[llvm] r214271 - Reapply "UseListOrder: Order GlobalValue uses after initializers"
Duncan P. N. Exon Smith
dexonsmith at apple.com
Tue Jul 29 18:22:16 PDT 2014
Author: dexonsmith
Date: Tue Jul 29 20:22:16 2014
New Revision: 214271
URL: http://llvm.org/viewvc/llvm-project?rev=214271&view=rev
Log:
Reapply "UseListOrder: Order GlobalValue uses after initializers"
This reverts commit r214249, reapplying r214242 and r214243, now that
r214270 has fixed the UB.
Modified:
llvm/trunk/lib/Bitcode/Writer/ValueEnumerator.cpp
llvm/trunk/test/Bitcode/local-linkage-default-visibility.3.4.ll
llvm/trunk/test/Bitcode/old-aliases.ll
llvm/trunk/test/Bitcode/use-list-order.ll
Modified: llvm/trunk/lib/Bitcode/Writer/ValueEnumerator.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Bitcode/Writer/ValueEnumerator.cpp?rev=214271&r1=214270&r2=214271&view=diff
==============================================================================
--- llvm/trunk/lib/Bitcode/Writer/ValueEnumerator.cpp (original)
+++ llvm/trunk/lib/Bitcode/Writer/ValueEnumerator.cpp Tue Jul 29 20:22:16 2014
@@ -28,6 +28,17 @@ using namespace llvm;
namespace {
struct OrderMap {
DenseMap<const Value *, std::pair<unsigned, bool>> IDs;
+ unsigned LastGlobalConstantID;
+ unsigned LastGlobalValueID;
+
+ OrderMap() : LastGlobalConstantID(0), LastGlobalValueID(0) {}
+
+ bool isGlobalConstant(unsigned ID) const {
+ return ID <= LastGlobalConstantID;
+ }
+ bool isGlobalValue(unsigned ID) const {
+ return ID <= LastGlobalValueID && !isGlobalConstant(ID);
+ }
unsigned size() const { return IDs.size(); }
std::pair<unsigned, bool> &operator[](const Value *V) { return IDs[V]; }
@@ -49,7 +60,7 @@ static void orderValue(const Value *V, O
if (const Constant *C = dyn_cast<Constant>(V))
if (C->getNumOperands() && !isa<GlobalValue>(C))
for (const Value *Op : C->operands())
- if (!isa<BasicBlock>(Op))
+ if (!isa<BasicBlock>(Op) && !isa<GlobalValue>(Op))
orderValue(Op, OM);
// Note: we cannot cache this lookup above, since inserting into the map
@@ -62,12 +73,11 @@ static OrderMap orderModule(const Module
// and ValueEnumerator::incorporateFunction().
OrderMap OM;
- for (const GlobalVariable &G : M->globals())
- orderValue(&G, OM);
- for (const Function &F : *M)
- orderValue(&F, OM);
- for (const GlobalAlias &A : M->aliases())
- orderValue(&A, OM);
+ // In the reader, initializers of GlobalValues are set *after* all the
+ // globals have been read. Rather than awkwardly modeling this behaviour
+ // directly in predictValueUseListOrderImpl(), just assign IDs to
+ // initializers of GlobalValues before GlobalValues themselves to model this
+ // implicitly.
for (const GlobalVariable &G : M->globals())
if (G.hasInitializer())
orderValue(G.getInitializer(), OM);
@@ -76,6 +86,23 @@ static OrderMap orderModule(const Module
for (const Function &F : *M)
if (F.hasPrefixData())
orderValue(F.getPrefixData(), OM);
+ OM.LastGlobalConstantID = OM.size();
+
+ // Initializers of GlobalValues are processed in
+ // BitcodeReader::ResolveGlobalAndAliasInits(). Match the order there rather
+ // than ValueEnumerator, and match the code in predictValueUseListOrderImpl()
+ // by giving IDs in reverse order.
+ //
+ // Since GlobalValues never reference each other directly (just through
+ // initializers), their relative IDs only matter for determining order of
+ // uses in their initializers.
+ for (const Function &F : *M)
+ orderValue(&F, OM);
+ for (const GlobalAlias &A : M->aliases())
+ orderValue(&A, OM);
+ for (const GlobalVariable &G : M->globals())
+ orderValue(&G, OM);
+ OM.LastGlobalValueID = OM.size();
for (const Function &F : *M) {
if (F.isDeclaration())
@@ -115,8 +142,8 @@ static void predictValueUseListOrderImpl
// We may have lost some users.
return;
- std::sort(List.begin(), List.end(),
- [&OM, ID](const Entry &L, const Entry &R) {
+ bool IsGlobalValue = OM.isGlobalValue(ID);
+ std::sort(List.begin(), List.end(), [&](const Entry &L, const Entry &R) {
const Use *LU = L.first;
const Use *RU = R.first;
if (LU == RU)
@@ -124,22 +151,36 @@ static void predictValueUseListOrderImpl
auto LID = OM.lookup(LU->getUser()).first;
auto RID = OM.lookup(RU->getUser()).first;
+
+ // Global values are processed in reverse order.
+ //
+ // Moreover, initializers of GlobalValues are set *after* all the globals
+ // have been read (despite having earlier IDs). Rather than awkwardly
+ // modeling this behaviour here, orderModule() has assigned IDs to
+ // initializers of GlobalValues before GlobalValues themselves.
+ if (OM.isGlobalValue(LID) && OM.isGlobalValue(RID))
+ return LID < RID;
+
// If ID is 4, then expect: 7 6 5 1 2 3.
if (LID < RID) {
if (RID < ID)
- return true;
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return true;
return false;
}
if (RID < LID) {
if (LID < ID)
- return false;
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return false;
return true;
}
+
// LID and RID are equal, so we have different operands of the same user.
// Assume operands are added in order for all instructions.
- if (LU->getOperandNo() < RU->getOperandNo())
- return LID < ID;
- return ID < LID;
+ if (LID < ID)
+ if (!IsGlobalValue) // GlobalValue uses don't get reversed.
+ return LU->getOperandNo() < RU->getOperandNo();
+ return LU->getOperandNo() > RU->getOperandNo();
});
if (std::is_sorted(
Modified: llvm/trunk/test/Bitcode/local-linkage-default-visibility.3.4.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/local-linkage-default-visibility.3.4.ll?rev=214271&r1=214270&r2=214271&view=diff
==============================================================================
--- llvm/trunk/test/Bitcode/local-linkage-default-visibility.3.4.ll (original)
+++ llvm/trunk/test/Bitcode/local-linkage-default-visibility.3.4.ll Tue Jul 29 20:22:16 2014
@@ -1,4 +1,5 @@
; RUN: llvm-dis < %s.bc | FileCheck %s
+; RUN: llvm-uselistorder < %s.bc -preserve-bc-use-list-order -num-shuffles=5
; local-linkage-default-visibility.3.4.ll.bc was generated by passing this file
; to llvm-as-3.4. The test checks that LLVM upgrades visibility of symbols
Modified: llvm/trunk/test/Bitcode/old-aliases.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/old-aliases.ll?rev=214271&r1=214270&r2=214271&view=diff
==============================================================================
--- llvm/trunk/test/Bitcode/old-aliases.ll (original)
+++ llvm/trunk/test/Bitcode/old-aliases.ll Tue Jul 29 20:22:16 2014
@@ -1,4 +1,5 @@
; RUN: llvm-dis < %s.bc | FileCheck %s
+; RUN: llvm-uselistorder < %s.bc -preserve-bc-use-list-order -num-shuffles=5
; old-aliases.bc consist of this file assembled with an old llvm-as (3.5 trunk)
; from when aliases contained a ConstantExpr.
Modified: llvm/trunk/test/Bitcode/use-list-order.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Bitcode/use-list-order.ll?rev=214271&r1=214270&r2=214271&view=diff
==============================================================================
--- llvm/trunk/test/Bitcode/use-list-order.ll (original)
+++ llvm/trunk/test/Bitcode/use-list-order.ll Tue Jul 29 20:22:16 2014
@@ -3,6 +3,20 @@
@a = global [4 x i1] [i1 0, i1 1, i1 0, i1 1]
@b = alias i1* getelementptr ([4 x i1]* @a, i64 0, i64 2)
+; Check use-list order of constants used by globals.
+ at glob1 = global i5 7
+ at glob2 = global i5 7
+ at glob3 = global i5 7
+
+; Check use-list order between variables and aliases.
+ at target = global i3 zeroinitializer
+ at alias1 = alias i3* @target
+ at alias2 = alias i3* @target
+ at alias3 = alias i3* @target
+ at var1 = global i3* @target
+ at var2 = global i3* @target
+ at var3 = global i3* @target
+
define i64 @f(i64 %f) {
entry:
%sum = add i64 %f, 0
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