Current implementation of Value::replaceUsesExceptBlockAddr() uses UseList

iterator to walk the list which keeps changing inside the loop. When the
UseList contains several uses with the same user, we end processing the same
user more than once, which leads to an assert.

With this fix, unique users are saved and processed later to avoid
processing duplicates.

Differential Revision: https://reviews.llvm.org/D39864

llvm-svn: 318477
This commit is contained in:
Dmitry Mikulin 2017-11-17 00:30:24 +00:00
parent 6497193cfe
commit 2f2ace985d
2 changed files with 35 additions and 1 deletions

View File

@ -15,6 +15,7 @@
#include "LLVMContextImpl.h"
#include "llvm/ADT/DenseMap.h"
#include "llvm/ADT/SmallString.h"
#include "llvm/ADT/SetVector.h"
#include "llvm/IR/CallSite.h"
#include "llvm/IR/Constant.h"
#include "llvm/IR/Constants.h"
@ -456,6 +457,7 @@ void Value::replaceUsesOutsideBlock(Value *New, BasicBlock *BB) {
}
void Value::replaceUsesExceptBlockAddr(Value *New) {
SmallSetVector<Constant *, 4> Constants;
use_iterator UI = use_begin(), E = use_end();
for (; UI != E;) {
Use &U = *UI;
@ -468,13 +470,19 @@ void Value::replaceUsesExceptBlockAddr(Value *New) {
// constant because they are uniqued.
if (auto *C = dyn_cast<Constant>(U.getUser())) {
if (!isa<GlobalValue>(C)) {
C->handleOperandChange(this, New);
// Save unique users to avoid processing operand replacement
// more than once.
Constants.insert(C);
continue;
}
}
U.set(New);
}
// Process operand replacement of saved constants.
for (auto *C : Constants)
C->handleOperandChange(this, New);
}
namespace {

View File

@ -0,0 +1,26 @@
; RUN: opt -S %s -lowertypetests | FileCheck %s
; CHECK: @badfileops = internal global %struct.f { void ()* @bad_f, void ()* @bad_f }
; CHECK: @bad_f = internal alias void (), void ()* @.cfi.jumptable
; CHECK: define internal void @bad_f.cfi() !type !0 {
; CHECK-NEXT: ret void
target triple = "x86_64-unknown-linux"
%struct.f = type { void ()*, void ()* }
@badfileops = internal global %struct.f { void ()* @bad_f, void ()* @bad_f }, align 8
declare i1 @llvm.type.test(i8*, metadata)
define internal void @bad_f() !type !1 {
ret void
}
define internal fastcc void @do_f() unnamed_addr !type !2 {
%1 = tail call i1 @llvm.type.test(i8* undef, metadata !"_ZTSFiP4fileP3uioP5ucrediP6threadE"), !nosanitize !3
ret void
}
!1 = !{i64 0, !"_ZTSFiP4fileP3uioP5ucrediP6threadE"}
!2 = !{i64 0, !"_ZTSFiP6threadiP4fileP3uioliE"}
!3 = !{}