Index: lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp =================================================================== --- lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp +++ lib/Target/ARM/MCTargetDesc/ARMAsmBackend.cpp @@ -747,13 +747,18 @@ // linker can handle it. GNU AS produces an error in this case. if (Sym->isExternal() || Value >= 0x400004) IsResolved = false; - // When an ARM function is called from a Thumb function, produce a - // relocation so the linker will use the correct branch instruction for ELF - // binaries. - if (Sym->isELF()) { - unsigned Type = dyn_cast(Sym)->getType(); - if ((Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC) && - !Asm.isThumbFunc(Sym)) + } + // Create relocations for unconditional branches to function symbols with + // different execution mode in ELF binaries. + if (Sym && Sym->isELF()) { + unsigned Type = dyn_cast(Sym)->getType(); + if ((Type == ELF::STT_FUNC || Type == ELF::STT_GNU_IFUNC)) { + unsigned FixupKind = Fixup.getKind() ; + if (Asm.isThumbFunc(Sym) && (FixupKind == ARM::fixup_arm_uncondbranch)) + IsResolved = false; + if (!Asm.isThumbFunc(Sym) && (FixupKind == ARM::fixup_arm_thumb_br || + FixupKind == ARM::fixup_arm_thumb_bl || + FixupKind == ARM::fixup_t2_uncondbranch)) IsResolved = false; } } Index: test/MC/ARM/arm-thumb-tail-call.ll =================================================================== --- /dev/null +++ test/MC/ARM/arm-thumb-tail-call.ll @@ -0,0 +1,25 @@ +; RUN: llc -O0 < %s -mtriple armv7-linux-gnueabi -o - \ +; RUN: | llvm-mc -triple armv7-linux-gnueabi -filetype=obj -o - \ +; RUN: | llvm-readobj -r | FileCheck %s + +target datalayout = "e-m:e-p:32:32-i64:64-v128:64:128-a:0:32-n32-S64" +target triple = "armv7--linux-gnueabihf" + +define internal i32 @arm_fn() #1 { + %1 = tail call i32 @thumb_fn() + ret i32 %1 +} + +define internal i32 @thumb_fn() #2 { + %1 = tail call i32 @arm_fn() + ret i32 %1 +} + +attributes #1 = { "target-features"="-thumb-mode" } +attributes #2 = { "target-features"="+thumb-mode" } + +; CHECK: Relocations [ +; CHECK-NEXT: Section (3) .rel.text { +; CHECK-NEXT: 0x0 R_ARM_JUMP24 thumb_fn 0x0 +; CHECK-NEXT: 0x4 R_ARM_THM_JUMP24 arm_fn 0x0 +; CHECK-NEXT: }