similar to: [RFC] A proposal for byval in a world with opaque pointers

> Do all tests need it? Align is just for non-default alignment (> align(1)) so it may be OK for the tests to omit it & it's probably not right to /require/ an align attribute on a byval parameter. I've had to fix some of the tests which checked that the right alignment was applied, by looking at the generated asm, but had no "align A" attributes and relied on the

2016-01-20 1:11 GMT+02:00 Antoine Pitrou via llvm-dev < llvm-dev at lists.llvm.org>: > On Wed, 20 Jan 2016 00:47:56 +0200 > "Eddy B. via llvm-dev" <llvm-dev at lists.llvm.org> wrote: > > > > I would love to know your thoughts on this, and more specifically: > > Which of the 3 (byval(T), byval(N) and byval + dereferenceable + align) > > do you

Moving this to llvm-dev where I should've sent it in the first place (& +Chandler, because we discussed this offline a bit) On Thu, Feb 19, 2015 at 11:32 AM, Reid Kleckner <rnk at google.com> wrote: > On Thu, Feb 19, 2015 at 10:57 AM, David Blaikie <dblaikie at gmail.com> > wrote: > >> >> >> On Thu, Feb 19, 2015 at 8:31 AM, Rafael Espíndola <

On Mon, Mar 9, 2015 at 12:38 PM, Reid Kleckner <rnk at google.com> wrote: > If we're keeping types on GEP, > You mean rather than just dropping gep entirely & doing manual pointer arithmetic? (& moving inbounds to an attribute on pointer addition, I guess?) > then IMO we should keep them on allocas and globals. It keeps the IR human > readable. > & what of

On Wed, Mar 16, 2016 at 11:00 AM, Ehsan Amiri <ehsanamiri at gmail.com> wrote: > David, > > Could you give us an update on the status of typeless pointer work? How > much work is left and when you think it might be ready? > It's a bit of an onion peel, really - since it will eventually involve generalizing/fixing every optimization that's currently leaning on typed

Back to the discussion on the RFC, I still see some advantage in following the proposed solution. I see two paths forward: 1- Change canonical form, possibly lower memcpy to non-integer load and store in InstCombine. Then teach the backends to convert that to integer load and store if that is more profitable. Notice that we are talking about loads that have no use other than store. So it is a

On Wed, Mar 16, 2016 at 8:34 AM, Mehdi Amini via llvm-dev < llvm-dev at lists.llvm.org> wrote: > Hi, > > How do it interact with the "typeless pointers" work? > Right - the goal of the typeless pointer work is to fix all these bugs related to "didn't look through bitcasts" in optimizations. Sometimes that's going to mean more work (because the code

I don't know enough about the tradeoff for 1, but 2 seems like a bandaid for something that is not a correctness issue neither a regression. I'm not sure it justifies "bandaid patches" while there is a clear path forward, i.e. typeless pointers, unless there is an acknowledgement that typeless pointers won't be there before a couple of years. -- Mehdi > On Mar 22, 2016,

I'd phrase this differently: being pointer-bitcast agnostic is a step towards support typeless pointers. :) We can either become bitcast agnostic all in one big change or incrementally. Personally, I'd prefer the later since it reduces the risk associated with enabling typeless pointers in the end. Philip On 03/22/2016 12:16 PM, Mehdi Amini via llvm-dev wrote: > I don't know

I don't really mind, but the intermediate stage will not be very nice: that a lot of code / tests that needs to be written with bitcast, and all of that while they are deemed to disappear. The added value isn't clear to me considering the added work. I'm not sure it wouldn't add more work for all the cleanup required by the "typeless pointer", but I'm not sure

Eric Christopher wrote: > How are you trying to call it? Do you have a DataLayout? In test/Analysis/ValueTracking/memory-dereferenceable.ll, just change byval to dereferenceable(8), and %dparam won't match (see lib/IR/Value.cpp:521 for the logic that is supposed to fire). How do I get it to pass? I tried introducing a target-triple and target-datalayout, but it didn't help.

I feel very strongly that blocking work on making optimization bitcast-ignorant on the typeless pointer work would be a major mistake. Unless we expected the typeless pointer work to be concluded within the near term (say 3-6 months maximum), we should not block any development which would be accepted in the typeless pointer work wasn't planned. In my view, this is one of the largest

Ultimately everything is going to be made to not rely on the types of pointers - that's nearly equivalent to bitcast-ignorant (the difference being that the presence of an extra instruction (the bitcast) might trip up some optimizations - but the presence of the /type/ information implied by the bitcast should not trip up or be necessary for optimizations (two sides of the same coin)) If

This is roughly what I wrote... > On Mar 22, 2016, at 1:31 PM, Philip Reames <listmail at philipreames.com> wrote: > > I feel very strongly that blocking work on making optimization bitcast-ignorant on the typeless pointer work would be a major mistake. Unless we expected the typeless pointer work to be concluded within the near term (say 3-6 months maximum), we should not block

----- Original Message ----- > From: "Mehdi Amini via llvm-dev" <llvm-dev at lists.llvm.org> > To: "Philip Reames" <listmail at philipreames.com>, "David Blaikie" > <dblaikie at gmail.com> > Cc: "llvm-dev" <llvm-dev at lists.llvm.org>, uweigand at de.ibm.com, "Tom > Stellard" <thomas.stellard at

But not what David was stating, unless I misread? I was specifically responding to David's wording: "If we're talking about making an optimization able to ignore the bitcast instructions - yes, that work is unnecessary & perhaps questionable given the typeless pointer work. Not outright off limits, but the same time might be better invested in moving typeless pointers

I wanted to mention that I'm planning to start writing and sending out patches for this. Naming the attribute 'alloca' was really confusing, so I'd like to change it to 'inalloca', which follows the preposition pattern of inreg and byval. After discussion, we decided it was silly to add stackbase uses to alloca instructions. They should stay simple. Instead, we'll

>> So at a high level I think we should put the serialization and Instruction >> changes in sooner rather than later, giving us a largely undocumented[2] dialect >> of IR with opaque pointers that we can write tests against to upstream the rest >> of what I've done (and others can use to continue work in parallel if they're >> inclined). > > My,

Hello, In my LLVM frontend (CLR/MSIL), I am currently using first-class aggregates to represent loaded value types on the "CLR stack". However, I noticed that when calling external method taking those aggregate by value, they were not passed as I expected: %COLORREF = type { i8, i8, i8, i8 } declare i32 @SetLayeredWindowAttributes(i8*, %COLORREF, i8, i32) I call this function with

Sorry I should have been more clear (writing to many email in parallel) You're right. I was adding a +1 to you here. Especially I wrote "unless there is an acknowledgement that typeless pointers won't be there before a couple of years" with the PassManager in mind, and I was expecting from David some good indication of a timeframe for the typeless pointers. If the typeless