win64-byval.ll
1.03 KB
; RUN: llc -mtriple x86_64-w64-mingw32 %s -o - | FileCheck %s
declare void @foo({ float, double }* byval)
@G = external constant { float, double }
define void @bar()
{
; Make sure we're creating a temporary stack slot, rather than just passing
; the pointer through unmodified.
; CHECK-LABEL: @bar
; CHECK: movq .refptr.G(%rip), %rax
; CHECK: movq (%rax), %rcx
; CHECK: movq 8(%rax), %rax
; CHECK: movq %rax, 40(%rsp)
; CHECK: movq %rcx, 32(%rsp)
; CHECK: leaq 32(%rsp), %rcx
call void @foo({ float, double }* byval @G)
ret void
}
define void @baz({ float, double }* byval %arg)
{
; On Win64 the byval is effectively ignored on declarations, since we do
; pass a real pointer in registers. However, by our semantics if we pass
; the pointer on to another byval function, we do need to make a copy.
; CHECK-LABEL: @baz
; CHECK: movq (%rcx), %rax
; CHECK: movq 8(%rcx), %rcx
; CHECK: movq %rcx, 40(%rsp)
; CHECK: movq %rax, 32(%rsp)
; CHECK: leaq 32(%rsp), %rcx
call void @foo({ float, double }* byval %arg)
ret void
}