Fix IPSCCP's code for deleting dead blocks to tolerate outstanding

blockaddress users. This fixes PR5569.


git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@89483 91177308-0d34-0410-b5e6-96231b3b80d8
This commit is contained in:
Dan Gohman 2009-11-20 20:19:14 +00:00
parent f7751c134a
commit 6a2392131e
2 changed files with 48 additions and 2 deletions

View File

@ -1869,8 +1869,12 @@ bool IPSCCP::runOnModule(Module &M) {
for (unsigned i = 0, e = BlocksToErase.size(); i != e; ++i) {
// If there are any PHI nodes in this successor, drop entries for BB now.
BasicBlock *DeadBB = BlocksToErase[i];
while (!DeadBB->use_empty()) {
Instruction *I = cast<Instruction>(DeadBB->use_back());
for (Value::use_iterator UI = DeadBB->use_begin(), UE = DeadBB->use_end();
UI != UE; ) {
// Ignore blockaddress users; BasicBlock's dtor will handle them.
Instruction *I = dyn_cast<Instruction>(*UI++);
if (!I) continue;
bool Folded = ConstantFoldTerminator(I->getParent());
if (!Folded) {
// The constant folder may not have been able to fold the terminator

View File

@ -0,0 +1,42 @@
; RUN: opt < %s -internalize -ipsccp -S | FileCheck %s
; PR5569
; IPSCCP should prove that the blocks are dead and delete them, and
; properly handle the dangling blockaddress constants.
; CHECK: @bar.l = internal constant [2 x i8*] [i8* inttoptr (i32 1 to i8*), i8* inttoptr (i32 1 to i8*)]
@code = global [5 x i32] [i32 0, i32 0, i32 0, i32 0, i32 1], align 4 ; <[5 x i32]*> [#uses=0]
@bar.l = internal constant [2 x i8*] [i8* blockaddress(@bar, %lab0), i8* blockaddress(@bar, %end)] ; <[2 x i8*]*> [#uses=1]
define void @foo(i32 %x) nounwind readnone {
entry:
%b = alloca i32, align 4 ; <i32*> [#uses=1]
volatile store i32 -1, i32* %b
ret void
}
define void @bar(i32* nocapture %pc) nounwind readonly {
entry:
br label %indirectgoto
lab0: ; preds = %indirectgoto
%indvar.next = add i32 %indvar, 1 ; <i32> [#uses=1]
br label %indirectgoto
end: ; preds = %indirectgoto
ret void
indirectgoto: ; preds = %lab0, %entry
%indvar = phi i32 [ %indvar.next, %lab0 ], [ 0, %entry ] ; <i32> [#uses=2]
%pc.addr.0 = getelementptr i32* %pc, i32 %indvar ; <i32*> [#uses=1]
%tmp1.pn = load i32* %pc.addr.0 ; <i32> [#uses=1]
%indirect.goto.dest.in = getelementptr inbounds [2 x i8*]* @bar.l, i32 0, i32 %tmp1.pn ; <i8**> [#uses=1]
%indirect.goto.dest = load i8** %indirect.goto.dest.in ; <i8*> [#uses=1]
indirectbr i8* %indirect.goto.dest, [label %lab0, label %end]
}
define i32 @main() nounwind readnone {
entry:
ret i32 0
}