F.getAttributes().hasAttribute(AttributeSet::FunctionIndex,
Attribute::ReturnsTwice);
for (Function::iterator BI = F.begin(), BE = F.end(); BI != BE; ++BI) {
- // Disallow inlining of functions which contain an indirect branch.
- if (isa<IndirectBrInst>(BI->getTerminator()))
+ // Disallow inlining of functions which contain an indirect branch,
+ // unless the always_inline attribute is set.
+ // The attribute serves as a assertion that no local address
+ // like a block label can escpape the function.
+ // Revisit enabling inlining for functions with indirect branches
+ // when a more sophisticated espape/points-to analysis becomes available.
+ if (isa<IndirectBrInst>(BI->getTerminator()) &&
+ !F.hasFnAttribute(Attribute::AlwaysInline))
return false;
for (BasicBlock::iterator II = BI->begin(), IE = BI->end(); II != IE;
--- /dev/null
+; RUN: opt < %s -O3 -S | FileCheck %s
+@gv = external global i32
+
+define i32 @main() nounwind {
+; CHECK-NOT: call i32 @foo
+ %1 = load i32* @gv, align 4
+ %2 = tail call i32 @foo(i32 %1)
+ unreachable
+}
+
+define internal i32 @foo(i32) alwaysinline {
+ br label %2
+
+; <label>:2 ; preds = %8, %1
+ %3 = phi i32 [ %0, %1 ], [ %10, %8 ]
+ %4 = phi i8* [ blockaddress(@foo, %2), %1 ], [ %6, %8 ]
+ %5 = icmp eq i32 %3, 1
+ %6 = select i1 %5, i8* blockaddress(@foo, %8), i8* %4
+ %7 = add nsw i32 %3, -1
+ br label %8
+
+; <label>:8 ; preds = %8, %2
+ %9 = phi i32 [ %7, %2 ], [ %10, %8 ]
+ %10 = add nsw i32 %9, -1
+ indirectbr i8* %6, [label %2, label %8]
+}