llvm-project/llvm/test/Transforms/FunctionAttrs/out-of-bounds-iterator-bug.ll

31 lines
1.1 KiB
LLVM

; RUN: opt -functionattrs -S < %s | FileCheck %s
; This checks for an iterator wraparound bug in FunctionAttrs. The previous
; "incorrect" behavior was inferring readonly for the %x argument in @caller.
; Inferring readonly for %x *is* actually correct, since @va_func is marked
; readonly, but FunctionAttrs was inferring readonly for the wrong reasons (and
; we _need_ the readonly on @va_func to trigger the problematic code path). It
; is possible that in the future FunctionAttrs becomes smart enough to infer
; readonly for %x for the right reasons, and at that point this test will have
; to be marked invalid.
declare void @llvm.va_start(i8*)
declare void @llvm.va_end(i8*)
define void @va_func(i32* readonly %b, ...) readonly nounwind {
; CHECK-LABEL: define void @va_func(i32* nocapture readonly %b, ...)
entry:
%valist = alloca i8
call void @llvm.va_start(i8* %valist)
call void @llvm.va_end(i8* %valist)
%x = call i32 @caller(i32* %b)
ret void
}
define i32 @caller(i32* %x) {
; CHECK-LABEL: define i32 @caller(i32* nocapture %x)
entry:
call void(i32*,...) @va_func(i32* null, i32 0, i32 0, i32 0, i32* %x)
ret i32 42
}