[Mesa-dev] [PATCH 2/4] nvc0/ir: don't dual issue instructions which depend on each other

[Tobias Klausmann]

On 13.08.2016 12:02, Karol Herbst wrote:
> no changes without a dual_issue pass
>
> changes with for ./GpuTest /test=pixmark_piano /benchmark /no_scorebox /msaa=0
> /benchmark_duration_ms=60000 /width=1024 /height=640:
>
> inst_executed: 1.03G
> inst_issued1: 538M -> 535M
> inst_issued2: 251M -> 254M
>
> score: 1038 -> 1052
>
> Signed-off-by: Karol Herbst <karolherbst at gmail.com>
> ---
>   src/gallium/drivers/nouveau/codegen/nv50_ir.cpp             | 11 +++++++++--
>   src/gallium/drivers/nouveau/codegen/nv50_ir.h               |  1 +
>   src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp |  4 ++++
>   3 files changed, 14 insertions(+), 2 deletions(-)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir.cpp
> index 179ad0b..7a90cb7 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir.cpp
> @@ -893,12 +893,19 @@ insnCheckCommutationDefDef(const Instruction *a, const Instruction *b)
>   bool
>   Instruction::isCommutationLegal(const Instruction *i) const
>   {
> -   bool ret = insnCheckCommutationDefDef(this, i);
> -   ret = ret && insnCheckCommutationDefSrc(this, i);
> +   bool ret = !i->dependsOn(this);
>      ret = ret && insnCheckCommutationDefSrc(i, this);
>      return ret;
>   }
>   
> +bool
> +Instruction::dependsOn(const Instruction *i) const
> +{
> +   bool ret = insnCheckCommutationDefDef(this, i);
> +   ret = ret && insnCheckCommutationDefSrc(i, this);
> +   return !ret;
> +}
> +
>   TexInstruction::TexInstruction(Function *fn, operation op)
>      : Instruction(fn, op, TYPE_F32)
>   {
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir.h b/src/gallium/drivers/nouveau/codegen/nv50_ir.h
> index 6d2ee8b..d81fca9 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir.h
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir.h
> @@ -831,6 +831,7 @@ public:
>      bool isDead() const;
>      bool isNop() const;
>      bool isCommutationLegal(const Instruction *) const; // must be adjacent !
> +   bool dependsOn(const Instruction *) const; // weaker form of isCommutationLegal
>      bool isActionEqual(const Instruction *) const;
>      bool isResultEqual(const Instruction *) const;
>   
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp
> index faf2121..8ce8c19 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nvc0.cpp
> @@ -620,6 +620,10 @@ bool TargetNVC0::canDualIssue(const Instruction *a, const Instruction *b) const
>         // not if the 2nd instruction isn't necessarily executed
>         if (clA == OPCLASS_TEXTURE || clA == OPCLASS_FLOW)
>            return false;
> +
> +      if (b->dependsOn(a))
> +         return false;
> +
>         // anything with MOV
>         if (a->op == OP_MOV || b->op == OP_MOV)
>            return true;

Reviewed-by: Tobias Klausmann <tobias.johannes.klausmann at mni.thm.de>