similar to: [LLVMdev] About register allocation

Displaying 20 results from an estimated 1000 matches similar to: "[LLVMdev] About register allocation"

2010 Nov 09
0
[LLVMdev] Questions on using Metadata in JIT mode
Hi LLVMdevs, I am trying to get the runtime values of variables (parameters and local variables) in a function running in JIT mode. I generated intrinsic calls to obtain the values of some variables as shown in the definition below. define void @foo(i32 %arg1) { entry: %X = alloca i32, !dbg !3 store i32 21, i32* %X, !dbg !3 %Y = alloca i32, !dbg !3 store i32 22, i32* %Y, !dbg !3
2011 Aug 06
0
[LLVMdev] How to differ from read and write operations for general stack objects
The following is the code fragment after "# *** IR Dump Before Prolog/Epilog Insertion & Frame Finalization ***:". * MOV32mi <fi#2>, 1, %reg0, 0, %reg0, 0 * * MOV32mr <fi#2>, 1, %reg0, 0, %reg0, %ECX<kill>* * %EAX<def> = MOV32rm <fi#2>, 1, %reg0, 0, %reg0* * MOV32mr %reg0, 1, %reg0, <ga:@one+4>, %reg0, %EAX<kill>* * %EAX<def> = MOV32rm
2010 Oct 29
1
[LLVMdev] [LLVMDev] Register Allocation and Kill Flags
I am wondering about register allocation when there is a kill flag on the MachineOperand. Do I need to remove the kill flag? This code below is just an example from test\CodeGen\X86\xor.ll # Machine code for function test3: Frame Objects: fi#-2: size=4, align=4, fixed, at location [SP+8] fi#-1: size=4, align=8, fixed, at location [SP+4] Function Live Outs: %EAX BB#0: derived from LLVM BB
2013 May 13
1
[LLVMdev] Problem with MachineFunctionPass and JMP
Hi ! I'm trying to modify the code in a machine function pass… I added a new basicblock and I want to add a jump to an another BB from my new BB. Here is my code : bool Obfuscation::runOnMachineFunction(MachineFunction &MF) { MachineBasicBlock *newEntry = MF.CreateMachineBasicBlock(); MF.insert(MF.begin(), newEntry); std::vector<MachineBasicBlock*> origBB;
2011 Jan 29
1
[LLVMdev] The type or size of virtual registers in machineinstr
Hi, I want to know what is the type or size of a virtual register in a Machineinstr::MachineOperand (If this MachineOperand is a register). For example, what is the size of reg16385 in the following MachineInstr. I know now in the llvm bitcode, the type of a Instruction could be obtained from the Value::GetType(), but what is the counterpart in MachineInstr (not derived from class Value)?
2013 Mar 18
5
[LLVMdev] Hit a snag while attempting to write a backend - any advice?
Hi, I've been experimenting with writing a backend for LLVM (3.2) (having already written a frontend http://savourysnax.github.com/EDL), everything was going reasonably ok ( calls/returns, epilogue, prologue, etc are all working), up until I tried to place support for conditional branches. Given this simple program : int test(int c,int d) { if (c) { return
2010 Nov 08
2
[LLVMdev] [LLVMDev] Register Allocation and copy instructions
Hi, while writing my register allocator, I have come across a case which confuses me because the llvm definition cannot be mapped to machine code. For instance I come across (1) and I reduce it to (2). However a copy instruction cannot move from EDX to CX. What mechanics in LLVM will tell me that I cannot make this move during register allocation, or how can I tell from (1) that I cannot execute
2009 Nov 24
0
[LLVMdev] X86InstrInfo::GetInstSizeInBytes() calculating incorrect size
I'm noticing the X86InstrInfo::GetInstSizeInBytes() function returning incorrect sizes for some instructions. I looked through the llvm-dev archives and noticed that a patch was submitted once in April 2009 for instruction length calculation on amd-64. I'm using Intel Core 2 Duo (64 bit) so maybe there is a similar issue? I don't have another computer I can test this on to see if
2009 Dec 16
1
[LLVMdev] incorrect x86 instruction size calculation
Hello, I'm trying to write some backends for LLVM that generate code that complies with SFI validation rules by re-implementing SFI for the LLVM x86 backend based on the Google NaCl project. However, in trying to implement 32-byte code alignment, X86InstrInfo::GetInstSizeInBytes() is returning incorrect instruction sizes for certain instructions (that I have seen so far): MOV32mi,
2007 Dec 20
1
[LLVMdev] Code Generation Problem llvm 1.9
I sent a long message yesterday describing a problem I thought had to do with the JIT stubs. After further investigating, the problem seems to be in the code generation. The following basic block seems to have an error in it's code generation: __exp.exit: ; preds = %codeRepl258, %__exp_bb_bb.exit phi double [ 1.000000e+00, %codeRepl258 ], [ %.reload.reload.i,
2011 Jun 14
0
[LLVMdev] Too many load/store in Machine code represtation
There are a lot of load/store instructions for accessing variable in stack slot. The following message is use "llc -march=ppc32" command and dump from MachineFunction. %reg16384<def> = LWZ 0, <fi#6>; mem:LD4[%b] GPRC:%reg16384 %reg16385<def> = LWZ 0, <fi#5>; mem:LD4[%c] GPRC:%reg16385 %reg16386<def> = ADD4 %reg16384<kill>,
2010 Nov 08
0
[LLVMdev] [LLVMDev] Register Allocation and copy instructions
On Nov 8, 2010, at 12:04 PM, Jeff Kunkel wrote: > Hi, while writing my register allocator, I have come across a case which confuses me because the llvm definition cannot be mapped to machine code. > > For instance I come across (1) and I reduce it to (2). However a copy instruction cannot move from EDX to CX. What mechanics in LLVM will tell me that I cannot make this move during
2010 May 18
2
[LLVMdev] Fast register allocation
As you may have noticed, I have been working on a fast register allocator in the last week. The new allocator is intended to replace the local allocator for debug builds. Both allocators use a local allocation strategy. Each basic block is scanned from top to bottom, and virtual registers are assigned to physical registers as they appear. There are no live registers between blocks. Everything is
2006 Jun 26
2
[LLVMdev] Mapping bytecode to X86
Dear guys, I am in need of more of your help. I'm implementing a register allocator, and I am having problems to make it produce correct code. Consider this program here: int main(int argc, char ** argv) { int i, j, sum; i = argv[0][0]; j = argv[0][1]; sum = (i + j) * j; printf("Sum = %d\n", sum); } that maps to this llvm bytecode: entry (0xa785590, LLVM
2013 Feb 08
0
[LLVMdev] help with X86 DAG->DAG Instruction Selection
Hi Peng, Can you please open a bugzilla and attache the LL file ? Can you please reproduce it on ToT ? Thanks, Nadav On Feb 7, 2013, at 9:08 PM, Peng Cheng <gm4cheng at gmail.com> wrote: > I have an llvm ir, which generates the following machine code using llc (llvm 3.0 on win32) after # *** IR Dump After X86 DAG->DAG Instruction Selection ***: > > The first three lines
2010 Sep 05
2
[LLVMdev] Possible missed optimization?
On Sep 4, 2010, at 5:40 PM, Eli Friedman wrote: > If you want to take a look at this yourself, the issue is easy to > reproduce with Thumb1: Thanks, Eli. Nice catch! This IR: target triple = "thumbv5-u-u" define arm_aapcscc i64 @foo(i64 %a, i64 %b) nounwind readnone { entry: %xor = xor i64 %a, 18 ; <i64> [#uses=1] %xor2 = xor i64 %xor, %b
2013 Feb 08
2
[LLVMdev] help with X86 DAG->DAG Instruction Selection
I have an llvm ir, which generates the following machine code using llc (llvm 3.0 on win32) after # *** IR Dump After X86 DAG->DAG Instruction Selection ***: The first three lines and the last two lines alone together are used to compute "sin" for some double number. - line 1: move the stack pointer down 8 - line 2: copy the updated stack pointer to a base register - line 3: copy a
2008 Jul 17
0
[PATCH 17/29] ia64/pv_ops/xen: define xen paravirtualized instructions for hand written assembly code
define xen paravirtualized instructions for hand written assembly code. Signed-off-by: Yaozu (Eddie) Dong <eddie.dong at intel.com> Signed-off-by: Isaku Yamahata <yamahata at valinux.co.jp> Cc: Akio Takebe <takebe_akio at jp.fujitsu.com> --- include/asm-ia64/xen/inst.h | 447 +++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 447 insertions(+), 0 deletions(-) create
2007 Dec 19
0
[LLVMdev] JIT Stub Problem
I'm having an issue with the Stubs used by the JIT Compiler. I'm not sure if it's a bug or if I'm doing something incorrectly. I've got a long complicated function with the following basic blocks at the end of it (The complete .ll file is attached): falseBlock: ; preds = %__exp.exit340 ret int 617 codeRepl: ; preds = %__exp.exit340
2016 Jun 22
2
LLVM Backend Issues
Thanks Anton and Krzysztof! Here is the dump using the -debug flag. At this point I am not making much sense of this, would it be too much to ask if one of you could walk me through one of these lines? One thing that I didn't point out is that I never defined any separate floating point registers, not sure if this will pose any issue? Thanks again for your time! Jeff jeff at