[LLVMdev] Vector immediates in tablegen w/o build_vector?

[Villmow, Micah]

I have two patterns in tablegen that do look like the exact same thing:

Pat 1)

  def MOV_v4i16 : ILFormat<IL_OP_MOV, (outs GPRV4I16:$dst),

      (ins i16imm:$val),

      asm, [(set GPRV4I16:$dst, (build_vector (i16 imm:$val)))]>;

Pat 2)

def v4i16imm : Operand<v4i16>;

  def MOV_v4i16 : ILFormat<IL_OP_MOV, (outs GPRV4I16:$dst),

      (ins v4i16imm:$val),

      asm, [(set GPRV4I16:$dst, (v4i16 imm:$val))]>;

 

The second pattern seems to build correctly, but doesn't match because of the build_vector opcode.

 

So, what I am trying to figure out, how do I get (build_vector (i16 imm:$val)) to be convert to v4i16 immediate directly?

 

I've tried pattern fragments, but I can't seem to get that to work correctly.

 

I tried this:

def v4i16imm : Operand<v4i16>;

def bvimm : PatFrag<(ops node:$val), (build_vector node:$val)>;

def _v4i16 : ILFormat<IL_OP_MOV, (outs GPRV4I16:$dst),

      (ins v4i16imm:$val),

      asm, [(set GPRV4I16:$dst, (v4i16 (bvimm imm:$val)))]>;

 

Any idea? Basically I am trying to get vector immediates to work in tablegen patterns.

 

Thanks,

Micah

[Villmow, Micah]

Here is my test case I am trying to match in as few instruction as possible, currently it takes a dozen or so.

define void @__OpenCL_bug7669_kernel(<4 x i16> addrspace(1)* nocapture %a) nounwind {

entry:

  store <4 x i16> <i16 0, i16 1, i16 2, i16 3>, <4 x i16> addrspace(1)* %a, align 8

  ret void

[Hal Finkel]

Micah,

This is related to a question that I asked back in October about
matching addsub instructions. Duncan had a suggestion, see:
http://lists.cs.uiuc.edu/pipermail/llvmdev/2011-October/044322.html

Unfortunately, as it stands, you currently cannot match build_vector
like this. IIRC, it is always turned into constant loads before nodes
are matched (see also the aforementioned thread). In my opinion, it
would be reasonable to change this.

-Hal

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--
Hal Finkel
Postdoctoral Appointee
Leadership Computing Facility
Argonne National Laboratory

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