Imported Upstream version 6.0.0.172

Former-commit-id: f3cc9b82f3e5bd8f0fd3ebc098f789556b44e9cd

external/llvm/test/Transforms/DeadArgElim/variadic_safety.ll

@@ -0,0 +1,38 @@
+; RUN: opt < %s -deadargelim -S | FileCheck %s
+
+declare void @llvm.va_start(i8*)
+
+define internal i32 @va_func(i32 %a, i32 %b, ...) {
+  %valist = alloca i8
+  call void @llvm.va_start(i8* %valist)
+
+  ret i32 %b
+}
+
+; Function derived from AArch64 ABI, where 8 integer arguments go in
+; registers but the 9th goes on the stack. We really don't want to put
+; just 7 args in registers and then start on the stack since any
+; va_arg implementation already present in va_func won't be expecting
+; it.
+define i32 @call_va(i32 %in) {
+  %stacked = alloca i32
+  store i32 42, i32* %stacked
+  %res = call i32(i32, i32, ...) @va_func(i32 %in, i32 %in, [6 x i32] undef, i32* byval %stacked)
+  ret i32 %res
+; CHECK: call i32 (i32, i32, ...) @va_func(i32 undef, i32 %in, [6 x i32] undef, i32* byval %stacked)
+}
+
+define internal i32 @va_deadret_func(i32 %a, i32 %b, ...) {
+  %valist = alloca i8
+  call void @llvm.va_start(i8* %valist)
+
+  ret i32 %a
+}
+
+define void @call_deadret(i32 %in) {
+  %stacked = alloca i32
+  store i32 42, i32* %stacked
+  call i32 (i32, i32, ...) @va_deadret_func(i32 undef, i32 %in, [6 x i32] undef, i32* byval %stacked)
+  ret void
+; CHECK: call void (i32, i32, ...) @va_deadret_func(i32 undef, i32 undef, [6 x i32] undef, i32* byval %stacked)
+}