[Mesa-dev] [PATCH 5/9] nvc0/ir: Allow 0/1 immediate value as source of OP_VOTE

[Samuel Pitoiset]

On 04/08/2017 11:51 AM, Boyan Ding wrote:
> Implementation of readFirstInvocationARB() on nvidia hardware needs a
> ballotARB(true) used to decide the first active thread. This expressed
> in gm107 asm as (supposing output is $r0):
> 	vote any $r0 0x1 0x1
> 
> To model the always true input, which corresponds to the second 0x1
> above, we make OP_VOTE accept immediate value 0/1 and emit "0x1" and
> "not 0x1" in the src field respectively.
> ---
>   .../drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp  | 21 +++++++++++++++++----
>   .../drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp  | 19 ++++++++++++++++---
>   .../drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp   | 21 +++++++++++++++++----
>   3 files changed, 50 insertions(+), 11 deletions(-)
> 
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
> index e82e3684b0..31af6dcc17 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gk110.cpp
> @@ -1615,7 +1615,7 @@ CodeEmitterGK110::emitSHFL(const Instruction *i)
>   void
>   CodeEmitterGK110::emitVOTE(const Instruction *i)
>   {
> -   assert(i->src(0).getFile() == FILE_PREDICATE);
> +   uint32_t imm;
>   
>      code[0] = 0x00000002;
>      code[1] = 0x86c00000 | (i->subOp << 19);
> @@ -1640,9 +1640,22 @@ CodeEmitterGK110::emitVOTE(const Instruction *i)
>         code[0] |= 255 << 2;
>      if (!(rp & 2))
>         code[1] |= 7 << 16;
> -   if (i->src(0).mod == Modifier(NV50_IR_MOD_NOT))
> -      code[1] |= 1 << 13;
> -   srcId(i->src(0), 42);
> +
> +   switch (i->src(0).getFile()) {
> +   case FILE_PREDICATE:
> +      if (i->src(0).mod == Modifier(NV50_IR_MOD_NOT))
> +         code[0] |= 1 << 13;
> +      srcId(i->src(0), 42);
> +      break;
> +   case FILE_IMMEDIATE:
> +      imm = i->src(0).get()->asImm()->reg.data.u32;

Usually we check that asImm() is not NULL, like

imm = i->src(0).get->asImm();
assert(imm);

Same in other emitters.

> +      assert(imm == 0 || imm == 1);
> +      code[1] |= (imm == 1 ? 0x7 : 0xf) << 10;
> +      break;
> +   default:
> +      assert(!"Unhandled src");
> +      break;
> +   }
>   }
>   
>   void
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
> index 4a741bf45b..ee1046fea0 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_gm107.cpp
> @@ -2930,7 +2930,7 @@ CodeEmitterGM107::emitMEMBAR()
>   void
>   CodeEmitterGM107::emitVOTE()
>   {
> -   assert(insn->src(0).getFile() == FILE_PREDICATE);
> +   uint32_t imm;
>   
>      int r = -1, p = -1;
>      for (int i = 0; insn->defExists(i); i++) {
> @@ -2950,8 +2950,21 @@ CodeEmitterGM107::emitVOTE()
>         emitPRED (0x2d, insn->def(p));
>      else
>         emitPRED (0x2d);
> -   emitField(0x2a, 1, insn->src(0).mod == Modifier(NV50_IR_MOD_NOT));
> -   emitPRED (0x27, insn->src(0));
> +
> +   switch (insn->src(0).getFile()) {
> +   case FILE_PREDICATE:
> +      emitField(0x2a, 1, insn->src(0).mod == Modifier(NV50_IR_MOD_NOT));
> +      emitPRED (0x27, insn->src(0));
> +      break;
> +   case FILE_IMMEDIATE:
> +      imm = insn->src(0).get()->asImm()->reg.data.u32;
> +      assert(imm == 0 || imm == 1);
> +      emitField(0x27, 4, imm == 1 ? 0x7 : 0xf);
> +      break;
> +   default:
> +      assert(!"Unhandled src");
> +      break;
> +   }
>   }
>   
>   void
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp
> index 8dd73bd77d..fafb65743e 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nvc0.cpp
> @@ -2579,7 +2579,7 @@ CodeEmitterNVC0::emitSHFL(const Instruction *i)
>   void
>   CodeEmitterNVC0::emitVOTE(const Instruction *i)
>   {
> -   assert(i->src(0).getFile() == FILE_PREDICATE);
> +   uint32_t imm;
>   
>      code[0] = 0x00000004 | (i->subOp << 5);
>      code[1] = 0x48000000;
> @@ -2604,9 +2604,22 @@ CodeEmitterNVC0::emitVOTE(const Instruction *i)
>         code[0] |= 63 << 14;
>      if (!(rp & 2))
>         code[1] |= 7 << 22;
> -   if (i->src(0).mod == Modifier(NV50_IR_MOD_NOT))
> -      code[0] |= 1 << 23;
> -   srcId(i->src(0), 20);
> +
> +   switch (i->src(0).getFile()) {
> +   case FILE_PREDICATE:
> +      if (i->src(0).mod == Modifier(NV50_IR_MOD_NOT))
> +         code[0] |= 1 << 23;
> +      srcId(i->src(0), 20);
> +      break;
> +   case FILE_IMMEDIATE:
> +      imm = i->src(0).get()->asImm()->reg.data.u32;
> +      assert(imm == 0 || imm == 1);
> +      code[0] |= (imm == 1 ? 0x7 : 0xf) << 20;
> +      break;
> +   default:
> +      assert(!"Unhandled src");
> +      break;
> +   }
>   }
>   
>   bool
>