[Nouveau] [PATCH v2] nv50/ir: make ARB_viewport_array behave like it does with other drivers

[Ilia Mirkin]

On Mon, Jun 23, 2014 at 2:15 PM, Tobias Klausmann
<tobias.johannes.klausmann at mni.thm.de> wrote:
> previously, if we had something like:
>
> gl_ViewportIndex = idx;
> for(int i = 0; i < gl_in.length(); i++) {
>    gl_Position = gl_in[i].gl_Position;
>    EmitVertex();
> }
> EndPrimitive();
>
> we failed to set the right ViewportIndex.
> To resolve this, save the ViewportIndex and store it to the right register on each emit.
>
> This fixes the remaining piglit tests in ARB_viewport_array for nvc0.
>
> Note: Not tested on nv50

I'll be sure to test it out.

>
> Signed-off-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>
> ---
> V2:
>   provide description
>   fix naming of vars
>
>  .../drivers/nouveau/codegen/nv50_ir_driver.h       |  1 +
>  .../drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp  | 30 ++++++++++++++++++++--
>  2 files changed, 29 insertions(+), 2 deletions(-)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_driver.h b/src/gallium/drivers/nouveau/codegen/nv50_ir_driver.h
> index c885c8c..b4086f7 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_driver.h
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_driver.h
> @@ -177,6 +177,7 @@ struct nv50_ir_prog_info
>        uint8_t vertexId;          /* system value index of VertexID */
>        uint8_t edgeFlagIn;
>        uint8_t edgeFlagOut;
> +      int8_t viewportId;        /* output index of ViewportId */

output index of ViewportIndex. (Hm, perhaps the var should be called
viewportIndex? Whatever... I don't really care.)

>        uint8_t fragDepth;         /* output index of FragDepth */
>        uint8_t sampleMask;        /* output index of SampleMask */
>        boolean sampleInterp;      /* perform sample interp on all fp inputs */
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
> index a0f1fe1..a77b342 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_from_tgsi.cpp
> @@ -790,6 +790,8 @@ bool Source::scanSource()
>        info->prop.gp.instanceCount = 1; // default value
>     }
>
> +   info->io.viewportId = -1;
> +
>     info->immd.data = (uint32_t *)MALLOC(scan.immediate_count * 16);
>     info->immd.type = (ubyte *)MALLOC(scan.immediate_count * sizeof(ubyte));
>
> @@ -982,6 +984,9 @@ bool Source::scanDeclaration(const struct tgsi_full_declaration *decl)
>           case TGSI_SEMANTIC_SAMPLEMASK:
>              info->io.sampleMask = i;
>              break;
> +         case TGSI_SEMANTIC_VIEWPORT_INDEX:
> +            info->io.viewportId = i;
> +            break;
>           default:
>              break;
>           }
> @@ -1258,6 +1263,8 @@ private:
>     Stack joinBBs;  // fork BB, for inserting join ops on ENDIF
>     Stack loopBBs;  // loop headers
>     Stack breakBBs; // end of / after loop
> +
> +   Value *viewport;
>  };
>
>  Symbol *
> @@ -1555,8 +1562,15 @@ Converter::storeDst(const tgsi::Instruction::DstRegister dst, int c,
>        mkOp2(OP_WRSV, TYPE_U32, NULL, dstToSym(dst, c), val);
>     } else
>     if (f == TGSI_FILE_OUTPUT && prog->getType() != Program::TYPE_FRAGMENT) {
> -      if (ptr || (info->out[idx].mask & (1 << c)))
> -         mkStore(OP_EXPORT, TYPE_U32, dstToSym(dst, c), ptr, val);
> +
> +      if (ptr || (info->out[idx].mask & (1 << c))) {
> +         /* Save the viewport index into a scratch register so that it can be
> +            exported at EMIT time */
> +         if (info->out[dst.getIndex(0)].sn == TGSI_SEMANTIC_VIEWPORT_INDEX && viewport != NULL)

Just noticed this now, but should this just be info->out[idx] ?

> +            mkOp1(OP_MOV, TYPE_U32, viewport, val);
> +         else
> +            mkStore(OP_EXPORT, TYPE_U32, dstToSym(dst, c), ptr, val);
> +      }
>     } else
>     if (f == TGSI_FILE_TEMPORARY ||
>         f == TGSI_FILE_PREDICATE ||
> @@ -2523,6 +2537,14 @@ Converter::handleInstruction(const struct tgsi_full_instruction *insn)
>           mkCvt(OP_CVT, dstTy, dst0[c], srcTy, fetchSrc(0, c));
>        break;
>     case TGSI_OPCODE_EMIT:
> +      /* export the saved viewport index */
> +      if (viewport != NULL) {
> +         Symbol *vpSym = mkSymbol(FILE_SHADER_OUTPUT, info->io.viewportId,

Pretty sure the second arg should be 0, not index of the vp in
info->out. Can you verify?

> +                                  TYPE_U32,
> +                                  info->out[info->io.viewportId].slot[0] * 4);
> +         mkStore(OP_EXPORT, TYPE_U32, vpSym, NULL, viewport);
> +      }
> +      /* fallthrough */
>     case TGSI_OPCODE_ENDPRIM:
>        // get vertex stream if specified (must be immediate)
>        src0 = tgsi.srcCount() ?
> @@ -2952,6 +2974,10 @@ Converter::run()
>        mkOp1(OP_RCP, TYPE_F32, fragCoord[3], fragCoord[3]);
>     }
>
> +   if (info->io.viewportId >= 0)
> +      viewport = getScratch();
> +   else viewport = NULL;

viewport=NULL should be on a separate line. (I used shorthand in my
earlier email... sorry.)

> +
>     for (ip = 0; ip < code->scan.num_instructions; ++ip) {
>        if (!handleInstruction(&code->insns[ip]))
>           return false;
> --
> 1.8.4.5
>