similar to: Incorrect placement of an instruction after PostRAScheduler pass

Hi, I am having some trouble understanding the scheduling scheme for the C-A9. Looking at the ARMScheduleA9.td file I find this line that overrides the target SchedWrite with processor specific latencies. def : SchedAlias<WriteALU, A9WriteALU>; However, in this same file, I find the lines presented below, which are mapping the SchedReadWrite to, for example, the ANDri instruction. //

Hi, Apologies this is a bit lengthy. TLDR: I'm using Dragonegg + LLVM 3.2 and uClibc, and am finding that using the Fast register allocator (i.e. -optimize-regalloc=0) causes miscompilation of setsockopt calls (5-arg system calls). The problem doesn't happen with the default register allocation path selected. It can be worked around by manually simplifying the system call setup

LLVM can model some quite complicated register banks now, and we even use registers to model some encoding constraints. For example, a few ARM instructions like strexd have two register operands that must be an aligned pair of consecutive GPR registers (like r0, r1). This constraint is modeled with the GPRPair register class containing R0_R1, R2_R3, ... pseudo-registers. Sometimes ISAs also

Jakob, I've implemented a patch that reworks the MCRegAliasIterator to dynamically compute the register aliases. The size reduction in the RegDiffLists are rather dramatic. Here are a few size differences for MCTargetDesc.o files (before and after) in bytes: R600 - 36160B - 11184B - 69% reduction ARM - 28480B - 8368B - 71% reduction Mips - 816B - 576B - 29% reduction One side effect of

hi, i'm writing a target dependent analysis on machine instruction level in llvm 2.0. the analysis needs to know if an inline assembly block reads from memory. the programmer is responsible to add 'm' constraints accordingly. i've seen the operand flags of the inline assembly SDNode and the machine instructions. but it seems that there is no difference between input and output

Hello, Consider this code (this is all after register allocation): R0<def> = ... R0 // Set lower half (based on the previous value) R1<def> = ... // Set upper half ... = R0_R1 // Use the pair It is my understanding that the use of the whole pair will need to have some sort of a reaching def, i.e. the code will need at least those flags: R0<def> =

Hi, I am experimenting with creating instructions that write into virtual registers that use the ARM GPRPair register class in Pre-RA phase. During register allocation, I hit an assertion because the code is not in SSA form: lib/CodeGen/MachineRegisterInfo.cpp:271: llvm::MachineInstr* llvm::MachineRegisterInfo::getVRegDef(unsigned int) const: Assertion `(I.atEnd() || llvm::next(I) ==

Consider this program: --- asm.c --- int G; int foo(char *p) { int rv; G = 0; asm ("" : "=r"(rv) : "r"(p) : "memory"); return rv + G; } ------------- Is the use of "memory" clobber sufficient to expect the optimizer not to optimize the "+ G" away in the return statement? I'll add here that

I'm looking at an issue where we want a particular pseudo-instruction to choose from a set of registers that is not included in the existing set of RegisterClass definitions. More concretely, there is a RegisterClass in ARMRegisterInfo.td defined as def rGPR : RegisterClass<"ARM", [i32], 32, (sub GPR, SP, PC)> { let AltOrders = [(add LR, rGPR), (trunc rGPR, 8)]; let

Hi, I'm working on the iterated register coalescing graph coloring allocator and try to test it with all backends available currently in LLVM. Initial tests with most of the backends are successful. It turned out that my allocator triggers a specific assertion in the RegScavenger and only for the ARM target. It looks like the LR register is used for frame pointer related things, but it is

Hi there, I am currently trying to create an LLVM Backend for a RISC architecture and running into problems with setCC and brcond. First a few explanations: The architecture doesn't have a dedicated flag register, but seven 1-bit-wide so called "condition registers", c0-c6, which can be set by e.g. a compare instruction: > cmp ne, c0, r1, 123 It also supports conditional

On 11/12/2009, at 10:43 AM, Anton Korobeynikov wrote: > Hi, Chris > >> That is target independent code, so you should not put sparc specific changes there. It sounds like one of the sparc-specific target hooks is wrong. > Since sparc does not provide any hooks for operation of branches (e.g. > AnalyzeBranch and friends) it might be possible that generic codegen > code is

On Jan 7, 2009, at 2:48 AM, Roman Levenstein wrote: > bb368: 0x8fdad00, LLVM BB @0x8fc2c98, ID#1: > Predecessors according to CFG: 0x8fdac90 (#0) > %R0<def> = MOVi 0, 14, %reg0, %reg0 > *** STR %LR<kill>, %R0<kill>, %reg0, 0, 14, %reg0, Mem:ST(4,4) > [0x8fc2d68 + 0] > %LR<def> = LDR <fi#0>, %reg0, 0, 14, %reg0 >

2009/1/13 Evan Cheng <echeng at apple.com>: > > On Jan 7, 2009, at 2:48 AM, Roman Levenstein wrote: > >> bb368: 0x8fdad00, LLVM BB @0x8fc2c98, ID#1: >> Predecessors according to CFG: 0x8fdac90 (#0) >> %R0<def> = MOVi 0, 14, %reg0, %reg0 >> *** STR %LR<kill>, %R0<kill>, %reg0, 0, 14, %reg0, Mem:ST(4,4) >> [0x8fc2d68 + 0]

On Mar 26, 2013, at 10:29 AM, Akira Hatanaka <ahatanak at gmail.com> wrote: > The size of general purpose integer registers for mips32 is 32-bit and accumulators are 64-bit registers consisting of 32-bit hi/lo register pairs. So you will need two instructions to copy two 32-bit GPR registers to a 64-bit accumulator register. If spilling to multiple registers is unsupported, perhaps I can

On Jan 13, 2009, at 12:27 AM, Roman Levenstein <romix.llvm at googlemail.com > wrote: > 2009/1/13 Evan Cheng <echeng at apple.com>: >> >> On Jan 7, 2009, at 2:48 AM, Roman Levenstein wrote: >> >>> bb368: 0x8fdad00, LLVM BB @0x8fc2c98, ID#1: >>> Predecessors according to CFG: 0x8fdac90 (#0) >>> %R0<def> = MOVi 0, 14, %reg0,

I'm writing a back-end for a target in which all dyadic instructions support one register and one memory operand but only some instructions support two register operations. For example ADDrm and ADDrr are supported, ANDrm is supported but ANDrr isn't. I've written descriptions for ADDrm, ADDrr and ANDrm in my InstrInfo.td file but instruction selection fails when presented with an AND

On Feb 8, 2010, at 12:37 AM, Nathan Keynes wrote: > Firstly, the BNE/BA pair should be reduced to a BE (I assume this is > the responsibility of AnalyzeBranch and friends that you mention). Right. Implementing AnalyzeBranch will allow a bunch of block layout and branch optimizations to happen. > However I still wouldn't have expected that to result in the label > being

Dear Tim, Thank you for your thorough reply. So, based on your reply I get every operand and check them to be (isDef && !isimplicit). Now my problem is that it gives me the physical register number.i.e, for example, instead of r0, it return %physreg66. Could you please help me on how to convert these physical register number to the ARM related register? I mean the 15 GPRs in ARM. Thank

On Apr 6, 2013, at 12:42 AM, Hal Finkel <hfinkel at anl.gov> wrote: > ----- Original Message ----- >> From: "Jakob Stoklund Olesen" <stoklund at 2pi.dk> >> To: "Akira Hatanaka" <ahatanak at gmail.com> >> Cc: "LLVM Developers Mailing List" <llvmdev at cs.uiuc.edu>, "Hal Finkel" <hfinkel at anl.gov> >>