Mikael Lepistö
2007-Aug-01 07:07 UTC
[LLVMdev] Adding custom operation intrinsic for ASIP architectures.
Chris Lattner wrote:> On Tue, 31 Jul 2007, [ISO-8859-1] Mikael Lepist� wrote: >> I was talking with aKor in #llvm how we could implement custom operation >> support for our ASIP architecture. We came into solution that the best >> way would be to write new custom operation intrinsic and optimization >> pass for raising certain type of function calls to those intrinsics >> (similar to raising mallocs). >> >> Basically our custom operation are like calls, with operand name and >> multiple inputs and outputs. e.g. C code: >> __llvm__custom_op_add(a,b,c) would be raised to customop add(i32 %tmp1, >> i32 %tmp24 , i32 %tmp25). Those "__llvm__custom_op_" prefixed function >> will not have function body, but pure declarations in C code level. >> >> Comments are welcome, especially if there anyone else, that needs this >> kind of functionality or if people has already implemented something >> similar. > > Sure, this works. This is exactly the idea of the builtin functions in > GCC. For example, in SSE, the __builtin_ia32_movntps function does a > nontemporal store. > > To answer David's question, we already have direct support for this in > tblgen, for example, include/llvm/IntrinsicsX86.td contains: > > let TargetPrefix = "x86" in { // All intrinsics start with "llvm.x86.". > def int_x86_sse_movnt_ps : GCCBuiltin<"__builtin_ia32_movntps">, > Intrinsic<[llvm_void_ty, llvm_ptr_ty, > llvm_v4f32_ty], [IntrWriteMem]>; > } > > and lib/Target/X86/X86InstrSSE.td contains: > > def MOVNTPSmr : PSI<0x2B, MRMDestMem, (outs), (ins i128mem:$dst, > VR128:$src), > "movntps {$src, $dst|$dst, $src}", > [(int_x86_sse_movnt_ps addr:$dst, VR128:$src)]>; > > There is corresponding code in llvm-gcc to tell GCC how to handle this > builtin. Is this what you're looking for? >Yes this is more or less, what we are looking for, except we need variable arguments for out intrinsic. I assume that it can be achieved by using llvm_vararg_ty as a argument type? Is there need to make changes to llvm-gcc for supporting new GCCBuiltin types that I define or are all of them automatically converted to intrinsics on gcc side? Mikael Lepistö
Chris Lattner
2007-Aug-02 05:07 UTC
[LLVMdev] Adding custom operation intrinsic for ASIP architectures.
On Wed, 1 Aug 2007, [UTF-8] Mikael Lepist? wrote:>> def MOVNTPSmr : PSI<0x2B, MRMDestMem, (outs), (ins i128mem:$dst, >> VR128:$src), >> "movntps {$src, $dst|$dst, $src}", >> [(int_x86_sse_movnt_ps addr:$dst, VR128:$src)]>; >> >> There is corresponding code in llvm-gcc to tell GCC how to handle this >> builtin. Is this what you're looking for? >> >Yes this is more or less, what we are looking for, except we need >variable arguments for out intrinsic. I assume that it can be achieved >by using llvm_vararg_ty as a argument type?Sure, that can be done. What sort of operations require variable arguments? It might be better implemented with pattern matching in the code generator than as an intrinsic.> Is there need to make changes to llvm-gcc for supporting new GCCBuiltin > types that I define or are all of them automatically converted to > intrinsics on gcc side?No, unfortunately you also have to use the GCC builtin mechanism to teach gcc about them. -Chris -- http://nondot.org/sabre/ http://llvm.org/
Mikael Lepistö
2007-Aug-02 10:16 UTC
[LLVMdev] Adding custom operation intrinsic for ASIP architectures.
Chris Lattner wrote:> On Wed, 1 Aug 2007, [UTF-8] Mikael Lepist? wrote: > >>> def MOVNTPSmr : PSI<0x2B, MRMDestMem, (outs), (ins i128mem:$dst, >>> VR128:$src), >>> "movntps {$src, $dst|$dst, $src}", >>> [(int_x86_sse_movnt_ps addr:$dst, VR128:$src)]>; >>> >>> There is corresponding code in llvm-gcc to tell GCC how to handle this >>> builtin. Is this what you're looking for? >>> >>> >> Yes this is more or less, what we are looking for, except we need >> variable arguments for out intrinsic. I assume that it can be achieved >> by using llvm_vararg_ty as a argument type? >> > > Sure, that can be done. What sort of operations require variable > arguments? It might be better implemented with pattern matching in the > code generator than as an intrinsic. >Need for variable arguments is that we don't know beforehand which custom operations we support. So practically we just give operation name and 1 or more parameters depending how many parameters custom operation has. e.g. __custom_operation("addsub", a, b, c) In lowering of intrinsic function we check from the processor, which type of parameters our current processor has for operation named "addsub" and write corresponding native code.>> Is there need to make changes to llvm-gcc for supporting new GCCBuiltin >> types that I define or are all of them automatically converted to >> intrinsics on gcc side? >> > > No, unfortunately you also have to use the GCC builtin mechanism to teach > gcc about them. >I already made optimizer pass for transforming certain function name to intrinsic function. For me it seemed to be a lot easier choice. Mikael Lepistö
Maybe Matching Threads
- [LLVMdev] Adding custom operation intrinsic for ASIP architectures.
- [LLVMdev] Adding custom operation intrinsic for ASIP architectures.
- [LLVMdev] Adding custom operation intrinsic for ASIP architectures.
- [LLVMdev] Adding custom operation intrinsic for ASIP architectures.
- [LLVMdev] Adding custom operation intrinsic for ASIP architectures.