RPCS3/llvm-mirror
1
0
Fork 0
mirror of https://github.com/RPCS3/llvm-mirror.git synced 2024-10-19 19:12:56 +02:00
Code Issues Projects Releases Wiki Activity

The rewriter may hold references to instructions that are deleted because they are trivially dead.

Browse Source 
Fix by clearing the rewriter cache before deleting the trivially dead
instructions.
Also make InsertedExpressions use an AssertingVH to catch these
bugs easier.

llvm-svn: 72364
This commit is contained in:
Torok Edwin 2009-05-24 14:23:16 +00:00
parent 39e1c1711d
commit 8936fc2e28
4 changed files with 45 additions and 2 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

2
include/llvm/Analysis/ScalarEvolutionExpander.h
View File

@ -28,7 +28,7 @@ namespace llvm {
/// memory.
struct SCEVExpander : public SCEVVisitor<SCEVExpander, Value*> {
ScalarEvolution &SE;
std::map<SCEVHandle, Value*> InsertedExpressions;
std::map<SCEVHandle, AssertingVH<Value> > InsertedExpressions;
std::set<Value*> InsertedValues;
BasicBlock::iterator InsertPt;

2
lib/Analysis/ScalarEvolutionExpander.cpp
View File

@ -526,7 +526,7 @@ Value *SCEVExpander::expandCodeFor(SCEVHandle SH, const Type *Ty) {
Value *SCEVExpander::expand(const SCEV *S) {
// Check to see if we already expanded this.
std::map<SCEVHandle, Value*>::iterator I = InsertedExpressions.find(S);
std::map<SCEVHandle, AssertingVH<Value> >::iterator I = InsertedExpressions.find(S);
if (I != InsertedExpressions.end())
return I->second;

2
lib/Transforms/Scalar/IndVarSimplify.cpp
View File

@ -298,6 +298,7 @@ void IndVarSimplify::RewriteLoopExitValues(Loop *L,
// in the loop, so we don't need an LCSSA phi node anymore.
if (NumPreds == 1) {
PN->replaceAllUsesWith(ExitVal);
Rewriter.clear();
RecursivelyDeleteTriviallyDeadInstructions(PN);
break;
}
@ -418,6 +419,7 @@ bool IndVarSimplify::runOnLoop(Loop *L, LPPassManager &LPM) {
// Reorder instructions to avoid use-before-def conditions.
FixUsesBeforeDefs(L, Rewriter);
Rewriter.clear();
// For completeness, inform IVUsers of the IV use in the newly-created
// loop exit test instruction.
if (NewICmp)

41
test/Transforms/IndVarSimplify/2009-05-24-useafterfree.ll Normal file
View File

@ -0,0 +1,41 @@
; RUN: llvm-as < %s | opt -indvars
; PR4258
target datalayout = "e-p:32:32:32-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:32:64-f32:32:32-f64:32:64-v64:64:64-v128:128:128-a0:0:64-f80:32:32"
target triple = "i386-linux-gnu"
define void @0(i32*, i32*, i32, i32) nounwind {
br i1 false, label %bb.nph1.preheader, label %.outer._crit_edge
bb.nph1.preheader: ; preds = %4
%smax = select i1 false, i32 -1, i32 0 ; <i32> [#uses=1]
%tmp12 = sub i32 0, %smax ; <i32> [#uses=1]
br label %bb.nph1
bb.nph1: ; preds = %.outer, %bb.nph1.preheader
br i1 false, label %bb.nph3.preheader, label %.outer
bb.nph3.preheader: ; preds = %bb.nph1
br label %bb.nph3
bb.nph3: ; preds = %bb.nph3, %bb.nph3.preheader
%indvar7 = phi i32 [ %indvar.next8, %bb.nph3 ], [ 0, %bb.nph3.preheader ] ; <i32> [#uses=3]
%tmp9 = mul i32 %indvar7, -1 ; <i32> [#uses=1]
%tmp13 = add i32 %tmp9, %tmp12 ; <i32> [#uses=1]
%tmp14 = add i32 %tmp13, -2 ; <i32> [#uses=1]
%5 = icmp sgt i32 %tmp14, 0 ; <i1> [#uses=1]
%indvar.next8 = add i32 %indvar7, 1 ; <i32> [#uses=1]
br i1 %5, label %bb.nph3, label %.outer.loopexit
.outer.loopexit: ; preds = %bb.nph3
%indvar7.lcssa = phi i32 [ %indvar7, %bb.nph3 ] ; <i32> [#uses=0]
br label %.outer
.outer: ; preds = %.outer.loopexit, %bb.nph1
br i1 false, label %bb.nph1, label %.outer._crit_edge.loopexit
.outer._crit_edge.loopexit: ; preds = %.outer
br label %.outer._crit_edge
.outer._crit_edge: ; preds = %.outer._crit_edge.loopexit, %4
ret void
}