r212263 - Move the calling of emitTargetMD() later.
Robert Lytton
robert at xmos.com
Sat Jul 19 02:13:10 PDT 2014
Hi Richard,
> I think the best approach (for locality) is to immediately emit the metadata in the common case where you can compute it,
> and to add it to a list of delayed entities if you can't compute it.
This sounds like my initial attempt where I emitted the metadata at the end of GetOrCreateLLVMFunction() and GetOrCreateLLVMGlobal().
The problem I had there was that declarations could change, hence why I moved the handling to the end of Release().
Should I persist with the original solution but either:
emit the changes too (the "if (Entry)" statements) and handle the multiple metadata entries in the back end;
create a map of entries (in XCoreTargetCodeGenInfo) and emit the metadata at the end - during Release()?
Would the second option would require adding a 3rd target hook or is there a hook already?
> You could add one, or perhaps change SetTargetAttributes so it's called on declarations as well as definitions.
So the target hook I added was emitTargetMD().
I need to look at how SetTargetAttributes() is called to see if it is beyond any new declarations and if I can include declarations too.
I did try to understand the different handling of declarations and definitions - need to look at this again.
My concern is calling which ever target hook on the "most complete" declaration.
Any help/insight into understanding the stages/dynamics of the module would be appreciated!
Robert
________________________________
From: metafoo at gmail.com [metafoo at gmail.com] on behalf of Richard Smith [richard at metafoo.co.uk]
Sent: 19 July 2014 02:21
To: Robert Lytton
Cc: cfe commits; alp at nuanti.com
Subject: Re: r212263 - Move the calling of emitTargetMD() later.
On Thu, Jul 17, 2014 at 1:47 AM, Robert Lytton <robert at xmos.com<mailto:robert at xmos.com>> wrote:
Hi Richard,
Thank you for the review.
I'll change the metadata numbers to use filecheck variables.
In regard to using getMostRecentDecl, is the problem that I am using it too soon or the way I use it?
I think one problem is that getMostRecentDecl() is being called too late: if this call is the only thing that causes us to pull in more declarations from a module, and we decide those things need to be handed off to the ASTConsumer, it cannot be called at the end of CodeGenModule finalization. But something here doesn't make much sense: if we actually need to emit those declarations, they should be pulled in regardless of your loop, and if we don't, they shouldn't be causing CodeGen to do extra work.
Another issue this exposes is that CodeGen can trigger deserialization, which can re-enter CodeGen in ways it's not expecting. That's bad independent of your patch. The interaction between modules and CodeGen is clearly not right, and I think it's not reasonable to block your work on fixing it...
Indeed, if I was to add a pass, would it be needed at all - maybe the pass should handle multiple list entries of a symbol.
I agree, building a target specific list and adding a pass seems good.
Should I handle all global declarations in this way or only those I can't compute?
I think the best approach (for locality) is to immediately emit the metadata in the common case where you can compute it, and to add it to a list of delayed entities if you can't compute it.
I need to understand the best places to discover/add-to-list the global declarations.
getTargetCodeGenInfo()::SetTargetAttributes only receives definitions (and their typestrings could be emitted).
Is there another target hook which receives all declarations rather than only definitions?
You could add one, or perhaps change SetTargetAttributes so it's called on declarations as well as definitions.
I'll look through the code again regarding how 'MangledDeclNames' is built up to try to gain insight.
Any guidance most welcome!
Robert
________________________________
From: metafoo at gmail.com<mailto:metafoo at gmail.com> [metafoo at gmail.com<mailto:metafoo at gmail.com>] on behalf of Richard Smith [richard at metafoo.co.uk<mailto:richard at metafoo.co.uk>]
Sent: 16 July 2014 04:07
To: Robert Lytton
Cc: cfe commits
Subject: Re: r212263 - Move the calling of emitTargetMD() later.
On Thu, Jul 3, 2014 at 2:30 AM, Robert Lytton <robert at xmos.com<mailto:robert at xmos.com>> wrote:
Author: rlytton
Date: Thu Jul 3 04:30:33 2014
New Revision: 212263
URL: http://llvm.org/viewvc/llvm-project?rev=212263&view=rev
Log:
Move the calling of emitTargetMD() later.
Summary:
Because a global created by GetOrCreateLLVMGlobal() is not finalised until later viz:
extern char a[];
char f(){ return a[5];}
char a[10];
Change MangledDeclNames to use a MapVector rather than a DenseMap so that the
Metadata is output in order of original declaration, so to make deterministic
and improve human readablity.
Sorry for not reviewing this before. I think this is completely the wrong approach. Please just keep a list of those variables for which you couldn't compute the type string when they are emitted (within XCoreTargetCodeGenInfo), and perform another pass at the end of IR generation to fix up those ones. That will have much better locality, and will avoid the target metadata emission loop that is redundant on almost all targets.
Differential Revision: http://reviews.llvm.org/D4176
Modified:
cfe/trunk/lib/CodeGen/CodeGenModule.cpp
cfe/trunk/lib/CodeGen/CodeGenModule.h
cfe/trunk/test/CodeGen/xcore-stringtype.c
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.cpp
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.cpp?rev=212263&r1=212262&r2=212263&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.cpp (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.cpp Thu Jul 3 04:30:33 2014
@@ -393,6 +393,8 @@ void CodeGenModule::Release() {
DebugInfo->finalize();
EmitVersionIdentMetadata();
+
+ EmitTargetMetadata();
}
void CodeGenModule::UpdateCompletedType(const TagDecl *TD) {
@@ -1534,8 +1536,6 @@ CodeGenModule::GetOrCreateLLVMFunction(S
}
}
- getTargetCodeGenInfo().emitTargetMD(D, F, *this);
-
// Make sure the result is of the requested type.
if (!IsIncompleteFunction) {
assert(F->getType()->getElementType() == Ty);
@@ -1685,8 +1685,6 @@ CodeGenModule::GetOrCreateLLVMGlobal(Str
if (AddrSpace != Ty->getAddressSpace())
return llvm::ConstantExpr::getAddrSpaceCast(GV, Ty);
- getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
-
return GV;
}
@@ -3340,6 +3338,14 @@ void CodeGenModule::EmitVersionIdentMeta
IdentMetadata->addOperand(llvm::MDNode::get(Ctx, IdentNode));
}
+void CodeGenModule::EmitTargetMetadata() {
+ for (auto &I : MangledDeclNames) {
+ const Decl *D = I.first.getDecl()->getMostRecentDecl();
This has introduced an iterator invalidation bug that breaks most modules builds: getMostRecentDecl can result in lazy deserialization, and thus in MangledDeclNames having entries added to it.
+ llvm::GlobalValue *GV = GetGlobalValue(I.second);
+ getTargetCodeGenInfo().emitTargetMD(D, GV, *this);
+ }
+}
+
void CodeGenModule::EmitCoverageFile() {
if (!getCodeGenOpts().CoverageFile.empty()) {
if (llvm::NamedMDNode *CUNode = TheModule.getNamedMetadata("llvm.dbg.cu<http://llvm.dbg.cu>")) {
Modified: cfe/trunk/lib/CodeGen/CodeGenModule.h
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/lib/CodeGen/CodeGenModule.h?rev=212263&r1=212262&r2=212263&view=diff
==============================================================================
--- cfe/trunk/lib/CodeGen/CodeGenModule.h (original)
+++ cfe/trunk/lib/CodeGen/CodeGenModule.h Thu Jul 3 04:30:33 2014
@@ -349,8 +349,8 @@ class CodeGenModule : public CodeGenType
/// emitted when the translation unit is complete.
CtorList GlobalDtors;
- /// A map of canonical GlobalDecls to their mangled names.
- llvm::DenseMap<GlobalDecl, StringRef> MangledDeclNames;
+ /// An ordered map of canonical GlobalDecls to their mangled names.
+ llvm::MapVector<GlobalDecl, StringRef> MangledDeclNames;
llvm::StringMap<GlobalDecl, llvm::BumpPtrAllocator> Manglings;
/// Global annotations.
@@ -1146,6 +1146,9 @@ private:
/// \brief Emit the Clang version as llvm.ident metadata.
void EmitVersionIdentMetadata();
+ /// Emits target specific Metadata for global declarations.
+ void EmitTargetMetadata();
+
/// Emit the llvm.gcov metadata used to tell LLVM where to emit the .gcno and
/// .gcda files in a way that persists in .bc files.
void EmitCoverageFile();
Modified: cfe/trunk/test/CodeGen/xcore-stringtype.c
URL: http://llvm.org/viewvc/llvm-project/cfe/trunk/test/CodeGen/xcore-stringtype.c?rev=212263&r1=212262&r2=212263&view=diff
==============================================================================
--- cfe/trunk/test/CodeGen/xcore-stringtype.c (original)
+++ cfe/trunk/test/CodeGen/xcore-stringtype.c Thu Jul 3 04:30:33 2014
@@ -9,13 +9,13 @@
// Please see 'Tools Development Guide' section 2.16.2 for format details:
// <https://www.xmos.com/download/public/Tools-Development-Guide%28X9114A%29.pdf>
-// CHECK: !xcore.typestrings = !{!0, !1, !2, !3, !4, !5, !6, !7, !8, !9, !10,
-// CHECK: !11, !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23,
-// CHECK: !24, !25, !26, !27, !28, !29, !30, !31, !32, !33, !34}
+// CHECK: !xcore.typestrings = !{!1, !2, !3, !4, !5, !6, !7, !8, !9, !10, !11,
+// CHECK: !12, !13, !14, !15, !16, !17, !18, !19, !20, !21, !22, !23, !24, !25,
+// CHECK: !26, !27, !28, !29, !30, !31, !32, !33, !34, !35, !36, !37, !38}
Please fix this test to not hardcode metadata numbers; these are extremely fragile, and will break if we start emitting more metadata for any reason. Instead, use FileCheck variables (http://llvm.org/docs/CommandGuide/FileCheck.html#filecheck-variables).
// test BuiltinType
-// CHECK: !0 = metadata !{void (i1, i8, i8, i8, i16, i16, i16, i32, i32, i32,
+// CHECK: !1 = metadata !{void (i1, i8, i8, i8, i16, i16, i16, i32, i32, i32,
// CHECK: i32, i32, i32, i64, i64, i64, float, double, double)*
// CHECK: @builtinType, metadata !"f{0}(b,uc,uc,sc,ss,us,ss,si,ui,si,sl,
// CHECK: ul,sl,sll,ull,sll,ft,d,ld)"}
@@ -28,14 +28,14 @@ double _Complex Complex; // not supporte
// test FunctionType & Qualifiers
-// CHECK: !1 = metadata !{void ()* @gI, metadata !"f{0}()"}
-// CHECK: !2 = metadata !{void (...)* @eI, metadata !"f{0}()"}
-// CHECK: !3 = metadata !{void ()* @gV, metadata !"f{0}(0)"}
-// CHECK: !4 = metadata !{void ()* @eV, metadata !"f{0}(0)"}
-// CHECK: !5 = metadata !{void (i32, ...)* @gVA, metadata !"f{0}(si,va)"}
-// CHECK: !6 = metadata !{void (i32, ...)* @eVA, metadata !"f{0}(si,va)"}
-// CHECK: !7 = metadata !{i32* (i32*)* @gQ, metadata !"f{crv:p(cv:si)}(p(cv:si))"}
-// CHECK: !8 = metadata !{i32* (i32*)* @eQ, metadata !"f{crv:p(cv:si)}(p(cv:si))"}
+// CHECK: !2 = metadata !{void ()* @gI, metadata !"f{0}()"}
+// CHECK: !3 = metadata !{void (...)* @eI, metadata !"f{0}()"}
+// CHECK: !4 = metadata !{void ()* @gV, metadata !"f{0}(0)"}
+// CHECK: !5 = metadata !{void ()* @eV, metadata !"f{0}(0)"}
+// CHECK: !6 = metadata !{void (i32, ...)* @gVA, metadata !"f{0}(si,va)"}
+// CHECK: !7 = metadata !{void (i32, ...)* @eVA, metadata !"f{0}(si,va)"}
+// CHECK: !8 = metadata !{i32* (i32*)* @gQ, metadata !"f{crv:p(cv:si)}(p(cv:si))"}
+// CHECK: !9 = metadata !{i32* (i32*)* @eQ, metadata !"f{crv:p(cv:si)}(p(cv:si))"}
extern void eI();
void gI() {eI();};
extern void eV(void);
@@ -49,10 +49,10 @@ const volatile int* volatile restrict co
// test PointerType
-// CHECK: !9 = metadata !{i32* (i32*, i32* (i32*)*)*
-// CHECK: @pointerType, metadata !"f{p(si)}(p(si),p(f{p(si)}(p(si))))"}
-// CHECK: !10 = metadata !{i32** @EP, metadata !"p(si)"}
-// CHECK: !11 = metadata !{i32** @GP, metadata !"p(si)"}
+// CHECK: !10 = metadata !{i32* (i32*, i32* (i32*)*)*
+// CHECK: @pointerType, metadata !"f{p(si)}(p(si),p(f{p(si)}(p(si))))"}
+// CHECK: !11 = metadata !{i32** @EP, metadata !"p(si)"}
+// CHECK: !12 = metadata !{i32** @GP, metadata !"p(si)"}
extern int* EP;
int* GP;
int* pointerType(int *I, int * (*FP)(int *)) {
@@ -60,25 +60,25 @@ int* pointerType(int *I, int * (*FP)(int
}
// test ArrayType
-// CHECK: !12 = metadata !{[2 x i32]* (i32*, i32*, [2 x i32]*, [2 x i32]*, i32*)*
+// CHECK: !13 = metadata !{[2 x i32]* (i32*, i32*, [2 x i32]*, [2 x i32]*, i32*)*
// CHECK: @arrayType, metadata !"f{p(a(2:si))}(p(si),p(cv:si),p(a(2:si)),
// CHECK: p(a(2:si)),p(si))"}
-// CHECK: !13 = metadata !{[0 x i32]* @EA1, metadata !"a(*:cv:si)"}
-// CHECK: !14 = metadata !{[2 x i32]* @EA2, metadata !"a(2:si)"}
-// CHECK: !15 = metadata !{[0 x [2 x i32]]* @EA3, metadata !"a(*:a(2:si))"}
-// CHECK: !16 = metadata !{[3 x [2 x i32]]* @EA4, metadata !"a(3:a(2:si))"}
-// CHECK: !17 = metadata !{[2 x i32]* @GA1, metadata !"a(2:cv:si)"}
-// CHECK: !18 = metadata !{void ([2 x i32]*)* @arrayTypeVariable1,
+// CHECK: !14 = metadata !{[0 x i32]* @EA1, metadata !"a(*:cv:si)"}
+// CHECK: !15 = metadata !{[2 x i32]* @EA2, metadata !"a(2:si)"}
+// CHECK: !16 = metadata !{[0 x [2 x i32]]* @EA3, metadata !"a(*:a(2:si))"}
+// CHECK: !17 = metadata !{[3 x [2 x i32]]* @EA4, metadata !"a(3:a(2:si))"}
+// CHECK: !18 = metadata !{[2 x i32]* @GA1, metadata !"a(2:cv:si)"}
+// CHECK: !19 = metadata !{void ([2 x i32]*)* @arrayTypeVariable1,
// CHECK: metadata !"f{0}(p(a(2:si)))"}
-// CHECK: !19 = metadata !{void (void ([2 x i32]*)*)* @arrayTypeVariable2,
+// CHECK: !20 = metadata !{void (void ([2 x i32]*)*)* @arrayTypeVariable2,
// CHECK: metadata !"f{0}(p(f{0}(p(a(2:si)))))"}
-// CHECK: !20 = metadata !{[3 x [2 x i32]]* @GA2, metadata !"a(3:a(2:si))"}
+// CHECK: !21 = metadata !{[3 x [2 x i32]]* @GA2, metadata !"a(3:a(2:si))"}
+extern int GA2[3][2];
extern const volatile int EA1[];
extern int EA2[2];
extern int EA3[][2];
extern int EA4[3][2];
const volatile int GA1[2];
-int GA2[3][2];
extern void arrayTypeVariable1(int[*][2]);
extern void arrayTypeVariable2( void(*fp)(int[*][2]) );
extern void arrayTypeVariable3(int[3][*]); // not supported
@@ -100,16 +100,16 @@ RetType* arrayType(int A1[], int const v
// test StructureType
-// CHECK: !21 = metadata !{void (%struct.S1*)* @structureType1, metadata
+// CHECK: !22 = metadata !{void (%struct.S1*)* @structureType1, metadata
// CHECK: !"f{0}(s(S1){m(ps2){p(s(S2){m(ps3){p(s(S3){m(s1){s(S1){}}})}})}})"}
-// CHECK: !22 = metadata !{void (%struct.S2*)* @structureType2, metadata
+// CHECK: !23 = metadata !{void (%struct.S2*)* @structureType2, metadata
// CHECK: !"f{0}(s(S2){m(ps3){p(s(S3){m(s1){s(S1){m(ps2){p(s(S2){})}}}})}})"}
-// CHECK: !23 = metadata !{void (%struct.S3*)* @structureType3, metadata
+// CHECK: !24 = metadata !{void (%struct.S3*)* @structureType3, metadata
// CHECK: !"f{0}(s(S3){m(s1){s(S1){m(ps2){p(s(S2){m(ps3){p(s(S3){})}})}}}})"}
-// CHECK: !24 = metadata !{void (%struct.S4*)* @structureType4, metadata
+// CHECK: !25 = metadata !{void (%struct.S4*)* @structureType4, metadata
// CHECK: !"f{0}(s(S4){m(s1){s(S1){m(ps2){p(s(S2){m(ps3){p(s(S3){m(s1){s(S1){}}})}})}}}})"}
-// CHECK: !25 = metadata !{%struct.anon* @StructAnon, metadata !"s(){m(A){si}}"}
-// CHECK: !26 = metadata !{i32 (%struct.SB*)* @structureTypeB, metadata
+// CHECK: !26 = metadata !{%struct.anon* @StructAnon, metadata !"s(){m(A){si}}"}
+// CHECK: !27 = metadata !{i32 (%struct.SB*)* @structureTypeB, metadata
// CHECK: !"f{si}(s(SB){m(){b(4:si)},m(){b(2:si)},m(N4){b(4:si)},
// CHECK: m(N2){b(2:si)},m(){b(4:ui)},m(){b(4:si)},m(){b(4:c:si)},
// CHECK: m(){b(4:c:si)},m(){b(4:cv:si)}})"}
@@ -130,16 +130,16 @@ int structureTypeB(struct SB sb){return
// test UnionType
-// CHECK: !27 = metadata !{void (%union.U1*)* @unionType1, metadata
+// CHECK: !28 = metadata !{void (%union.U1*)* @unionType1, metadata
// CHECK: !"f{0}(u(U1){m(pu2){p(u(U2){m(pu3){p(u(U3){m(u1){u(U1){}}})}})}})"}
-// CHECK: !28 = metadata !{void (%union.U2*)* @unionType2, metadata
+// CHECK: !29 = metadata !{void (%union.U2*)* @unionType2, metadata
// CHECK: !"f{0}(u(U2){m(pu3){p(u(U3){m(u1){u(U1){m(pu2){p(u(U2){})}}}})}})"}
-// CHECK: !29 = metadata !{void (%union.U3*)* @unionType3, metadata
+// CHECK: !30 = metadata !{void (%union.U3*)* @unionType3, metadata
// CHECK: !"f{0}(u(U3){m(u1){u(U1){m(pu2){p(u(U2){m(pu3){p(u(U3){})}})}}}})"}
-// CHECK: !30 = metadata !{void (%union.U4*)* @unionType4, metadata
+// CHECK: !31 = metadata !{void (%union.U4*)* @unionType4, metadata
// CHECK: !"f{0}(u(U4){m(u1){u(U1){m(pu2){p(u(U2){m(pu3){p(u(U3){m(u1){u(U1){}}})}})}}}})"}
-// CHECK: !31 = metadata !{%union.anon* @UnionAnon, metadata !"u(){m(A){si}}"}
-// CHECK: !32 = metadata !{i32 (%union.UB*)* @unionTypeB, metadata
+// CHECK: !32 = metadata !{%union.anon* @UnionAnon, metadata !"u(){m(A){si}}"}
+// CHECK: !33 = metadata !{i32 (%union.UB*)* @unionTypeB, metadata
// CHECK: !"f{si}(u(UB){m(N2){b(2:si)},m(N4){b(4:si)},m(){b(2:si)},
// CHECK: m(){b(4:c:si)},m(){b(4:c:si)},m(){b(4:cv:si)},m(){b(4:si)},
// CHECK: m(){b(4:si)},m(){b(4:ui)}})"}
@@ -160,9 +160,20 @@ int unionTypeB(union UB ub) {return Unio
// test EnumType
-// CHECK: !33 = metadata !{i32* @EnumAnon, metadata !"e(){m(EA){3}}"}
-// CHECK: !34 = metadata !{i32 (i32)* @enumType, metadata
+// CHECK: !34 = metadata !{i32* @EnumAnon, metadata !"e(){m(EA){3}}"}
+// CHECK: !35 = metadata !{i32 (i32)* @enumType, metadata
// CHECK: !"f{si}(e(E){m(A){7},m(B){6},m(C){5},m(D){0}})"}
enum E {D, C=5, B, A};
enum {EA=3} EnumAnon = EA;
int enumType(enum E e) {return EnumAnon;}
+
+
+// CHECK: !36 = metadata !{i32 ()* @testReDecl, metadata !"f{si}()"}
+// CHECK: !37 = metadata !{[10 x i32]* @After, metadata !"a(10:si)"}
+// CHECK: !38 = metadata !{[10 x i32]* @Before, metadata !"a(10:si)"}
+extern int After[];
+extern int Before[10];
+int testReDecl() {return After[0] + Before[0];}
+int After[10];
+int Before[];
+
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