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PR14904: Segmentation fault running pass 'Recognize loop idioms' 

The root cause is mistakenly taking for granted that 
    "dyn_cast<Instruction>(a-Value)"
return a non-NULL instruction.

llvm-svn: 172145
This commit is contained in:
Shuxin Yang 2013-01-10 23:32:01 +00:00
parent cc7f008b85
commit c5c730b0e0
2 changed files with 21 additions and 1 deletions
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2
llvm/lib/Transforms/Scalar/LoopIdiomRecognize.cpp
View File

@ -407,7 +407,7 @@ bool NclPopcountRecognize::detectIdiom(Instruction *&CntInst,
// step 2: detect instructions corresponding to "x2 = x1 & (x1 - 1)"
{
if (DefX2->getOpcode() != Instruction::And)
if (!DefX2 || DefX2->getOpcode() != Instruction::And)
return false;
BinaryOperator *SubOneOp;

20
llvm/test/Transforms/LoopIdiom/X86/popcnt.ll
View File

@ -118,3 +118,23 @@ while.end: ; preds = %while.body, %entry
%c.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.body ]
ret i32 %c.0.lcssa
}
define i32 @PopCntCrash3(i64 %a, i32 %x) {
entry:
%tobool3 = icmp eq i64 %a, 0
%cmp = icmp eq i32 %x, 0
br i1 %tobool3, label %while.end, label %while.body
while.body: ; preds = %entry, %while.body
%c.05 = phi i32 [ %inc, %while.body ], [ 0, %entry ]
%a.addr.04 = phi i64 [ %and, %while.body ], [ %a, %entry ]
%inc = add nsw i32 %c.05, 1
%sub = add i64 %a.addr.04, -1
%and = and i64 %sub, %a.addr.04
%tobool = icmp eq i64 %and, 0
br i1 %cmp, label %while.end, label %while.body
while.end: ; preds = %while.body, %entry
%c.0.lcssa = phi i32 [ 0, %entry ], [ %inc, %while.body ]
ret i32 %c.0.lcssa
}