Update unwind logic

Author: DeepakRajendrakumaran

src/coreclr/jit/codegenxarch.cpp

@@ -10359,8 +10359,7 @@ void CodeGen::genPushCalleeSavedRegisters()
 
             GetEmitter()->emitIns_R_R(INS_push2, EA_PTRSIZE, reg1, reg2,
                                       (insOpts)(INS_OPTS_EVEX_nd | INS_OPTS_APX_ppx));
-            compiler->unwindPush(reg1);
-            compiler->unwindPush(reg2);
+            compiler->unwindPush2(reg1, reg2);
         }
 
         if (regStack.Height() == 1)

src/coreclr/jit/compiler.h

@@ -8806,6 +8806,7 @@ class Compiler
     //
 
     void unwindPush(regNumber reg);
+    void unwindPush2(regNumber reg1, regNumber reg2);
     void unwindAllocStack(unsigned size);
     void unwindSetFrameReg(regNumber reg, unsigned offset);
     void unwindSaveReg(regNumber reg, unsigned offset);
@@ -8878,6 +8879,7 @@ class Compiler
 
     void unwindBegPrologWindows();
     void unwindPushWindows(regNumber reg);
+    void unwindPush2Windows(regNumber reg1, regNumber reg2);
     void unwindAllocStackWindows(unsigned size);
     void unwindSetFrameRegWindows(regNumber reg, unsigned offset);
     void unwindSaveRegWindows(regNumber reg, unsigned offset);
@@ -8896,6 +8898,7 @@ class Compiler
     short mapRegNumToDwarfReg(regNumber reg);
     void  createCfiCode(FuncInfoDsc* func, UNATIVE_OFFSET codeOffset, UCHAR opcode, short dwarfReg, INT offset = 0);
     void  unwindPushPopCFI(regNumber reg);
+    void  unwindPush2Pop2CFI(regNumber reg1, regNumber reg2);
     void  unwindBegPrologCFI();
     void  unwindPushPopMaskCFI(regMaskTP regMask, bool isFloat);
     void  unwindAllocStackCFI(unsigned size);

src/coreclr/jit/unwind.cpp

@@ -176,6 +176,20 @@ void Compiler::unwindPushPopCFI(regNumber reg)
     }
 }
 
+//------------------------------------------------------------------------
+// Compiler::unwindPush2Pop2CFI: Record  push/save of 2 registers simultaneously.
+//
+// Arguments:
+//    reg1 - The first register being pushed/saved.
+//    reg2 - The second register being pushed/saved.
+//
+void Compiler::unwindPush2Pop2CFI(regNumber reg1, regNumber reg2)
+{
+    // ToDo: This is a placeholder till OS has unwind support for push2/pop2.
+    unwindPushPopCFI(reg1);
+    unwindPushPopCFI(reg2);
+}
+
 typedef jitstd::vector<CFI_CODE> CFICodeVector;
 
 void Compiler::unwindBegPrologCFI()

src/coreclr/jit/unwindamd64.cpp

@@ -225,6 +225,27 @@ void Compiler::unwindPush(regNumber reg)
     }
 }
 
+//------------------------------------------------------------------------
+// Compiler::unwindPush2Windows: Record  push/save of 2 registers simultaneously.
+//
+// Arguments:
+//    reg1 - The first register being pushed/saved.
+//    reg2 - The second register being pushed/saved.
+//
+void Compiler::unwindPush2(regNumber reg1, regNumber reg2)
+{
+#ifdef UNIX_AMD64_ABI
+    if (generateCFIUnwindCodes())
+    {
+        unwindPush2Pop2CFI(reg1, reg2);
+    }
+    else
+#endif // UNIX_AMD64_ABI
+    {
+        unwindPush2Windows(reg1, reg2);
+    }
+}
+
 void Compiler::unwindPushWindows(regNumber reg)
 {
     assert(compGeneratingProlog);
@@ -260,6 +281,20 @@ void Compiler::unwindPushWindows(regNumber reg)
     }
 }
 
+//------------------------------------------------------------------------
+// Compiler::unwindPush2Windows: Record  push/save of 2 registers simultaneously in windows OS.
+//
+// Arguments:
+//    reg1 - The first register being pushed/saved.
+//    reg2 - The second register being pushed/saved.
+//
+void Compiler::unwindPush2Windows(regNumber reg1, regNumber reg2)
+{
+    // ToDo: This is a placeholder till Windows OS has unwind support for push2/pop2.
+    unwindPushWindows(reg1);
+    unwindPushWindows(reg2);
+}
+
 #ifdef UNIX_AMD64_ABI
 #endif // UNIX_AMD64_ABI
 

src/coreclr/jit/unwindarm64.cpp

@@ -230,6 +230,11 @@ void Compiler::unwindPush(regNumber reg)
     unreached(); // use one of the unwindSaveReg* functions instead.
 }
 
+void Compiler::unwindPush2(regNumber reg1, regNumber reg2)
+{
+    unreached(); // use one of the unwindSaveReg* functions instead.
+}
+
 void Compiler::unwindAllocStack(unsigned size)
 {
 #if defined(FEATURE_CFI_SUPPORT)

src/coreclr/jit/unwindloongarch64.cpp

@@ -230,6 +230,11 @@ void Compiler::unwindPush(regNumber reg)
     unreached(); // use one of the unwindSaveReg* functions instead.
 }
 
+void Compiler::unwindPush2(regNumber reg1, regNumber reg2)
+{
+    unreached(); // use one of the unwindSaveReg* functions instead.
+}
+
 void Compiler::unwindAllocStack(unsigned size)
 {
 #if defined(FEATURE_CFI_SUPPORT)

src/coreclr/jit/unwindriscv64.cpp

@@ -42,6 +42,11 @@ void Compiler::unwindPush(regNumber reg)
     unreached(); // use one of the unwindSaveReg* functions instead.
 }
 
+void Compiler::unwindPush2(regNumber reg1, regNumber reg2)
+{
+    unreached(); // use one of the unwindSaveReg* functions instead.
+}
+
 void Compiler::unwindAllocStack(unsigned size)
 {
 #if defined(FEATURE_CFI_SUPPORT)

src/coreclr/jit/unwindx86.cpp

@@ -50,6 +50,10 @@ void Compiler::unwindPush(regNumber reg)
 {
 }
 
+void Compiler::unwindPush2(regNumber reg1, regNumber reg2)
+{
+}
+
 void Compiler::unwindAllocStack(unsigned size)
 {
 }