similar to: [LLVMdev] LLVM-GCC generating too much code from inline assembly

You may find it helpful to reference http://www.ibiblio.org/gferg/ldp/GCC-Inline-Assembly-HOWTO.html. In particular, the information regarding clobbers and constraints. Generally speaking, it's best not to use inline assembly at all. What are you trying to do that you find it necessary? On Mar 16, 2010, at 12:30 AM, Fred / Kettch wrote: > Hi, > > I recently switched to LLVM-GCC

Yeah, I used that document as a reference to rewrite all the assembly blocks that were failing, but since the code is pretty central to my software, I'd like to be able to revert to the old code (that GCC 4.2 was producing right) if I need to check for differences between the two, or just if other problems arise... In my case, I absolutely need inline asm, since I'm writing

Hello Mentors, I am currently finding bug in Local Function related optimization due to which runtime failures are observed in some test cases, as those test cases are containing very large function with recursion and object oriented code so I am not able to find a pattern which is causing failure. So I tried following simple case to understand expected behavior from this optimization. Consider

Hello, Nathan > or if it should be a configure test, which might be safer. Are there > any x86 platforms (other than apple) that don't need PLT-indirect calls? Yes, mingw. However just tweaking the define is not enough - we're not loading address of GOT into ebx before the call (on 32 bit ABIs) thus the call will be to nowhere. -- With best regards, Anton Korobeynikov Faculty of

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

I don't know how to file a PR, but I have a patch (see below), that should work regardless of abi differences, since it relies on the compiler to do the though job. void X86CompilationCallback_SSE(void) { char * SAVEBUF= (char*) alloca(64+12); // alloca is 16byte aligned asm volatile ( "movl %%eax,(%0)\n" "movl %%edx,4(%0)\n" // Save EAX/EDX/ECX

Hi all, I'm having some trouble with inline asm expressions, more specifically how to create the right FunctionType for a given constraint set. So far it has worked well for inputs, but not for outputs. The inline asm support in this language (which is D, LLVMDC[1]) is through asm *statements*. I never have inline asm *expressions*, and outputs are always via memory. I D my test looks like

Hello, Corrado > Before you can correctly invoke a function via the Procedure Linkage > Table (plt), the ABI mandates that ebx is pointing to the GOT (Global > Offset Table) (see http://www.greyhat.ch/lab/downloads/pic.html) This is known issue, just nobody realized, that we have bunch of non- PIC-aware assembler code. :) Fixing would be not so trivial though, mostly due to ABI

Hello. I found that the X86CompilationCallback_SSE wrapper for X86CompilationCallback2 is not setting up properly for the PIC invocation. Before you can correctly invoke a function via the Procedure Linkage Table (plt), the ABI mandates that ebx is pointing to the GOT (Global Offset Table) (see http://www.greyhat.ch/lab/downloads/pic.html) Dump of assembler code for function

Hello, I have an issue with the llvm optimizations. I need to create object codes. the -ON PURPOSE poor && useless- code : --------------------------------------------------- #include <stdio.h> #include <stdlib.h> int ci(int a){ return 23; } int flop(int a, char ** c){ a += 71; int b = 0; if (a == 56){ b = 69; b += ci(a); } puts("ok"); return a +

Hi all, I've encountered a couple of minor build issues on Solaris that have crept in since 2.5, fixes below: 1. In lib/Target/X86/X86JITInfo.cpp, there is: // Check if building with -fPIC #if defined(__PIC__) && __PIC__ && defined(__linux__) #define ASMCALLSUFFIX "@PLT" #else #define ASMCALLSUFFIX #endif Which causes a link failure due to the non-PLT

On Fri, Jun 6, 2008 at 6:32 AM, Tomas Lindquist Olsen <tomas.l.olsen at gmail.com> wrote: > Hi all, > > I'm having some trouble with inline asm expressions, more specifically > how to create the right FunctionType for a given constraint set. > So far it has worked well for inputs, but not for outputs. The inline > asm support in this language (which is D, LLVMDC[1]) is

On Sun, Aug 5, 2018 at 5:49 PM, Dimitry Andric <dimitry at andric.com> wrote: > On 3 Aug 2018, at 13:37, Hans Wennborg via Release-testers <release-testers at lists.llvm.org> wrote: >> >> 7.0.0-rc1 was just tagged (from the branch at r338847). >> >> It's early in the release process, but I'd like to find out what the >> status is of the branch

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

Hi all, I've been looking at finding common ground between the VMI, Xen and other paravirtualization approaches, and after some discussion, we're getting somewhere. These first two patches are the fundamentals, stolen mainly from the VMI patches: removing assumptions about the kernel running in ring 0, and macro-izing all the obvious para-virtualize-needing insns. The third patch is

Hi all, I've been looking at finding common ground between the VMI, Xen and other paravirtualization approaches, and after some discussion, we're getting somewhere. These first two patches are the fundamentals, stolen mainly from the VMI patches: removing assumptions about the kernel running in ring 0, and macro-izing all the obvious para-virtualize-needing insns. The third patch is

On Mon, Jun 5, 2017 at 1:34 PM, Nikodemus Siivola < nikodemus at random-state.net> wrote: > Uh. Turns out that if I hide the pointer to @foo from LLVM by passing it > through an opaque identity function ... then everything works fine. > > Is this a bug in LLVM or is there some magic involving globals I'm > misunderstanding? > This looks like a bug in the handling of

On Sep 21, 2010, at 2:45 PMPDT, John Thompson wrote: > fatal error: error in backend: Ran out of registers during register allocation! > Please check your inline asm statement for invalid constraints: > INLINEASM <es:>, 0, 10, %reg16396<def>, 10, %reg16397<def>, 10, %reg16398<def>, 10, %reg16399<def>, 10, %reg16400<def>, 10, %reg16401<def>,10,

Dale, Sorry, I see you did say I should run the gcc tests. I apologize for forgetting this. I'll work on getting them to run here. Chris et. all, I have a fix for the assertion failure in the enclosed llvmmultalt8.patch file. I didn't realize the input constraints could have different numbers of alternatives from the outputs, which now makes sense. The pr20314-2.c file now compiles

Hi all, I'm working on using LLVM as a back-end for the Haskell GHC compiler. As part of that work I have modified LLVM to include a new custom calling convention for performance reasons as outlined previously in a conversation on this mailing list: http://nondot.org/sabre/LLVMNotes/GlobalRegisterVariables.txt This custom calling convention on x86-32 needs to handle just 4 parameters,