[llvm] r268715 - ThinLTO: fix assertion and refactor check for hidden use from inline ASM in a helper function
Mehdi Amini via llvm-commits
llvm-commits at lists.llvm.org
Fri May 6 01:25:34 PDT 2016
Author: mehdi_amini
Date: Fri May 6 03:25:33 2016
New Revision: 268715
URL: http://llvm.org/viewvc/llvm-project?rev=268715&view=rev
Log:
ThinLTO: fix assertion and refactor check for hidden use from inline ASM in a helper function
This test was crashing, and currently it breaks bootstrapping clang with debuginfo
Differential Revision: http://reviews.llvm.org/D20008
From: Mehdi Amini <mehdi.amini at apple.com>
Added:
llvm/trunk/test/ThinLTO/X86/Inputs/llvm.used.ll
llvm/trunk/test/ThinLTO/X86/llvm.used.ll
Modified:
llvm/trunk/include/llvm/Analysis/ModuleSummaryAnalysis.h
llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp
llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp
Modified: llvm/trunk/include/llvm/Analysis/ModuleSummaryAnalysis.h
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/include/llvm/Analysis/ModuleSummaryAnalysis.h?rev=268715&r1=268714&r2=268715&view=diff
==============================================================================
--- llvm/trunk/include/llvm/Analysis/ModuleSummaryAnalysis.h (original)
+++ llvm/trunk/include/llvm/Analysis/ModuleSummaryAnalysis.h Fri May 6 03:25:33 2016
@@ -81,6 +81,11 @@ public:
// object for the module, to be written to bitcode or LLVM assembly.
//
ModulePass *createModuleSummaryIndexWrapperPass();
+
+/// Returns true if \p M is eligible for ThinLTO promotion.
+///
+/// Currently we check if it has any any InlineASM that uses an internal symbol.
+bool moduleCanBeRenamedForThinLTO(const Module &M);
}
#endif
Modified: llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp?rev=268715&r1=268714&r2=268715&view=diff
==============================================================================
--- llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp (original)
+++ llvm/trunk/lib/Analysis/ModuleSummaryAnalysis.cpp Fri May 6 03:25:33 2016
@@ -120,37 +120,11 @@ ModuleSummaryIndexBuilder::ModuleSummary
const Module *M,
std::function<BlockFrequencyInfo *(const Function &F)> Ftor)
: Index(llvm::make_unique<ModuleSummaryIndex>()), M(M) {
- // We cannot currently promote or rename anything used in inline assembly,
- // which are not visible to the compiler. Detect a possible case by looking
- // for a llvm.used local value, in conjunction with an inline assembly call
- // in the module. Prevent importing of any modules containing these uses by
- // suppressing generation of the index. This also prevents importing
- // into this module, which is also necessary to avoid needing to rename
- // in case of a name clash between a local in this module and an imported
- // global.
- // FIXME: If we find we need a finer-grained approach of preventing promotion
- // and renaming of just the functions using inline assembly we will need to:
- // - Add flag in the function summaries to identify those with inline asm.
- // - Prevent importing of any functions with flag set.
- // - Prevent importing of any global function with the same name as a
- // function in current module that has the flag set.
- // - For any llvm.used value that is exported and promoted, add a private
- // alias to the original name in the current module (even if we don't
- // export the function using those values in inline asm, another function
- // with a reference could be exported).
- SmallPtrSet<GlobalValue *, 8> Used;
- collectUsedGlobalVariables(*M, Used, /*CompilerUsed*/ false);
- bool LocalIsUsed = false;
- for (GlobalValue *V : Used) {
- if ((LocalIsUsed |= V->hasLocalLinkage()))
- break;
- }
- if (LocalIsUsed)
- for (auto &F : *M)
- for (auto &I : instructions(F))
- if (const CallInst *CallI = dyn_cast<CallInst>(&I))
- if (CallI->isInlineAsm())
- return;
+ // Check if the module can be promoted, otherwise just disable importing from
+ // it by not emitting any summary.
+ // FIXME: we could still import *into* it most of the time.
+ if (!moduleCanBeRenamedForThinLTO(*M))
+ return;
// Compute summaries for all functions defined in module, and save in the
// index.
@@ -216,3 +190,41 @@ void ModuleSummaryIndexWrapperPass::getA
AU.setPreservesAll();
AU.addRequired<BlockFrequencyInfoWrapperPass>();
}
+
+bool llvm::moduleCanBeRenamedForThinLTO(const Module &M) {
+ // We cannot currently promote or rename anything used in inline assembly,
+ // which are not visible to the compiler. Detect a possible case by looking
+ // for a llvm.used local value, in conjunction with an inline assembly call
+ // in the module. Prevent importing of any modules containing these uses by
+ // suppressing generation of the index. This also prevents importing
+ // into this module, which is also necessary to avoid needing to rename
+ // in case of a name clash between a local in this module and an imported
+ // global.
+ // FIXME: If we find we need a finer-grained approach of preventing promotion
+ // and renaming of just the functions using inline assembly we will need to:
+ // - Add flag in the function summaries to identify those with inline asm.
+ // - Prevent importing of any functions with flag set.
+ // - Prevent importing of any global function with the same name as a
+ // function in current module that has the flag set.
+ // - For any llvm.used value that is exported and promoted, add a private
+ // alias to the original name in the current module (even if we don't
+ // export the function using those values in inline asm, another function
+ // with a reference could be exported).
+ SmallPtrSet<GlobalValue *, 8> Used;
+ collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
+ bool LocalIsUsed =
+ llvm::any_of(Used, [](GlobalValue *V) { return V->hasLocalLinkage(); });
+ if (!LocalIsUsed)
+ return true;
+
+ // Walk all the instructions in the module and find if one is inline ASM
+ auto HasInlineAsm = llvm::any_of(M, [](const Function &F) {
+ return llvm::any_of(instructions(F), [](const Instruction &I) {
+ const CallInst *CallI = dyn_cast<CallInst>(&I);
+ if (!CallI)
+ return false;
+ return CallI->isInlineAsm();
+ });
+ });
+ return !HasInlineAsm;
+}
Modified: llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp?rev=268715&r1=268714&r2=268715&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/FunctionImportUtils.cpp Fri May 6 03:25:33 2016
@@ -12,6 +12,7 @@
//
//===----------------------------------------------------------------------===//
+#include "llvm/Analysis/ModuleSummaryAnalysis.h"
#include "llvm/Transforms/Utils/FunctionImportUtils.h"
#include "llvm/IR/InstIterator.h"
#include "llvm/IR/Instructions.h"
@@ -213,31 +214,13 @@ void FunctionImportGlobalProcessing::pro
}
void FunctionImportGlobalProcessing::processGlobalsForThinLTO() {
- // We cannot currently promote or rename anything used in inline assembly,
- // which are not visible to the compiler. Detect a possible case by looking
- // for a llvm.used local value, in conjunction with an inline assembly call
- // in the module. Prevent changing any such values on the exporting side,
- // since we would already have guarded against an import from this module by
- // suppressing its index generation. See comments on what is required
- // in order to implement a finer grained solution in
- // ModuleSummaryIndexBuilder::ModuleSummaryIndexBuilder().
- SmallPtrSet<GlobalValue *, 8> Used;
- collectUsedGlobalVariables(M, Used, /*CompilerUsed*/ false);
- bool LocalIsUsed = false;
- for (GlobalValue *V : Used) {
+ if (!moduleCanBeRenamedForThinLTO(M)) {
// We would have blocked importing from this module by suppressing index
- // generation.
- assert((!V->hasLocalLinkage() || !isPerformingImport()) &&
- "Should have blocked importing from module with local used");
- if ((LocalIsUsed |= V->hasLocalLinkage()))
- break;
+ // generation. We still may be able to import into this module though.
+ assert(!isPerformingImport() &&
+ "Should have blocked importing from module with local used in ASM");
+ return;
}
- if (LocalIsUsed)
- for (auto &F : M)
- for (auto &I : instructions(F))
- if (const CallInst *CallI = dyn_cast<CallInst>(&I))
- if (CallI->isInlineAsm())
- return;
for (GlobalVariable &GV : M.globals())
processGlobalForThinLTO(GV);
Added: llvm/trunk/test/ThinLTO/X86/Inputs/llvm.used.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ThinLTO/X86/Inputs/llvm.used.ll?rev=268715&view=auto
==============================================================================
--- llvm/trunk/test/ThinLTO/X86/Inputs/llvm.used.ll (added)
+++ llvm/trunk/test/ThinLTO/X86/Inputs/llvm.used.ll Fri May 6 03:25:33 2016
@@ -0,0 +1,11 @@
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.11.0"
+
+
+define i32 @main() #0 {
+entry:
+ call void (...) @globalfunc()
+ ret i32 0
+}
+
+declare void @globalfunc(...)
\ No newline at end of file
Added: llvm/trunk/test/ThinLTO/X86/llvm.used.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/ThinLTO/X86/llvm.used.ll?rev=268715&view=auto
==============================================================================
--- llvm/trunk/test/ThinLTO/X86/llvm.used.ll (added)
+++ llvm/trunk/test/ThinLTO/X86/llvm.used.ll Fri May 6 03:25:33 2016
@@ -0,0 +1,25 @@
+; Do setup work for all below tests: generate bitcode and combined index
+; RUN: opt -module-summary %s -o %t.bc
+; RUN: opt -module-summary %p/Inputs/llvm.used.ll -o %t2.bc
+; RUN: llvm-lto -thinlto-action=thinlink -o %t3.bc %t.bc %t2.bc
+
+
+; RUN: llvm-lto -thinlto-action=import %t2.bc -thinlto-index=%t3.bc -o - | llvm-dis -o - | FileCheck %s
+; CHECK: define available_externally void @globalfunc
+
+
+target datalayout = "e-m:o-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-apple-macosx10.11.0"
+
+
+
+define internal void @_ZN12_GLOBAL__N_16Module4dumpEv() {
+ ret void
+}
+ at llvm.used = appending global [1 x i8*] [i8* bitcast (void ()* @_ZN12_GLOBAL__N_16Module4dumpEv to i8*)], section "llvm.metadata"
+
+
+define void @globalfunc() #0 {
+entry:
+ ret void
+}
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