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1; RUN: opt -function-attrs -S < %s | FileCheck %s
2; RUN: opt -passes=function-attrs -S < %s | FileCheck %s
3
4; This checks for an iterator wraparound bug in FunctionAttrs.  The previous
5; "incorrect" behavior was inferring readonly for the %x argument in @caller.
6; Inferring readonly for %x *is* actually correct, since @va_func is marked
7; readonly, but FunctionAttrs was inferring readonly for the wrong reasons (and
8; we _need_ the readonly on @va_func to trigger the problematic code path).  It
9; is possible that in the future FunctionAttrs becomes smart enough to infer
10; readonly for %x for the right reasons, and at that point this test will have
11; to be marked invalid.
12
13declare void @llvm.va_start(i8*)
14declare void @llvm.va_end(i8*)
15
16define void @va_func(i32* readonly %b, ...) readonly nounwind {
17; CHECK-LABEL: define void @va_func(i32* nocapture readonly %b, ...)
18 entry:
19  %valist = alloca i8
20  call void @llvm.va_start(i8* %valist)
21  call void @llvm.va_end(i8* %valist)
22  %x = call i32 @caller(i32* %b)
23  ret void
24}
25
26define i32 @caller(i32* %x) {
27; CHECK-LABEL: define i32 @caller(i32* nocapture %x)
28 entry:
29  call void(i32*,...) @va_func(i32* null, i32 0, i32 0, i32 0, i32* %x)
30  ret i32 42
31}
32