thr3ads.net - Nouveau - [Nouveau] [PATCH 1/2] nv50/ir: Add support for MAD short+IMM notation [Jan 2015]

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Roy Spliet

2015-Jan-23 21:46 UTC

[Nouveau] [PATCH 1/2] nv50/ir: Add support for MAD short+IMM notation

Add emission rules for negative and saturate flags for MAD 4-byte opcodes,
and get rid of constraints. Short MAD has a very specific SDST == SSRC2
requirement, and since MAD IMM is short notation + 4-byte immediate, don't
have the compiler create MAD IMM instructions yet.

V2: Document MAD as supported short form

Signed-off-by: Roy Spliet <rspliet at eclipso.eu>
---
 .../drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp      | 18 ++++++++++++------
 .../drivers/nouveau/codegen/nv50_ir_target_nv50.cpp    |  4 ++--
 2 files changed, 14 insertions(+), 8 deletions(-)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
index 2077388..b1e7409 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
@@ -939,9 +939,20 @@ CodeEmitterNV50::emitFMAD(const Instruction *i)
 
    code[0] = 0xe0000000;
 
+   if (i->src(1).getFile() == FILE_IMMEDIATE) {
+      code[1] = 0;
+      emitForm_IMM(i);
+      code[0] |= neg_mul << 15;
+      code[0] |= neg_add << 22;
+      if (i->saturate)
+         code[0] |= 1 << 8;
+   } else
    if (i->encSize == 4) {
       emitForm_MUL(i);
-      assert(!neg_mul && !neg_add);
+      code[0] |= neg_mul << 15;
+      code[0] |= neg_add << 22;
+      if (i->saturate)
+         code[0] |= 1 << 8;
    } else {
       code[1]  = neg_mul << 26;
       code[1] |= neg_add << 27;
@@ -1931,11 +1942,6 @@ CodeEmitterNV50::getMinEncodingSize(const Instruction *i)
const
 
    // check constraints on short MAD
    if (info.srcNr >= 2 && i->srcExists(2)) {
-      if (i->saturate || i->src(2).mod)
-         return 8;
-      if ((i->src(0).mod ^ i->src(1).mod) ||
-          (i->src(0).mod | i->src(1).mod).abs())
-         return 8;
       if (!i->defExists(0) ||
           i->def(0).rep()->reg.data.id !=
i->src(2).rep()->reg.data.id)
          return 8;
diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
index 48f996b..178a167 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
@@ -117,8 +117,8 @@ void TargetNV50::initOpInfo()
    };
    static const uint32_t shortForm[(OP_LAST + 31) / 32]     {
-      // MOV,ADD,SUB,MUL,SAD,L/PINTERP,RCP,TEX,TXF
-      0x00010e40, 0x00000040, 0x00000498, 0x00000000
+      // MOV,ADD,SUB,MUL,MAD,SAD,L/PINTERP,RCP,TEX,TXF
+      0x00014e40, 0x00000040, 0x00000498, 0x00000000
    };
    static const operation noDestList[]     {
-- 
2.1.0

Roy Spliet

2015-Jan-23 21:46 UTC

head link

[Nouveau] [PATCH 2/2] nv50/ir: Fold IMM into MAD

Add a specific optimisation pass for NV50 to check whether SRC0 or SRC1 is
a MOV dst, IMM. If so: fold the IMM in and try to drop the MOV. Must be
done post-RA because it requires that SDST == SSRC2.

V2: improve readability and add comments to clarify decisions
V3: Remove redundant code... compiler already attempts to put the IMM in
SSRC1

Signed-off-by: Roy Spliet <rspliet at eclipso.eu>
---
 .../drivers/nouveau/codegen/nv50_ir_peephole.cpp   | 53 ++++++++++++++++++++++
 1 file changed, 53 insertions(+)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
index 21d20ca..62d2ef7 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
@@ -2259,6 +2259,56 @@ FlatteningPass::tryPredicateConditional(BasicBlock *bb)
 
 // ============================================================================
+// Fold Immediate into MAD; must be done after register allocation due to
+// constraint SDST == SSRC2
+// TODO:
+// Does NVC0+ have other situations where this pass makes sense?
+class NV50PostRaConstantFolding : public Pass
+{
+private:
+   virtual bool visit(BasicBlock *);
+};
+
+bool
+NV50PostRaConstantFolding::visit(BasicBlock *bb)
+{
+   Value *vtmp;
+   Instruction *def;
+
+   for (Instruction *i = bb->getFirst(); i; i = i->next) {
+      switch (i->op) {
+      case OP_MAD:
+         if (i->def(0).getFile() != FILE_GPR ||
+             i->src(0).getFile() != FILE_GPR ||
+             i->src(1).getFile() != FILE_GPR ||
+             i->src(2).getFile() != FILE_GPR ||
+             i->getDef(0)->reg.data.id !=
i->getSrc(2)->reg.data.id)
+            break;
+
+         def = i->getSrc(1)->getInsn();
+         if (def->op == OP_MOV && def->src(0).getFile() ==
FILE_IMMEDIATE) {
+            vtmp = i->getSrc(1);
+            i->setSrc(1, def->getSrc(0));
+
+            /* 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 (vtmp->refCount() == 0)
+               delete_Instruction(bb->getProgram(), def);
+
+            break;
+         }
+         break;
+      default:
+         break;
+      }
+   }
+
+   return true;
+}
+
+//
============================================================================+
 // Common subexpression elimination. Stupid O^2 implementation.
 class LocalCSE : public Pass
 {
@@ -2629,6 +2679,9 @@ bool
 Program::optimizePostRA(int level)
 {
    RUN_PASS(2, FlatteningPass, run);
+   if (getTarget()->getChipset() < 0xc0)
+      RUN_PASS(2, NV50PostRaConstantFolding, run);
+
    return true;
 }
 
-- 
2.1.0

Ilia Mirkin

2015-Jan-23 22:19 UTC

head link

[Nouveau] [PATCH 1/2] nv50/ir: Add support for MAD short+IMM notation

On Fri, Jan 23, 2015 at 1:46 PM, Roy Spliet <rspliet at eclipso.eu>
wrote:> Add emission rules for negative and saturate flags for MAD 4-byte opcodes,
> and get rid of constraints. Short MAD has a very specific SDST == SSRC2
> requirement, and since MAD IMM is short notation + 4-byte immediate,
don't
> have the compiler create MAD IMM instructions yet.
>
> V2: Document MAD as supported short form
>
> Signed-off-by: Roy Spliet <rspliet at eclipso.eu>
> ---
>  .../drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp      | 18
++++++++++++------
>  .../drivers/nouveau/codegen/nv50_ir_target_nv50.cpp    |  4 ++--
>  2 files changed, 14 insertions(+), 8 deletions(-)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
> index 2077388..b1e7409 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_emit_nv50.cpp
> @@ -939,9 +939,20 @@ CodeEmitterNV50::emitFMAD(const Instruction *i)
>
>     code[0] = 0xe0000000;
>
> +   if (i->src(1).getFile() == FILE_IMMEDIATE) {
> +      code[1] = 0;
> +      emitForm_IMM(i);
> +      code[0] |= neg_mul << 15;
> +      code[0] |= neg_add << 22;
> +      if (i->saturate)
> +         code[0] |= 1 << 8;
> +   } else
>     if (i->encSize == 4) {
>        emitForm_MUL(i);
> -      assert(!neg_mul && !neg_add);
> +      code[0] |= neg_mul << 15;
> +      code[0] |= neg_add << 22;
> +      if (i->saturate)
> +         code[0] |= 1 << 8;
>     } else {
>        code[1]  = neg_mul << 26;
>        code[1] |= neg_add << 27;
> @@ -1931,11 +1942,6 @@ CodeEmitterNV50::getMinEncodingSize(const
Instruction *i) const
>
>     // check constraints on short MAD
>     if (info.srcNr >= 2 && i->srcExists(2)) {
> -      if (i->saturate || i->src(2).mod)
> -         return 8;
> -      if ((i->src(0).mod ^ i->src(1).mod) ||
> -          (i->src(0).mod | i->src(1).mod).abs())
> -         return 8;
Please confirm that you tested shaders with these specific
instructions being generated, i.e. short form mad + sat and mad +
neg/abs.

Separately, please split this (and related bits) from the mad + imm
change, which is separate. When there's a regression because of this,
I want the bisected change to say "enable sat/neg/abs for mad short
form", not "add mad imm but don't enable it" :)
>        if (!i->defExists(0) ||
>            i->def(0).rep()->reg.data.id !=
i->src(2).rep()->reg.data.id)
>           return 8;
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
> index 48f996b..178a167 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_target_nv50.cpp
> @@ -117,8 +117,8 @@ void TargetNV50::initOpInfo()
>     };
>     static const uint32_t shortForm[(OP_LAST + 31) / 32] >     {
> -      // MOV,ADD,SUB,MUL,SAD,L/PINTERP,RCP,TEX,TXF
> -      0x00010e40, 0x00000040, 0x00000498, 0x00000000
> +      // MOV,ADD,SUB,MUL,MAD,SAD,L/PINTERP,RCP,TEX,TXF
> +      0x00014e40, 0x00000040, 0x00000498, 0x00000000
>     };
>     static const operation noDestList[] >     {
> --
> 2.1.0
>
>
>
> _______________________________________________
> Nouveau mailing list
> Nouveau at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/nouveau

Ilia Mirkin

2015-Jan-23 22:21 UTC

head link

[Nouveau] [PATCH 2/2] nv50/ir: Fold IMM into MAD

On Fri, Jan 23, 2015 at 1:46 PM, Roy Spliet <rspliet at eclipso.eu>
wrote:> Add a specific optimisation pass for NV50 to check whether SRC0 or SRC1 is
> a MOV dst, IMM. If so: fold the IMM in and try to drop the MOV. Must be
> done post-RA because it requires that SDST == SSRC2.
>
> V2: improve readability and add comments to clarify decisions
> V3: Remove redundant code... compiler already attempts to put the IMM in
> SSRC1
>
> Signed-off-by: Roy Spliet <rspliet at eclipso.eu>
Reviewed-by: Ilia Mirkin <imirkin at alum.mit.edu>
> ---
>  .../drivers/nouveau/codegen/nv50_ir_peephole.cpp   | 53
++++++++++++++++++++++
>  1 file changed, 53 insertions(+)
>
> diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> index 21d20ca..62d2ef7 100644
> --- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> +++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
> @@ -2259,6 +2259,56 @@ FlatteningPass::tryPredicateConditional(BasicBlock
*bb)
>
>  //
============================================================================>
> +// Fold Immediate into MAD; must be done after register allocation due to
> +// constraint SDST == SSRC2
> +// TODO:
> +// Does NVC0+ have other situations where this pass makes sense?
> +class NV50PostRaConstantFolding : public Pass
> +{
> +private:
> +   virtual bool visit(BasicBlock *);
> +};
> +
> +bool
> +NV50PostRaConstantFolding::visit(BasicBlock *bb)
> +{
> +   Value *vtmp;
> +   Instruction *def;
> +
> +   for (Instruction *i = bb->getFirst(); i; i = i->next) {
> +      switch (i->op) {
> +      case OP_MAD:
> +         if (i->def(0).getFile() != FILE_GPR ||
> +             i->src(0).getFile() != FILE_GPR ||
> +             i->src(1).getFile() != FILE_GPR ||
> +             i->src(2).getFile() != FILE_GPR ||
> +             i->getDef(0)->reg.data.id !=
i->getSrc(2)->reg.data.id)
> +            break;
> +
> +         def = i->getSrc(1)->getInsn();
> +         if (def->op == OP_MOV && def->src(0).getFile() ==
FILE_IMMEDIATE) {
> +            vtmp = i->getSrc(1);
> +            i->setSrc(1, def->getSrc(0));
> +
> +            /* 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 (vtmp->refCount() == 0)
> +               delete_Instruction(bb->getProgram(), def);
> +
> +            break;
> +         }
> +         break;
> +      default:
> +         break;
> +      }
> +   }
> +
> +   return true;
> +}
> +
> +//
============================================================================>
+
>  // Common subexpression elimination. Stupid O^2 implementation.
>  class LocalCSE : public Pass
>  {
> @@ -2629,6 +2679,9 @@ bool
>  Program::optimizePostRA(int level)
>  {
>     RUN_PASS(2, FlatteningPass, run);
> +   if (getTarget()->getChipset() < 0xc0)
> +      RUN_PASS(2, NV50PostRaConstantFolding, run);
> +
>     return true;
>  }
>
> --
> 2.1.0
>
>
>
> _______________________________________________
> Nouveau mailing list
> Nouveau at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/nouveau

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