All memory beyond the current address of RSP is considered volatile: The OS, or a debugger, may overwrite this memory during a user debug session, or an interrupt handler. Thus, RSP must always be set before attempting to read or write values to a stack frame.

This section discusses the allocation of stack space for local variables and the alloca intrinsic.

• Stack Allocation

• Dynamic Parameter Stack Area Construction

• Function Types

• malloc Alignment

• alloca

x64 Software Conventions