1 files changed, 119 insertions, 0 deletions
diff --git a/test/CodeGen/X86/musttail-varargs.ll b/test/CodeGen/X86/musttail-varargs.ll
new file mode 100644
index 0000000..1e99c14
--- /dev/null
+++ b/test/CodeGen/X86/musttail-varargs.ll
@@ -0,0 +1,119 @@
+; RUN: llc < %s -enable-tail-merge=0 -mtriple=x86_64-linux | FileCheck %s --check-prefix=LINUX
+; RUN: llc < %s -enable-tail-merge=0 -mtriple=x86_64-windows | FileCheck %s --check-prefix=WINDOWS
+
+; Test that we actually spill and reload all arguments in the variadic argument
+; pack. Doing a normal call will clobber all argument registers, and we will
+; spill around it. A simple adjustment should not require any XMM spills.
+
+declare void(i8*, ...)* @get_f(i8* %this)
+
+define void @f_thunk(i8* %this, ...) {
+  %fptr = call void(i8*, ...)*(i8*)* @get_f(i8* %this)
+  musttail call void (i8*, ...)* %fptr(i8* %this, ...)
+  ret void
+}
+
+; Save and restore 6 GPRs, 8 XMMs, and AL around the call.
+
+; LINUX-LABEL: f_thunk:
+; LINUX-DAG: movq %rdi, {{.*}}
+; LINUX-DAG: movq %rsi, {{.*}}
+; LINUX-DAG: movq %rdx, {{.*}}
+; LINUX-DAG: movq %rcx, {{.*}}
+; LINUX-DAG: movq %r8, {{.*}}
+; LINUX-DAG: movq %r9, {{.*}}
+; LINUX-DAG: movb %al, {{.*}}
+; LINUX-DAG: movaps %xmm0, {{[0-9]*}}(%rsp)
+; LINUX-DAG: movaps %xmm1, {{[0-9]*}}(%rsp)
+; LINUX-DAG: movaps %xmm2, {{[0-9]*}}(%rsp)
+; LINUX-DAG: movaps %xmm3, {{[0-9]*}}(%rsp)
+; LINUX-DAG: movaps %xmm4, {{[0-9]*}}(%rsp)
+; LINUX-DAG: movaps %xmm5, {{[0-9]*}}(%rsp)
+; LINUX-DAG: movaps %xmm6, {{[0-9]*}}(%rsp)
+; LINUX-DAG: movaps %xmm7, {{[0-9]*}}(%rsp)
+; LINUX: callq get_f
+; LINUX-DAG: movaps {{[0-9]*}}(%rsp), %xmm0
+; LINUX-DAG: movaps {{[0-9]*}}(%rsp), %xmm1
+; LINUX-DAG: movaps {{[0-9]*}}(%rsp), %xmm2
+; LINUX-DAG: movaps {{[0-9]*}}(%rsp), %xmm3
+; LINUX-DAG: movaps {{[0-9]*}}(%rsp), %xmm4
+; LINUX-DAG: movaps {{[0-9]*}}(%rsp), %xmm5
+; LINUX-DAG: movaps {{[0-9]*}}(%rsp), %xmm6
+; LINUX-DAG: movaps {{[0-9]*}}(%rsp), %xmm7
+; LINUX-DAG: movq {{.*}}, %rdi
+; LINUX-DAG: movq {{.*}}, %rsi
+; LINUX-DAG: movq {{.*}}, %rdx
+; LINUX-DAG: movq {{.*}}, %rcx
+; LINUX-DAG: movq {{.*}}, %r8
+; LINUX-DAG: movq {{.*}}, %r9
+; LINUX-DAG: movb {{.*}}, %al
+; LINUX: jmpq *{{.*}}  # TAILCALL
+
+; WINDOWS-LABEL: f_thunk:
+; WINDOWS-NOT: mov{{.}}ps
+; WINDOWS-DAG: movq %rdx, {{.*}}
+; WINDOWS-DAG: movq %rcx, {{.*}}
+; WINDOWS-DAG: movq %r8, {{.*}}
+; WINDOWS-DAG: movq %r9, {{.*}}
+; WINDOWS-NOT: mov{{.}}ps
+; WINDOWS: callq get_f
+; WINDOWS-NOT: mov{{.}}ps
+; WINDOWS-DAG: movq {{.*}}, %rdx
+; WINDOWS-DAG: movq {{.*}}, %rcx
+; WINDOWS-DAG: movq {{.*}}, %r8
+; WINDOWS-DAG: movq {{.*}}, %r9
+; WINDOWS-NOT: mov{{.}}ps
+; WINDOWS: jmpq *{{.*}} # TAILCALL
+
+; This thunk shouldn't require any spills and reloads, assuming the register
+; allocator knows what it's doing.
+
+define void @g_thunk(i8* %fptr_i8, ...) {
+  %fptr = bitcast i8* %fptr_i8 to void (i8*, ...)*
+  musttail call void (i8*, ...)* %fptr(i8* %fptr_i8, ...)
+  ret void
+}
+
+; LINUX-LABEL: g_thunk:
+; LINUX-NOT: movq
+; LINUX: jmpq *%rdi  # TAILCALL
+
+; WINDOWS-LABEL: g_thunk:
+; WINDOWS-NOT: movq
+; WINDOWS: jmpq *%rcx # TAILCALL
+
+; Do a simple multi-exit multi-bb test.
+
+%struct.Foo = type { i1, i8*, i8* }
+
+@g = external global i32
+
+define void @h_thunk(%struct.Foo* %this, ...) {
+  %cond_p = getelementptr %struct.Foo* %this, i32 0, i32 0
+  %cond = load i1* %cond_p
+  br i1 %cond, label %then, label %else
+
+then:
+  %a_p = getelementptr %struct.Foo* %this, i32 0, i32 1
+  %a_i8 = load i8** %a_p
+  %a = bitcast i8* %a_i8 to void (%struct.Foo*, ...)*
+  musttail call void (%struct.Foo*, ...)* %a(%struct.Foo* %this, ...)
+  ret void
+
+else:
+  %b_p = getelementptr %struct.Foo* %this, i32 0, i32 2
+  %b_i8 = load i8** %b_p
+  %b = bitcast i8* %b_i8 to void (%struct.Foo*, ...)*
+  store i32 42, i32* @g
+  musttail call void (%struct.Foo*, ...)* %b(%struct.Foo* %this, ...)
+  ret void
+}
+
+; LINUX-LABEL: h_thunk:
+; LINUX: jne
+; LINUX: jmpq *{{.*}} # TAILCALL
+; LINUX: jmpq *{{.*}} # TAILCALL
+; WINDOWS-LABEL: h_thunk:
+; WINDOWS: jne
+; WINDOWS: jmpq *{{.*}} # TAILCALL
+; WINDOWS: jmpq *{{.*}} # TAILCALL