[Mesa-dev] [PATCH v2 3/6] nv50/ir: replace post_ra_dead by Instruction::isDead

[Samuel Pitoiset]

I'm definitely in favour of my first solution, ie.:

if (postRA)
   return post_ra_dead(this);

On 10/09/2016 11:04 AM, Karol Herbst wrote:
> Signed-off-by: Karol Herbst <karolherbst at gmail.com>
> ---
>  src/gallium/drivers/nouveau/codegen/nv50_ir.h        |  2 +-
>  .../drivers/nouveau/codegen/nv50_ir_peephole.cpp     | 20 +++++++-------------
>  2 files changed, 8 insertions(+), 14 deletions(-)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir.h b/src/gallium/drivers/nouveau/codegen/nv50_ir.h
> index bedbdcc..9d1a72f 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir.h
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir.h
> @@ -829,7 +829,7 @@ public:
>     }
>
>     inline bool isPseudo() const { return op < OP_MOV; }
> -   bool isDead() const;
> +   bool isDead(bool postRA = false) const;
>     bool isNop() const;
>     bool isCommutationLegal(const Instruction *) const; // must be adjacent !
>     bool isActionEqual(const Instruction *) const;
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> index 6efb29e..fd1fec6 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> @@ -61,7 +61,7 @@ Instruction::isNop() const
>     return false;
>  }
>
> -bool Instruction::isDead() const
> +bool Instruction::isDead(bool postRA) const
>  {
>     if (op == OP_STORE ||
>         op == OP_EXPORT ||
> @@ -70,8 +70,11 @@ bool Instruction::isDead() const
>         op == OP_WRSV)
>        return false;
>
> +   if (postRA && op == OP_MOV && subOp == NV50_IR_SUBOP_MOV_FINAL)
> +      return false;
> +
>     for (int d = 0; defExists(d); ++d)
> -      if (getDef(d)->refCount() || getDef(d)->reg.data.id >= 0)
> +      if (getDef(d)->refCount() || (!postRA && getDef(d)->reg.data.id >= 0))
>           return false;
>
>     if (terminator || asFlow())
> @@ -2959,15 +2962,6 @@ private:
>     virtual bool visit(BasicBlock *);
>  };
>
> -static bool
> -post_ra_dead(Instruction *i)
> -{
> -   for (int d = 0; i->defExists(d); ++d)
> -      if (i->getDef(d)->refCount())
> -         return false;
> -   return true;
> -}
> -
>  bool
>  NV50PostRaConstantFolding::visit(BasicBlock *bb)
>  {
> @@ -3014,13 +3008,13 @@ NV50PostRaConstantFolding::visit(BasicBlock *bb)
>              /* There's no post-RA dead code elimination, so do it here
>               * XXX: if we add more code-removing post-RA passes, we might
>               *      want to create a post-RA dead-code elim pass */
> -            if (post_ra_dead(vtmp->getInsn())) {
> +            if (vtmp->getInsn()->isDead(true)) {
>                 Value *src = vtmp->getInsn()->getSrc(0);
>                 // Careful -- splits will have already been removed from the
>                 // functions. Don't double-delete.
>                 if (vtmp->getInsn()->bb)
>                    delete_Instruction(prog, vtmp->getInsn());
> -               if (src->getInsn() && post_ra_dead(src->getInsn()))
> +               if (src->getInsn() && src->getInsn()->isDead(true))
>                    delete_Instruction(prog, src->getInsn());
>              }
>
>