[llvm] r214642 - [SimplifyCFG] fix accessing deleted PHINodes in switch-to-table conversion.
Manman Ren
manman.ren at gmail.com
Sat Aug 2 16:41:55 PDT 2014
Author: mren
Date: Sat Aug 2 18:41:54 2014
New Revision: 214642
URL: http://llvm.org/viewvc/llvm-project?rev=214642&view=rev
Log:
[SimplifyCFG] fix accessing deleted PHINodes in switch-to-table conversion.
When we have a covered lookup table, make sure we don't delete PHINodes that
are cached in PHIs.
rdar://17887153
Added:
llvm/trunk/test/Transforms/SimplifyCFG/X86/switch-covered-bug.ll
Modified:
llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
Modified: llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp?rev=214642&r1=214641&r2=214642&view=diff
==============================================================================
--- llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp (original)
+++ llvm/trunk/lib/Transforms/Utils/SimplifyCFG.cpp Sat Aug 2 18:41:54 2014
@@ -3830,7 +3830,10 @@ static bool SwitchToLookupTable(SwitchIn
const bool GeneratingCoveredLookupTable = MaxTableSize == TableSize;
if (GeneratingCoveredLookupTable) {
Builder.CreateBr(LookupBB);
- SI->getDefaultDest()->removePredecessor(SI->getParent());
+ // We cached PHINodes in PHIs, to avoid accessing deleted PHINodes later,
+ // do not delete PHINodes here.
+ SI->getDefaultDest()->removePredecessor(SI->getParent(),
+ true/*DontDeleteUselessPHIs*/);
} else {
Value *Cmp = Builder.CreateICmpULT(TableIndex, ConstantInt::get(
MinCaseVal->getType(), TableSize));
Added: llvm/trunk/test/Transforms/SimplifyCFG/X86/switch-covered-bug.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/Transforms/SimplifyCFG/X86/switch-covered-bug.ll?rev=214642&view=auto
==============================================================================
--- llvm/trunk/test/Transforms/SimplifyCFG/X86/switch-covered-bug.ll (added)
+++ llvm/trunk/test/Transforms/SimplifyCFG/X86/switch-covered-bug.ll Sat Aug 2 18:41:54 2014
@@ -0,0 +1,50 @@
+; RUN: opt -S -simplifycfg < %s -mtriple=x86_64-apple-darwin12.0.0 | FileCheck %s
+; rdar://17887153
+target datalayout = "e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f16:16:16-f32:32:32-f64:64:64-f128:128:128-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
+target triple = "x86_64-apple-darwin12.0.0"
+
+; When we have a covered lookup table, make sure we don't delete PHINodes that
+; are cached in PHIs.
+; CHECK-LABEL: @test
+; CHECK: entry:
+; CHECK-NEXT: sub i3 %arg, -4
+; CHECK-NEXT: zext i3 %switch.tableidx to i4
+; CHECK-NEXT: getelementptr inbounds [8 x i64]* @switch.table, i32 0, i4 %switch.tableidx.zext
+; CHECK-NEXT: load i64* %switch.gep
+; CHECK-NEXT: add i64
+; CHECK-NEXT: ret i64
+define i64 @test(i3 %arg) {
+entry:
+ switch i3 %arg, label %Default [
+ i3 -2, label %Label6
+ i3 1, label %Label1
+ i3 2, label %Label2
+ i3 3, label %Label3
+ i3 -4, label %Label4
+ i3 -3, label %Label5
+ ]
+
+Default:
+ %v1 = phi i64 [ 7, %Label6 ], [ 11, %Label5 ], [ 6, %Label4 ], [ 13, %Label3 ], [ 9, %Label2 ], [ 15, %Label1 ], [ 8, %entry ]
+ %v2 = phi i64 [ 0, %Label6 ], [ 0, %Label5 ], [ 0, %Label4 ], [ 0, %Label3 ], [ 0, %Label2 ], [ 0, %Label1 ], [ 0, %entry ]
+ %v3 = add i64 %v1, %v2
+ ret i64 %v3
+
+Label1:
+ br label %Default
+
+Label2:
+ br label %Default
+
+Label3:
+ br label %Default
+
+Label4:
+ br label %Default
+
+Label5:
+ br label %Default
+
+Label6:
+ br label %Default
+}
More information about the llvm-commits
mailing list