vISA: Do not generate mac instructions with HW restrictions

Author: DianaChen

visa/AccSubstitution.cpp

@@ -682,7 +682,18 @@ bool AccSubPass::replaceDstWithAcc(G4_INST* inst, int accNum)
         G4_SrcRegRegion* accSrc = builder.createSrcRegRegion(oldSrc->getModifier(), Direct,
             accReg, (short)accNum, 0, builder.getRegionStride1(), dst->getType());
         accSrc->setAccRegSel(oldSrc->getAccRegSel());
-        if (useInst->opcode() == G4_mad && srcId == 0 && !builder.canMadHaveSrc0Acc())
+
+        bool canReplaceToMac = useInst->opcode() == G4_mad && srcId == 0 && !builder.canMadHaveSrc0Acc();
+        if (canReplaceToMac && builder.noDFTypeMac()) {
+            // dst and all src cannot be DF
+            if ((useInst->getDst() && IS_DFTYPE(useInst->getDst()->getType())) ||
+                (useInst->getSrc(0) && IS_DFTYPE(useInst->getSrc(0)->getType())) ||
+                (useInst->getSrc(1) && IS_DFTYPE(useInst->getSrc(1)->getType())) ||
+                (useInst->getSrc(2) && IS_DFTYPE(useInst->getSrc(2)->getType())))
+                canReplaceToMac = false;
+        }
+
+        if (canReplaceToMac)
         {
             // change mad to mac as src0 of 3-src does not support acc
             auto updateDefSrcPos = [](G4_INST* useInst, Gen4_Operand_Number origPos)

visa/HWCaps.inc

@@ -96,6 +96,11 @@ SPDX-License-Identifier: MIT
         return getOption(vISA_noSrc1Byte) || getPlatform() >= GENX_ICLLP;
     }
 
+    bool noDFTypeMac() const
+    {
+        return false;
+    }
+
     bool needsFenceCommitEnable() const
     {
         if (m_options->getTarget() == VISA_CM)

visa/Optimizer.cpp

@@ -9517,6 +9517,12 @@ bool MadSequenceInfo::checkMadSequence()
         if (!src0 || !src1 || !src2)
             return false;
 
+        if (builder.noDFTypeMac()) {
+            if (IS_DFTYPE(src0->getType()) || IS_DFTYPE(src1->getType()) || IS_DFTYPE(src2->getType()) ||
+                IS_DFTYPE(inst->getDst()->getType()))
+                return false;
+        }
+
         if (IS_FTYPE(src0->getType()) && IS_FTYPE(src1->getType()) &&
             IS_FTYPE(src2->getType()))
         {