fix PR13390: do not loop forever with self-referencing self instructions
git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@160876 91177308-0d34-0410-b5e6-96231b3b80d8
diff --git a/lib/Analysis/MemoryBuiltins.cpp b/lib/Analysis/MemoryBuiltins.cpp
index 4833b52..c0cc27b 100644
--- a/lib/Analysis/MemoryBuiltins.cpp
+++ b/lib/Analysis/MemoryBuiltins.cpp
@@ -506,6 +506,10 @@
}
SizeOffsetType ObjectSizeOffsetVisitor::visitSelectInst(SelectInst &I) {
+ // ignore malformed self-looping selects
+ if (I.getTrueValue() == &I || I.getFalseValue() == &I)
+ return unknown();
+
SizeOffsetType TrueSide = compute(I.getTrueValue());
SizeOffsetType FalseSide = compute(I.getFalseValue());
if (bothKnown(TrueSide) && bothKnown(FalseSide) && TrueSide == FalseSide)
@@ -711,6 +715,10 @@
}
SizeOffsetEvalType ObjectSizeOffsetEvaluator::visitSelectInst(SelectInst &I) {
+ // ignore malformed self-looping selects
+ if (I.getTrueValue() == &I || I.getFalseValue() == &I)
+ return unknown();
+
SizeOffsetEvalType TrueSide = compute_(I.getTrueValue());
SizeOffsetEvalType FalseSide = compute_(I.getFalseValue());
diff --git a/test/Transforms/InstCombine/objsize.ll b/test/Transforms/InstCombine/objsize.ll
index 1818d89..dbb0ffc 100644
--- a/test/Transforms/InstCombine/objsize.ll
+++ b/test/Transforms/InstCombine/objsize.ll
@@ -219,3 +219,22 @@
; CHECK: ret i32 8
ret i32 %1
}
+
+; CHECK: @PR13390
+define i32 @PR13390(i1 %bool, i8* %a) {
+entry:
+ %cond = or i1 %bool, true
+ br i1 %cond, label %return, label %xpto
+
+xpto:
+ %select = select i1 %bool, i8* %select, i8* %a
+ %select2 = select i1 %bool, i8* %a, i8* %select2
+ %0 = tail call i32 @llvm.objectsize.i32(i8* %select, i1 true)
+ %1 = tail call i32 @llvm.objectsize.i32(i8* %select2, i1 true)
+ %2 = add i32 %0, %1
+; CHECK: ret i32 undef
+ ret i32 %2
+
+return:
+ ret i32 42
+}