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llvm-project/llvm/test/CodeGen/ARM/tail-call-weak.ll

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ARM: permit tail calls to weak externals on COFF Weak externals are resolved statically, so we can actually generate the tail call on PE/COFF targets without breaking the requirements. It is questionable whether we want to propagate the current behaviour for MachO as the requirements are part of the ARM ELF specifications, and it seems that prior to the SVN r215890, we would have tail'ed the call. For now, be conservative and only permit it on PE/COFF where the call will always be fully resolved. llvm-svn: 225119
2015-01-04 05:35:00 +08:00
; RUN: llc -mtriple thumbv7-windows-coff -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-COFF
ARM: stop emitting blx instructions for most calls on MachO. I'm really not sure why we were in the first place, it's the linker's job to convert between BL/BLX as necessary. Even worse, using BLX left Thumb calls that could be locally resolved completely unencodable since all offsets to BLX are multiples of 4. rdar://26182344 llvm-svn: 269101
2016-05-11 03:17:47 +08:00
; RUN: llc -mtriple thumbv7-elf -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-OTHER
; RUN: llc -mtriple thumbv7-macho -filetype asm -o - %s | FileCheck %s -check-prefix CHECK-OTHER
ARM: permit tail calls to weak externals on COFF Weak externals are resolved statically, so we can actually generate the tail call on PE/COFF targets without breaking the requirements. It is questionable whether we want to propagate the current behaviour for MachO as the requirements are part of the ARM ELF specifications, and it seems that prior to the SVN r215890, we would have tail'ed the call. For now, be conservative and only permit it on PE/COFF where the call will always be fully resolved. llvm-svn: 225119
2015-01-04 05:35:00 +08:00
declare i8* @f()
declare extern_weak i8* @g(i8*)
; weak symbol resolution occurs statically in PE/COFF, ensure that we permit
; tail calls on weak externals when targeting a COFF environment.
define void @test() {
%call = tail call i8* @f()
%call1 = tail call i8* @g(i8* %call)
ret void
}
; CHECK-COFF: b g
ARM: stop emitting blx instructions for most calls on MachO. I'm really not sure why we were in the first place, it's the linker's job to convert between BL/BLX as necessary. Even worse, using BLX left Thumb calls that could be locally resolved completely unencodable since all offsets to BLX are multiples of 4. rdar://26182344 llvm-svn: 269101
2016-05-11 03:17:47 +08:00
; CHECK-OTHER: bl {{_?}}g
ARM: permit tail calls to weak externals on COFF Weak externals are resolved statically, so we can actually generate the tail call on PE/COFF targets without breaking the requirements. It is questionable whether we want to propagate the current behaviour for MachO as the requirements are part of the ARM ELF specifications, and it seems that prior to the SVN r215890, we would have tail'ed the call. For now, be conservative and only permit it on PE/COFF where the call will always be fully resolved. llvm-svn: 225119
2015-01-04 05:35:00 +08:00