similar to: RFC: module flag for hosted mode

+Eric and Akira (for thoughts on module flags) > On 2016-Sep-16, at 12:47, Mehdi Amini <mehdi.amini at apple.com> wrote: > >> On Sep 16, 2016, at 12:30 PM, Peter Collingbourne <peter at pcc.me.uk> wrote: >> >> In PR30403 we've been discussing how to encode -ffreestanding when using LTO. This bit is currently dropped during LTO because its only

(summarising IRC) Rethinking a little, I would be inclined to agree that combined hosted and freestanding modules should not be compiled in hosted mode. Here's one scenario where we may break: suppose I LTO-link an implementation of memset compiled with -ffreestanding with a program compiled with -fhosted. With the proposed rule, the loop idiom recognizer may transform the body of the memset

On 27.10.2012, at 18:24, Benjamin Kramer <benny.kra at gmail.com> wrote: > > On 27.10.2012, at 18:15, Sean Silva <silvas at purdue.edu> wrote: > >> How does this affect freestanding implementations? > > This transform is disabled with -fno-builtin or -ffreestanding. Thinking a bit more about this, it looks like the way -ffreestanding is implemented in clang is

> On Aug 7, 2014, at 4:12 AM, Anton Korobeynikov <anton at korobeynikov.info> wrote: > >> I downloaded the latest NDK (r10) and compiled with the following cmd: >> arm-linux-androideabi-clang myMemcpy.c -S -fno-builtin -o0 >> It still produces assembly with a call to "memcpy". Maybe the -fno-builtin >> is broken also in the latest release. >

On Tue, May 29, 2012 at 9:16 PM, Chandler Carruth <chandlerc at google.com>wrote: > > How do I disable that feature? I've tried -fno-builtin and/or >>> -ffreestanding >>> > with no success. >>> clang (as well as gcc) requires that freestanding environment provides >>> memcpy, memmove, memset and memcmp. >>> >>> PS: Consider

On Tue, May 29, 2012 at 9:40 PM, Chandler Carruth <chandlerc at google.com>wrote: > > How do I disable that feature? I've tried -fno-builtin and/or >>>>> -ffreestanding >>>>> > with no success. >>>>> clang (as well as gcc) requires that freestanding environment provides >>>>> memcpy, memmove, memset and memcmp.

On Tue, May 29, 2012 at 8:46 PM, Anton Korobeynikov <anton at korobeynikov.info > wrote: > > How do I disable that feature? I've tried -fno-builtin and/or > -ffreestanding > > with no success. > clang (as well as gcc) requires that freestanding environment provides > memcpy, memmove, memset and memcmp. > > PS: Consider emailing cfedev, not llvmdev. > Hi,

On Tue, May 29, 2012 at 10:50 AM, Chandler Carruth <chandlerc at google.com> wrote: > On Tue, May 29, 2012 at 10:46 AM, Dmitry Vyukov <dvyukov at google.com> wrote: >> >> On Tue, May 29, 2012 at 9:40 PM, Chandler Carruth <chandlerc at google.com> >> wrote: >>>>>>> >>>>>>> > How do I disable that feature? I've

On Tue, May 29, 2012 at 10:46 AM, Dmitry Vyukov <dvyukov at google.com> wrote: > On Tue, May 29, 2012 at 9:40 PM, Chandler Carruth <chandlerc at google.com>wrote: > >> > How do I disable that feature? I've tried -fno-builtin and/or >>>>>> -ffreestanding >>>>>> > with no success. >>>>>> clang (as well as gcc)

On Tue, May 29, 2012 at 11:11 AM, Jeffrey Yasskin <jyasskin at googlers.com>wrote: > On Tue, May 29, 2012 at 10:50 AM, Chandler Carruth <chandlerc at google.com> > wrote: > > On Tue, May 29, 2012 at 10:46 AM, Dmitry Vyukov <dvyukov at google.com> > wrote: > >> > >> On Tue, May 29, 2012 at 9:40 PM, Chandler Carruth <chandlerc at google.com >

The discussion of malloc optimization from two (three?) weeks ago prompts me to be concerned about implications for kernel compilation. Basically, I have two questions: 1. The particular optimization that was done there was based on the compiler substituting an alternate implementation of malloc(). This may not be appropriate in kernel or deeply embedded systems. Is there a way for someone who is

New clang versions need the '-ffreestanding' flag because new changes convert system calls to their unlocked versions, which don't exist in the kernel library. Signed-off-by: Bill Wendling <morbo at google.com> diff --git a/scripts/Kbuild.klibc b/scripts/Kbuild.klibc index f500d535..9cf4b2d9 100644 --- a/scripts/Kbuild.klibc +++ b/scripts/Kbuild.klibc @@ -67,7 +67,8 @@ include

On Tue, May 29, 2012 at 10:28 AM, Dmitry Vyukov <dvyukov at google.com> wrote: > On Tue, May 29, 2012 at 9:16 PM, Chandler Carruth <chandlerc at google.com>wrote: > >> > How do I disable that feature? I've tried -fno-builtin and/or >>>> -ffreestanding >>>> > with no success. >>>> clang (as well as gcc) requires that

> 1. The particular optimization that was done there was based on the > compiler substituting an alternate implementation of malloc(). This may > not be appropriate in kernel or deeply embedded systems. Is there a way > for someone who is building that sort of system to enable/disable the > builtin library magic selectively? -ffreestanding > I assume that LLVM can support

On Tue, May 29, 2012 at 9:50 PM, Chandler Carruth <chandlerc at google.com>wrote: > > How do I disable that feature? I've tried -fno-builtin and/or >>>>>>> -ffreestanding >>>>>>> > with no success. >>>>>>> clang (as well as gcc) requires that freestanding environment >>>>>>> provides

> How do I disable that feature? I've tried -fno-builtin and/or -ffreestanding > with no success. clang (as well as gcc) requires that freestanding environment provides memcpy, memmove, memset and memcmp. PS: Consider emailing cfedev, not llvmdev. -- With best regards, Anton Korobeynikov Faculty of Mathematics and Mechanics, Saint Petersburg State University

On Tue, May 29, 2012 at 9:52 AM, Dmitry Vyukov <dvyukov at google.com> wrote: > On Tue, May 29, 2012 at 8:46 PM, Anton Korobeynikov < > anton at korobeynikov.info> wrote: > >> > How do I disable that feature? I've tried -fno-builtin and/or >> -ffreestanding >> > with no success. >> clang (as well as gcc) requires that freestanding environment

Even with -ffreestanding LLVM generates memcpy/memset? Does this mean some passes do not honor this flag? If you really wanted to prevent libcalls, you could technically translate those memcpy/memset to loops in lowering. Kevin On Sat, Oct 15, 2016 at 4:10 PM, Wolfgang McSneed via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Hi Mehdi and Joerg, > > Thanks for your fast

Hi, I have the following program: // test.c #include <stdlib.h> struct foo_t { int x[1024]; }; __thread struct foo_t g_foo; void bar(struct foo_t* foo) { g_foo = *foo; } int main() { struct foo_t* f = (struct foo_t*)malloc(sizeof(struct foo_t)); bar(f); return 0; } When I compile it with clang I see that it inserts memcpy() in function bar(): $ clang -v clang version 3.2 (trunk

On Sat, Oct 15, 2016 at 04:01:36PM -0700, Mehdi Amini via llvm-dev wrote: > > > On Oct 15, 2016, at 3:56 PM, Wolfgang McSneed via llvm-dev <llvm-dev at lists.llvm.org> wrote: > > > > Hi, > > > > I am hoping that someone can help me figure out how to prevent the insertion of "memcpy" from the assembly source. > > > > My target is an