Displaying 20 results from an estimated 4000 matches similar to: "[LLVMdev] Data layout of structs"
2010 Nov 17
1
[LLVMdev] Copy Instruction from one Basic block to another
I want to do the following:
suppose the program structure:
bb
/ \
bb1 bb2
\ /
bb3
2012 Jul 25
2
[LLVMdev] Question about an unusual jump instruction
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
2012 Jul 25
0
[LLVMdev] Question about an unusual jump instruction
On Wed, Jul 25, 2012 at 12:48 AM, Michele Scandale
<michele.scandale at gmail.com> wrote:
> 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
2011 Nov 21
1
[LLVMdev] Fwd: Order of Basic Blocks
---------- Forwarded message ----------
From: Ryan Taylor <ryta1203 at gmail.com>
Date: Mon, Nov 21, 2011 at 10:30 AM
Subject: Re: [LLVMdev] Order of Basic Blocks
To: Benjamin Kramer <benny.kra at googlemail.com>
This worked, though the RPO_iterator apparently wasn't what I was looking
for anyways, it seems it doesn't rreally go top->down.
I have a simple example code,
2015 Mar 24
2
[LLVMdev] RFC - Improvements to PGO profile support
Example. Assuming the cap is 'C'
void bar()
{
// ENTRY count is 4*C, after capping it becomes 'C'
...
}
void test()
{
// BB1: count(BB1) = C
bar();
// BB2: count(BB2) = C
bar();
}
void test2()
{
// BB3: count(BB3) = C
bar();
// BB4: count(BB4) = C
bar();
}
What would inliner see here ? When it sees callsite1 -- it might mistaken
that is the
2010 Jul 17
2
[LLVMdev] How to insert a basic block in an edge
Hi all,
Suppose in a CFG bb1 has two succesor bb3 and bb4, and bb3 has two
predecessor bb1 and bb2. Now how can I insert a basic block between
bb1 and bb3 that at the edge bb1-->bb3 .
In general how can I insert a basic block on an edge?
Regards,
Chayan
2010 Jul 18
2
[LLVMdev] How to insert a basic block in an edge
Hi,
I have tried to use SplitEdge function, but failed. Actually the third
parameter is a variable of type Pass and it need to be non-null. But I
could not figure out how to use it. Please help me out.
Regards,
Chayan
On Sat, Jul 17, 2010 at 10:16 PM, Nick Lewycky <nicholas at mxc.ca> wrote:
> Chayan Sarkar wrote:
>>
>> Hi all,
>>
>> Suppose in a CFG bb1 has two
2016 Sep 21
2
Propagation of debug information for variable into basic blocks.
> On Sep 21, 2016, at 2:23 PM, Daniel Berlin <dberlin at dberlin.org> wrote:
>
>
>
> // For all predecessors of this MBB, find the set of VarLocs that
> // can be joined.
> for (auto p : MBB.predecessors()) {
> auto OL = OutLocs.find(p);
> // Join is null in case of empty OutLocs from any of the pred.
> if (OL == OutLocs.end())
>
2010 Jul 20
2
[LLVMdev] How to insert a basic block in an edge
Hi All,
Still I could not figure out how to use Pass* while calling
SplitEdge() function. Can anyone provide me some example?
Regards,
Chayan
On Sun, Jul 18, 2010 at 11:49 PM, Nick Lewycky <nicholas at mxc.ca> wrote:
> Chayan Sarkar wrote:
>>
>> Hi,
>>
>> I have tried to use SplitEdge function, but failed. Actually the third
>> parameter is a variable of
2010 Jul 17
0
[LLVMdev] How to insert a basic block in an edge
Chayan Sarkar wrote:
> Hi all,
>
> Suppose in a CFG bb1 has two succesor bb3 and bb4, and bb3 has two
> predecessor bb1 and bb2. Now how can I insert a basic block between
> bb1 and bb3 that at the edge bb1-->bb3 .
>
> In general how can I insert a basic block on an edge?
Use llvm::SplitEdge in Transforms/Utils/BasicBlockUtils.h.
The technique is to create a new bb with a
2010 Jul 18
0
[LLVMdev] How to insert a basic block in an edge
Chayan Sarkar wrote:
> Hi,
>
> I have tried to use SplitEdge function, but failed. Actually the third
> parameter is a variable of type Pass and it need to be non-null. But I
> could not figure out how to use it. Please help me out.
The only reason it needs a non-NULL Pass* is to call llvm::SplitBlock
which uses P->getAnalysisIfAvailable unconditionally. Feel free to wrap
2011 Jan 25
2
[LLVMdev] Update PHINode after extracting code
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 ]
2010 Jul 21
0
[LLVMdev] How to insert a basic block in an edge
Hi,
I could not figure out, how to declare a Pass*. Can anyone give me an
example, how to use SplitEdge() function ?
Please help me out.
Regards,
Chayan
On Tue, Jul 20, 2010 at 10:12 AM, Chayan Sarkar <chayan.ju at gmail.com> wrote:
> Hi All,
>
> Still I could not figure out how to use Pass* while calling
> SplitEdge() function. Can anyone provide me some example?
>
>
2011 Jan 27
0
[LLVMdev] Update PHINode after extracting code
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
2008 Jan 22
3
[LLVMdev] Walking all the predecessors for a basic block
Hi all,
Is there a way to walk through ALL the predecessors of a basic block
in a CFG. I tried to iterate over the preds using this method
for (pred_iterator PI = pred_begin(BB), E = pred_end(BB); PI != E; ++I) {
BasicBlock *PredBB = *PI;
}
but this only gives the immediate predecessors for a basic block.
For example, in this sample control flow graph.
entry -> bb1 -> bb2 -> bb4
2013 Oct 10
2
[LLVMdev] Are there implicit rules or conventions for an llvm frontend to generate llvm IR?
Hi, this question might be a bit silly: apart from the language
reference(http://llvm.org/docs/LangRef.html#switch-instruction) page, are
there additional rules for a regular llvm frontend to generate llvm IRs?
There are a few cases that I got from clang/llvm-gcc/dragonegg when
compiling *C* source code into llvm IR:
1. It seems that there is ONLY ONE ReturnInst(and NO InvokeInst) for such
llvm
2009 Sep 03
2
[LLVMdev] Non-local DSE optimization
Hi,
It looks like PDT.getRootNode() returns NULL for:
define fastcc void @c974001__lengthy_calculation.
1736(%struct.FRAME.c974001* nocapture %CHAIN.185) noreturn {
entry:
br label %bb
bb:
br label %bb
}
Isn't it a bug in PostDominatorTree?
Please note that this crashes:
opt -postdomtree -debug dom_crash.bc
I think this should be reported as a bug,
-Jakub
On Sep 3, 2009, at
2008 Jan 22
0
[LLVMdev] Walking all the predecessors for a basic block
Hi Pabhat,
Have you checked out DepthFirstIterator? (include/llvm/ADT/
DepthFirstIterator.h). It provides an iterator abstraction to perform
a forward/reverse DFS traversal of a graph.
Many of the LLVM datatypes that represent graphs have a template
specialization of the GraphTraits<> class which allows separate
algorithms to treat them as graphs, walk them, etc. (Both BasicBlock
2009 Sep 06
0
[LLVMdev] Non-local DSE optimization
Jakub Staszak wrote:
> Hi,
>
> It looks like PDT.getRootNode() returns NULL for:
>
> define fastcc void @c974001__lengthy_calculation.
> 1736(%struct.FRAME.c974001* nocapture %CHAIN.185) noreturn {
> entry:
> br label %bb
>
> bb:
> br label %bb
> }
>
>
> Isn't it a bug in PostDominatorTree?
>
> Please note that this crashes:
>
2010 Jun 24
2
[LLVMdev] How to prevent an instruction to be executed more than once?
Hi LLVM-devs,
I am looking for a way to prevent an instruction to be executed more than
once, or duplicated .. I know that by default everything can be duplicated,
but is there a work-around?
The structure of the code is
BB1 BB2
| |
| |
| |
|----------|
|
v
BB3
where the first instruction in BB3 is inserting an inline assembly