similar to: [LLVMdev] IR in SSA form?

On 3/29/11 12:26 PM, George Baah wrote: > Hi All, > When I run the following command > llvm-gcc -03 -emit-llvm test.cpp -c -o test.bc or llvm-gcc -emit-llvm > test.cpp -c -o test.bc > > on the program test.cpp, the IR representation is not in SSA form. > I do not see any phi functions. Actually, it is in SSA form (or more precisely, the virtual registers are in SSA form;

But, the mem2reg pass removes all load store instructions. It replaces all variables by their if possible (kind of constant propagation). I have generated the bitcode of the source program and the applied the mem2reg pass and obviously not getting desired thing. What I want is convert it into SSA form without replacing any variable by their constant value. Please elaborate on your point. Also,

Hi, Can anyone tell me, whether it is possible to convert a program into SSA form without considering algebric equivalence ? regards, Chayan

Hello, for some my use case, I'd like to temporary break SSA property and then ask LLVM to restore it. Here's more details: if (i < 0) { i = -i; } This is a C code example. I'm trying to create a value range analysis, which will determine, that after this code, 'i' is non-negative. In SSA form, this will become i = 0; if (i < 0) { i.2 = -i; }

E-path PRE requires the program in SSA form like SSAPRE algorithm. Then it finds the eliminatable path (e-path) for an expression and converts partially redundant to fully redundant and removes redundancy Chayan On Mon, Jun 7, 2010 at 1:58 PM, Eli Friedman <eli.friedman at gmail.com> wrote: > On Sun, Jun 6, 2010 at 8:56 PM, Chayan Sarkar <chayan.ju at gmail.com> wrote: >> Hi

You can use STOREs and LOADs on memory and then use mem2reg pass. 2010/6/1 Chayan Sarkar <chayan.ju at gmail.com>: > Hi, > > Can anyone tell me, whether it is possible to convert a program into > SSA form without considering algebric equivalence ? > > regards, > Chayan > _______________________________________________ > LLVM Developers mailing list > LLVMdev at

On Sun, Jun 6, 2010 at 8:56 PM, Chayan Sarkar <chayan.ju at gmail.com> wrote: > Hi Jeffrey, > > Actually I am trying to implement "E-path PRE" which is based on > non-algebric equivallence. So, the  variable names need to be > preserved. Then why do you want to run mem2reg before your optimization in the first place? -Eli

I am experimenting with LLVM optimizer and found that the bit code file clang emits is already in SSA form, but I want to generate it in non-SSA form. Would you let me know if there is any way of doing it? Cheera,Amruth -------------- next part -------------- An HTML attachment was scrubbed... URL:

Dear All, Could someone tell me how to convert LLVM bytecode into minimal SSA form ? or just depend on GCC frontend ? thanks aqex

Suppose my Input function is like : myfunc(int x,int y){ int a=2, b=3,c=5; if(x>y) { c=a+b; a=6; } else { c=a*b; b=4; } a=c+a; c=a+b; } and the output should be : myfunc(int x,int y){ int a.0=2, b.0=3,c.0=5; if(x>y) { c.1=a.0+b.0; a.1=6; } else { c.2=a.0*b.0; b.1=4; }

Hi Amruth, If you do not specify any optimization flag for 'clang' and do not run 'opt -mem2reg' pass on the generated IR file, it is in non-SSA form. However, many variables stay in memory instead of registers in this case. Thanks, Jiesheng On Wed, Jun 13, 2012 at 1:17 PM, <amruth.rd at knights.ucf.edu> wrote: > I am experimenting with LLVM optimizer and found that

> > Here's 'foo' is always called with positive value. However, the value > range > assigned to 'i' variable can be only [-inf, +inf], because uses of 'i' > outside of condition can get any value. So, I'd like to convert the > above to: > > i = 0; > if (i > 0) { > i = change_value_range(i); > foo(i); > } I

On Sat, Jun 5, 2010 at 2:03 AM, Chayan Sarkar <chayan.ju at gmail.com> wrote: > But, the mem2reg pass removes all load store instructions. It replaces > all variables by their if possible (kind of constant propagation). I > have generated the bitcode of the source program and the applied the > mem2reg pass and obviously not getting desired thing. > > What I want is convert

There is no existing pass to do this in LLVM, mostly because it wouldn't be useful for optimizing programs. From your input, mem2reg produces: define i32 @myfunc(i32 %x, i32 %y) nounwind { entry: %cmp = icmp sgt i32 %x, %y ; <i1> [#uses=1] br i1 %cmp, label %if.then, label %if.else if.then: ; preds = %entry %add = add

llvm-as file.bc | opt -mem2reg | llvm-dis > file.ll On Wed, 2006-01-04 at 09:12 +0800, lizhuo wrote: > meone tell me how to convert LLVM bytecode into minimal SSA form ? > or just depend on GCC frontend ? -------------- next part -------------- A non-text attachment was scrubbed... Name: signature.asc Type: application/pgp-signature Size: 189 bytes Desc: This is a digitally signed

Well, it *is* in SSA form, but it "cheats" by keeping values in memory. --Sean Silva On Wed, Jun 13, 2012 at 2:00 PM, Jiesheng Wei <jwei at ece.ubc.ca> wrote: > Hi Amruth, > > If you do not specify any optimization flag for 'clang' and do not run > 'opt -mem2reg' pass on the generated IR file, it is in non-SSA form. > However, many variables stay

Hi Jeffrey, Actually I am trying to implement "E-path PRE" which is based on non-algebric equivallence. So, the variable names need to be preserved. You said that I need to insert these to preserve variable %a.0 = bitcast i32 2 to i32 So, these need to be inserted before the mem2reg pass or within the pass. In first case, how to call an inbuilt pass after doing some analysis from my

Hi, I am interested in obtaining LLVM IR without any optimization performed on it.( IR obtained from cfrontend's AST). Is this LLVM IR in SSA form? Secondly, I want to make a transformation on this unoptimized IR, and convert it back to C. I believe llc -c does that. Thirdly, is it possible to use LLVM tool suite on LLVM IR that's not in SSA form, if we have such LLVM so.

On Wed, 11 Jan 2006, Reid Spencer wrote: > llvm-as file.bc | opt -mem2reg | llvm-dis > file.ll llvm-as < file.bc | opt -mem2reg | llvm-dis > file.ll Note the extra "<". -Chris > On Wed, 2006-01-04 at 09:12 +0800, lizhuo wrote: >> meone tell me how to convert LLVM bytecode into minimal SSA form ? >> or just depend on GCC frontend ? > -Chris --

Hi Everyone, I am trying to construct the print statement : printf("value:%d\n", value); This is my llvm code. It is seg faulting at builder.CreateGlobalStringPtr(str,""). Thanks. George vector<const Type *> params; params.push_back(Type::getInt8PtrTy(M.getContext())); FunctionType *fType = FunctionType::get(Type::getInt32Ty(M.getContext()), params, true); Constant