[llvm-commits] [llvm] r145120 - in /llvm/trunk: lib/CodeGen/MachineBlockPlacement.cpp test/CodeGen/X86/block-placement.ll
Chandler Carruth
chandlerc at gmail.com
Thu Nov 24 03:23:16 PST 2011
Author: chandlerc
Date: Thu Nov 24 05:23:15 2011
New Revision: 145120
URL: http://llvm.org/viewvc/llvm-project?rev=145120&view=rev
Log:
Fix a silly use-after-free issue. A much earlier version of this code
need lots of fanciness around retaining a reference to a Chain's slot in
the BlockToChain map, but that's all gone now. We can just go directly
to allocating the new chain (which will update the mapping for us) and
using it.
Somewhat gross mechanically generated test case replicates the issue
Duncan spotted when actually testing this out.
Modified:
llvm/trunk/lib/CodeGen/MachineBlockPlacement.cpp
llvm/trunk/test/CodeGen/X86/block-placement.ll
Modified: llvm/trunk/lib/CodeGen/MachineBlockPlacement.cpp
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/lib/CodeGen/MachineBlockPlacement.cpp?rev=145120&r1=145119&r2=145120&view=diff
==============================================================================
--- llvm/trunk/lib/CodeGen/MachineBlockPlacement.cpp (original)
+++ llvm/trunk/lib/CodeGen/MachineBlockPlacement.cpp Thu Nov 24 05:23:15 2011
@@ -640,8 +640,8 @@
SmallVector<MachineOperand, 4> Cond; // For AnalyzeBranch.
for (MachineFunction::iterator FI = F.begin(), FE = F.end(); FI != FE; ++FI) {
MachineBasicBlock *BB = FI;
- BlockChain *&Chain = BlockToChain[BB];
- Chain = new (ChainAllocator.Allocate()) BlockChain(BlockToChain, BB);
+ BlockChain *Chain
+ = new (ChainAllocator.Allocate()) BlockChain(BlockToChain, BB);
// Also, merge any blocks which we cannot reason about and must preserve
// the exact fallthrough behavior for.
for (;;) {
Modified: llvm/trunk/test/CodeGen/X86/block-placement.ll
URL: http://llvm.org/viewvc/llvm-project/llvm/trunk/test/CodeGen/X86/block-placement.ll?rev=145120&r1=145119&r2=145120&view=diff
==============================================================================
--- llvm/trunk/test/CodeGen/X86/block-placement.ll (original)
+++ llvm/trunk/test/CodeGen/X86/block-placement.ll Thu Nov 24 05:23:15 2011
@@ -649,3 +649,214 @@
ret void
}
+define void @many_unanalyzable_branches() {
+; Ensure that we don't crash as we're building up many unanalyzable branches,
+; blocks, and loops.
+;
+; CHECK: many_unanalyzable_branches
+; CHECK: %entry
+; CHECK: %exit
+
+entry:
+ br label %0
+
+ %val0 = volatile load float* undef
+ %cmp0 = fcmp une float %val0, undef
+ br i1 %cmp0, label %1, label %0
+ %val1 = volatile load float* undef
+ %cmp1 = fcmp une float %val1, undef
+ br i1 %cmp1, label %2, label %1
+ %val2 = volatile load float* undef
+ %cmp2 = fcmp une float %val2, undef
+ br i1 %cmp2, label %3, label %2
+ %val3 = volatile load float* undef
+ %cmp3 = fcmp une float %val3, undef
+ br i1 %cmp3, label %4, label %3
+ %val4 = volatile load float* undef
+ %cmp4 = fcmp une float %val4, undef
+ br i1 %cmp4, label %5, label %4
+ %val5 = volatile load float* undef
+ %cmp5 = fcmp une float %val5, undef
+ br i1 %cmp5, label %6, label %5
+ %val6 = volatile load float* undef
+ %cmp6 = fcmp une float %val6, undef
+ br i1 %cmp6, label %7, label %6
+ %val7 = volatile load float* undef
+ %cmp7 = fcmp une float %val7, undef
+ br i1 %cmp7, label %8, label %7
+ %val8 = volatile load float* undef
+ %cmp8 = fcmp une float %val8, undef
+ br i1 %cmp8, label %9, label %8
+ %val9 = volatile load float* undef
+ %cmp9 = fcmp une float %val9, undef
+ br i1 %cmp9, label %10, label %9
+ %val10 = volatile load float* undef
+ %cmp10 = fcmp une float %val10, undef
+ br i1 %cmp10, label %11, label %10
+ %val11 = volatile load float* undef
+ %cmp11 = fcmp une float %val11, undef
+ br i1 %cmp11, label %12, label %11
+ %val12 = volatile load float* undef
+ %cmp12 = fcmp une float %val12, undef
+ br i1 %cmp12, label %13, label %12
+ %val13 = volatile load float* undef
+ %cmp13 = fcmp une float %val13, undef
+ br i1 %cmp13, label %14, label %13
+ %val14 = volatile load float* undef
+ %cmp14 = fcmp une float %val14, undef
+ br i1 %cmp14, label %15, label %14
+ %val15 = volatile load float* undef
+ %cmp15 = fcmp une float %val15, undef
+ br i1 %cmp15, label %16, label %15
+ %val16 = volatile load float* undef
+ %cmp16 = fcmp une float %val16, undef
+ br i1 %cmp16, label %17, label %16
+ %val17 = volatile load float* undef
+ %cmp17 = fcmp une float %val17, undef
+ br i1 %cmp17, label %18, label %17
+ %val18 = volatile load float* undef
+ %cmp18 = fcmp une float %val18, undef
+ br i1 %cmp18, label %19, label %18
+ %val19 = volatile load float* undef
+ %cmp19 = fcmp une float %val19, undef
+ br i1 %cmp19, label %20, label %19
+ %val20 = volatile load float* undef
+ %cmp20 = fcmp une float %val20, undef
+ br i1 %cmp20, label %21, label %20
+ %val21 = volatile load float* undef
+ %cmp21 = fcmp une float %val21, undef
+ br i1 %cmp21, label %22, label %21
+ %val22 = volatile load float* undef
+ %cmp22 = fcmp une float %val22, undef
+ br i1 %cmp22, label %23, label %22
+ %val23 = volatile load float* undef
+ %cmp23 = fcmp une float %val23, undef
+ br i1 %cmp23, label %24, label %23
+ %val24 = volatile load float* undef
+ %cmp24 = fcmp une float %val24, undef
+ br i1 %cmp24, label %25, label %24
+ %val25 = volatile load float* undef
+ %cmp25 = fcmp une float %val25, undef
+ br i1 %cmp25, label %26, label %25
+ %val26 = volatile load float* undef
+ %cmp26 = fcmp une float %val26, undef
+ br i1 %cmp26, label %27, label %26
+ %val27 = volatile load float* undef
+ %cmp27 = fcmp une float %val27, undef
+ br i1 %cmp27, label %28, label %27
+ %val28 = volatile load float* undef
+ %cmp28 = fcmp une float %val28, undef
+ br i1 %cmp28, label %29, label %28
+ %val29 = volatile load float* undef
+ %cmp29 = fcmp une float %val29, undef
+ br i1 %cmp29, label %30, label %29
+ %val30 = volatile load float* undef
+ %cmp30 = fcmp une float %val30, undef
+ br i1 %cmp30, label %31, label %30
+ %val31 = volatile load float* undef
+ %cmp31 = fcmp une float %val31, undef
+ br i1 %cmp31, label %32, label %31
+ %val32 = volatile load float* undef
+ %cmp32 = fcmp une float %val32, undef
+ br i1 %cmp32, label %33, label %32
+ %val33 = volatile load float* undef
+ %cmp33 = fcmp une float %val33, undef
+ br i1 %cmp33, label %34, label %33
+ %val34 = volatile load float* undef
+ %cmp34 = fcmp une float %val34, undef
+ br i1 %cmp34, label %35, label %34
+ %val35 = volatile load float* undef
+ %cmp35 = fcmp une float %val35, undef
+ br i1 %cmp35, label %36, label %35
+ %val36 = volatile load float* undef
+ %cmp36 = fcmp une float %val36, undef
+ br i1 %cmp36, label %37, label %36
+ %val37 = volatile load float* undef
+ %cmp37 = fcmp une float %val37, undef
+ br i1 %cmp37, label %38, label %37
+ %val38 = volatile load float* undef
+ %cmp38 = fcmp une float %val38, undef
+ br i1 %cmp38, label %39, label %38
+ %val39 = volatile load float* undef
+ %cmp39 = fcmp une float %val39, undef
+ br i1 %cmp39, label %40, label %39
+ %val40 = volatile load float* undef
+ %cmp40 = fcmp une float %val40, undef
+ br i1 %cmp40, label %41, label %40
+ %val41 = volatile load float* undef
+ %cmp41 = fcmp une float %val41, undef
+ br i1 %cmp41, label %42, label %41
+ %val42 = volatile load float* undef
+ %cmp42 = fcmp une float %val42, undef
+ br i1 %cmp42, label %43, label %42
+ %val43 = volatile load float* undef
+ %cmp43 = fcmp une float %val43, undef
+ br i1 %cmp43, label %44, label %43
+ %val44 = volatile load float* undef
+ %cmp44 = fcmp une float %val44, undef
+ br i1 %cmp44, label %45, label %44
+ %val45 = volatile load float* undef
+ %cmp45 = fcmp une float %val45, undef
+ br i1 %cmp45, label %46, label %45
+ %val46 = volatile load float* undef
+ %cmp46 = fcmp une float %val46, undef
+ br i1 %cmp46, label %47, label %46
+ %val47 = volatile load float* undef
+ %cmp47 = fcmp une float %val47, undef
+ br i1 %cmp47, label %48, label %47
+ %val48 = volatile load float* undef
+ %cmp48 = fcmp une float %val48, undef
+ br i1 %cmp48, label %49, label %48
+ %val49 = volatile load float* undef
+ %cmp49 = fcmp une float %val49, undef
+ br i1 %cmp49, label %50, label %49
+ %val50 = volatile load float* undef
+ %cmp50 = fcmp une float %val50, undef
+ br i1 %cmp50, label %51, label %50
+ %val51 = volatile load float* undef
+ %cmp51 = fcmp une float %val51, undef
+ br i1 %cmp51, label %52, label %51
+ %val52 = volatile load float* undef
+ %cmp52 = fcmp une float %val52, undef
+ br i1 %cmp52, label %53, label %52
+ %val53 = volatile load float* undef
+ %cmp53 = fcmp une float %val53, undef
+ br i1 %cmp53, label %54, label %53
+ %val54 = volatile load float* undef
+ %cmp54 = fcmp une float %val54, undef
+ br i1 %cmp54, label %55, label %54
+ %val55 = volatile load float* undef
+ %cmp55 = fcmp une float %val55, undef
+ br i1 %cmp55, label %56, label %55
+ %val56 = volatile load float* undef
+ %cmp56 = fcmp une float %val56, undef
+ br i1 %cmp56, label %57, label %56
+ %val57 = volatile load float* undef
+ %cmp57 = fcmp une float %val57, undef
+ br i1 %cmp57, label %58, label %57
+ %val58 = volatile load float* undef
+ %cmp58 = fcmp une float %val58, undef
+ br i1 %cmp58, label %59, label %58
+ %val59 = volatile load float* undef
+ %cmp59 = fcmp une float %val59, undef
+ br i1 %cmp59, label %60, label %59
+ %val60 = volatile load float* undef
+ %cmp60 = fcmp une float %val60, undef
+ br i1 %cmp60, label %61, label %60
+ %val61 = volatile load float* undef
+ %cmp61 = fcmp une float %val61, undef
+ br i1 %cmp61, label %62, label %61
+ %val62 = volatile load float* undef
+ %cmp62 = fcmp une float %val62, undef
+ br i1 %cmp62, label %63, label %62
+ %val63 = volatile load float* undef
+ %cmp63 = fcmp une float %val63, undef
+ br i1 %cmp63, label %64, label %63
+ %val64 = volatile load float* undef
+ %cmp64 = fcmp une float %val64, undef
+ br i1 %cmp64, label %65, label %64
+
+ br label %exit
+exit:
+ ret void
+}
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