Refactor some common code into lower.cpp.

Some code will conflict with latest changes. I've squashed so we
can discuss how to merge in properly.

Author: anthonycanino

src/coreclr/jit/codegeninterface.h

@@ -871,5 +871,4 @@ struct GenConditionDesc
 };
 #endif // !defined(TARGET_LOONGARCH64) && !defined(TARGET_RISCV64)
 
-
 #endif // _CODEGEN_INTERFACE_H_

src/coreclr/jit/codegenxarch.cpp

@@ -9012,7 +9012,7 @@ insOpts CodeGen::OptsFromCFlags(insCflags flags)
 //    None.
 //
 // Notes:
-//    This function generates code for a conditional compare operation. On X86, it supports integer 
+//    This function generates code for a conditional compare operation. On X86,
 //    comparisons using the extended EVEX encoding and ccmp instruction.
 void CodeGen::genCodeForCCMP(GenTreeCCMP* ccmp)
 {

src/coreclr/jit/emitxarch.cpp

@@ -20116,6 +20116,14 @@ emitter::insFormat emitter::ExtractMemoryFormat(insFormat insFmt) const
     return IF_NONE;
 }
 
+#ifdef TARGET_AMD64
+// true if this 'imm' can be encoded as a input operand to a ccmp instruction
+/*static*/ bool emitter::emitIns_valid_imm_for_ccmp(INT64 imm)
+{
+    return (((INT32)imm) == imm);
+}
+#endif
+
 #if defined(DEBUG) || defined(LATE_DISASM)
 
 //----------------------------------------------------------------------------------------

src/coreclr/jit/emitxarch.h

@@ -1327,4 +1327,9 @@ inline bool HasExtendedGPReg(const instrDesc* id) const;
 
 inline bool HasMaskReg(const instrDesc* id) const;
 
+#ifdef TARGET_AMD64
+// true if this 'imm' can be encoded as a input operand to a ccmp instruction
+static bool emitIns_valid_imm_for_ccmp(INT64 imm);
+#endif // TARGET_AMD64
+
 #endif // TARGET_XARCH

src/coreclr/jit/lower.cpp

@@ -859,7 +859,7 @@ GenTree* Lowering::LowerArrLength(GenTreeArrCommon* node)
  *                          and LinearCodeGen will be responsible to generate downstream).
  *
  *     This way there are no implicit temporaries.
- 
+
  * b) For small-sized switches, we will actually morph them into a series of conditionals of the form
  *     if (case falls into the default){ goto jumpTable[size]; // last entry in the jump table is the default case }
  *     (For the default case conditional, we'll be constructing the exact same code as the jump table case one).
@@ -4528,6 +4528,7 @@ bool Lowering::TryLowerConditionToFlagsNode(GenTree*      parent,
 
         *cond = condition->AsCC()->gtCondition;
 
+#ifdef TARGET_XARCH
         if (!allowMultipleFlagsChecks)
         {
             const GenConditionDesc& desc = GenConditionDesc::Get(*cond);
@@ -4537,6 +4538,7 @@ bool Lowering::TryLowerConditionToFlagsNode(GenTree*      parent,
                 return false;
             }
         }
+#endif
 
         LIR::Range range = BlockRange().Remove(flagsDef, condition->gtPrev);
         BlockRange().InsertBefore(parent, std::move(range));
@@ -11079,6 +11081,29 @@ bool Lowering::TryLowerAndNegativeOne(GenTreeOp* node, GenTree** nextNode)
     return true;
 }
 
+#if defined(TARGET_AMD64) || defined(TARGET_ARM64)
+//------------------------------------------------------------------------
+// ContainCheckConditionalCompare: determine whether the source of a compare within a compare chain should be contained.
+//
+// Arguments:
+//    node - pointer to the node
+//
+void Lowering::ContainCheckConditionalCompare(GenTreeCCMP* cmp)
+{
+    GenTree* op2 = cmp->gtOp2;
+
+    if (op2->IsCnsIntOrI() && !op2->AsIntCon()->ImmedValNeedsReloc(comp))
+    {
+        target_ssize_t immVal = (target_ssize_t)op2->AsIntCon()->gtIconVal;
+
+        if (emitter::emitIns_valid_imm_for_ccmp(immVal))
+        {
+            MakeSrcContained(cmp, op2);
+        }
+    }
+}
+#endif
+
 #if defined(FEATURE_HW_INTRINSICS)
 //----------------------------------------------------------------------------------------------
 // Lowering::InsertNewSimdCreateScalarUnsafeNode: Inserts a new simd CreateScalarUnsafe node

src/coreclr/jit/lowerarmarch.cpp

@@ -3301,28 +3301,6 @@ insCflags Lowering::TruthifyingFlags(GenCondition condition)
             return INS_FLAGS_NONE;
     }
 }
-
-//------------------------------------------------------------------------
-// ContainCheckConditionalCompare: determine whether the source of a compare within a compare chain should be contained.
-//
-// Arguments:
-//    node - pointer to the node
-//
-void Lowering::ContainCheckConditionalCompare(GenTreeCCMP* cmp)
-{
-    GenTree* op2 = cmp->gtOp2;
-
-    if (op2->IsCnsIntOrI() && !op2->AsIntCon()->ImmedValNeedsReloc(comp))
-    {
-        target_ssize_t immVal = (target_ssize_t)op2->AsIntCon()->gtIconVal;
-
-        if (emitter::emitIns_valid_imm_for_ccmp(immVal))
-        {
-            MakeSrcContained(cmp, op2);
-        }
-    }
-}
-
 #endif // TARGET_ARM64
 
 //------------------------------------------------------------------------

src/coreclr/jit/lowerxarch.cpp

@@ -338,7 +338,6 @@ GenTree* Lowering::LowerBinaryArithmetic(GenTreeOp* binOp)
 }
 
 #ifdef TARGET_AMD64
-
 //------------------------------------------------------------------------
 // TryLowerAndOrToCCMP : Lower AND/OR of two conditions into test + CCMP + SETCC nodes.
 //
@@ -378,11 +377,6 @@ bool Lowering::TryLowerAndOrToCCMP(GenTreeOp* tree, GenTree** next)
     // For the other operand we can allow more arbitrary operations that set
     // the condition flags; the final transformation into the flags def is done
     // by TryLowerConditionToFlagsNode.
-    //
-    //
-    // On X86, a FP compare is implemented as a fallthrough, which requires two flag checks; hence,
-    // we cannot simply get a single output condition to feed into a ccmp. Might be possible to chain
-    // this, but skipping those cases for now
     GenCondition cond1;
     if (op2->OperIsCmpCompare() && varTypeIsIntegralOrI(op2->gtGetOp1()) && IsInvariantInRange(op2, tree) &&
         TryLowerConditionToFlagsNode(tree, op1, &cond1, false))
@@ -485,29 +479,6 @@ insCflags Lowering::TruthifyingFlags(GenCondition condition)
             return INS_FLAGS_NONE;
     }
 }
-
-//------------------------------------------------------------------------
-// ContainCheckConditionalCompare: determine whether the source of a compare within a compare chain should be contained.
-//
-// Arguments:
-//    node - pointer to the node
-//
-void Lowering::ContainCheckConditionalCompare(GenTreeCCMP* cmp)
-{
-    GenTree* op2 = cmp->gtOp2;
-
-    if (op2->IsCnsIntOrI() && !op2->AsIntCon()->ImmedValNeedsReloc(comp))
-    {
-        target_ssize_t immVal = (target_ssize_t)op2->AsIntCon()->gtIconVal;
-
-        // TODO-XArch-APX: make this check work
-        // if (emitter::emitIns_valid_imm_for_ccmp(immVal))
-        //{
-        MakeSrcContained(cmp, op2);
-        //}
-    }
-}
-
 #endif // TARGET_AMD64
 
 //------------------------------------------------------------------------