abi

问题 From this question, What registers are preserved through a linux x86-64 function call, it says that the following registers are saved across function calls: r12, r13, r14, r15, rbx, rsp, rbp So, I went ahead and did a test with the following: .globl _start _start: mov $5, %r12 mov $5, %r13 mov $5, %r14 mov $5, %r15 call get_array_size mov $60, %eax syscall get_array_size: mov $0, %r12 mov $0, %r13 mov $0, %r14 mov $0, %r15 ret And, I was thinking that after the call get_array_size that my

问题 Consider the following C code: #include <stdint.h> void func(void) { uint32_t var = 0; return; } The unoptimized (i.e.: -O0 option) assembly code generated by GCC 4.7.2 for the code above is: func: pushl %ebp movl %esp, %ebp subl $16, %esp movl $0, -4(%ebp) nop leave ret According to the stack alignment requirements of the System V ABI , the stack must be aligned by 16 bytes before every call instruction (the stack boundary is 16 bytes by default when not changed with the option -mpreferred

问题 with _GLIBCXX_USE_CXX11_ABI=0 std::function of GCC-4 is different of GCC-5 and follwing versions. The following code show you the fact: ==> lib.cc <== #include <functional> std::function<int(const void*p)> holder; int run_holder(const void *p) { return holder(p); } ==> main.cc <== #include <stdio.h> #include <functional> extern int run_holder(const void*p); extern std::function<int(const void*p)> holder; int foo(const void* p) { printf("p=%p\n", p); return 0; } int main() { holder = foo; foo(

问题 Related question: Standard-layout and tail padding Snippet: #include <iostream> #include <type_traits> struct A0 { int a; char c; }; struct B0 : A0 { char d; }; struct A1 { int a; private: char c; }; struct B1 : A1 { char d; }; struct A2 { private: int a; char c; }; struct B2 : A2 { char d; }; int main() { std::cout << std::is_pod<A0>::value << ' ' << sizeof(B0) << std::endl; // 1 12 std::cout << std::is_pod<A1>::value << ' ' << sizeof(B1) << std::endl; // 0 8 std::cout << std::is_pod<A2>:

问题 I'm listening to events of my deployed contract. Whenever a transaction gets completed and event is fired receiving the response causes following error: Uncaught Error: Returned values aren't valid, did it run Out of Gas? at ABICoder.push../node_modules/web3-eth-abi/src/index.js.ABICoder.decodeParameters (index.js:227) at ABICoder.push../node_modules/web3-eth-abi/src/index.js.ABICoder.decodeLog (index.js:277) Web3 version: 1.0.0-beta36 Metamask version: 4.16.0 How to fix it? 回答1: Try the

问题 I'm listening to events of my deployed contract. Whenever a transaction gets completed and event is fired receiving the response causes following error: Uncaught Error: Returned values aren't valid, did it run Out of Gas? at ABICoder.push../node_modules/web3-eth-abi/src/index.js.ABICoder.decodeParameters (index.js:227) at ABICoder.push../node_modules/web3-eth-abi/src/index.js.ABICoder.decodeLog (index.js:277) Web3 version: 1.0.0-beta36 Metamask version: 4.16.0 How to fix it? 回答1: Try the

问题 I am constantly getting this warning while building my android studio code using terminal command gradle clean assembleRelease : Unable to strip library 'lib.so' due to missing strip tool for ABI 'ARMEABI'. Packaging it as is. Please help me on how to get this warning resolved. Note: I know this won't affect the behaviour of my app, but my APK is too bulky and this will surely help me reduce APK size. So I need this resolved. 回答1: The default installed NDK doesn't seem to have the tools

问题 Why does al contain the number of vector parameters in assembly? Why are vector parameters any different from normal parameters for the callee? 回答1: The value is used for optimization as stated in the ABI document The prologue should use %al to avoid unnecessarily saving XMM registers. This is especially important for integer only programs to prevent the initialization of the XMM unit. 3.5.7 Variable Argument Lists - The Register Save Area. System V Application Binary Interface version 1.0

问题 Why does al contain the number of vector parameters in assembly? Why are vector parameters any different from normal parameters for the callee? 回答1: The value is used for optimization as stated in the ABI document The prologue should use %al to avoid unnecessarily saving XMM registers. This is especially important for integer only programs to prevent the initialization of the XMM unit. 3.5.7 Variable Argument Lists - The Register Save Area. System V Application Binary Interface version 1.0

问题 Why does al contain the number of vector parameters in assembly? Why are vector parameters any different from normal parameters for the callee? 回答1: The value is used for optimization as stated in the ABI document The prologue should use %al to avoid unnecessarily saving XMM registers. This is especially important for integer only programs to prevent the initialization of the XMM unit. 3.5.7 Variable Argument Lists - The Register Save Area. System V Application Binary Interface version 1.0