search for: nobuiltins

Hi LLVMites! This patch adds the 'nobuiltin' attribute to to LLVM. This is needed during LTO, which right now ignores this attribute and command line flag. I want to make this an IR-level attribute instead of a target-dependent attribute because it's used during IR modification and not code generation. -bw -------------- next part -------------- A non-text attachment was scrubbed...

On Feb 18, 2013, at 1:54 PM, Bill Wendling <wendling at apple.com> wrote: > Hi LLVMites! > > This patch adds the 'nobuiltin' attribute to to LLVM. This is needed during LTO, which right now ignores this attribute and command line flag. I want to make this an IR-level attribute instead of a target-dependent attribute because it's used during IR modification and not code

On Feb 20, 2013, at 8:40 AM, David Blaikie <dblaikie at gmail.com> wrote: > Sure, if you're willing to sacrifice the possible simplification of all indirect calls in any function that has even one nobuiltin requirement. > I don't understand what you mean by this. > 1) annotate calls > Pro: you can inline calls without pessimizing the function you inline into > Con:

On Wed, May 15, 2013 at 7:49 PM, Chandler Carruth <chandlerc at google.com>wrote: > On Wed, May 15, 2013 at 8:31 PM, Richard Smith <richard at metafoo.co.uk>wrote: > >> Hi, >> >> LLVM classifies _Znwm as a builtin by default. After some discussion, the >> C++ core working group have decreed that that is not correct: calls to >> "operator

On Feb 19, 2013, at 10:18 AM, Chris Lattner <clattner at apple.com> wrote: > On Feb 18, 2013, at 10:31 PM, Bill Wendling <wendling at apple.com> wrote: > >>>>> >>>>> In the context of LTO, it makes sense for the attribute to be on function bodies, not on prototypes. >>>>> >>>> Yeah, I noticed that after sending this

On Feb 18, 2013, at 4:45 PM, Chris Lattner <clattner at apple.com> wrote: > > On Feb 18, 2013, at 1:54 PM, Bill Wendling <wendling at apple.com> wrote: > >> Hi LLVMites! >> >> This patch adds the 'nobuiltin' attribute to to LLVM. This is needed during LTO, which right now ignores this attribute and command line flag. I want to make this an

On May 16, 2013, at 12:36 PM, Richard Smith <richard at metafoo.co.uk> wrote: > > > Since it would probably help to quantify the complexity increase, I've implemented my more recent suggestion (patch attached). This patch allows 'nobuiltin' on a function declaration or definition, and adds a 'builtin' attribute which can only be present on a call site for a

On May 15, 2013, at 8:50 PM, Richard Smith <richard at metafoo.co.uk> wrote: >> 1) The 'nobuiltin' attribute doesn't actually prevent the optimization (see recent patch on llvmcommits) >> 2) We can't block the optimization if the call happens through a function pointer, unless we also annotate all calls through function pointers as 'nobuiltin' >>

On Wed, Feb 20, 2013 at 12:39 PM, Chris Lattner <clattner at apple.com> wrote: > On Feb 20, 2013, at 8:40 AM, David Blaikie <dblaikie at gmail.com> wrote: > > Sure, if you're willing to sacrifice the possible simplification of all > indirect calls in any function that has even one nobuiltin requirement. > > I don't understand what you mean by this. > 1)

On Thu, May 16, 2013 at 10:13 AM, Chris Lattner <clattner at apple.com> wrote: > On May 15, 2013, at 10:32 PM, Richard Smith <richard at metafoo.co.uk> wrote: > > Initially, I'm just concerned about keeping the optimizations we already >>> perform, such as globalopt lowering a new/delete pair into a global, while >>> disabling the non-conforming

On Feb 19, 2013, at 1:17 PM, Bill Wendling <wendling at apple.com> wrote: >>>>> Once we have support for the `-fno-builtin-FUNCTION' flag, I expect the attribute to look something like this: >>>>> >>>>> "no-builtin-functions" = "puts,foo,bar" >>>> >>>> I guess this could work, this means that

On Feb 18, 2013, at 4:49 PM, Bill Wendling <wendling at apple.com> wrote: >> Hi Bill, >> >> I think the concept of this patch makes sense, but the implementation does not. >> >> I have: >> >> void foo() { >> printf("hello\n"); >> } >> >> and I build with -fno-builtin-puts. If I understand correctly, *foo* will

On 2/19/2013 12:23 PM, Chris Lattner wrote: > > I think that there is general confusion here about what -fno-builtin does. It is *not* an attribute that affects the definition of builtin functions, it is a statement that the code being compiled in the current translation unit should change behavior. Here are the cases that I see: (1) Nobuiltin attribute on printf, telling the compiler that

On Feb 18, 2013, at 10:31 PM, Bill Wendling <wendling at apple.com> wrote: >>>> >>>> In the context of LTO, it makes sense for the attribute to be on function bodies, not on prototypes. >>>> >>> Yeah, I noticed that after sending this patch. I modified it to check the function CI is in for that attribute. >> >> Was that in the

On 2/18/2013 8:08 PM, Chris Lattner wrote: > > That code is presumably compiled by someone. If whoever compiles it specifies -fno-builtin, the attribute would be added to it. It doesn't affect its clients. After reading the description quoted by Bill, I'm not sure what you mean by attaching the attribute to the function body. Suppose I have my own version of strlen, written in

Hi, LLVM classifies _Znwm as a builtin by default. After some discussion, the C++ core working group have decreed that that is not correct: calls to "operator new" *can* be optimized, but only if they come from new-expressions, and not if they come from explicit calls to ::operator new. We cannot work around this in the frontend by marking the call as 'nobuiltin' for two

On Wed, May 15, 2013 at 8:57 PM, Chris Lattner <clattner at apple.com> wrote: > > On May 15, 2013, at 8:50 PM, Richard Smith <richard at metafoo.co.uk> wrote: > > 1) The 'nobuiltin' attribute doesn't actually prevent the optimization >>>>> (see recent patch on llvmcommits) >>>>> 2) We can't block the optimization if the call

On May 15, 2013, at 10:32 PM, Richard Smith <richard at metafoo.co.uk> wrote: >>> Initially, I'm just concerned about keeping the optimizations we already perform, such as globalopt lowering a new/delete pair into a global, while disabling the non-conforming variations of those optimizations. But we're also permitted to merge multiple allocations into one if they have

On Feb 19, 2013, at 6:50 AM, Krzysztof Parzyszek <kparzysz at codeaurora.org> wrote: > On 2/18/2013 8:08 PM, Chris Lattner wrote: >> >> That code is presumably compiled by someone. If whoever compiles it specifies -fno-builtin, the attribute would be added to it. It doesn't affect its clients. > > After reading the description quoted by Bill, I'm not sure

On Mon, Feb 18, 2013 at 4:49 PM, Bill Wendling <wendling at apple.com> wrote: > On Feb 18, 2013, at 4:45 PM, Chris Lattner <clattner at apple.com> wrote: > > > > > On Feb 18, 2013, at 1:54 PM, Bill Wendling <wendling at apple.com> wrote: > > > >> Hi LLVMites! > >> > >> This patch adds the 'nobuiltin' attribute to to