Revert "Allow cooperative matrix types for OpMatrixTimesScalar (#2124)" (#2276)

Per discussion in Khronos and the spec itself, OpMatrixTimesScalar should not be used in OpenCL environment, as long as the same can be achieved either via an elementwise multiplication with a cooperative matrix object created from the scalar using OpConstantComposite or by iterating over the elements of the cooperative matrix to multiply each element by the scalar.

Spec: https://github.com/KhronosGroup/SPIRV-Registry/blob/main/extensions/KHR/SPV_KHR_cooperative_matrix.asciidoc

This reverts commit 6522c4ac4764cc1f251edd4266d06cba64549928.

Original commit:
KhronosGroup/SPIRV-LLVM-Translator@3b6ff3e

Author: vmaksimo

llvm-spirv/lib/SPIRV/SPIRVReader.cpp

@@ -1964,12 +1964,6 @@ Value *SPIRVToLLVM::transValueWithoutDecoration(SPIRVValue *BV, Function *F,
     IRBuilder<> Builder(BB);
     auto *Scalar = transValue(MTS->getScalar(), F, BB);
     auto *Matrix = transValue(MTS->getMatrix(), F, BB);
-
-    if (MTS->getMatrix()->getType()->isTypeCooperativeMatrixKHR()) {
-      return mapValue(BV, transSPIRVBuiltinFromInst(
-                              static_cast<SPIRVInstruction *>(BV), BB));
-    }
-
     uint64_t ColNum = Matrix->getType()->getArrayNumElements();
     auto *ColType = cast<ArrayType>(Matrix->getType())->getElementType();
     auto VecSize = cast<FixedVectorType>(ColType)->getNumElements();

llvm-spirv/lib/SPIRV/SPIRVWriter.cpp

@@ -6246,11 +6246,6 @@ LLVMToSPIRVBase::transBuiltinToInstWithoutDecoration(Op OC, CallInst *CI,
     return BM->addCompositeConstructInst(transType(CI->getType()), Operands,
                                          BB);
   }
-  case OpMatrixTimesScalar: {
-    return BM->addMatrixTimesScalarInst(
-        transType(CI->getType()), transValue(CI->getArgOperand(0), BB)->getId(),
-        transValue(CI->getArgOperand(1), BB)->getId(), BB);
-  }
   default: {
     if (isCvtOpCode(OC) && OC != OpGenericCastToPtrExplicit) {
       return BM->addUnaryInst(OC, transScavengedType(CI),

llvm-spirv/lib/SPIRV/libSPIRV/SPIRVType.cpp

@@ -142,9 +142,6 @@ SPIRVType *SPIRVType::getScalarType() const {
     return getVectorComponentType();
   case OpTypeMatrix:
     return getMatrixColumnType()->getVectorComponentType();
-  case OpTypeCooperativeMatrixKHR:
-    return static_cast<const SPIRVTypeCooperativeMatrixKHR *>(this)
-        ->getCompType();
   case OpTypeInt:
   case OpTypeFloat:
   case OpTypeBool: