[LangRef] Clarify alloca of zero bytes.

Let's be conservative here; it matches what we actually implemented, and
it should be rare in practice anyway.

Differential Revision: https://reviews.llvm.org/D49042

llvm-svn: 336744
This commit is contained in:
Eli Friedman 2018-07-11 00:02:01 +00:00
parent f3731d4e9c
commit 18f882c8b8
1 changed files with 3 additions and 3 deletions

View File

@ -7862,9 +7862,9 @@ memory is automatically released when the function returns. The
'``alloca``' instruction is commonly used to represent automatic
variables that must have an address available. When the function returns
(either with the ``ret`` or ``resume`` instructions), the memory is
reclaimed. Allocating zero bytes is legal, but the result is undefined.
The order in which memory is allocated (ie., which way the stack grows)
is not specified.
reclaimed. Allocating zero bytes is legal, but the returned pointer may not
be unique. The order in which memory is allocated (ie., which way the stack
grows) is not specified.
Example:
""""""""