[Mesa-dev] [PATCH 3/8] nv50/ir: optimize ADD(ADD(a, b), c) to ADD3(a, b, c)

[Samuel Pitoiset]

Signed-off-by: Samuel Pitoiset <samuel.pitoiset at gmail.com>
---
 .../drivers/nouveau/codegen/nv50_ir_peephole.cpp   | 55 ++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
index 3213188..928923c 100644
--- a/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
+++ b/src/gallium/drivers/nouveau/codegen/nv50_ir_peephole.cpp
@@ -1531,6 +1531,7 @@ private:
    void handleABS(Instruction *);
    bool handleADD(Instruction *);
    bool tryADDToMADOrSAD(Instruction *, operation toOp);
+   bool tryADDToADD3(Instruction *);
    void handleMINMAX(Instruction *);
    void handleRCP(Instruction *);
    void handleSLCT(Instruction *);
@@ -1604,6 +1605,8 @@ AlgebraicOpt::handleADD(Instruction *add)
       changed = tryADDToMADOrSAD(add, OP_MAD);
    if (!changed && prog->getTarget()->isOpSupported(OP_SAD, add->dType))
       changed = tryADDToMADOrSAD(add, OP_SAD);
+   if (!changed && prog->getTarget()->isOpSupported(OP_ADD3, add->dType))
+      changed = tryADDToADD3(add);
    return changed;
 }
 
@@ -1674,6 +1677,58 @@ AlgebraicOpt::tryADDToMADOrSAD(Instruction *add, operation toOp)
    return true;
 }
 
+// ADD(ADD(a,b), c) -> ADD3(a,b,c)
+bool
+AlgebraicOpt::tryADDToADD3(Instruction *add)
+{
+   Value *src0 = add->getSrc(0);
+   Value *src1 = add->getSrc(1);
+   const Modifier modBad = Modifier(~NV50_IR_MOD_NEG);
+   Modifier mod[4];
+   Value *src;
+   int s;
+
+   if (src0->refCount() == 1 &&
+       src0->getUniqueInsn() && src0->getUniqueInsn()->op == OP_ADD)
+      s = 0;
+   else
+   if (src1->refCount() == 1 &&
+       src1->getUniqueInsn() && src1->getUniqueInsn()->op == OP_ADD)
+      s = 1;
+   else
+      return false;
+
+   src = add->getSrc(s);
+
+   if (src->getUniqueInsn() && src->getUniqueInsn()->bb != add->bb)
+      return false;
+
+   if (src->getInsn()->saturate)
+      return false;
+
+   if (typeSizeof(add->dType) != typeSizeof(src->getInsn()->dType))
+      return false;
+
+   mod[0] = add->src(0).mod;
+   mod[1] = add->src(1).mod;
+   mod[2] = src->getUniqueInsn()->src(0).mod;
+   mod[3] = src->getUniqueInsn()->src(1).mod;
+
+   if (((mod[0] | mod[1]) | (mod[2] | mod[3])) & modBad)
+      return false;
+
+   add->op = OP_ADD3;
+   add->dType = src->getInsn()->dType;
+   add->sType = src->getInsn()->sType;
+
+   add->setSrc(s, src->getInsn()->getSrc(0));
+   add->src(s).mod = mod[s] ^ mod[2];
+   add->setSrc(2, src->getInsn()->getSrc(1));
+   add->src(2).mod = mod[3];
+
+   return true;
+}
+
 void
 AlgebraicOpt::handleMINMAX(Instruction *minmax)
 {
-- 
2.8.3