similar to: [LLVMdev] Misc optimization issue

Hi, Seems pass scalar-evolution+indvars fail to get the loop trip count of the following case: int foo(int x, int y, int lam[256], int alp[256]) { int i; int z = y; for (i = 255; i >= 0; i--) { z += x; lam[i] = alp[i]; } return z; } The final optimized ll code is : define i32 @foo(i32 %x, i32 %y, i32* %lam, i32* %alp) nounwind { entry: br label %bb bb:

Hi, I would like some help regarding the LSR pass. It seems that it likes to duplicate address calculations as in the case above, which is highly undesirable on my target. I wonder if there is any way to tell LSR to not duplicate the code in cases like this? Or could I perhaps run CSE after LSR again? What is the logic behind this transformation? It seems that a LSR pass should not insert a

Ok. Let me describe the problem again in some detail. The following is the original bitcode from a real testcase: bb7: %46 = load i32* %j, align 4 %47 = add nsw i32 %46, 1 store i32 %47, i32* %j, align 4 br label %bb8 To protect the operand of the store I duplicate the input chain of operands and insert a comparison to check whether the operand of the stores are correct. As a result of

Hi, I'm using LLVM 2.7 right now, and I found "opt -std-compile-opts" has missed some opportunities for optimization: define void @spa.main() readonly { entry: %tmp = load i32* @dst-ip ; <i32> [#uses=3] %tmp1 = and i32 %tmp, -16777216 ; <i32> [#uses=1] %tmp2 = icmp eq i32 %tmp1, 167772160 ; <i1> [#uses=2]

On Jun 29, 2010, at 7:08 AM, ether zhhb wrote: > > why computeSCEVAtScope not try to get the operands in the current > scope like the function do with SCEVCommutativeExpr, like: > > if (const SCEVAddRecExpr *AddRec = dyn_cast<SCEVAddRecExpr>(V)) { > if (!L || !AddRec->getLoop()->contains(L)) { > ... > // Then, evaluate the AddRec. >

hi all, i have SCEVAddRec {{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1> where Loop0 and Loop1 are brothers (loops at the same level of the loopnest), and Loop0 have a computable backedge taken count. when i call getSCEVAtScope({{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1> , Loop1), it just give me a {{(32 + @edge.8265),+,32}<Loop0>,+,4}<Loop1>, instead of

Dear all, after optimizing a small LLVM example program (i.e., with opt -O3), the resulting code contains several basic blocks, which I consider identical or redundant. For instance, return: ; preds = %min.exit ret i32 0 bb15: ; preds = %min.exit ret i32 0 or, bb7.i:

Hello, I've come across another example: I'm compiling with clang -S -emit-llvm -std=gnu99 -O3 clang version 2.9 (trunk 118238) Target: x86_64-unknown-linux-gnu Thread model: posix I take the code: int loops(int x) { int ret = 0; for(int i = 0; i < x; i++) { for(int j = 0; j < x; j++) { ret += 1; } } return ret; } and the

I would like to be able to instrument va_arg, but when I generate a bc file for a test case using: llvm-gcc -O3 -emit-llvm vararg.c -c -o vararg.bc I do not see va_arg. Instead, it seems the args are accessed through %struct.__va_list_tag, which makes things a bit trickier to instrument. Is there a way to force llvm-gcc to use va_arg? Perhaps there is some documentation about va_list_tag or

The branch folding pass does this, but it operates later, on the target-dependent form in llc. On May 8, 2010, at 8:48 AM, Heinz Riener wrote: > Dear all, > > after optimizing a small LLVM example program (i.e., with opt -O3), > the > resulting code contains several basic blocks, which I consider > identical > or redundant. For instance, > > return:

Would it make sense to have a similar pass that operates on llvm main IR? On Sat, May 8, 2010 at 5:15 PM, Dale Johannesen <dalej at apple.com> wrote: > The branch folding pass does this, but it operates later, on the > target-dependent form in llc. > > On May 8, 2010, at 8:48 AM, Heinz Riener wrote: > >> Dear all, >> >> after optimizing a small LLVM example

Hello. I have a problem which is quite basic for array optimization, amd I wonder whether I am missing something, but I could not find the LLVM pass that does it. Consider the following code snippet: int test() { int mat[7][7][7]; int i,j,k,sum=0; for(i=0;i<7;i++){ for(j=0;j<7;j++){ for(k=0;k<7;k++){ sum+=mat[i][j][k]^mat[i][j][k^1]; } } } return

Eugene Toder wrote: > Would it make sense to have a similar pass that operates on llvm main IR? > The unify exit return node (-mergereturn?) pass should take care of the first example. The -simplifycfg option might take care of the second example. Both work on LLVM IR. -- John T. > On Sat, May 8, 2010 at 5:15 PM, Dale Johannesen <dalej at apple.com> wrote: > >>

[+Arnold] > On Jun 10, 2015, at 1:29 PM, Sanjoy Das <sanjoy at playingwithpointers.com> wrote: > > [+CC Andy] > >> Can anyone familiar with ScalarRevolution tell me whether this is an >> expected behavior or a bug? > > Assuming you're talking about 2*k, this is a bug. ScalarEvolution > should be able to prove that {0,+,4} is <nsw> and

---------- 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,

The following piece of IR is a fixed point for opt -std-compile-opts/-O3: --- target datalayout = "e-p:64:64:64-S128-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f16:16:16-f32:32:32-f64:64:64-f128:128:128-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64" target triple = "x86_64-unknown-linux-gnu" ; Function Attrs: nounwind readonly define i32 @get32Bits(i8*

Hello, I want to compile a LLVM file into an executable running on ARM platform. I use LLVM 2.0 with the following command lines: llvm-as -f -o test.bc test.ll llc -march=arm -mcpu=arm1136j-s -mattr=+v6 -f -o test.s test.bc arm-linux-gnu-as -mcpu=arm1136j-s test.s With the last command, I obtain the following error: rd and rm should be different in mul The bad instruction is

Hi Mikael, You are obtaining warning, not an error, right? The most arm cores, including arm1136, can execute mul with rd = rm. So, you can ignore this warning. Lauro 2007/6/12, Peltier, Mikael <m-peltier at ti.com>: > > > > > Hello, > > > > I want to compile a LLVM file into an executable running on ARM platform. > > I use LLVM 2.0 with the following

hm.... I think, that is valid in c but next code too doesn't works right: ; ModuleID = 'sample.lz' @.str1 = internal global [6 x i8] c"world\00" ; <[6 x i8]*> [#uses=1] @.str2 = internal global [7 x i8] c"hello \00" ; <[7 x i8]*> [#uses=1] @.str7 = internal global [7 x i8] c"father\00" ; <[7 x i8]*> [#uses=1]

In my ongoing work on refactoring the asmprinters, I've found that PIC16 doesn't put ':' after labels in some cases. Specifically, it looks like basic block labels are emitted without a ':': movwf @__floatunsidf.frame. + 2 movlp .BB1_2 goto .BB1_2 .BB1_2 ; %bb7 movlw 0 banksel @__floatunsidf.frame. but that