1; RUN: opt -functionattrs -S < %s | FileCheck %s
2
3; This checks for an iterator wraparound bug in FunctionAttrs.  The previous
4; "incorrect" behavior was inferring readonly for the %x argument in @caller.
5; Inferring readonly for %x *is* actually correct, since @va_func is marked
6; readonly, but FunctionAttrs was inferring readonly for the wrong reasons (and
7; we _need_ the readonly on @va_func to trigger the problematic code path).  It
8; is possible that in the future FunctionAttrs becomes smart enough to infer
9; readonly for %x for the right reasons, and at that point this test will have
10; to be marked invalid.
11
12declare void @llvm.va_start(i8*)
13declare void @llvm.va_end(i8*)
14
15define void @va_func(i32* readonly %b, ...) readonly nounwind {
16; CHECK-LABEL: define void @va_func(i32* nocapture readonly %b, ...)
17 entry:
18  %valist = alloca i8
19  call void @llvm.va_start(i8* %valist)
20  call void @llvm.va_end(i8* %valist)
21  %x = call i32 @caller(i32* %b)
22  ret void
23}
24
25define i32 @caller(i32* %x) {
26; CHECK-LABEL: define i32 @caller(i32* nocapture %x)
27 entry:
28  call void(i32*,...) @va_func(i32* null, i32 0, i32 0, i32 0, i32* %x)
29  ret i32 42
30}
31