similar to: [LLVMdev] How to delete a instruction?

lucefe wrote: > Hi, > > when I delete some instruction, I got some error prompt message. Deleting instructions can be a little tricky. The problem is that you can't delete an instruction until there are no other instructions that are using it. There are two things that you can do: 1) Order your deletions so that the instructions at the end of def-use chains are deleted first;

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'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]

False Alarm!! Still don't know how to do it! I am trying to write a transformation pass to extract a loop body into a function. For example: The Loop in question is: for (i2 = 0; i2 < LOOP_SIZE; i2++) { A[B[i2]] = 2 * B[i2]; } The IR for which is: bb13: ; preds = %bb13, %bb %i2.0.reg2mem.0 = phi i32 [ 0, %bb ], [ %indvar.next62, %bb13 ] ; <i32>

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

I'm attempting to modify a parser generator to emit LLVM code instead of C. So far the experience has been trivial, but I am now running into an error regarding labels that I can't seem to solve. Situation 1: A label is used immediately after a void function call (l6 in this case): <snip> %tmp26 = load i32* @yybegin, align 4 %tmp27 = load i32* @yyend, align 4 call void

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

The following C code : #include <stdio.h> #include <stdlib.h> int TESTE2( int parami , int paraml ,double paramd ) { int varx=0,vary; int nI =0; //varx= parami; if( parami > 0 ) { varx = parami; vary = varx + 1; } else { varx = vary + 1; vary = paraml; } varx = varx + parami + paraml; for( nI = 1 ; nI <= paraml; nI++) { varx =

Sorry! It worked with ExtractBasicBlock() ----- Original Message ----- From: "Mrunal J Shah" <mrunal.shah at gatech.edu> To: "llvmdev" <llvmdev at cs.uiuc.edu> Sent: Saturday, December 6, 2008 8:30:33 PM GMT -05:00 US/Canada Eastern Subject: [LLVMdev] How to extract loop body into a new function? Hi All, I am having trouble extracting loop body into a new

Hi All, I am having trouble extracting loop body into a new function. The ExtractLoop() or ExtractBasicBlock() extracts the entire loop along with the header into a new function. All I want is to extract the body of the loop into a new function(without the header). Is this possible? Thanks, Mrunal

On Oct 27, 2013 2:16 PM, "David Nadlinger" <code at klickverbot.at> wrote: > > 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"

Try breaking the critical edges (-break-crit-edges). This way, a new block will be created between BB13 and BB11 (call this BB11.break) and BB15 and BB12 (call this BB12.break). The predecessors of the dominance frontier will, thus, be BB11.break, BB12.break, and BB14. When we enter through a block with a call to malloc(), we will end up in one of the blocks in the dominance frontier (kind of).

Hi All, I am creating an instrumentation pass using LLVM libraries. I am using clang++ (version 2.9) to compile cpp code into LLVM bit code. When I generate the llvm bit code using clang++ using -O3, I get many instances of instructions that look like the following. br i1 icmp ne (i8* bitcast (i32 (i32)* @pthread_cancel to i8*), i8* null), label %bb23, label %bb25 Here three LLVM instructions

Hi Henrique, I have tried using -mergereturn and inserting a free into the predecessors of dominance frontier of malloc block and it caused double free. It is possible for multiple free's to be inserted on the path from malloc to an exit. For example, in the following CFG: BB10 (malloc) / \ BB11 BB12 ... / \ / \

David Peixotto <dmp <at> rice.edu> writes: > I am seeing the wf loop get optimized just fine with llvm 2.8 (and almost as good with head). I rechecked this and am I actually seeing the same results as you. I think I must have made a stupid mistake in my tests before - sorry for the noise. However, I found that we have a phase ordering problem which is preventing us getting as much

> > It seems that placing the calls to free at the predecessors of dominance > frontier is inadequate. It is possible that there are exit blocks that are > dominated by BB12 (calls to malloc). I guess we can also insert calls to > free at these exit blocks too. That crossed my mind a few minutes later. : ) If you're interested, PRE.cpp existed last at r25315. It calculates the

Hi Henrique, Thanks for the quick reply! On Tue, Nov 12, 2013 at 9:13 PM, Henrique Santos < henrique.nazare.santos at gmail.com> wrote: > PRE normally uses a latest placement algorithm to do something of the sort. > I don't know about GVN/PRE, but older version of PRE might have it. > Just placing the calls to free at the predecessors (dominated by BB12) of > the dominance

PRE normally uses a latest placement algorithm to do something of the sort. I don't know about GVN/PRE, but older version of PRE might have it. Just placing the calls to free at the predecessors (dominated by BB12) of the dominance frontier of BB12 seems to work, however. Is there anything wrong with this? H. On Tue, Nov 12, 2013 at 11:30 PM, Bin Tzeng <bintzeng at gmail.com> wrote: