search for: movls

Sorry I missed that important detail. The relevant part of the command line is: -cc1 -S -triple i386-pc-win32 I don't expect it matters if it's for Windows or Linux in this case. On Fri, Sep 14, 2018 at 9:16 PM David Blaikie <dblaikie at gmail.com> wrote: > Can't say I've observed that behavior (though I'm just building from > top-of-tree rather than 6.0,

Hi everyone, I found that LLVM generates redundant code when calling functions with constant parameters, with optimizations disabled. Consider the following C code snippet: int foo(int x, int y); void bar() { foo(1, 2); foo(3, 4); } Clang/LLVM 6.0 generates the following assembly code: _bar: subl $32, %esp movl $1, %eax movl $2, %ecx movl $1, (%esp) movl $2, 4(%esp) movl %eax, 28(%esp) movl

Hi, I am looking for a solution to boot MY system on any PC. To store most of the system and all of my data I want to use an USB storage (in my case an external USB harddisk (2.0 capable)). Since booting off an USB device is not an universal thing I would prefer to have a boot disk with a minimal system - just enough to load most (all?) of the system from the attached USB device. Is this an

Problem seems not only with operator overloading, It occurs with struct value returning also. gdb while debugging expects the return value in eax, gcc does returns in eax, But Clang returns in edx(it can be checked in gdb by printing the contents of edx). Code(sample code) struct A1 { int x; int y; }; A1 sum(const A1 one, const A1 two) { A1 plus = {0,0}; plus.x = one.x + two.x; plus.y

For the given test: class A1 { int x; int y; public: A1(int a, int b) { x=a; y=b; } A1 operator+(const A1&); }; A1 A1::operator+(const A1& second) { A1 sum(0,0); sum.x = x + second.x; sum.y = y + second.y; return (sum); } int main (void) { A1 one(2,3); A1 two(4,5); return 0; } when the exectable of this code is debugged in gdb for i386, we dont get the

Hi, Chris (cc) and I try to get the SGE master monitor work with Apple Leopard dtrace. Unfortunately we are stuck with the error msg below. Anyone having an idea what could be the cause? What I can rule out as cause is function inlining for the reasons explained below. Background information on SGE master monitor implementation is under http://wiki.gridengine.info/wiki/index.php/Dtrace

Hello all, In r223757 I've committed a patch that performs, for the 32-bit x86 calling convention, the transformation of MOV instructions that push function arguments onto the stack into actual PUSH instructions. For example, it will transform this: subl $16, %esp movl $4, 12(%esp) movl $3, 8(%esp) movl $2, 4(%esp) movl $1, (%esp) calll _func addl $16, %esp

Hi, all I want to make a function such as void add512(uint512_t *pz, const uint512_t *px, const uint512_t *py) { *pz = *px + *py; } # uint512_t means 512-bit unsigned integer register. Then, I make a sample code: >cat t.ll define void @add512(i512*noalias %pz, i512*noalias %px, i512*noalias %py) { %x = load i512* %px %y = load i512* %py %z = add i512 %x, %y store i512 %z, i512* %pz

Hi, Structures are passed by pointer, so the return value is not actually in eax. That code gets transformed into something like: void sum(A1 *out, const A1 one, const A1 two) { out->x = one.x + two.x out->y = one.y + two.y } So actually the function ends up returning void and operating on a hidden parameter, so %eax is dead at the end of the function and should not be being relied

Hello again! I took a stab at PR4898[1]. The attached patch improves Clang's __builtin_constant_p support so that the Linux kernel is happy. With this improvement, Clang can determine if __builtin_constant_p is true or false after inlining. As an example: static __attribute__((always_inline)) int foo(int x) { if (__builtin_constant_p(x)) return 1; return 0; } static

When I try running one llvm function in JIT without optimization I get SEGV. Looking at assembly (below) I see that the local value 0xffffffffffffffe0(%rbp) is used without being ever initialized (see my comment in asm). Same code on i386 works fine, with and w/out optimization. My guess is that this is a bug in LLVM. Yuri --- llvm --- %struct.mystruct = type { i32, i8, i8, i8, i8 } define

Hi Duncan, David, Sean. Thanks for your reply. > It'd be interesting if you could find a design that also treated these > the same: > > (B ^ A) | ((A ^ B) ^ C) -> (A ^ B) | C > (B ^ A) | ((B ^ C) ^ A) -> (A ^ B) | C > (B ^ A) | ((C ^ A) ^ B) -> (A ^ B) | C > > I.e., `^` is also associative. Agree with Duncan on including associative operation too.

Which performance guidelines are you referring to? I'm not that familiar with decade-old CPUs, but to the best of my knowledge, this is not true on current hardware. There is one specific circumstance where PUSHes should be avoided - for Atom/Silvermont processors, the memory form of PUSH is inefficient, so the register-freeing optimization below may not be profitable (see 14.3.3.6 and

Hello, I have this simple IR: ------------------------------------------------------------------------ define internal i32 @tmp(i32 %x) { entry: br label %entry2 entry2: %x1 = alloca i32 %x2 = alloca i32 %retval = alloca i32 %dummy = alloca i32 store i32 %x, i32* %x1 store i32 %x, i32* %x2 %tmp1 = load i32* %x1 %tmp2 = add i32 %tmp1, %tmp1

I discovered recently that RegAllocFast spills all the registers before every function call. This is the root cause of one of our recursive functions that takes about 150 bytes of stack when built with gcc (same at -O0 and -O2, or 120 bytes at llc -O2) taking 960 bytes of stack when built by llc -O0. That's pretty bad for situations where you have small stacks, which is not uncommon for

I was told that my writeup lacked an example and details so I reproduced the code that X uses and I was able to boil down the issue to a couple of lines of code. Sorry again for the length of this email. Code was compiled on OpenBSD with clang 3.0-release. ======================================================================== With -O0 which works as X expects:

That's useful to know that the static compilation code path works. Furthermore, as expected from that: 52: c7 05 04 00 00 00 d5 00 00 00 movl $213, 4 00000054: IMAGE_REL_I386_DIR32 _foo It looks like the offset `4` of the second field of your struct is correct in the object file, so this does seem to be a problem in the JIT-specific linking/loading.

From: Joerg Roedel <jroedel at suse.de> Make sure segments are properly set up before setting up an IDT and doing anything that might cause a #VC exception. This is later needed for early exception handling. Signed-off-by: Joerg Roedel <jroedel at suse.de> --- arch/x86/kernel/head_64.S | 52 +++++++++++++++++++-------------------- 1 file changed, 26 insertions(+), 26 deletions(-)

I found a something that I quite not understand when compiling a common piece of code using the -Os flags. I found it while testing my own backend but then I got deeper and found that at least the x86 is affected as well. This is the referred code: char pp[3]; char *scscx = pp; int tst( char i, char j, char k ) { scscx[0] = i; scscx[1] = j; scscx[2] = k; return 0; } The above gets

Hi, As you told that function ends up returning void, I just confirmed it in the IR, the function is defined as: define *void* @_Z3sum2A1S_(*%struct.A1* noalias sret %agg.result*, %struct.A1* byval align 4 %one, %struct.A1* byval align 4 %two). But when i checked the register values in g++, eax contains an address of stack, which points to the value (object) returned by sum. That is if we