Backout "Remove bf_cvt (#47152)"

Revert "[IGC Refactor][IGC Core]: Remove bf_cvt (#47152)"

Author: jgu222

IGC/Compiler/CISACodeGen/CISABuilder.cpp

@@ -6819,6 +6819,22 @@ namespace IGC
             addressOpnd, srcOpnd));
     }
 
+    void CEncoder::bf_cvt(CVariable* dst, CVariable* src)
+    {
+        VISA_PredOpnd* predOpnd = GetFlagOperand(m_encoderState.m_flag);
+        VISA_VectorOpnd* dstOpnd = GetDestinationOperand(dst, m_encoderState.m_dstOperand);
+        VISA_VectorOpnd* srcOpnd0 = GetSourceOperand(src, m_encoderState.m_srcOperand[0]);
+
+        V(vKernel->AppendVISADataMovementInst(
+            ISA_BF_CVT,
+            predOpnd,
+            false,
+            GetAluEMask(dst),
+            visaExecSize(dst->IsUniform()
+                ? m_encoderState.m_uniformSIMDSize : m_encoderState.m_simdSize),
+            dstOpnd,
+            srcOpnd0));
+    }
 
     std::string CEncoder::GetVariableName(CVariable* var)
     {

IGC/Compiler/CISACodeGen/CISABuilder.hpp

@@ -318,6 +318,7 @@ namespace IGC
         void dpas(CVariable* dst, CVariable* input, CVariable* weight, PrecisionType weight_precision,
             CVariable* actication, PrecisionType activation_precision, uint8_t systolicDepth,
             uint8_t repeatCount, bool IsDpasw);
+        void bf_cvt(CVariable* dst, CVariable* src);
         void fcvt(CVariable* dst, CVariable* src);
         void Bfn(uint8_t booleanFuncCtrl, CVariable* dst, CVariable* src0, CVariable* src1, CVariable* src2);
         void QWGather(CVariable* dst, const ResourceDescriptor& resource, CVariable* offset, unsigned elementSize, unsigned numElems);

IGC/Compiler/CISACodeGen/EmitVISAPass.cpp

@@ -18660,28 +18660,31 @@ void EmitPass::emitfcvt(llvm::GenIntrinsicInst* GII)
     if (FP_RM != ERoundingMode::ROUND_TO_ANY)
         SetRoundingMode_FP(FP_RM);
 
-    // vISA instruction doesn't support immediate source of type BF
-    if (id == GenISAIntrinsic::GenISA_bftof && src->IsImmediate())
-    {
-        uint32_t imm32 = ((uint32_t)src->GetImmediateValue()) & 0xFFFF;
-        imm32 = imm32 << 16; // make it as float immediate
-        CVariable* fSrc = m_currShader->ImmToVariable((uint64_t)imm32, ISA_TYPE_F);
-        m_encoder->Copy(dst, fSrc);
-        m_encoder->Push();
-        return;
+    // BF_CVT vISA instruction doesn't support immediate source
+    if (id == GenISAIntrinsic::GenISA_ftobf ||
+        id == GenISAIntrinsic::GenISA_bftof) {
+        if (src->IsImmediate()) {
+            CVariable* tempMov = m_currShader->GetNewVariable(
+                1, src->GetType(), EALIGN_GRF, true, src->getName());
+            m_encoder->Copy(tempMov, src);
+            m_encoder->Push();
+            src = tempMov;
+        }
     }
 
     if (id == GenISAIntrinsic::GenISA_ftobf ||
         id == GenISAIntrinsic::GenISA_bftof)
     {
+        /// Use UW as we are not exposing BF for now.
+        /// vISA will convert it to BF.
         CVariable* tDst = nullptr, * tSrc = nullptr;
         if (id == GenISAIntrinsic::GenISA_ftobf) {
-            tDst = m_currShader->GetNewAlias(dst, ISA_TYPE_BF, 0, 0);
+            tDst = m_currShader->GetNewAlias(dst, ISA_TYPE_UW, 0, 0);
             tSrc = src;
         }
         else if (id == GenISAIntrinsic::GenISA_bftof) {
             tDst = dst;
-            tSrc = m_currShader->GetNewAlias(src, ISA_TYPE_BF, 0, 0);
+            tSrc = m_currShader->GetNewAlias(src, ISA_TYPE_UW, 0, 0);
         }
         else {
             IGC_ASSERT_EXIT_MESSAGE(0, "Something wrong in cvt!");
@@ -18706,7 +18709,7 @@ void EmitPass::emitfcvt(llvm::GenIntrinsicInst* GII)
                     uint32_t stride = (esize >= 8 ? 8 : esize);
                     m_encoder->SetSrcRegion(0, stride, stride, 1);
                 }
-                m_encoder->Copy(tDst, tSrc);
+                m_encoder->bf_cvt(tDst, tSrc);
                 m_encoder->Push();
             }
         }
@@ -18717,7 +18720,7 @@ void EmitPass::emitfcvt(llvm::GenIntrinsicInst* GII)
             {
                 m_encoder->SetDstSubReg(dstOff);
                 m_encoder->SetSrcSubReg(0, srcOff);
-                m_encoder->Copy(tDst, tSrc);
+                m_encoder->bf_cvt(tDst, tSrc);
                 m_encoder->Push();
 
                 dstOff += (isDstUniform ? 1 : nsimdsize);
@@ -18730,7 +18733,7 @@ void EmitPass::emitfcvt(llvm::GenIntrinsicInst* GII)
         CVariable* srcs[2];
         srcs[0] = src;
         srcs[1] = GetSymbol(GII->getOperand(1));
-        CVariable* tDst = m_currShader->GetNewAlias(dst, ISA_TYPE_BF, 0, 0);
+        CVariable* tDst = m_currShader->GetNewAlias(dst, ISA_TYPE_HF, 0, 0);
         SmallVector<uint32_t, 16> insts;
         getAllExecsize(insts, nelts);
         for (int e = 0; e < 2; ++e)
@@ -18755,7 +18758,7 @@ void EmitPass::emitfcvt(llvm::GenIntrinsicInst* GII)
                         uint32_t stride = (esize >= 8 ? 8 : esize);
                         m_encoder->SetSrcRegion(0, stride, stride, 1);
                     }
-                    m_encoder->Copy(tDst, tSrc);
+                    m_encoder->bf_cvt(tDst, tSrc);
                     m_encoder->Push();
                 }
             }
@@ -18767,7 +18770,7 @@ void EmitPass::emitfcvt(llvm::GenIntrinsicInst* GII)
                     m_encoder->SetDstSubReg(2 * dstOff + e);
                     m_encoder->SetDstRegion(2);
                     m_encoder->SetSrcSubReg(0, srcOff);
-                    m_encoder->Copy(tDst, tSrc);
+                    m_encoder->bf_cvt(tDst, tSrc);
                     m_encoder->Push();
 
                     dstOff += (isDstUniform ? 1 : nsimdsize);