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

Villmow, Micah Micah.Villmow at amd.com
Thu Dec 15 16:07:39 PST 2011


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
}

From: llvmdev-bounces at cs.uiuc.edu [mailto:llvmdev-bounces at cs.uiuc.edu] On Behalf Of Villmow, Micah
Sent: Thursday, December 15, 2011 4:04 PM
To: LLVM Developers Mailing List
Subject: [LLVMdev] Vector immediates in tablegen w/o build_vector?

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
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