[GR-64008] Improve saving of the callee save registers

PullRequest: graal/20483

Author: mur47x111

compiler/src/jdk.graal.compiler/src/jdk/graal/compiler/lir/alloc/SaveCalleeSaveRegisters.java

@@ -33,7 +33,6 @@
 import jdk.graal.compiler.lir.LIRInsertionBuffer;
 import jdk.graal.compiler.lir.LIRInstruction;
 import jdk.graal.compiler.lir.StandardOp;
-import jdk.graal.compiler.lir.Variable;
 import jdk.graal.compiler.lir.gen.LIRGenerationResult;
 import jdk.graal.compiler.lir.gen.LIRGeneratorTool;
 import jdk.graal.compiler.lir.gen.MoveFactory;
@@ -43,6 +42,7 @@
 import jdk.vm.ci.code.Register;
 import jdk.vm.ci.code.RegisterValue;
 import jdk.vm.ci.code.TargetDescription;
+import jdk.vm.ci.meta.AllocatableValue;
 import jdk.vm.ci.meta.PlatformKind;
 
 public class SaveCalleeSaveRegisters extends PreAllocationOptimizationPhase {
@@ -54,7 +54,7 @@ protected void run(TargetDescription target, LIRGenerationResult lirGenRes, PreA
             return;
         }
         LIR lir = lirGenRes.getLIR();
-        RegisterMap<Variable> savedRegisters = saveAtEntry(lir, context.lirGen, lirGenRes, calleeSaveRegisters, target.arch);
+        RegisterMap<AllocatableValue> savedRegisters = saveAtEntry(lir, context.lirGen, lirGenRes, calleeSaveRegisters, target.arch);
 
         for (int blockId : lir.getBlocks()) {
             if (LIR.isBlockDeleted(blockId)) {
@@ -67,7 +67,7 @@ protected void run(TargetDescription target, LIRGenerationResult lirGenRes, PreA
         }
     }
 
-    private static RegisterMap<Variable> saveAtEntry(LIR lir, LIRGeneratorTool lirGen, LIRGenerationResult lirGenRes, List<Register> calleeSaveRegisters, Architecture arch) {
+    private static RegisterMap<AllocatableValue> saveAtEntry(LIR lir, LIRGeneratorTool lirGen, LIRGenerationResult lirGenRes, List<Register> calleeSaveRegisters, Architecture arch) {
         BasicBlock<?> startBlock = lir.getControlFlowGraph().getStartBlock();
         ArrayList<LIRInstruction> instructions = lir.getLIRforBlock(startBlock);
         int insertionIndex = lirGenRes.getFirstInsertPosition();
@@ -76,12 +76,15 @@ private static RegisterMap<Variable> saveAtEntry(LIR lir, LIRGeneratorTool lirGe
         StandardOp.LabelOp entry = (StandardOp.LabelOp) instructions.get(insertionIndex - 1);
         RegisterValue[] savedRegisterValues = new RegisterValue[calleeSaveRegisters.size()];
         int savedRegisterValueIndex = 0;
-        RegisterMap<Variable> saveMap = new RegisterMap<>(arch);
+        List<Register> allocatables = lirGenRes.getRegisterConfig().getAllocatableRegisters();
+        RegisterMap<AllocatableValue> saveMap = new RegisterMap<>(arch);
         for (Register register : calleeSaveRegisters) {
-            PlatformKind registerPlatformKind = arch.getLargestStorableKind(register.getRegisterCategory());
+            PlatformKind registerPlatformKind = lirGenRes.getRegisterConfig().getCalleeSaveRegisterStorageKind(arch, register);
             LIRKind lirKind = LIRKind.value(registerPlatformKind);
             RegisterValue registerValue = register.asValue(lirKind);
-            Variable saveVariable = lirGen.newVariable(lirKind);
+            // Force a non-allocatable register to be saved to a stack slot
+            // so as to avoid unnecessary register pressure.
+            AllocatableValue saveVariable = allocatables.contains(registerValue.getRegister()) ? lirGen.newVariable(lirKind) : lirGenRes.getFrameMapBuilder().allocateSpillSlot(lirKind);
             LIRInstruction save = lirGen.getSpillMoveFactory().createMove(saveVariable, registerValue);
             buffer.append(insertionIndex, save);
             save.setComment(lirGenRes, "SaveCalleeSavedRegisters: saveAtEntry");
@@ -93,14 +96,14 @@ private static RegisterMap<Variable> saveAtEntry(LIR lir, LIRGeneratorTool lirGe
         return saveMap;
     }
 
-    private static void restoreAtExit(LIR lir, MoveFactory moveFactory, LIRGenerationResult lirGenRes, RegisterMap<Variable> calleeSaveRegisters, BasicBlock<?> block) {
+    private static void restoreAtExit(LIR lir, MoveFactory moveFactory, LIRGenerationResult lirGenRes, RegisterMap<AllocatableValue> calleeSaveRegisters, BasicBlock<?> block) {
         ArrayList<LIRInstruction> instructions = lir.getLIRforBlock(block);
         int insertionIndex = instructions.size() - 1;
         LIRInsertionBuffer buffer = new LIRInsertionBuffer();
         buffer.init(instructions);
         LIRInstruction lirInstruction = instructions.get(insertionIndex);
         assert lirInstruction instanceof StandardOp.BlockEndOp : lirInstruction;
-        calleeSaveRegisters.forEach((Register register, Variable saved) -> {
+        calleeSaveRegisters.forEach((Register register, AllocatableValue saved) -> {
             LIRInstruction restore = moveFactory.createMove(register.asValue(saved.getValueKind()), saved);
             buffer.append(insertionIndex, restore);
             restore.setComment(lirGenRes, "SaveCalleeSavedRegisters: restoreAtExit");

substratevm/src/com.oracle.svm.core.graal.amd64/src/com/oracle/svm/core/graal/amd64/SubstrateAMD64RegisterConfig.java

@@ -64,6 +64,7 @@
 import static jdk.vm.ci.amd64.AMD64.xmm7;
 import static jdk.vm.ci.amd64.AMD64.xmm8;
 import static jdk.vm.ci.amd64.AMD64.xmm9;
+import static jdk.vm.ci.amd64.AMD64Kind.V128_QWORD;
 
 import java.util.ArrayList;
 import java.util.Arrays;
@@ -87,6 +88,7 @@
 import jdk.graal.compiler.core.common.LIRKind;
 import jdk.vm.ci.amd64.AMD64;
 import jdk.vm.ci.amd64.AMD64Kind;
+import jdk.vm.ci.code.Architecture;
 import jdk.vm.ci.code.CallingConvention;
 import jdk.vm.ci.code.CallingConvention.Type;
 import jdk.vm.ci.code.Register;
@@ -239,6 +241,15 @@ public List<Register> getCalleeSaveRegisters() {
         return calleeSaveRegisters;
     }
 
+    @Override
+    public PlatformKind getCalleeSaveRegisterStorageKind(Architecture arch, Register calleeSaveRegister) {
+        if (Platform.includedIn(Platform.WINDOWS.class) && AMD64.XMM.equals(calleeSaveRegister.getRegisterCategory())) {
+            VMError.guarantee(calleeSaveRegister.encoding() >= xmm6.encoding() && calleeSaveRegister.encoding() <= xmm15.encoding(), "unexpected callee saved register");
+            return V128_QWORD;
+        }
+        return SubstrateRegisterConfig.super.getCalleeSaveRegisterStorageKind(arch, calleeSaveRegister);
+    }
+
     @Override
     public List<Register> getCallerSaveRegisters() {
         return getAllocatableRegisters();
@@ -410,7 +421,7 @@ public CallingConvention getCallingConvention(Type t, JavaType returnType, JavaT
             kinds = Arrays.copyOf(kinds, kinds.length + 1);
             locations = Arrays.copyOf(locations, locations.length + 1);
             kinds[kinds.length - 1] = JavaKind.Int;
-            locations[locations.length - 1] = AMD64.rax.asValue(LIRKind.value(AMD64Kind.DWORD));
+            locations[locations.length - 1] = rax.asValue(LIRKind.value(AMD64Kind.DWORD));
             if (type.customABI()) {
                 var extendsParametersAssignment = Arrays.copyOf(type.fixedParameterAssignment, type.fixedParameterAssignment.length + 1);
                 extendsParametersAssignment[extendsParametersAssignment.length - 1] = AssignedLocation.forRegister(rax, JavaKind.Long);