Change Details

This change avoids inlining a function involved in a mutual-recursive cycle. Due to the lack of a global inline history, such inlining may cause an exponential size growth as the inlining extends up along the call graph. Consider the following example, void A() { B(); B();} void B() { A(); } void C() { B(); } void D() { C(); } When processing C, inlining B will result in void C() { B(); B(); } When processing D, inlining C and futher the two B callsites will result in void D() { B(); B(); B(); B(); } We've also seen that one of our internal services suffered from the inliner hanging for 6 hours.

This change avoids inlining a function involved in a mutual-recursive cycle. Due to the lack of a global inline history, such inlining may cause an exponential size growth as the inlining extends up along the call graph. Consider the following example, void A() { B(); B();} void B() { A(); } void C() { B(); } void D() { C(); } When processing `C`, inlining `B` will result in void C() { B(); B(); } When processing `D`, inlining `C` and further the two `B` callsites will result in void D() { B(); B(); B(); B(); } We've also seen that one of our internal services suffered from the inliner hanging for 6 hours.

This change avoids inlining a function involved in a mutual-recursive cycle. Due to the lack of a global inline history, such inlining may cause an exponential size growth as the inlining extends up along the call graph. Consider the following example, void A() { B(); B();} void B() { A(); } void C() { B(); } void D() { C(); } When processing C`C`, inlining B`B` will result in void C() { B(); B(); } When processing D`D`, inlining C`C` and further the two B`B` callsites will result in void D() { B(); B(); B(); B(); } We've also seen that one of our internal services suffered from the inliner hanging for 6 hours.