cpp
index 99bff45..6d643b6 100644
--- a/lib/AsmParser/LLLexer.cpp
+++ b/lib/AsmParser/LLLexer.cpp
@@ -504,6 +504,7 @@
KEYWORD(zeroinitializer);
KEYWORD(undef);
KEYWORD(null);
+ KEYWORD(notaddrtaken);
KEYWORD(to);
KEYWORD(tail);
KEYWORD(target);
diff --git a/lib/AsmParser/LLParser.cpp b/lib/AsmParser/LLParser.cpp
index 74c0ea4..9b5fb27 100644
--- a/lib/AsmParser/LLParser.cpp
+++ b/lib/AsmParser/LLParser.cpp
@@ -704,7 +704,7 @@
unsigned Linkage, bool HasLinkage,
unsigned Visibility) {
unsigned AddrSpace;
- bool IsConstant, UnnamedAddr, IsExternallyInitialized;
+ bool IsConstant, UnnamedAddr, IsExternallyInitialized, notAddrTaken;
GlobalVariable::ThreadLocalMode TLM;
LocTy UnnamedAddrLoc;
LocTy IsExternallyInitializedLoc;
@@ -719,6 +719,7 @@
IsExternallyInitialized,
&IsExternallyInitializedLoc) ||
ParseGlobalType(IsConstant) ||
+ ParseOptionalToken(lltok::kw_notaddrtaken, notAddrTaken) ||
ParseType(Ty, TyLoc))
return true;
@@ -776,6 +777,7 @@
GV->setLinkage((GlobalValue::LinkageTypes)Linkage);
GV->setVisibility((GlobalValue::VisibilityTypes)Visibility);
GV->setExternallyInitialized(IsExternallyInitialized);
+ GV->setAddressMaybeTaken(!notAddrTaken);
GV->setThreadLocalMode(TLM);
GV->setUnnamedAddr(UnnamedAddr);
diff --git a/lib/AsmParser/LLToken.h b/lib/AsmParser/LLToken.h
index e1382fd..7832e81 100644
--- a/lib/AsmParser/LLToken.h
+++ b/lib/AsmParser/LLToken.h
@@ -51,6 +51,7 @@
kw_localdynamic, kw_initialexec, kw_localexec,
kw_zeroinitializer,
kw_undef, kw_null,
+ kw_notaddrtaken,
kw_to,
kw_tail,
kw_target,
diff --git a/lib/Bitcode/Reader/BitcodeReader.cpp b/lib/Bitcode/Reader/BitcodeReader.cpp
index e408cd1..3fca4ab 100644
--- a/lib/Bitcode/Reader/BitcodeReader.cpp
+++ b/lib/Bitcode/Reader/BitcodeReader.cpp
@@ -1848,6 +1848,9 @@
new GlobalVariable(*TheModule, Ty, isConstant, Linkage, 0, "", 0,
TLM, AddressSpace, ExternallyInitialized);
NewGV->setAlignment(Alignment);
+ if (Record.size() > 10)
+ NewGV->setAddressMaybeTaken(Record[10]);
+
if (!Section.empty())
NewGV->setSection(Section);
NewGV->setVisibility(Visibility);
diff --git a/lib/Bitcode/Writer/BitcodeWriter.cpp b/lib/Bitcode/Writer/BitcodeWriter.cpp
index b082ba6..4f631b9 100644
--- a/lib/Bitcode/Writer/BitcodeWriter.cpp
+++ b/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -616,11 +616,13 @@
Vals.push_back(GV->hasSection() ? SectionMap[GV->getSection()] : 0);
if (GV->isThreadLocal() ||
GV->getVisibility() != GlobalValue::DefaultVisibility ||
- GV->hasUnnamedAddr() || GV->isExternallyInitialized()) {
+ GV->hasUnnamedAddr() || GV->isExternallyInitialized() ||
+ !GV->AddressMaybeTaken()) {
Vals.push_back(getEncodedVisibility(GV));
Vals.push_back(getEncodedThreadLocalMode(GV));
Vals.push_back(GV->hasUnnamedAddr());
Vals.push_back(GV->isExternallyInitialized());
+ Vals.push_back(GV->AddressMaybeTaken());
} else {
AbbrevToUse = SimpleGVarAbbrev;
}
diff --git a/lib/IR/AsmWriter.cpp b/lib/IR/AsmWriter.cpp
index 6e3b853..dc337c1 100644
--- a/lib/IR/AsmWriter.cpp
+++ b/lib/IR/AsmWriter.cpp
@@ -1459,6 +1459,7 @@
if (GV->hasUnnamedAddr()) Out << "unnamed_addr ";
if (GV->isExternallyInitialized()) Out << "externally_initialized ";
Out << (GV->isConstant() ? "constant " : "global ");
+ if (!GV->AddressMaybeTaken()) Out << "notaddrtaken ";
TypePrinter.print(GV->getType()->getElementType(), Out);
if (GV->hasInitializer()) {
diff --git a/lib/IR/Globals.cpp b/lib/IR/Globals.cpp
index da3b02a..8c28ec1 100644
--- a/lib/IR/Globals.cpp
+++ b/lib/IR/Globals.cpp
@@ -99,6 +99,7 @@
}
LeakDetector::addGarbageObject(this);
+ setAddressMaybeTaken(true);
}
GlobalVariable::GlobalVariable(Module &M, Type *Ty, bool constant,
@@ -125,6 +126,7 @@
Before->getParent()->getGlobalList().insert(Before, this);
else
M.getGlobalList().push_back(this);
+ setAddressMaybeTaken(true);
}
void GlobalVariable::setParent(Module *parent) {
@@ -185,6 +187,7 @@
GlobalValue::copyAttributesFrom(Src);
const GlobalVariable *SrcVar = cast<GlobalVariable>(Src);
setThreadLocal(SrcVar->isThreadLocal());
+ setAddressMaybeTaken(SrcVar->AddressMaybeTaken());
}
diff --git a/lib/Transforms/IPO/GlobalOpt.cpp b/lib/Transforms/IPO/GlobalOpt.cpp
index 82a59ed..a259b4d 100644
--- a/lib/Transforms/IPO/GlobalOpt.cpp
+++ b/lib/Transforms/IPO/GlobalOpt.cpp
@@ -1723,6 +1723,7 @@
if (GlobalStatus::analyzeGlobal(GV, GS))
return false;
+ GV->setAddressMaybeTaken(false);
if (!GS.IsCompared && !GV->hasUnnamedAddr()) {
GV->setUnnamedAddr(true);
NumUnnamed++;
diff --git a/test/Analysis/BasicAA/noaddrtaken.ll b/test/Analysis/BasicAA/noaddrtaken.ll
new file mode 100644
index 0000000..14aa45b
--- /dev/null
+++ b/test/Analysis/BasicAA/noaddrtaken.ll
@@ -0,0 +1,29 @@
+; RUN: opt < %s -basicaa -aa-eval -print-all-alias-modref-info 2>&1 | FileCheck %s
+
+; ModuleID = 'b.c'
+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-S128"
+target triple = "x86_64-apple-macosx10.8.0"
+
+; CHECK: NoAlias: i32* %p, i32* @xyz
+
+;@xyz = global i32 12, align 4
+@xyz = internal unnamed_addr global notaddrtaken i32 12, align 4
+
+; Function Attrs: nounwind ssp uwtable
+define i32 @foo(i32* nocapture %p, i32* nocapture %q) #0 {
+entry:
+ %0 = load i32* @xyz, align 4, !tbaa !0
+ %inc = add nsw i32 %0, 1
+ store i32 %inc, i32* @xyz, align 4, !tbaa !0
+ store i32 1, i32* %p, align 4, !tbaa !0
+ %1 = load i32* @xyz, align 4, !tbaa !0
+ store i32 %1, i32* %q, align 4, !tbaa !0
+ ret i32 undef
+}
+
+attributes #0 = { nounwind ssp uwtable "less-precise-fpmad"="false" "no-frame-pointer-elim"="true" "no-frame-pointer-elim-non-leaf" "no-infs-fp-math"="false" "no-nans-fp-math"="false" "stack-protector-buffer-size"="8" "unsafe-fp-math"="false" "use-soft-float"="false" }
+
+!0 = metadata !{metadata !1, metadata !1, i64 0}
+!1 = metadata !{metadata !"int", metadata !2, i64 0}
+!2 = metadata !{metadata !"omnipotent char", metadata !3, i64 0}
+!3 = metadata !{metadata !"Simple C/C++ TBAA"}
diff --git a/test/Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll b/test/Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll
index 059af1c..87f2889 100644
--- a/test/Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll
+++ b/test/Transforms/GlobalOpt/2009-03-07-PromotePtrToBool.ll
@@ -1,4 +1,4 @@
-; RUN: opt < %s -globalopt -S | grep "@X = internal unnamed_addr global i32"
+; RUN: opt < %s -globalopt -S | grep "@X = internal unnamed_addr global notaddrtaken i32"
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:128:128"
target triple = "i386-apple-darwin7"
@X = internal global i32* null ; <i32**> [#uses=2]
diff --git a/test/Transforms/GlobalOpt/2009-11-16-MallocSingleStoreToGlobalVar.ll b/test/Transforms/GlobalOpt/2009-11-16-MallocSingleStoreToGlobalVar.ll
index b73f62b..fd7b4dd 100644
--- a/test/Transforms/GlobalOpt/2009-11-16-MallocSingleStoreToGlobalVar.ll
+++ b/test/Transforms/GlobalOpt/2009-11-16-MallocSingleStoreToGlobalVar.ll
@@ -8,7 +8,7 @@
target triple = "x86_64-apple-darwin10.0"
@TOP = internal global i64* null ; <i64**> [#uses=2]
-; CHECK: @TOP = internal unnamed_addr global i64* null
+; CHECK: @TOP = internal unnamed_addr global notaddrtaken i64* null
@channelColumns = internal global i64 0 ; <i64*> [#uses=2]
; Derived from @DescribeChannel() in yacr2
diff --git a/test/Transforms/GlobalOpt/atomic.ll b/test/Transforms/GlobalOpt/atomic.ll
index ac05bfd..d0fb970 100644
--- a/test/Transforms/GlobalOpt/atomic.ll
+++ b/test/Transforms/GlobalOpt/atomic.ll
@@ -3,8 +3,8 @@
@GV1 = internal global i64 1
@GV2 = internal global i32 0
-; CHECK: @GV1 = internal unnamed_addr constant i64 1
-; CHECK: @GV2 = internal unnamed_addr global i32 0
+; CHECK: @GV1 = internal unnamed_addr constant notaddrtaken i64 1
+; CHECK: @GV2 = internal unnamed_addr global notaddrtaken i32 0
define void @test1() {
entry:
diff --git a/test/Transforms/GlobalOpt/globalsra-unknown-index.ll b/test/Transforms/GlobalOpt/globalsra-unknown-index.ll
index cc655e9..a854d94 100644
--- a/test/Transforms/GlobalOpt/globalsra-unknown-index.ll
+++ b/test/Transforms/GlobalOpt/globalsra-unknown-index.ll
@@ -1,5 +1,5 @@
; RUN: opt < %s -globalopt -S > %t
-; RUN: grep "@Y = internal unnamed_addr global \[3 x [%]struct.X\] zeroinitializer" %t
+; RUN: grep "@Y = internal unnamed_addr global notaddrtaken \[3 x [%]struct.X\] zeroinitializer" %t
; RUN: grep load %t | count 6
; RUN: grep "add i32 [%]a, [%]b" %t | count 3
diff --git a/test/Transforms/GlobalOpt/integer-bool.ll b/test/Transforms/GlobalOpt/integer-bool.ll
index abf5fdd..a75614e 100644
--- a/test/Transforms/GlobalOpt/integer-bool.ll
+++ b/test/Transforms/GlobalOpt/integer-bool.ll
@@ -4,7 +4,7 @@
@G = internal addrspace(1) global i32 0
; CHECK: @G
; CHECK: addrspace(1)
-; CHECK: global i1 false
+; CHECK: global notaddrtaken i1 false
define void @set1() {
store i32 0, i32 addrspace(1)* @G
diff --git a/test/Transforms/GlobalOpt/unnamed-addr.ll b/test/Transforms/GlobalOpt/unnamed-addr.ll
index 2ca91e5..7b049ec 100644
--- a/test/Transforms/GlobalOpt/unnamed-addr.ll
+++ b/test/Transforms/GlobalOpt/unnamed-addr.ll
@@ -6,10 +6,10 @@
@d = internal constant [4 x i8] c"foo\00", align 1
@e = linkonce_odr global i32 0
-; CHECK: @a = internal global i32 0, align 4
+; CHECK: @a = internal global notaddrtaken i32 0, align 4
; CHECK: @b = internal global i32 0, align 4
-; CHECK: @c = internal unnamed_addr global i32 0, align 4
-; CHECK: @d = internal unnamed_addr constant [4 x i8] c"foo\00", align 1
+; CHECK: @c = internal unnamed_addr global notaddrtaken i32 0, align 4
+; CHECK: @d = internal unnamed_addr constant notaddrtaken [4 x i8] c"foo\00", align 1
; CHECK: @e = linkonce_odr global i32 0
define i32 @get_e() {