similar to: [LLVMdev] Question to Chris

Thank you, Bill. Seems to be better. Anyway...Is there a way I can do what you showed for me? Thanks, Seung J. Lee ---- Original message ---- >Date: Sat, 26 Jan 2008 22:10:01 -0800 >From: Bill Wendling <isanbard at gmail.com> >Subject: Re: [LLVMdev] Question to Chris >To: LLVM Developers Mailing List <llvmdev at cs.uiuc.edu> > >On Jan 26, 2008, at 9:48 AM, Seung

Hi Seung, It should be fairly straight-forward to do in LLVM. Once you identify the loops, then identify the PHI nodes that you need to convert, then apply the transformation below. The fine details on how to create an instruction and replace one instruction with another are documented in the docs section and in other code. :-) One thing to be careful of, if you convert a variable like

Bill, Depending on what Seung's problem is, converting *out* of SSA form may actually be the wrong thing to do. Seung needs to explain exactly problem he is unable solve using SSA form. --Vikram http://www.cs.uiuc.edu/~vadve http://llvm.org/ On Jan 28, 2008, at 1:10 AM, Bill Wendling wrote: > Hi Seung, > > It should be fairly straight-forward to do in LLVM. Once you

Hello, guys. I am trying to construct higher-level 'for' from the low-level LLVM bitcode(ver 1.9). It's partly successful thanks to David A. Greene's advice suggested to use Control Dependence Graph(CDG). I could find which BB contributes to form which loop with CDG. For example, for this simple function: ----------------------------------------------------------- void bsloop(int

So my best bet is to try and work in reg2mem mode and then go back to mem2reg? I'm curious, it seems though when you split a block that the phis get updated, right? On Thu, Feb 2, 2012 at 5:05 PM, Eric Christopher <echristo at apple.com> wrote: > Not that I'm aware of. > > -eric > > On Feb 2, 2012, at 3:47 PM, Ryan Taylor wrote: > > So essentially I'm

---------- Forwarded message ---------- From: Ryan Taylor <ryta1203 at gmail.com> Date: Mon, Feb 6, 2012 at 10:36 AM Subject: Re: [LLVMdev] Updating PHI for Instruction Domination? To: Eric Christopher <echristo at apple.com> Since I'm not sure which instructions I might want to replicate, would it be possible to cast the Value from "PHINode::getIncomingValue" to

Hi all, I have problem with ExtractCodeRegion (CodeExtractor.cpp). My original program is as follows. bb: ... %tmp.15 = load %struct.MYSQL_ROWS** %3, align 4 ... bb1: ... %tmp.1 = load %struct.MYSQL_ROWS** %6, align 4 ... bb4: ; preds = %bb1, %bb, %entry %tmp.0 = phi %struct.MYSQL_ROWS* [ null, %entry ], [ %tmp.15, %bb ], [ %tmp.1, %bb1 ]

On May 22, 2014, at 3:51 PM, Chandler Carruth <chandlerc at google.com> wrote: > > On Thu, May 22, 2014 at 4:42 PM, Louis Gerbarg <lgg at apple.com> wrote: > The problem that the above transform is technically illegal because “When indexing into a (optionally packed) structure, only i32 integer constants are allowed (when using a vector of indices they must all be the same

Dear All, Is there a pass (or set of passes) that will replace a phi whose input operands all compute the same value with an instruction that computes that value? In other words, something that will convert: define internal i32 @function(i32 %x) { ... bb1: %y = add %x, 10 ... bb2: %z = add %x, 10 ... bb3: %phi = [bb1, %y], [bb2, %z] into define internal i32 @function(i32 %x) { ... bb1: ...

I guess I didn't have a clear question. Suppose we have BB1 and BB2 both point to BB3. BB1 has variable x. BB2 also as variable x. BB3 will have PHINode for x with 2 value from BB1 and BB2. BB1 BB2 \ / BB3 Now if BB1 and BB2 is extracted into a function (using ExtractCodeRegion), they will be replaced by a basic block called codeRepl (which has a call to the extracted

On Feb 2, 2012, at 5:13 PM, Ryan Taylor wrote: > So my best bet is to try and work in reg2mem mode and then go back to mem2reg? > I wouldn't. That sounds painful. > I'm curious, it seems though when you split a block that the phis get updated, right? Sure. There's code in splitBasicBlock to do this. It should just take a little bit of work to get what you want done.

I guess not since Value is a superclass of Instruction. On Mon, Feb 6, 2012 at 10:36 AM, Ryan Taylor <ryta1203 at gmail.com> wrote: > > > ---------- Forwarded message ---------- > From: Ryan Taylor <ryta1203 at gmail.com> > Date: Mon, Feb 6, 2012 at 10:36 AM > Subject: Re: [LLVMdev] Updating PHI for Instruction Domination? > To: Eric Christopher <echristo at

You're creating a new path that doesn't include L. For all values defined in L and used outside of L, you need to determine the new reaching def. That's specific to your transformation and can't be automated. Once you do that, creating the phi in F is natural. -Andy On Feb 6, 2012, at 11:51 AM, Ryan Taylor <ryta1203 at gmail.com> wrote: > I guess not since Value is a

On 01/26/2011 07:50 PM, Vu Le wrote: > I guess I didn't have a clear question. > > Suppose we have BB1 and BB2 both point to BB3. > BB1 has variable x. BB2 also as variable x. > BB3 will have PHINode for x with 2 value from BB1 and BB2. > BB1 BB2 > \ / > BB3 > > Now if BB1 and BB2 is extracted into a function > (using ExtractCodeRegion), they

>> all the zero paths from entry to %a pass by %b. > > > That is a graph-wise definition, sure. > So, this is an interesting definition, and maybe this is part of the source > of the problem. > > For SSA, at least GCC requires that both "definition block dominates use > block" (which would be true here), *and* > that "definition appears before use in

On Fri, Jun 28, 2019 at 3:35 PM James Y Knight <jyknight at google.com> wrote: > On Fri, Jun 28, 2019 at 5:53 PM Bill Wendling <isanbard at gmail.com> wrote: > >> On Fri, Jun 28, 2019 at 1:48 PM James Y Knight <jyknight at google.com> >> wrote: >> >>> On Fri, Jun 28, 2019 at 3:00 PM Bill Wendling <isanbard at gmail.com> >>> wrote:

On Mon, Jul 1, 2019 at 6:25 PM Finkel, Hal J. <hfinkel at anl.gov> wrote: > On 7/1/19 1:38 PM, Bill Wendling via llvm-dev wrote: > > On Fri, Jun 28, 2019 at 3:35 PM James Y Knight <jyknight at google.com> > wrote: > >> On Fri, Jun 28, 2019 at 5:53 PM Bill Wendling <isanbard at gmail.com> wrote: >> >>> On Fri, Jun 28, 2019 at 1:48 PM James Y

Hi I am developing some machine function pass. I want to split MachineBasicBlcok when I find some specific machine instruction. But I don't insert or delete any machine instruction. I just "simply" , "purely" split the MachineBasicBlcok. (So, I stole the idea from ARM64BranchRelaxation::splitBlockBeforeInstr.) This is my code : // I would pass call instruction to

Hi John, On 30/07/13 16:12, John Criswell wrote: > Dear All, > > Is there a pass (or set of passes) that will replace a phi whose input operands > all compute the same value with an instruction that computes that value? In > other words, something that will convert: > > define internal i32 @function(i32 %x) { > ... > bb1: > %y = add %x, 10 > ... > bb2: > %z

Dear all, I'm working on an exploratory backend on llvm. In the instruction set I'm using I have an instruction (called DECJNZ) that decrements a register and, if the decremented value is not zero, jumps (with a relative jump) to a given offset. I've described in tablegen this instruction as follow: def DECJNZ : Instruction { let Namespace = "MyTarget"; let