[llvm-commits] [llvm] r80768 - in /llvm/trunk: lib/Transforms/Scalar/DeadStoreElimination.cpp test/Transforms/DeadStoreElimination/crash.ll
Chris Lattner
sabre at nondot.org
Tue Sep 1 23:31:02 PDT 2009
Author: lattner
Date: Wed Sep 2 01:31:02 2009
New Revision: 80768
URL: http://llvm.org/viewvc/llvm-project?rev=80768&view=rev
Log:
fix PR4815: some cases where DeleteDeadInstruction can delete
the instruction BBI points to.
Added:
llvm/trunk/test/Transforms/DeadStoreElimination/crash.ll
Modified:
llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp
Modified: llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp?rev=80768&r1=80767&r2=80768&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp (original)
+++ llvm/trunk/lib/Transforms/Scalar/DeadStoreElimination.cpp Wed Sep 2 01:31:02 2009
@@ -83,7 +83,7 @@
bool MadeChange = false;
- // Do a top-down walk on the BB
+ // Do a top-down walk on the BB.
for (BasicBlock::iterator BBI = BB.begin(), BBE = BB.end(); BBI != BBE; ) {
Instruction *Inst = BBI++;
@@ -124,7 +124,10 @@
DeleteDeadInstruction(DepStore);
NumFastStores++;
MadeChange = true;
-
+
+ // DeleteDeadInstruction can delete the current instruction in loop
+ // cases, reset BBI.
+ BBI = Inst;
if (BBI != BB.begin())
--BBI;
continue;
@@ -135,8 +138,15 @@
if (LoadInst *DepLoad = dyn_cast<LoadInst>(InstDep.getInst())) {
if (SI->getPointerOperand() == DepLoad->getPointerOperand() &&
SI->getOperand(0) == DepLoad) {
+ // DeleteDeadInstruction can delete the current instruction. Save BBI
+ // in case we need it.
+ WeakVH NextInst(BBI);
+
DeleteDeadInstruction(SI);
- if (BBI != BB.begin())
+
+ if (NextInst == 0) // Next instruction deleted.
+ BBI = BB.begin();
+ else if (BBI != BB.begin()) // Revisit this instruction if possible.
--BBI;
NumFastStores++;
MadeChange = true;
Added: llvm/trunk/test/Transforms/DeadStoreElimination/crash.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/DeadStoreElimination/crash.ll?rev=80768&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/DeadStoreElimination/crash.ll (added)
+++ llvm/trunk/test/Transforms/DeadStoreElimination/crash.ll Wed Sep 2 01:31:02 2009
@@ -0,0 +1,26 @@
+; RUN: llvm-as < %s | opt -dse | llvm-dis
+
+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-f80:128:128"
+target triple = "i386-apple-darwin10.0"
+
+ at g80 = external global i8 ; <i8*> [#uses=3]
+
+declare signext i8 @foo(i8 signext, i8 signext) nounwind readnone ssp
+
+declare i32 @func68(i32) nounwind readonly ssp
+
+; PR4815
+define void @test1(i32 %int32p54) noreturn nounwind ssp {
+entry:
+ br label %bb
+
+bb: ; preds = %bb, %entry
+ %storemerge = phi i8 [ %2, %bb ], [ 1, %entry ] ; <i8> [#uses=1]
+ store i8 %storemerge, i8* @g80
+ %0 = tail call i32 @func68(i32 1) nounwind ssp ; <i32> [#uses=1]
+ %1 = trunc i32 %0 to i8 ; <i8> [#uses=1]
+ store i8 %1, i8* @g80, align 1
+ store i8 undef, i8* @g80, align 1
+ %2 = tail call signext i8 @foo(i8 signext undef, i8 signext 1) nounwind ; <i8> [#uses=1]
+ br label %bb
+}
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