similar to: [LLVMdev] Simpler subreg ops in machine code IR

On Jun 15, 2010, at 2:48 PM, Jakob Stoklund Olesen wrote: > I am considering adding a new target independent codegen-only COPY instruction to our MachineInstr representation. It would be used to replace INSERT_SUBREG, EXTRACT_SUBREG, and virtual register copies after instruction selection. Selection DAG still needs {INSERT,EXTRACT}_SUBREG, but they would not appear as MachineInstrs any longer.

Hi Hisham, Most likely the basic blocks are the headers of two different loops. Try running viewCFG() on the function in question to see if this is the case. Tom ----- Original Message ----- From: "Hisham Chowdhury" <hisham_chow at yahoo.com> To: llvmdev at cs.uiuc.edu Sent: Wednesday, June 16, 2010 7:22:00 PM GMT -05:00 US/Canada Eastern Subject: [LLVMdev] Loopinfo Analysis

Hello, I have a question regrading the analysis pass that generates loop info from an .ll code. My previous understanding was there will be just one loop header(in the loop info) for a particular loop. But, when i use isLoopHeader() member function from the loop info class I get 'true' return value for two different basic blocks. Note both basic blocks are loop conditional block(break

Hi all, When compiling some programs using the Mips backend i'm getting this assert message on lib/CodeGen/LiveInterval.cpp:227: "Range is not entirely in interval!" I don't know yet if it's something that is missing on the backend code or why the range to be removed it outside the interval, does anyone have any clue? A more detailed output is attached. The program i tried

Folks, I'm running into something which looks like a bug in linearscan allocator. Of course I can't be 100% sure it's not some unobvious mistake on my part, so I'd like to hear your opinion. First, I attach two files -- LLVM asm and the asm for my target. The problem with assembler is: on line 171 it uses register gr2, which is copied from gr6 above, on line 161. The only

The function TII::canCombineSubRegIndices has been gone for a while now, and I was wondering if there is a target-independent way of determining if a certain set of physical registers "adds up" to a larger register. For example, on X86, AL and AH together form AX. On Hexagon, R0 and R1 are D0. The context here is an attempt to coalesce multiple loads/stores into fewer loads/stores

I've been working on patches to improve subregister liveness tracking on llvm and I wanted to inform the llvm community about the overal design/motivation for them. I will send the patches to llvm-commits later today. Greetings Matthias Braun Subregisters in llvm ==================== Some targets can access registers in different ways resulting in wider or narrower accesses. For

Currently it will always spill / restore the whole vreg but only spilling the parts that are actually live would be a nice addition in the future. Looking at r192119': if "mtlo" writes to $LO and sets $HI to an unpredictable value, then it should just have an additional (dead) def operand for $hi, shouldn't it? Greetings Matthias Am 10/8/13, 11:03 AM, schrieb Akira

On Oct 8, 2013, at 2:06 PM, Akira Hatanaka <ahatanak at gmail.com> wrote: > What I didn't mention in r192119 is that mthi/lo clobbers the other sub-register only if the contents of hi and lo are produced by mult or other arithmetic instructions (div, madd, etc.) It doesn't have this side-effect if it is produced by another mthi/lo. So I don't think making mthi/lo clobber the

What I didn't mention in r192119 is that mthi/lo clobbers the other sub-register only if the contents of hi and lo are produced by mult or other arithmetic instructions (div, madd, etc.) It doesn't have this side-effect if it is produced by another mthi/lo. So I don't think making mthi/lo clobber the other half would work. For example, this is an illegal sequence of instructions,

On Wed, 2005-09-07 at 15:09 +0800, Tzu-Chien Chiu wrote: > I don't understand the following code snippet in LiveIntervalAnalysis.cpp. > > Why changing the type of the opreand from a virtual register to a > machine register? The register number (reg) is still a virtual > register index (>1024). > > > bool LiveIntervals::runOnMachineFunction(MachineFunction &fn)

Does anyone know exactly what ComposerIndices in Target.td is all about? I see just one place where it's used in X86 but it's not clear from the comments in Target.td and it's one usage, exactly what this feature is about. Tia. Reed

I don't understand the following code snippet in LiveIntervalAnalysis.cpp. Why changing the type of the opreand from a virtual register to a machine register? The register number (reg) is still a virtual register index (>1024). bool LiveIntervals::runOnMachineFunction(MachineFunction &fn) { // perform a final pass over the instructions and compute spill // weights, coalesce

Hi, The PHI elimination pass calls the function copyRegToReg for copy placement and then later tries to setkill to the temporary virtual register used in copy placement. For this setkill action it looks only in one instruction (last instruction for copyRegToReg) for virtual register with no use. My target has only one register and I can't do copyRegToReg in one instruction only. So I

Hey, guys, I am creating some move instructions with MRegisterInfo::copyRegToReg. How do I get a pointer to the instruction that I just created? Is there a way to do something like: // mbb is MachineBasicBlock, reg_info is MRegisterInfo MachineBasicBlock::iterator iter = mbb.getFirstTerminator(); reg_info->copyRegToReg(mbb, iter, dst, src, rc); iter--; (???) MachineInstr *

How do I get the TargetRegisterClass for a physical register? SSARegMap::getRegClass only works for virtual registers. -Dave

copyRegToReg() always insert the move instruction before "iter". Just use prior(iter) after the insertion to reference the newly created move instruction. Evan On Feb 21, 2007, at 11:17 PM, Fernando Magno Quintao Pereira wrote: > > Hey, guys, I am creating some move instructions with > MRegisterInfo::copyRegToReg. How do I get a pointer to the instruction > that I just

Hi Anton & Duncan, When I try to compile on Darwin now, I get this: $ /Volumes/Gir/devel/llvm/llvm-gcc-4.0.obj/gcc/xgcc <options> -o eh_alloc.o Assertion failed: (false && "Couldn't find the register class"), function getPhysicalRegisterRegClass, file /Volumes/Gir/devel/llvm/ llvm.src/lib/CodeGen/SelectionDAG/ScheduleDAG.cpp, line 269.

On Jul 26, 2012, at 10:28 AM, dag at cray.com wrote: > Jakob Stoklund Olesen <jolesen at apple.com> writes: > >>> What happens if the result of the above pattern using COPY_TO_REGCLASS >>> is spilled? Will we get a 64-bit store or a 128-bit store? >> >> This behavior isn't affected by the change. FR64 registers are spilled >> with 64-bit

On Sep 1, 2010, at 11:14 AM, Dale Johannesen wrote: > > On Sep 1, 2010, at 6:25 AMPDT, Argyrios Kyrtzidis wrote: > >> The attached .ll files seem equivalent, but the resulting asm from >> 'opt-fail.ll' causes a crash to webkit. >> I suspect the usage of registers is wrong, can someone take a look ? > > Yes, the code here is wrong: > >> movl