search for: __asm

...via llvm-dev > <llvm-dev at lists.llvm.org> wrote: >> LLVM/clang generates wrong code for the following program >> (see <https://godbolt.org/z/UZrrkG>): > > It looks like all of these issues come down to mismatched expectations > on what goes into and out of an __asm block. If you look at the MSVC > documentation (which I think Clang is trying to be compatible with), > it warns against assuming known values are in particular registers at > any point, and even using __fastcall at all for a function with an > __asm block for that reason: > https://...

Hi @ll, LLVM/clang generates wrong code for the following program (see <https://godbolt.org/z/UZrrkG>): --- sample.c --- unsigned __fastcall lfsr32(unsigned argument, unsigned polynomial) { __asm { add ecx, ecx ; ecx = argument << 1 sbb eax, eax ; eax = CF ? -1 : 0 and eax, edx ; eax = CF ? polynomial : 0 xor eax, ecx ; eax = (argument << 1) ^ (CF ? polynomial : 0) } } int main() { unsigned lfsr = 123456789; unsigned period = 0;...

...rsp movq __image_base(%rip), %rsi leaq start(%rip), %rdx subq __start_static(%rip), %rdx call __start_c In C: /* run C++ constructors in __libc_start_main for x86_64-xnu-musl */ typedef void (*__init_fn)(int, char **, char **, char **); extern __init_fn __init_start __asm("section$start$__DATA$__mod_init_func"); extern __init_fn __init_end __asm("section$end$__DATA$__mod_init_func”); static void __init_mod(int argc, char **argv, char **envp, char **applep) { for (__init_fn *p = &__init_start; p < &__init_end; ++p) {...

...and he was proposing to add a Pre-Read file. > > Do you have any other opinions too ? We have a similar requirement in darwin's ld64 linker, but even more general. Any binary can do the following to introspect itself: struct stuff { int a; int b; }; extern struct stuff* stuff_start __asm("section$start$__DATA$__my"); extern struct stuff* stuff_end __asm("section$end$__DATA$__my"); void examineSection() { const struct stuff* p; for (p = stuff_start; p < stuff_end; ++p) { // do stuff with p } } That is, there are magic symbol names which reference the...

...still susceptible to being duplicated: #include <stdint.h> uint32_t f(uint32_t x); uint32_t g(uint32_t x); uint32_t f(uint32_t x) { uint32_t returnValue = g(x); if (returnValue > 0U) { returnValue = 0x40000000; } else { returnValue = 0x80000000; } __asm __volatile__ ("\t.global my_hook_fcn\nmy_hook_fcn:\n"); return returnValue; } uint32_t g(uint32_t x) { return x >> 1U; } If the above definition of f() is compiled with optimization at level 1 or higher, the TailDuplication optimization pass will duplicate and move the asm...

...still susceptible to being duplicated: #include <stdint.h> uint32_t f(uint32_t x); uint32_t g(uint32_t x); uint32_t f(uint32_t x) { uint32_t returnValue = g(x); if (returnValue > 0U) { returnValue = 0x40000000; } else { returnValue = 0x80000000; } __asm __volatile__ ("\t.global my_hook_fcn\nmy_hook_fcn:\n"); return returnValue; } uint32_t g(uint32_t x) { return x >> 1U; } If the above definition of f() is compiled with optimization at level 1 or higher, the TailDuplication optimization pass will duplicate and move the asm...

Hi Nick, We have few symbols like __bss_start, __bss_end, which are Undefined symbols in the code. I want a way in the Reader to create specific atoms before the linker bootstraps. I didnt find a way to do that with the existing interfaces. The way it needs to work is as below :- 1) ReaderELF creates Absolute symbols (for __bss_start, __bss_end etc) 2) ReaderELF reads each file and adds

...~ Todd From: Snider, Todd Sent: Wednesday, February 13, 2019 11:40 AM To: 'paul.robinson at sony.com'; efriedma at quicinc.com Cc: llvm-dev at lists.llvm.org Subject: RE: [llvm-dev] [RFC] Potential extension to asm statement functionality The proposed "lbl" constraint below: __asm __volatile__ ("\t.global\t%0\n%0:\n" : "lbl" (my_hook_fcn)); is not quite a "No Touchie!" constraint, but it does allow the user to set the isNotDuplicable flag on the INLINEASM that comes out of the asm statement in order to circumvent optimizations like Tail Duplica...

...day I'm still using the following code before speex_encoder_init and erverything works great: // fix denormals performance issue // http://software.intel.com/en-us/articles/x87-and-sse-floating-point-assists-in-ia-32-flush-to-zero-ftz-and-denormals-are-zero-daz/ __m128 state[32]; __int32 temp; __asm fxsave state; memcpy(&temp, (char*)state + 24, 4); temp |= (1 << 11); // UNDERFLOW_EXCEPTION_MASK temp |= (1 << 15); // FTZ_BIT __asm ldmxcsr temp; Tested with Visual Studio 2010 on x86. Please let me know if it works for you too. Mark -- NEU: FreePhone 3-fach-Flat mit kostenlos...

Hi Nick, On 12/7/2012 4:59 PM, Nick Kledzik wrote: > > We have a similar requirement in darwin's ld64 linker, but even more general. Any binary can do the following to introspect itself: > > struct stuff { int a; int b; }; > > extern struct stuff* stuff_start __asm("section$start$__DATA$__my"); > extern struct stuff* stuff_end __asm("section$end$__DATA$__my"); > > void examineSection() { > const struct stuff* p; > for (p = stuff_start; p < stuff_end; ++p) { > // do stuff with p > } > } > > That is,...

...leaq start(%rip), %rdx > subq __start_static(%rip), %rdx > call __start_c > > In C: > > /* run C++ constructors in __libc_start_main for x86_64-xnu-musl */ > > typedef void (*__init_fn)(int, char **, char **, char **); > extern __init_fn __init_start __asm("section$start$__DATA$__mod_init_func"); > extern __init_fn __init_end __asm("section$end$__DATA$__mod_init_func”); > > static void __init_mod(int argc, char **argv, char **envp, char **applep) > { > for (__init_fn *p = &__init_start; p < &__ini...

...n creating * trampoline functions on the stack for use with nested functions. @@ -108,6 +104,7 @@ void __clear_cache(void *start, void *end) { sysarch(ARM_SYNC_ICACHE, &arg); #elif defined(__linux__) + #define __ARM_NR_cacheflush 0x0f0002 register int start_reg __asm("r0") = (int) (intptr_t) start; const register int end_reg __asm("r1") = (int) (intptr_t) end; const register int flags __asm("r2") = 0; -------------- next part -------------- A non-text attachment was scrubbed... Name: compiler-rt-remove-kernel-...

...ight code, it use the same register in inline asm, and the binary will segment fault in MIPS environment. My test case: /* constraint.c */ #include <stdio.h> int main(int argc, char* argv[]) { int a = 4; int b = 10; int c = 0xffbbccdd; int *p = &a; int out = 0; __asm volatile ( "lw %0, %1\n\t" : "=r"(out) : "R"(*p) ); printf("out is %d\n", out); p = &b; __asm volatile ( "lw %0, %1\n\t" : "=r"(out) : "R"(*p) );...

...and run a C program containing inline assembly using MCJIT but I am not able to. I have cloned and build LLVM-3.1. Below are more details. Arch : x86 OS : Linux ubuntu 2.6.35-22-generic Sample program : test_inline_asm.c ------------------- #include <stdio.h> int main(){ int a=0; __asm __volatile("movl $5,%%eax\t" "\n movl %%eax,%0":"=r"(a)::"cc","memory" ); printf("a= %d\n",a); } Commands ------------- clang -emit-llvm -S test_inline_asm.c lli -use-mcjit test_inline_asm.s throws, LLVM ERROR: Inline asm no...

Hi lists, Sorry for cross-posting, but these two patches are of concern to clang and llvm. I'm compiling C-code which includes inline assembler which looks like the following using the sparc-target: static inline float fabsf(float a) { float res; __asm __volatile__("fabss %1, %0;" : "=f"(res) : "f"(a)); return res; } This fails with llvm/clang - trunk/master. I patched clang and llvm and, as I'm new to both project, I'm having doubts that it is enough - however i...

...roblem on LLVM-GCC. In my code, there's a file with a bunch of inline assembly blocks, that worked fine with GCC 4.2. Now, when compiling with LLVM-GCC 4.2, weird things happen. Here's an example: (the blocks are larger than that, but a single line will do to show you what's happening) __asm { mov ebx, iObject } When compiling in release, everything goes fine, and the produced assembly looks like this : ## InlineAsm Start .file "... my filename" ## InlineAsm End ## InlineAsm Start .line 1454 ## InlineAsm End ## InlineAsm Start movl -20(%ebp), $ebx ## InlineAsm End The pr...

...n a situation where I need to build x86 and arm assembly sources for some sources while the rest will be built with C. I do know that just adding `-fembed-bitcode` to a C sources would embed bitcode, but doing the same for the assembly files will not do that (at least, it will add the 1-byte `_LLVM,__asm` section, but not the `__LLVM,__bitcode` section). Furthermore, I do need the final output to contain bitcode for all files used. So, my question is if it is possible to add the `__LLVM,__bitcode` section later to the MachO object file. I tried to archive the bitcode using `xar` and run `llvm-objc...

...;/var/empty\" -DHAVE_CONFIG_H -c log.c -o log.o In file included from /usr/include/sys/cdefs.h:587:0, from /usr/include/sys/types.h:75, from includes.h:25, from log.c:37: /usr/include/sys/syslog.h:227:124: error: expected ',' or ';' before '__asm' void syslog(int, const char *, ...) __printflike(2, 3) __not_tail_called __DARWIN_ALIAS_STARTING(__MAC_10_13, __IPHONE_NA, __DARWIN_EXTSN(syslog)); The corresponding bits from syslog.h are [lines wrapped] #if defined(__ENVIRONMENT_MAC_OS_X_VERSION_MIN_REQUIRED__) && __DARWIN_C_LEV...

...register long _r8 asm ("r8"); \ + register long _r10 asm ("r10"); \ + register long _r15 asm ("r15") = __NR_##name; \ + long _retval; \ + __asm __volatile (__IA64_BREAK \ + : "=r" (_r8), "=r" (_r10), "=r" (_r15) \ + : "2" (_r15) ASM_ARGS_0 \ + : "memory" A...

...Pre-Read file. >> >> Do you have any other opinions too ? > We have a similar requirement in darwin's ld64 linker, but even more general. Any binary can do the following to introspect itself: > > struct stuff { int a; int b; }; > > extern struct stuff* stuff_start __asm("section$start$__DATA$__my"); > extern struct stuff* stuff_end __asm("section$end$__DATA$__my"); > > void examineSection() { > const struct stuff* p; > for (p = stuff_start; p < stuff_end; ++p) { > // do stuff with p > } > } > > That is,...