[llvm] 195087d - [llvm-reduce] Try harder to not create invalid aliases
Arthur Eubanks via llvm-commits
llvm-commits at lists.llvm.org
Fri Aug 12 10:39:37 PDT 2022
Author: Arthur Eubanks
Date: 2022-08-12T10:39:05-07:00
New Revision: 195087d8152c3750a1aace67406140bd9e21244e
URL: https://github.com/llvm/llvm-project/commit/195087d8152c3750a1aace67406140bd9e21244e
DIFF: https://github.com/llvm/llvm-project/commit/195087d8152c3750a1aace67406140bd9e21244e.diff
LOG: [llvm-reduce] Try harder to not create invalid aliases
This was done by adding --abort-on-invalid-reduction to remove-function-bodies-used-in-globals.ll and fixing the fallout.
Aliases must have a GlobalValue or ConstantExpr aliasee and the aliasee must be a definition if it's a GlobalValue.
Don't RAUW functions with null if there's an alias pointing to it, and similarly don't delete the body of a function.
Don't delete the entire body of a function when reducing blocks, preserve at least one block.
Also make debugging these sorts of things easier by dumping the module when --abort-on-invalid-reduction triggers.
Reviewed By: regehr
Differential Revision: https://reviews.llvm.org/D131505
Added:
Modified:
llvm/test/tools/llvm-reduce/remove-bbs-entry.ll
llvm/test/tools/llvm-reduce/remove-function-bodies-used-in-globals.ll
llvm/test/tools/llvm-reduce/temporary-files-as-bitcode-split.ll
llvm/test/tools/llvm-reduce/temporary-files-as-bitcode.ll
llvm/tools/llvm-reduce/deltas/Delta.cpp
llvm/tools/llvm-reduce/deltas/ReduceBasicBlocks.cpp
llvm/tools/llvm-reduce/deltas/ReduceFunctionBodies.cpp
llvm/tools/llvm-reduce/deltas/ReduceFunctions.cpp
llvm/tools/llvm-reduce/deltas/Utils.cpp
llvm/tools/llvm-reduce/deltas/Utils.h
Removed:
llvm/test/tools/llvm-reduce/remove-bbs-comdat.ll
################################################################################
diff --git a/llvm/test/tools/llvm-reduce/remove-bbs-comdat.ll b/llvm/test/tools/llvm-reduce/remove-bbs-comdat.ll
deleted file mode 100644
index 9a6dba151155b..0000000000000
--- a/llvm/test/tools/llvm-reduce/remove-bbs-comdat.ll
+++ /dev/null
@@ -1,21 +0,0 @@
-; RUN: llvm-reduce --delta-passes=basic-blocks --abort-on-invalid-reduction --test FileCheck --test-arg --check-prefixes=CHECK-ALL,CHECK-INTERESTINGNESS --test-arg %s --test-arg --input-file %s -o %t
-; RUN: cat %t | FileCheck --check-prefixes=CHECK-ALL,CHECK-FINAL %s
-
-; CHECK-FINAL-NOT: = comdat
-; CHECK-INTERESTINGNESS: @callee(
-; CHECK-FINAL: declare void @callee()
-
-$foo = comdat any
-
-define void @callee() comdat($foo) {
- ret void
-}
-
-; CHECK-ALL: define void @caller()
-define void @caller() {
-entry:
-; CHECK-ALL: call void @callee()
-; CHECK-ALL: ret void
- call void @callee()
- ret void
-}
diff --git a/llvm/test/tools/llvm-reduce/remove-bbs-entry.ll b/llvm/test/tools/llvm-reduce/remove-bbs-entry.ll
index 04f26f4136519..03a461d74cb6a 100644
--- a/llvm/test/tools/llvm-reduce/remove-bbs-entry.ll
+++ b/llvm/test/tools/llvm-reduce/remove-bbs-entry.ll
@@ -1,18 +1,14 @@
-; Test that llvm-reduce correctly removes the entry block of functions for
-; linkages other than external and weak.
+; Test that llvm-reduce does not remove the entry block of functions.
;
; RUN: llvm-reduce --abort-on-invalid-reduction --delta-passes=basic-blocks --test FileCheck --test-arg --check-prefixes=CHECK-INTERESTINGNESS --test-arg %s --test-arg --input-file %s -o %t
; RUN: cat %t | FileCheck %s
-; CHECK-INTERESTINGNESS: interesting1:
+; CHECK-INTERESTINGNESS: foo
-; CHECK-NOT: uninteresting
-define linkonce_odr i32 @foo() {
+; CHECK: add i32
+define i32 @foo() {
uninteresting:
+ %a = add i32 0, 0
ret i32 0
}
-define i32 @main(i1 %c) {
-interesting1:
- ret i32 0
-}
diff --git a/llvm/test/tools/llvm-reduce/remove-function-bodies-used-in-globals.ll b/llvm/test/tools/llvm-reduce/remove-function-bodies-used-in-globals.ll
index f09160a05201e..48e4e1ce90e91 100644
--- a/llvm/test/tools/llvm-reduce/remove-function-bodies-used-in-globals.ll
+++ b/llvm/test/tools/llvm-reduce/remove-function-bodies-used-in-globals.ll
@@ -1,4 +1,4 @@
-; RUN: llvm-reduce --test FileCheck --test-arg --check-prefix=CHECK-INTERESTINGNESS --test-arg %s --test-arg --input-file %s -o %t
+; RUN: llvm-reduce --test FileCheck --test-arg --check-prefix=CHECK-INTERESTINGNESS --abort-on-invalid-reduction --test-arg %s --test-arg --input-file %s -o %t
; RUN: FileCheck --check-prefix=CHECK-FINAL %s < %t
; We cannot change the @alias to undef, because it would result in invalid IR
diff --git a/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode-split.ll b/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode-split.ll
index 6fbdbde907d60..a7bbe65864666 100644
--- a/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode-split.ll
+++ b/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode-split.ll
@@ -1,5 +1,5 @@
; RUN: opt --thinlto-bc --thinlto-split-lto-unit %s -o %t0
-; RUN: llvm-reduce -write-tmp-files-as-bitcode --delta-passes=basic-blocks %t0 -o %t1 \
+; RUN: llvm-reduce -write-tmp-files-as-bitcode --delta-passes=function-bodies,basic-blocks %t0 -o %t1 \
; RUN: --test %python --test-arg %p/Inputs/llvm-dis-and-filecheck.py --test-arg llvm-dis --test-arg FileCheck --test-arg --check-prefixes=CHECK-ALL,CHECK-INTERESTINGNESS --test-arg %s
; RUN: cat %t1* | FileCheck --check-prefixes=CHECK-ALL,CHECK-FINAL %s
diff --git a/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode.ll b/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode.ll
index 06cf789d04fc1..c1790bf4e0807 100644
--- a/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode.ll
+++ b/llvm/test/tools/llvm-reduce/temporary-files-as-bitcode.ll
@@ -1,4 +1,4 @@
-; RUN: llvm-reduce -write-tmp-files-as-bitcode --delta-passes=basic-blocks %s -o %t \
+; RUN: llvm-reduce -write-tmp-files-as-bitcode --delta-passes=function-bodies,basic-blocks %s -o %t \
; RUN: --test %python --test-arg %p/Inputs/llvm-dis-and-filecheck.py --test-arg llvm-dis --test-arg FileCheck --test-arg --check-prefixes=CHECK-ALL,CHECK-INTERESTINGNESS --test-arg %s
; RUN: cat %t | FileCheck --check-prefixes=CHECK-ALL,CHECK-FINAL %s
diff --git a/llvm/tools/llvm-reduce/deltas/Delta.cpp b/llvm/tools/llvm-reduce/deltas/Delta.cpp
index 55b96d84c9c81..a9f20368d47e7 100644
--- a/llvm/tools/llvm-reduce/deltas/Delta.cpp
+++ b/llvm/tools/llvm-reduce/deltas/Delta.cpp
@@ -173,7 +173,8 @@ CheckChunk(Chunk &ChunkToCheckForUninterestingness,
// Some reductions may result in invalid IR. Skip such reductions.
if (verifyReducerWorkItem(*Clone, &errs())) {
if (AbortOnInvalidReduction) {
- errs() << "Invalid reduction\n";
+ errs() << "Invalid reduction, aborting.\n";
+ Clone->print(errs());
exit(1);
}
errs() << " **** WARNING | reduction resulted in invalid module, "
diff --git a/llvm/tools/llvm-reduce/deltas/ReduceBasicBlocks.cpp b/llvm/tools/llvm-reduce/deltas/ReduceBasicBlocks.cpp
index f3f844fd2bb12..fdd5770cd988c 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceBasicBlocks.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceBasicBlocks.cpp
@@ -104,25 +104,32 @@ removeUninterestingBBsFromSwitch(SwitchInst &SwInst,
/// It's OK to add a block to the set of removed blocks if the first
/// basic block in the function that survives all of the deletions is
-/// a legal entry block
+/// a legal entry block. Keep at least one block in a function.
static bool okToRemove(BasicBlock &Candidate, Function &F,
const DenseSet<BasicBlock *> &BBsToDelete) {
+ size_t NumBlocksDeleted = 0;
+ bool FoundNewEntryBlock = false;
for (auto &B : F) {
if (&B == &Candidate)
continue;
- if (BBsToDelete.count(&B))
+ if (BBsToDelete.count(&B)) {
+ ++NumBlocksDeleted;
continue;
- /// Ok we've found the first block that's not going to be deleted,
- /// it will be the new entry block -- that's only legal if this
- /// block has no predecessors among blocks that survive the
- /// deletions
- for (BasicBlock *Pred : predecessors(&B)) {
- if (!BBsToDelete.contains(Pred))
- return false;
}
- return true;
+ if (!FoundNewEntryBlock) {
+ /// Ok we've found the first block that's not going to be deleted,
+ /// it will be the new entry block -- that's only legal if this
+ /// block has no predecessors among blocks that survive the
+ /// deletions
+ for (BasicBlock *Pred : predecessors(&B)) {
+ if (!BBsToDelete.contains(Pred))
+ return false;
+ }
+ FoundNewEntryBlock = true;
+ }
}
- return true;
+ // Don't delete the last block.
+ return NumBlocksDeleted + 1 < F.size();
}
/// Removes out-of-chunk arguments from functions, and modifies their calls
@@ -161,19 +168,13 @@ static void extractBasicBlocksFromModule(Oracle &O, Module &Program) {
// Instructions might be referenced in other BBs
for (auto &I : *BB)
I.replaceAllUsesWith(getDefaultValue(I.getType()));
- if (BB->getParent()->size() == 1) {
- // this is the last basic block of the function, thus we must also make
- // sure to remove comdat and set linkage to external
- auto F = BB->getParent();
- F->deleteBody();
- F->setComdat(nullptr);
- } else {
- BB->eraseFromParent();
- }
+ // Should not be completely removing the body of a function.
+ assert(BB->getParent()->size() > 1);
+ BB->eraseFromParent();
}
}
void llvm::reduceBasicBlocksDeltaPass(TestRunner &Test) {
- outs() << "*** Reducing Basic Blocks...\n";
+ errs() << "*** Reducing Basic Blocks...\n";
runDeltaPass(Test, extractBasicBlocksFromModule);
}
diff --git a/llvm/tools/llvm-reduce/deltas/ReduceFunctionBodies.cpp b/llvm/tools/llvm-reduce/deltas/ReduceFunctionBodies.cpp
index 63dd2f03b18f6..ed583e9cf5736 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceFunctionBodies.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceFunctionBodies.cpp
@@ -13,6 +13,7 @@
#include "ReduceFunctionBodies.h"
#include "Delta.h"
+#include "Utils.h"
#include "llvm/IR/GlobalValue.h"
using namespace llvm;
@@ -21,12 +22,12 @@ using namespace llvm;
/// desired Chunks.
static void extractFunctionBodiesFromModule(Oracle &O, Module &Program) {
// Delete out-of-chunk function bodies
- std::vector<Function *> FuncDefsToReduce;
- for (auto &F : Program)
- if (!F.isDeclaration() && !O.shouldKeep()) {
+ for (auto &F : Program) {
+ if (!F.isDeclaration() && !hasAliasUse(F) && !O.shouldKeep()) {
F.deleteBody();
F.setComdat(nullptr);
}
+ }
}
void llvm::reduceFunctionBodiesDeltaPass(TestRunner &Test) {
diff --git a/llvm/tools/llvm-reduce/deltas/ReduceFunctions.cpp b/llvm/tools/llvm-reduce/deltas/ReduceFunctions.cpp
index 346e2c30936e3..faade8a581026 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceFunctions.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceFunctions.cpp
@@ -16,8 +16,6 @@
#include "Delta.h"
#include "Utils.h"
#include "llvm/ADT/STLExtras.h"
-#include "llvm/IR/Constants.h"
-#include "llvm/IR/Instructions.h"
#include <iterator>
#include <vector>
@@ -33,7 +31,8 @@ static void extractFunctionsFromModule(Oracle &O, Module &Program) {
// Intrinsics don't have function bodies that are useful to
// reduce. Additionally, intrinsics may have additional operand
// constraints. But, do drop intrinsics that are not referenced.
- return (!F.isIntrinsic() || F.use_empty()) && !O.shouldKeep();
+ return (!F.isIntrinsic() || F.use_empty()) && !hasAliasUse(F) &&
+ !O.shouldKeep();
});
// Then, drop body of each of them. We want to batch this and do nothing else
diff --git a/llvm/tools/llvm-reduce/deltas/Utils.cpp b/llvm/tools/llvm-reduce/deltas/Utils.cpp
index 0434eb70146b3..46ebffda40dbd 100644
--- a/llvm/tools/llvm-reduce/deltas/Utils.cpp
+++ b/llvm/tools/llvm-reduce/deltas/Utils.cpp
@@ -12,9 +12,14 @@
#include "Utils.h"
#include "llvm/IR/Constants.h"
+#include "llvm/IR/GlobalAlias.h"
using namespace llvm;
Value *llvm::getDefaultValue(Type *T) {
return T->isVoidTy() ? PoisonValue::get(T) : Constant::getNullValue(T);
}
+
+bool llvm::hasAliasUse(Function &F) {
+ return any_of(F.users(), [](User *U) { return isa<GlobalAlias>(U); });
+}
diff --git a/llvm/tools/llvm-reduce/deltas/Utils.h b/llvm/tools/llvm-reduce/deltas/Utils.h
index e0c8f8e24d040..748b6de39b618 100644
--- a/llvm/tools/llvm-reduce/deltas/Utils.h
+++ b/llvm/tools/llvm-reduce/deltas/Utils.h
@@ -13,11 +13,13 @@
#ifndef LLVM_TOOLS_LLVM_REDUCE_DELTAS_UTILS_H
#define LLVM_TOOLS_LLVM_REDUCE_DELTAS_UTILS_H
+#include "llvm/IR/Function.h"
#include "llvm/IR/Value.h"
namespace llvm {
Value *getDefaultValue(Type *T);
+bool hasAliasUse(Function &F);
} // namespace llvm
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