JIT: Enable range-based for over ABI passing segments (#107174)

dotnet · Oct 7, 2024 · f944a77 · f944a77
1 parent 438cf85
commit f944a77
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Showing 10 changed files with 91 additions and 54 deletions.
diff --git a/src/coreclr/jit/abi.cpp b/src/coreclr/jit/abi.cpp
@@ -246,6 +246,30 @@ ABIPassingSegment& ABIPassingInformation::Segment(unsigned index)
     return const_cast<ABIPassingSegment&>(static_cast<const ABIPassingInformation&>(*this).Segment(index));
 }
 
+//-----------------------------------------------------------------------------
+// Segments:
+//   Get an iterator pair that can be used with range-based for to iterate the
+//   segments.
+//
+// Returns:
+//   Iterator pair.
+//
+IteratorPair<ABIPassingSegmentIterator> ABIPassingInformation::Segments() const
+{
+    const ABIPassingSegment* begin;
+    if (NumSegments == 1)
+    {
+        begin = &m_singleSegment;
+    }
+    else
+    {
+        begin = m_segments;
+    }
+
+    return IteratorPair<ABIPassingSegmentIterator>(ABIPassingSegmentIterator(begin),
+                                                   ABIPassingSegmentIterator(begin + NumSegments));
+}
+
 //-----------------------------------------------------------------------------
 // HasAnyRegisterSegment:
 //   Check if any part of this value is passed in a register.
@@ -255,9 +279,9 @@ ABIPassingSegment& ABIPassingInformation::Segment(unsigned index)
 //
 bool ABIPassingInformation::HasAnyRegisterSegment() const
 {
-    for (unsigned i = 0; i < NumSegments; i++)
+    for (const ABIPassingSegment& seg : Segments())
     {
-        if (Segment(i).IsPassedInRegister())
+        if (seg.IsPassedInRegister())
         {
             return true;
         }
@@ -274,9 +298,9 @@ bool ABIPassingInformation::HasAnyRegisterSegment() const
 //
 bool ABIPassingInformation::HasAnyFloatingRegisterSegment() const
 {
-    for (unsigned i = 0; i < NumSegments; i++)
+    for (const ABIPassingSegment& seg : Segments())
     {
-        if (Segment(i).IsPassedInRegister() && genIsValidFloatReg(Segment(i).GetRegister()))
+        if (seg.IsPassedInRegister() && genIsValidFloatReg(seg.GetRegister()))
         {
             return true;
         }
@@ -293,9 +317,9 @@ bool ABIPassingInformation::HasAnyFloatingRegisterSegment() const
 //
 bool ABIPassingInformation::HasAnyStackSegment() const
 {
-    for (unsigned i = 0; i < NumSegments; i++)
+    for (const ABIPassingSegment& seg : Segments())
     {
-        if (Segment(i).IsPassedOnStack())
+        if (seg.IsPassedOnStack())
         {
             return true;
         }
@@ -365,9 +389,8 @@ unsigned ABIPassingInformation::CountRegsAndStackSlots() const
 {
     unsigned numSlots = 0;
 
-    for (unsigned i = 0; i < NumSegments; i++)
+    for (const ABIPassingSegment& seg : Segments())
     {
-        const ABIPassingSegment& seg = Segment(i);
         if (seg.IsPassedInRegister())
         {
             numSlots++;
@@ -547,9 +570,9 @@ ABIPassingInformation SwiftABIClassifier::Classify(Compiler*    comp,
             var_types             elemType = JITtype2varType(lowering->loweredElements[i]);
             ABIPassingInformation elemInfo = m_classifier.Classify(comp, elemType, nullptr, WellKnownArg::None);
 
-            for (unsigned j = 0; j < elemInfo.NumSegments; j++)
+            for (const ABIPassingSegment& seg : elemInfo.Segments())
             {
-                ABIPassingSegment newSegment = elemInfo.Segment(j);
+                ABIPassingSegment newSegment = seg;
                 newSegment.Offset += lowering->offsets[i];
                 // Adjust the tail size if necessary; the lowered sequence can
                 // pass the tail as a larger type than the tail size.

diff --git a/src/coreclr/jit/abi.h b/src/coreclr/jit/abi.h
@@ -40,6 +40,41 @@ class ABIPassingSegment
     static ABIPassingSegment OnStack(unsigned stackOffset, unsigned offset, unsigned size);
 };
 
+class ABIPassingSegmentIterator
+{
+    const ABIPassingSegment* m_value;
+public:
+    explicit ABIPassingSegmentIterator(const ABIPassingSegment* value)
+        : m_value(value)
+    {
+    }
+
+    const ABIPassingSegment& operator*() const
+    {
+        return *m_value;
+    }
+    const ABIPassingSegment* operator->() const
+    {
+        return m_value;
+    }
+
+    ABIPassingSegmentIterator& operator++()
+    {
+        m_value++;
+        return *this;
+    }
+
+    bool operator==(const ABIPassingSegmentIterator& other) const
+    {
+        return m_value == other.m_value;
+    }
+
+    bool operator!=(const ABIPassingSegmentIterator& other) const
+    {
+        return m_value != other.m_value;
+    }
+};
+
 struct ABIPassingInformation
 {
 private:
@@ -71,8 +106,9 @@ struct ABIPassingInformation
 
     ABIPassingInformation(Compiler* comp, unsigned numSegments);
 
-    const ABIPassingSegment& Segment(unsigned index) const;
-    ABIPassingSegment&       Segment(unsigned index);
+    const ABIPassingSegment&                Segment(unsigned index) const;
+    ABIPassingSegment&                      Segment(unsigned index);
+    IteratorPair<ABIPassingSegmentIterator> Segments() const;
 
     bool     HasAnyRegisterSegment() const;
     bool     HasAnyFloatingRegisterSegment() const;

diff --git a/src/coreclr/jit/codegenarmarch.cpp b/src/coreclr/jit/codegenarmarch.cpp
@@ -3503,9 +3503,8 @@ void CodeGen::genCallInstruction(GenTreeCall* call)
 
         for (CallArg& arg : call->gtArgs.Args())
         {
-            for (unsigned i = 0; i < arg.NewAbiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& seg : arg.NewAbiInfo.Segments())
             {
-                const ABIPassingSegment& seg = arg.NewAbiInfo.Segment(i);
                 if (seg.IsPassedInRegister() && ((trashedByEpilog & seg.GetRegisterMask()) != 0))
                 {
                     JITDUMP("Tail call node:\n");
@@ -3738,9 +3737,8 @@ void CodeGen::genJmpPlaceVarArgs()
     for (unsigned varNum = 0; varNum < compiler->info.compArgsCount; varNum++)
     {
         const ABIPassingInformation& abiInfo = compiler->lvaGetParameterABIInfo(varNum);
-        for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+        for (const ABIPassingSegment& segment : abiInfo.Segments())
         {
-            const ABIPassingSegment& segment = abiInfo.Segment(i);
             if (segment.IsPassedInRegister())
             {
                 potentialArgs &= ~segment.GetRegisterMask();

diff --git a/src/coreclr/jit/codegencommon.cpp b/src/coreclr/jit/codegencommon.cpp
@@ -3253,9 +3253,8 @@ void CodeGen::genSpillOrAddRegisterParam(unsigned lclNum, RegGraph* graph)
     unsigned                     paramLclNum = varDsc->lvIsStructField ? varDsc->lvParentLcl : lclNum;
     LclVarDsc*                   paramVarDsc = compiler->lvaGetDesc(paramLclNum);
     const ABIPassingInformation& abiInfo     = compiler->lvaGetParameterABIInfo(paramLclNum);
-    for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+    for (const ABIPassingSegment& seg : abiInfo.Segments())
     {
-        const ABIPassingSegment& seg = abiInfo.Segment(i);
         if (!seg.IsPassedInRegister() || ((paramRegs & genRegMask(seg.GetRegister())) == 0))
         {
             continue;
@@ -3376,9 +3375,8 @@ void CodeGen::genHomeRegisterParams(regNumber initReg, bool* initRegStillZeroed)
             }
 
             const ABIPassingInformation& abiInfo = compiler->lvaGetParameterABIInfo(lclNum);
-            for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& seg : abiInfo.Segments())
             {
-                const ABIPassingSegment& seg = abiInfo.Segment(i);
                 if (seg.IsPassedInRegister() && ((paramRegs & genRegMask(seg.GetRegister())) != 0))
                 {
                     var_types storeType = genParamStackType(lclDsc, seg);
@@ -4425,9 +4423,8 @@ void CodeGen::genHomeSwiftStructParameters(bool handleStack)
         const ABIPassingInformation& abiInfo = compiler->lvaGetParameterABIInfo(lclNum);
         DBEXEC(VERBOSE, abiInfo.Dump());
 
-        for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+        for (const ABIPassingSegment& seg : abiInfo.Segments())
         {
-            const ABIPassingSegment& seg = abiInfo.Segment(i);
             if (seg.IsPassedOnStack() != handleStack)
             {
                 continue;
@@ -7489,9 +7486,8 @@ void CodeGen::genCallPlaceRegArgs(GenTreeCall* call)
         if (argNode->OperIs(GT_FIELD_LIST))
         {
             GenTreeFieldList::Use* use = argNode->AsFieldList()->Uses().begin().GetUse();
-            for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& seg : abiInfo.Segments())
             {
-                const ABIPassingSegment& seg = abiInfo.Segment(i);
                 if (!seg.IsPassedInRegister())
                 {
                     continue;
@@ -7519,9 +7515,8 @@ void CodeGen::genCallPlaceRegArgs(GenTreeCall* call)
             assert(compFeatureArgSplit());
             genConsumeArgSplitStruct(argNode->AsPutArgSplit());
             unsigned regIndex = 0;
-            for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& seg : abiInfo.Segments())
             {
-                const ABIPassingSegment& seg = abiInfo.Segment(i);
                 if (!seg.IsPassedInRegister())
                 {
                     continue;
@@ -7557,9 +7552,8 @@ void CodeGen::genCallPlaceRegArgs(GenTreeCall* call)
     {
         for (CallArg& arg : call->gtArgs.Args())
         {
-            for (unsigned i = 0; i < arg.NewAbiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& seg : arg.NewAbiInfo.Segments())
             {
-                const ABIPassingSegment& seg = arg.NewAbiInfo.Segment(i);
                 if (seg.IsPassedInRegister() && genIsValidFloatReg(seg.GetRegister()))
                 {
                     regNumber targetReg = compiler->getCallArgIntRegister(seg.GetRegister());
@@ -7640,9 +7634,8 @@ void CodeGen::genJmpPlaceArgs(GenTree* jmp)
         LclVarDsc* varDsc = compiler->lvaGetDesc(varNum);
 
         const ABIPassingInformation& abiInfo = compiler->lvaGetParameterABIInfo(varNum);
-        for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+        for (const ABIPassingSegment& segment : abiInfo.Segments())
         {
-            const ABIPassingSegment& segment = abiInfo.Segment(i);
             if (segment.IsPassedOnStack())
             {
                 continue;

diff --git a/src/coreclr/jit/codegenxarch.cpp b/src/coreclr/jit/codegenxarch.cpp
@@ -6559,9 +6559,8 @@ void CodeGen::genJmpPlaceVarArgs()
     for (unsigned varNum = 0; varNum < compiler->info.compArgsCount; varNum++)
     {
         const ABIPassingInformation& abiInfo = compiler->lvaGetParameterABIInfo(varNum);
-        for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+        for (const ABIPassingSegment& segment : abiInfo.Segments())
         {
-            const ABIPassingSegment& segment = abiInfo.Segment(i);
             if (segment.IsPassedOnStack())
             {
                 continue;

diff --git a/src/coreclr/jit/lclvars.cpp b/src/coreclr/jit/lclvars.cpp
@@ -1741,9 +1741,8 @@ void Compiler::lvaClassifyParameterABI()
                 }
             }
 
-            for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& segment : abiInfo.Segments())
             {
-                const ABIPassingSegment& segment = abiInfo.Segment(i);
                 if (segment.IsPassedInRegister())
                 {
                     argRegs |= segment.GetRegisterMask();
@@ -5959,9 +5958,8 @@ bool Compiler::lvaGetRelativeOffsetToCallerAllocatedSpaceForParameter(unsigned l
 {
     const ABIPassingInformation& abiInfo = lvaGetParameterABIInfo(lclNum);
 
-    for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+    for (const ABIPassingSegment& segment : abiInfo.Segments())
     {
-        const ABIPassingSegment& segment = abiInfo.Segment(i);
         if (!segment.IsPassedOnStack())
         {
 #if defined(WINDOWS_AMD64_ABI)

diff --git a/src/coreclr/jit/lsrabuild.cpp b/src/coreclr/jit/lsrabuild.cpp
@@ -2292,9 +2292,8 @@ void LinearScan::buildIntervals()
             }
 
             const ABIPassingInformation& abiInfo = compiler->lvaGetParameterABIInfo(lclNum);
-            for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& seg : abiInfo.Segments())
             {
-                const ABIPassingSegment& seg = abiInfo.Segment(i);
                 if (seg.IsPassedInRegister())
                 {
                     RegState* regState = genIsValidFloatReg(seg.GetRegister()) ? floatRegState : intRegState;

diff --git a/src/coreclr/jit/lsraxarch.cpp b/src/coreclr/jit/lsraxarch.cpp
@@ -1226,9 +1226,8 @@ int LinearScan::BuildCall(GenTreeCall* call)
     {
         for (CallArg& arg : call->gtArgs.LateArgs())
         {
-            for (unsigned i = 0; i < arg.NewAbiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& seg : arg.NewAbiInfo.Segments())
             {
-                const ABIPassingSegment& seg = arg.NewAbiInfo.Segment(i);
                 if (seg.IsPassedInRegister() && genIsValidFloatReg(seg.GetRegister()))
                 {
                     regNumber argReg           = seg.GetRegister();

diff --git a/src/coreclr/jit/morph.cpp b/src/coreclr/jit/morph.cpp
@@ -2162,9 +2162,8 @@ void CallArgs::AddFinalArgsAndDetermineABIInfo(Compiler* comp, GenTreeCall* call
             arg.AbiInfo.SetSplit(true);
             arg.AbiInfo.ByteOffset = 0;
             unsigned regNumIndex   = 0;
-            for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& segment : abiInfo.Segments())
             {
-                const ABIPassingSegment& segment = abiInfo.Segment(i);
                 if (segment.IsPassedInRegister())
                 {
                     if (regNumIndex < MAX_ARG_REG_COUNT)
@@ -2187,10 +2186,8 @@ void CallArgs::AddFinalArgsAndDetermineABIInfo(Compiler* comp, GenTreeCall* call
             m_hasRegArgs = true;
 
             unsigned regNumIndex = 0;
-            for (unsigned i = 0; i < abiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& segment : abiInfo.Segments())
             {
-                const ABIPassingSegment& segment = abiInfo.Segment(i);
-
                 if (regNumIndex < MAX_ARG_REG_COUNT)
                 {
                     arg.AbiInfo.SetRegNum(regNumIndex, segment.GetRegister());
@@ -2976,9 +2973,8 @@ GenTree* Compiler::fgMorphMultiregStructArg(CallArg* arg)
         {
             bool fieldsMatch = true;
 
-            for (unsigned i = 0; i < arg->NewAbiInfo.NumSegments; i++)
+            for (const ABIPassingSegment& seg : arg->NewAbiInfo.Segments())
             {
-                const ABIPassingSegment& seg = arg->NewAbiInfo.Segment(i);
                 if (seg.IsPassedInRegister())
                 {
                     unsigned fieldLclNum = lvaGetFieldLocal(varDsc, seg.Offset);
@@ -3119,9 +3115,8 @@ GenTree* Compiler::fgMorphMultiregStructArg(CallArg* arg)
 
         newArg = new (this, GT_FIELD_LIST) GenTreeFieldList();
 
-        for (unsigned i = 0; i < arg->NewAbiInfo.NumSegments; i++)
+        for (const ABIPassingSegment& seg : arg->NewAbiInfo.Segments())
         {
-            const ABIPassingSegment& seg = arg->NewAbiInfo.Segment(i);
             if (seg.IsPassedInRegister())
             {
                 var_types regType = seg.GetRegisterType();

diff --git a/src/coreclr/jit/promotion.cpp b/src/coreclr/jit/promotion.cpp
@@ -2133,10 +2133,8 @@ bool ReplaceVisitor::ReplaceCallArgWithFieldList(GenTreeCall* call, GenTreeLclVa
     assert(layout != nullptr);
     StructDeaths      deaths    = m_liveness->GetDeathsForStructLocal(argNode);
     GenTreeFieldList* fieldList = new (m_compiler, GT_FIELD_LIST) GenTreeFieldList;
-    for (unsigned i = 0; i < callArg->NewAbiInfo.NumSegments; i++)
+    for (const ABIPassingSegment& seg : callArg->NewAbiInfo.Segments())
     {
-        const ABIPassingSegment& seg = callArg->NewAbiInfo.Segment(i);
-
         Replacement* rep = nullptr;
         if (agg->OverlappingReplacements(argNode->GetLclOffs() + seg.Offset, seg.Size, &rep, nullptr) &&
             rep->NeedsWriteBack)
@@ -2228,9 +2226,8 @@ bool ReplaceVisitor::CanReplaceCallArgWithFieldListOfReplacements(GenTreeCall*
     assert(agg != nullptr);
 
     bool anyReplacements = false;
-    for (unsigned i = 0; i < callArg->NewAbiInfo.NumSegments; i++)
+    for (const ABIPassingSegment& seg : callArg->NewAbiInfo.Segments())
     {
-        const ABIPassingSegment& seg = callArg->NewAbiInfo.Segment(i);
         assert(seg.IsPassedInRegister());
 
         auto callback = [=, &anyReplacements, &seg](Replacement& rep) {