supporting TARGET_XARCH.

Author: shushanhf

src/coreclr/jit/lclvars.cpp

@@ -5168,6 +5168,10 @@ void Compiler::lvaFixVirtualFrameOffsets()
 {
     LclVarDsc* varDsc;
 
+#if defined(TARGET_LOONGARCH64) || defined(TARGET_XARCH)
+
+    // For X86/AMD64/LoongArch64, there is no need to recompute the offset.
+
 #if defined(FEATURE_EH_FUNCLETS) && defined(TARGET_AMD64)
     if (lvaPSPSym != BAD_VAR_NUM)
     {
@@ -5177,18 +5181,12 @@ void Compiler::lvaFixVirtualFrameOffsets()
         varDsc = lvaGetDesc(lvaPSPSym);
         assert(varDsc->lvFramePointerBased); // We always access it RBP-relative.
         assert(!varDsc->lvMustInit);         // It is never "must init".
-        varDsc->SetStackOffset(codeGen->genCallerSPtoInitialSPdelta() + lvaLclSize(lvaOutgoingArgSpaceVar));
-
-        if (opts.IsOSR())
-        {
-            // With OSR RBP points at the base of the OSR frame, but the virtual offsets
-            // are from the base of the Tier0 frame. Adjust.
-            //
-            varDsc->SetStackOffset(varDsc->GetStackOffset() - info.compPatchpointInfo->TotalFrameSize());
-        }
+        varDsc->SetStackOffset(lvaLclSize(lvaOutgoingArgSpaceVar) - codeGen->genTotalFrameSize());
     }
 #endif
 
+#else
+
     // The delta to be added to virtual offset to adjust it relative to frame pointer or SP
     int delta = 0;
 
@@ -5224,8 +5222,6 @@ void Compiler::lvaFixVirtualFrameOffsets()
     }
 #endif // TARGET_AMD64 || TARGET_ARM64 || TARGET_RISCV64
 
-#if !defined(TARGET_LOONGARCH64)
-    // For LoongArch64, there is no need to recompute the offset.
     if (opts.IsOSR())
     {
 #if defined(TARGET_AMD64) || defined(TARGET_ARM64) || defined(TARGET_RISCV64)
@@ -5334,14 +5330,15 @@ void Compiler::lvaFixVirtualFrameOffsets()
 
 #endif // FEATURE_FIXED_OUT_ARGS
 
-#if defined(TARGET_ARM64) || defined(TARGET_LOONGARCH64)
+#if defined(TARGET_ARM64) || defined(TARGET_LOONGARCH64) || defined(TARGET_XARCH)
     // We normally add alignment below the locals between them and the outgoing
     // arg space area. When we store fp/lr(ra) at the bottom, however, this will
     // be below the alignment. So we should not apply the alignment adjustment to
     // them. It turns out we always store these at +0 and +8 of the FP,
     // so instead of dealing with skipping adjustment just for them we just set
     // them here always.
     // For LoongArch64, the RA is above the fp. see the `genPushCalleeSavedRegisters`
+    // On x86/amd64, the return address has already been pushed by the call instruction in the caller.
     assert(codeGen->isFramePointerUsed());
     if (lvaRetAddrVar != BAD_VAR_NUM)
     {
@@ -5423,7 +5420,7 @@ void Compiler::lvaAssignVirtualFrameOffsetsToArgs()
     unsigned lclNum  = 0;
     int      argOffs = 0;
 #ifdef UNIX_AMD64_ABI
-    int callerArgOffset = 0;
+    int callerArgOffset = TARGET_POINTER_SIZE * 2; // return address and rbp.
 #endif // UNIX_AMD64_ABI
 
     /*
@@ -5676,7 +5673,7 @@ int Compiler::lvaAssignVirtualFrameOffsetToArg(unsigned lclNum,
         // location on the callee stack (like any other local var.) In such a case, the register passed, stack homed
         // arguments are accessed using negative offsets and the stack passed arguments are accessed using positive
         // offset (from the caller's stack.)
-        // For  System V platforms if there is no frame pointer the caller stack parameter offset should include the
+        // For System V platforms if there is no frame pointer the caller stack parameter offset should include the
         // callee allocated space. If frame register is used, the callee allocated space should not be included for
         // accessing the caller stack parameters. The last two requirements are met in lvaFixVirtualFrameOffsets
         // method, which fixes the offsets, based on frame pointer existence, existence of alloca instructions, ret
@@ -6088,38 +6085,21 @@ void Compiler::lvaAssignVirtualFrameOffsetsToLocals()
     }
 #endif // TARGET_ARM64
 
-#ifdef TARGET_XARCH
-    // On x86/amd64, the return address has already been pushed by the call instruction in the caller.
-    stkOffs -= TARGET_POINTER_SIZE; // return address;
-    if (lvaRetAddrVar != BAD_VAR_NUM)
-    {
-        lvaTable[lvaRetAddrVar].SetStackOffset(stkOffs);
-    }
-#endif
-
     // If we are an OSR method, we "inherit" the frame of the original method
     //
     if (opts.IsOSR())
     {
 #if defined(TARGET_LOONGARCH64)
         originalFrameStkOffs = (compCalleeRegsPushed << 3) + info.compPatchpointInfo->CalleeSaveRegisters();
+#elif defined(TARGET_XARCH)
+        originalFrameStkOffs = info.compPatchpointInfo->TotalFrameSize() + TARGET_POINTER_SIZE; // add RA.
 #else
         originalFrameSize    = info.compPatchpointInfo->TotalFrameSize();
         originalFrameStkOffs = stkOffs;
         stkOffs -= originalFrameSize;
 #endif
     }
 
-#ifdef TARGET_XARCH
-    // TODO-AMD64-CQ: for X64 eventually this should be pushed with all the other
-    // calleeregs.  When you fix this, you'll also need to fix
-    // the assert at the bottom of this method
-    if (codeGen->doubleAlignOrFramePointerUsed())
-    {
-        stkOffs -= REGSIZE_BYTES;
-    }
-#endif
-
     int  preSpillSize    = 0;
     bool mustDoubleAlign = false;
 
@@ -6962,14 +6942,6 @@ void Compiler::lvaAssignVirtualFrameOffsetsToLocals()
     }
 #endif
 
-#ifdef TARGET_XARCH
-    if (codeGen->doubleAlignOrFramePointerUsed())
-    {
-        pushedCount += 1; // pushed EBP (frame pointer)
-    }
-    pushedCount += 1; // pushed PC (return address)
-#endif
-
     noway_assert(compLclFrameSize + originalFrameSize ==
                  (unsigned)-(stkOffs + (pushedCount * (int)TARGET_POINTER_SIZE)));
 #endif