JIT: remove anticipated demand for throw helpers

src/coreclr/jit/codegenarm64.cpp

@@ -5937,7 +5937,7 @@ BasicBlock* CodeGen::genGetThrowHelper(SpecialCodeKind codeKind)
     {
         // For code with throw helper blocks, find and use the helper block for
         // raising the exception. The block may be shared by other trees too.
-        Compiler::AddCodeDsc* add = compiler->fgFindExcptnTarget(codeKind, compiler->compCurBB);
+        Compiler::AddCodeDsc* add = compiler->fgGetExcptnTarget(codeKind, compiler->compCurBB);
         assert((add != nullptr) && ("ERROR: failed to find exception throw block"));
         assert(add->acdUsed);
         excpRaisingBlock = add->acdDstBlk;

src/coreclr/jit/codegencommon.cpp

@@ -1623,7 +1623,7 @@ void CodeGen::genExitCode(BasicBlock* block)
 // genJumpToThrowHlpBlk: Generate code for an out-of-line exception.
 //
 // Notes:
-//   For code that uses throw helper blocks, we share the helper blocks created by fgAddCodeRef().
+//   For code that uses throw helper blocks, we share the helper blocks.
 //   Otherwise, we generate the 'throw' inline.
 //
 // Arguments:
@@ -1653,7 +1653,7 @@ void CodeGen::genJumpToThrowHlpBlk(emitJumpKind jumpKind, SpecialCodeKind codeKi
             excpRaisingBlock = failBlk;
 
 #ifdef DEBUG
-            Compiler::AddCodeDsc* add = compiler->fgFindExcptnTarget(codeKind, compiler->compCurBB);
+            Compiler::AddCodeDsc* add = compiler->fgGetExcptnTarget(codeKind, compiler->compCurBB);
             assert(add->acdUsed);
             assert(excpRaisingBlock == add->acdDstBlk);
 #if !FEATURE_FIXED_OUT_ARGS
@@ -1664,7 +1664,7 @@ void CodeGen::genJumpToThrowHlpBlk(emitJumpKind jumpKind, SpecialCodeKind codeKi
         else
         {
             // Find the helper-block which raises the exception.
-            Compiler::AddCodeDsc* add = compiler->fgFindExcptnTarget(codeKind, compiler->compCurBB);
+            Compiler::AddCodeDsc* add = compiler->fgGetExcptnTarget(codeKind, compiler->compCurBB);
             assert((add != nullptr) && ("ERROR: failed to find exception throw block"));
             assert(add->acdUsed);
             excpRaisingBlock = add->acdDstBlk;

src/coreclr/jit/codegenloongarch64.cpp

@@ -6514,7 +6514,7 @@ inline void CodeGen::genJumpToThrowHlpBlk_la(
             excpRaisingBlock = failBlk;
 
 #ifdef DEBUG
-            Compiler::AddCodeDsc* add = compiler->fgFindExcptnTarget(codeKind, compiler->compCurBB);
+            Compiler::AddCodeDsc* add = compiler->fgGetExcptnTarget(codeKind, compiler->compCurBB);
             assert(add->acdUsed);
             assert(excpRaisingBlock == add->acdDstBlk);
 #if !FEATURE_FIXED_OUT_ARGS
@@ -6525,7 +6525,7 @@ inline void CodeGen::genJumpToThrowHlpBlk_la(
         else
         {
             // Find the helper-block which raises the exception.
-            Compiler::AddCodeDsc* add = compiler->fgFindExcptnTarget(codeKind, compiler->compCurBB);
+            Compiler::AddCodeDsc* add = compiler->fgGetExcptnTarget(codeKind, compiler->compCurBB);
             assert((add != nullptr) && ("ERROR: failed to find exception throw block"));
             assert(add->acdUsed);
             excpRaisingBlock = add->acdDstBlk;

src/coreclr/jit/codegenriscv64.cpp

@@ -6202,7 +6202,7 @@ void CodeGen::genJumpToThrowHlpBlk_la(
             excpRaisingBlock = failBlk;
 
 #ifdef DEBUG
-            Compiler::AddCodeDsc* add = compiler->fgFindExcptnTarget(codeKind, compiler->compCurBB);
+            Compiler::AddCodeDsc* add = compiler->fgGetExcptnTarget(codeKind, compiler->compCurBB);
             assert(add->acdUsed);
             assert(excpRaisingBlock == add->acdDstBlk);
 #if !FEATURE_FIXED_OUT_ARGS
@@ -6213,7 +6213,7 @@ void CodeGen::genJumpToThrowHlpBlk_la(
         else
         {
             // Find the helper-block which raises the exception.
-            Compiler::AddCodeDsc* add = compiler->fgFindExcptnTarget(codeKind, compiler->compCurBB);
+            Compiler::AddCodeDsc* add = compiler->fgGetExcptnTarget(codeKind, compiler->compCurBB);
             assert((add != nullptr) && ("ERROR: failed to find exception throw block"));
             assert(add->acdUsed);
             excpRaisingBlock = add->acdDstBlk;

src/coreclr/jit/codegenwasm.cpp

@@ -1192,7 +1192,7 @@ void CodeGen::genCodeForNullCheck(GenTreeIndir* tree)
     // TODO-WASM: refactor once we have implemented other cases invoking throw helpers
     if (compiler->fgUseThrowHelperBlocks())
     {
-        Compiler::AddCodeDsc* const add = compiler->fgFindExcptnTarget(SCK_NULL_CHECK, compiler->compCurBB);
+        Compiler::AddCodeDsc* const add = compiler->fgGetExcptnTarget(SCK_NULL_CHECK, compiler->compCurBB);
 
         if (add == nullptr)
         {

src/coreclr/jit/compiler.cpp

@@ -4898,10 +4898,6 @@ void Compiler::compCompile(void** methodCodePtr, uint32_t* methodCodeSize, JitFl
     // Insert GC Polls
     DoPhase(this, PHASE_INSERT_GC_POLLS, &Compiler::fgInsertGCPolls);
 
-    // Create any throw helper blocks that might be needed
-    //
-    DoPhase(this, PHASE_CREATE_THROW_HELPERS, &Compiler::fgCreateThrowHelperBlocks);
-
     if (opts.OptimizationEnabled())
     {
         // Conditional to switch conversion, and switch peeling

src/coreclr/jit/compiler.h

@@ -6774,7 +6774,7 @@ class Compiler
 
     struct AddCodeDsc
     {
-        // After fgCreateThrowHelperBlocks, the block to which
+        // The block to which
         // we jump to raise the exception.
         BasicBlock*     acdDstBlk;
 
@@ -6838,16 +6838,15 @@ class Compiler
 private:
     static unsigned acdHelper(SpecialCodeKind codeKind);
 
-    bool        fgRngChkThrowAdded = false;
     AddCodeDscMap* fgAddCodeDscMap = nullptr;
-
-    void fgAddCodeRef(BasicBlock* srcBlk, SpecialCodeKind kind);
-    PhaseStatus fgCreateThrowHelperBlocks();
+    AddCodeDsc* fgCreateAddCodeDsc(BasicBlock* fromBlock, SpecialCodeKind kind);
+    void fgCreateThrowHelperBlock(AddCodeDsc* add);
 
 public:
 
+    bool fgRngChkThrowAdded = false;
     bool fgHasAddCodeDscMap() const { return fgAddCodeDscMap != nullptr; }
-    AddCodeDsc* fgFindExcptnTarget(SpecialCodeKind kind, BasicBlock* fromBlock);
+    AddCodeDsc* fgGetExcptnTarget(SpecialCodeKind kind, BasicBlock* fromBlock, bool createIfNeeded = false);
     bool fgUseThrowHelperBlocks();
     void fgCreateThrowHelperBlockCode(AddCodeDsc* add);
     void fgSequenceLocals(Statement* stmt);