diff options
| -rw-r--r-- | test/CFrontend/2008-01-25-ByValReadNone.c | 15 |
1 files changed, 10 insertions, 5 deletions
diff --git a/test/CFrontend/2008-01-25-ByValReadNone.c b/test/CFrontend/2008-01-25-ByValReadNone.c index afbf97066c..8ec60525af 100644 --- a/test/CFrontend/2008-01-25-ByValReadNone.c +++ b/test/CFrontend/2008-01-25-ByValReadNone.c @@ -1,10 +1,15 @@ -// RUN: %llvmgcc -O3 -S -o - -emit-llvm %s | grep readonly +// RUN: %llvmgcc -O3 -S -o - -emit-llvm %s | not grep readonly // RUN: %llvmgcc -O3 -S -o - -emit-llvm %s | not grep readnone -// The struct being passed byval means that we need to mark the -// function readonly instead of readnone. Readnone would allow -// stores to the arg to be deleted in the caller. +// The struct being passed byval means that we cannot mark the +// function readnone. Readnone would allow stores to the arg to +// be deleted in the caller. We also don't allow readonly since +// the callee might write to the byval parameter. The inliner +// would have to assume the worse and introduce an explicit +// temporary when inlining such a function, which is costly for +// the common case in which the byval argument is not written. struct S { int A[1000]; }; int __attribute__ ((const)) f(struct S x) { return x.A[0]; } - +int g(struct S x) __attribute__ ((pure)); +int h(struct S x) { return g(x); } |