Fix broken BasicBlock in Emu64OpsPass

InstExpander::convertUIToFP32 did not set its insertion point
correctly and were thus adding instructions to a non-existing
BasicBlock.

Fix by ensuring that the insertion point is set to the right
instruction in the new block and allow the callers to continue from
where convertUIToFP32 left off.

IGC/Compiler/CISACodeGen/Emu64OpsPass.cpp

@@ -1425,18 +1425,9 @@ bool InstExpander::visitFPToSI(FPToSIInst& F2S) {
     return true;
 }
 
-// Note: This method uses splitBasciBlock() which moves Pos (and all
-// instructions following it till the end of basic block) to a new basic block.
-// If IRB's insert point is set to Pos or an instruction after Pos in the same
-// basic block than the insert basic block value in IRB will be invalid after
-// this method completes. A correct insert point should be set in IRB after this
-// method is called.
-//
 Value* InstExpander::convertUIToFP32(Type* DstTy, Value* Lo, Value* Hi, Instruction* Pos) {
     IGC_ASSERT(nullptr != Pos);
     IGC_ASSERT(nullptr != IRB);
-    BuilderType::InsertPointGuard Guard(*IRB);
-    IRB->SetInsertPoint(Pos);
 
     IGCLLVM::Intrinsic IID;
     IID = Intrinsic::ctlz;
@@ -1449,6 +1440,10 @@ Value* InstExpander::convertUIToFP32(Type* DstTy, Value* Lo, Value* Hi, Instruct
     BasicBlock* OldBB = Pos->getParent();
     IGC_ASSERT(nullptr != OldBB);
     BasicBlock* JointBB = OldBB->splitBasicBlock(Pos);
+
+    // Set insert point to Pos in the new block JointBB
+    IRB->SetInsertPoint(Pos);
+
     PHINode* Res = PHINode::Create(IRB->getInt32Ty(), 2, ".u2f.outer.merge", Pos);
 
     {
@@ -1497,7 +1492,7 @@ Value* InstExpander::convertUIToFP32(Type* DstTy, Value* Lo, Value* Hi, Instruct
         BasicBlock* RoundingJBB = InnerJBB->splitBasicBlock(InnerJmp);
         PHINode* RoundingRes = PHINode::Create(IRB->getInt32Ty(), 2, ".u2f.rounding.merge.hi", InnerJmp);
 
-        BasicBlock* RoundingBB = BasicBlock::Create(*Emu->getContext(), ".u2f.roudning.branch");
+        BasicBlock* RoundingBB = BasicBlock::Create(*Emu->getContext(), ".u2f.rounding.branch");
         RoundingBB->insertInto(Emu->getFunction(), RoundingJBB);
         BranchInst::Create(RoundingJBB, RoundingBB);
 
@@ -1555,7 +1550,6 @@ bool InstExpander::visitUIToFP(UIToFPInst& U2F) {
     }
     else {
         NewVal = convertUIToFP32(IRB->getFloatTy(), Lo, Hi, &U2F);
-        IRB->SetInsertPoint(&U2F);
         // It's OK to apply the same approach in `convertUIToFP32` to convert 64-bit
         // integer into half. But, it would introduce a little more instructions to
         // properly round the remaining 48 bits into the high 16 bits. Instead, that
@@ -1617,7 +1611,6 @@ bool InstExpander::visitSIToFP(SIToFPInst& S2F) {
         Hi = IRB->CreateExtractValue(V, 1);
 
         NewVal = convertUIToFP32(IRB->getFloatTy(), Lo, Hi, &S2F);
-        IRB->SetInsertPoint(&S2F);
         NewVal = IRB->CreateBitCast(NewVal, IRB->getInt32Ty());
         Sign = IRB->CreateAnd(Sign, IRB->getInt32(0x80000000));
         NewVal = IRB->CreateOr(NewVal, Sign);