Moving gen stack level to code gen interface (#23328)

* Make genStackLevel accessible from CodeGenInterface

* Initializing stackLevel before fist BasicBlock's code is generated

* Typo

* Removing extra line on comments

4 files changed, 16 insertions, 4 deletions

diff --git a/src/jit/codegen.h b/src/jit/codegen.h
index 11c81c4b91..046addff4c 100644
--- a/src/jit/codegen.h
+++ b/src/jit/codegen.h
@@ -126,10 +126,6 @@ private:
     bool     genUseBlockInit;  // true if we plan to block-initialize the local stack frame
     unsigned genInitStkLclCnt; // The count of local variables that we need to zero init
 
-    //  Keeps track of how many bytes we've pushed on the processor's stack.
-    //
-    unsigned genStackLevel;
-
     void SubtractStackLevel(unsigned adjustment)
     {
         assert(genStackLevel >= adjustment);
diff --git a/src/jit/codegencommon.cpp b/src/jit/codegencommon.cpp
index 2b5236b82a..2e15383025 100644
--- a/src/jit/codegencommon.cpp
+++ b/src/jit/codegencommon.cpp
@@ -11578,3 +11578,8 @@ void CodeGen::genStackPointerCheck(bool doStackPointerCheck, unsigned lvaStackPo
 }
 
 #endif // defined(DEBUG) && defined(_TARGET_XARCH_)
+
+unsigned CodeGenInterface::getCurrentStackLevel() const
+{
+    return genStackLevel;
+}
diff --git a/src/jit/codegeninterface.h b/src/jit/codegeninterface.h
index 9a67649084..6935a77e3f 100644
--- a/src/jit/codegeninterface.h
+++ b/src/jit/codegeninterface.h
@@ -542,6 +542,13 @@ public:
             const LclVarDsc* varDsc, var_types type, regNumber baseReg, int offset, bool isFramePointerUsed);
     };
 
+public:
+    unsigned getCurrentStackLevel() const;
+
+protected:
+    //  Keeps track of how many bytes we've pushed on the processor's stack.
+    unsigned genStackLevel;
+
 #ifdef LATE_DISASM
 public:
     virtual const char* siRegVarName(size_t offs, size_t size, unsigned reg) = 0;
diff --git a/src/jit/codegenlinear.cpp b/src/jit/codegenlinear.cpp
index c0a20343a3..595f86016e 100644
--- a/src/jit/codegenlinear.cpp
+++ b/src/jit/codegenlinear.cpp
@@ -114,6 +114,10 @@ void CodeGen::genInitialize()
     // Make sure a set is allocated for compiler->compCurLife (in the long case), so we can set it to empty without
     // allocation at the start of each basic block.
     VarSetOps::AssignNoCopy(compiler, compiler->compCurLife, VarSetOps::MakeEmpty(compiler));
+
+    // We initialize the stack level before first "BasicBlock" code is generated in case we need to report stack
+    // variable needs home and so its stack offset.
+    SetStackLevel(0);
 }
 
 //------------------------------------------------------------------------