llvm-project

f10e0f73 - [MergeFuncs] Don't introduce calls to (linkonce,weak)_odr functions. (#125050)

[MergeFuncs] Don't introduce calls to (linkonce,weak)_odr functions. (#125050) Avoid creating new calls to linkonce_odr/weak_odr functions when merging 2 functions, as this may introduce an infinite call cycle. Consider 2 functions below, both present in 2 modules. Module X -- define linkonce_odr void @"A"() { call void @"foo"() } define linkonce_odr void @"B"() { call void @"foo"() } --- Module Y --- global @"g" = @"B" define linkonce_odr void @"A"() { %l = load @"g" call void %l() } define linkonce_odr void @"B"() { call void @"foo"() } --- @"A" and @"B" in both modules are semantically equivalent Module X after function merging: --- define linkonce_odr void @"A"() { call void @"foo"() } define linkonce_odr void @"B"() { call void @"A"() } --- Module Y is unchanged. Then the linker picks @"A" from module Y and @"B" from module X. Now there's an infinite call cycle PR: https://github.com/llvm/llvm-project/pull/125050