similar to: [LLVMdev] Pseudo instructions expansion

Hi Vladimir, The pass you refer to isn't used by the assembler at all. That's strictly a compiler codegen thing. The assembler equivalents are expressed via InstAlias constructions. Again, though, those are for a single output instruction, so you need something more. Sprecifically, you can handle assembly pseudo-instructions in C++ code. Something like the ARM assembler's

Hi Jim, thank you for the quick response. I have used InstAlias in some cases, but these are really simple pseudo instructions where the pseudo instruction is more like a special case of existing one, like using fixed operand or simply a more human understandable way of presenting an operation. I know that there are predicates available to improve matching, but can InstAlias use conditions to

The TableGen PseudoLoweringEmitter backend is responsible for lowering pseudo-instructions to real machine instructions. In the code is this comment: // FIXME: This pass currently can only expand a pseudo to a single instruction. // The pseudo expansion really should take a list of dags, not just // a single dag, so we can do fancier things. Does anyone think that enhancing it to

Are there any examples of using tablegen to generate multiple machine instructions from a single pattern? Or do these cases always have to be manually expanded? -Dave

Sadly the latest optimization broke completely everything. The asm code isn't gas compliant. the libFLAC linker script has a typo, disabling the asm optimization and/or altivec won't let a correct build anyway. Instant fixes for the asm stuff: sed -i -e"s:;:\#:" on the lpc_asm.s to load address instead of addis+ori you could use lis and la and PLEASE use the @l(register)

On Tue, 9 Jan 2007, Evan Cheng wrote: >> - How does one deal with multiple instruction sequences in a pattern? >> To load a constant is a two instruction sequence, but both >> instructions only take two operands (assume that r3 is a 32-bit >> register): >> >> ilhu $3, 45 # r3 = (45 << 16) >> iohl $3, 5 # r3 |= 5

On Sep 23, 2008, at 11:26 AM, David Greene wrote: > Are there any examples of using tablegen to generate multiple machine > instructions from a single pattern? Or do these cases always have > to be > manually expanded? PPC has a bunch of examples, for example: // Arbitrary immediate support. Implement in terms of LIS/ORI. def : Pat<(i32 imm:$imm), (ORI (LIS (HI16

Chris Lattner wrote: >>It is possible to write multi-instruction pattern, e.g. >>X86InstrSSE.td line 1911. But how are you defining HI16 and LO16? >>Sounds like you want to define them as SDNodeXform that returns upper >>and lower 16 bits respectively. Take a look at PSxLDQ_imm in >>X86InstrSSE.td as an example. > > > Another good example is the PPC

Hi all, I'm working on llvm assembler support for Mips and for a while I'm trying to solve a problem regarding complex macro instructions. As mips assembler supports macro instructions that can develop to more then one real instruction depending on the operand type(usually two or three) we can't use InstAlias to exploit tableGen generated code. Currently we expand these in

Thanks for your reply. We are trying to implement a simple Mips-based CPU with just for teaching purpose, so we delete some instructions which are not commonly used, thus the task won't be too hard for students. I am responsible for modifying the compiler so that the compiler won't emit unsupported instructions. In order to avoid "can not select" error, I am trying to expand

I'm trying to implement the standalone assembler for mips and I have encountered a problem in instruction operands matcher. In mips instruction set there are math instructions with two format flags in the mnemonic, one for source and one for destination register. For example ceil.w.s means both source and destination are F32 registers while ceil.l.d means both source and destination are F64

YOu have to look for which DAG fragments are not being matched. Then you can create patterns for those using alternate sequences. When you disablea given instruction, don't just disable it, but also look at what pattern it was matching. Then create a patten for that using remaining instructions or in some cases you might have to call a library function, as in the case of floating

On May 22, 2012, at 8:05 AM, "Medic, Vladimir" <vmedic at mips.com> wrote: > I'm trying to implement the standalone assembler for mips and I have encountered a problem in instruction operands matcher. > In mips instruction set there are math instructions with two format flags in the mnemonic, one for source and one for destination register. > For example ceil.w.s

I do not have access to a subtraction routine, as it is considered add with negation on the second parameter, so I have this pattern: // integer subtraction // a - b ==> a + (-b) def ISUB : Pat<(sub GPRI32:$src0, GPRI32:$src1), (IADD GPRI32:$src0, (INEGATE GPRI32:$src1))>; I am attemping to do 64 bit integer shifts and using the following pattern: def LSHL :

Chris Lattner wrote: > On Sep 23, 2008, at 11:26 AM, David Greene wrote: > >> Are there any examples of using tablegen to generate multiple machine >> instructions from a single pattern? Or do these cases always have >> to be >> manually expanded? > > PPC has a bunch of examples, for example: > > // Arbitrary immediate support. Implement in terms of

Hi Vladimir, ARM does similar things for complex assembly pseudos. Have a look at the definition and use of AsmPseudoInst in the ARM backend. They’re not typically expanding to multiple “real” instructions, but that’s an implementation detail, not a constraint. -Jim On Oct 1, 2013, at 5:36 AM, Vladimir Medic <Vladimir.Medic at imgtec.com> wrote: > Hi all, > I'm working on llvm

Hi Jim, I did look at the ARMAsmParser and it seems to me that it is using a switch/case construct to change the opcode and the operands, but this construct may become too large eventually. I was wondering if it is possible to use isAsmParser only flag to call dedicated methods, like dedicated parsers for AsmOperands. Regards Vladimir ________________________________ From: Jim Grosbach [grosbach

On Jan 9, 2007, at 10:01 AM, Scott Michel wrote: > I was able to resolve my previous question about dealing with custom > loads/stores, and following Chris' suggestion, the IBM Cell SPU > backend > can generate code for "int main(void) { return 0; }" without crashing > llc. There's a lot of work still to be done... like getting frame > offsets correctly

I was able to resolve my previous question about dealing with custom loads/stores, and following Chris' suggestion, the IBM Cell SPU backend can generate code for "int main(void) { return 0; }" without crashing llc. There's a lot of work still to be done... like getting frame offsets correctly computed and hauling in the raft of intrinsics that the Cell SDK defines. Three quick

I've had this a long time but haven't submitted it yet. I've tried to mirror the ia32 setup, so there should be a new subdirectory src/libFLAC/ppc . The first two attachments go there. The third is a context diff for src/libFLAC/Makefile.am . I have some more modified files, which I figured I'd submit after the above are checked in and working for somebody other than me. If you