llvm-6502/test/CodeGen/X86/win64_call_epi.ll
Reid Kleckner 0b04cf6e71 Fix failure to invoke exception handler on Win64
When the last instruction prior to a function epilogue is a call, we
need to emit a nop so that the return address is not in the epilogue IP
range.  This is consistent with MSVC's behavior, and may be a workaround
for a bug in the Win64 unwinder.

Differential Revision: http://reviews.llvm.org/D4751

Patch by Vadim Chugunov!

git-svn-id: https://llvm.org/svn/llvm-project/llvm/trunk@214775 91177308-0d34-0410-b5e6-96231b3b80d8
2014-08-04 21:05:27 +00:00

66 lines
1.3 KiB
LLVM

; RUN: llc < %s -mtriple=x86_64-pc-mingw32 | FileCheck %s -check-prefix=WIN64
declare void @bar()
declare void @baz()
declare i32 @personality(...)
; Check for 'nop' between the last call and the epilogue.
define void @foo1() {
invoke void @bar()
to label %normal
unwind label %catch
normal:
ret void
catch:
%1 = landingpad { i8*, i32 } personality i32 (...)* @personality cleanup
resume { i8*, i32 } %1
}
; WIN64-LABEL: foo1:
; WIN64: .seh_proc foo1
; WIN64: callq bar
; WIN64: nop
; WIN64: addq ${{[0-9]+}}, %rsp
; WIN64: retq
; Check for 'ud2' after noreturn call
; WIN64: callq _Unwind_Resume
; WIN64-NEXT: ud2
; WIN64: .seh_endproc
; Check it still works when blocks are reordered.
@something = global i32 0
define void @foo2(i1 zeroext %cond ) {
br i1 %cond, label %a, label %b, !prof !0
a:
call void @bar()
br label %done
b:
call void @baz()
store i32 0, i32* @something
br label %done
done:
ret void
}
!0 = metadata !{metadata !"branch_weights", i32 100, i32 0}
; WIN64-LABEL: foo2:
; WIN64: callq bar
; WIN64: nop
; WIN64: addq ${{[0-9]+}}, %rsp
; WIN64: retq
; Check nop is not emitted when call is not adjacent to epilogue.
define i32 @foo3() {
call void @bar()
ret i32 0
}
; WIN64-LABEL: foo3:
; WIN64: callq bar
; WIN64: xorl
; WIN64-NOT: nop
; WIN64: addq ${{[0-9]+}}, %rsp
; WIN64: retq