It comes from C function that was declared (in contrast to a C function that was not declared which was common in K&R C). At the time it was coexisting with pascal calling convention (wher the callee cleared the stack), so it kind of made sense to call it after the programming language. Everything you … Read more
The Shadow space (also sometimes called Spill space or Home space) is 32 bytes above the return address which the called function owns (and can use as scratch space), below stack args if any. The caller has to reserve space for their callee’s shadow space before running a call instruction. It is meant to be … Read more
As MSDN says, the correct way to write this is typedef void (__stdcall *MessageHandler)(const Task*);
It depends on the platform. For a Xenon PowerPC, for example, it can be an order of magnitude difference due to a load-hit-store issue with passing data on the stack. I empirically timed the overhead of a cdecl function at about 45 cycles compared to ~4 for a fastcall. For an out-of-order x86 (Intel and … Read more
I’m not sure this is the best, but: function A{ Param([scriptblock]$FunctionToCall) Write-Host “I’m calling $($FunctionToCall.Invoke(4))” } function B($x){ Write-Output “Function B with $x” } Function C{ Param($x) Write-Output “Function C with $x” } PS C:\WINDOWS\system32> A -FunctionToCall $function:B I’m calling Function B with 4 PS C:\WINDOWS\system32> A -FunctionToCall $function:C I’m calling Function C with 4 … Read more
In the x86_64 ABI, if a function has variable arguments then AL (which is part of EAX) is expected to hold the number of vector registers used to hold arguments to that function. In your example: printf(“%d”, 1); has an integer argument so there’s no need for a vector register, hence AL is set to … Read more
This debug error means that the stack pointer register is not returned to its original value after the function call, i.e. that the number of pushes before the function call were not followed by the equal number of pops after the call. There are 2 reasons for this that I know (both with dynamically loaded … Read more
Here’s the complete table of registers and their use from the documentation [PDF Link]: r12, r13, r14, r15, rbx, rsp, rbp are the callee-saved registers – they have a “Yes” in the “Preserved across function calls” column.
It depends on the ABI for the platform you are compiling for. On Linux, there are two ARM ABIs; the old one and the new one. AFAIK, the new one (EABI) is in fact ARM’s AAPCS. The complete EABI definitions currently live here on ARM’s infocenter. From the AAPCS, §5.1.1: r0-r3 are the argument and … Read more
Caller-saved registers (AKA volatile registers, or call-clobbered) are used to hold temporary quantities that need not be preserved across calls. For that reason, it is the caller’s responsibility to push these registers onto the stack or copy them somewhere else if it wants to restore this value after a procedure call. It’s normal to let … Read more