Don't zero-initialize CORINFO_FPSTRUCT_LOWERING

dotnet · Jul 12, 2024 · 823df8b · 823df8b
1 parent d4be92c
commit 823df8b
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Showing 6 changed files with 42 additions and 36 deletions.
diff --git a/src/coreclr/inc/corinfo.h b/src/coreclr/inc/corinfo.h
@@ -1934,11 +1934,9 @@ struct CORINFO_SWIFT_LOWERING
 #define MAX_FPSTRUCT_LOWERED_ELEMENTS 2
 
 // Lowering information on fields of a struct passed by hardware floating-point calling convention on RISC-V and LoongArch
-// NOTE: all array elements past numLoweredElements are zero-initialized
 struct CORINFO_FPSTRUCT_LOWERING
 {
     // Whether the struct should be passed by integer calling convention (cannot be passed by FP calling convention).
-    // If true, all other fields of CORINFO_FPSTRUCT_LOWERING are zeroed.
     bool byIntegerCallConv;
     // Types of lowered struct fields.
     CorInfoType loweredElements[MAX_FPSTRUCT_LOWERED_ELEMENTS];

diff --git a/src/coreclr/jit/compiler.cpp b/src/coreclr/jit/compiler.cpp
@@ -931,17 +931,20 @@ var_types Compiler::getReturnTypeForStruct(CORINFO_CLASS_HANDLE     clsHnd,
     if (structSize <= (TARGET_POINTER_SIZE * 2))
     {
         const CORINFO_FPSTRUCT_LOWERING* lowering = GetFpStructLowering(clsHnd);
-        if (lowering->numLoweredElements == 1)
+        if (!lowering->byIntegerCallConv)
         {
-            useType = JITtype2varType(lowering->loweredElements[0]);
-            assert(varTypeIsFloating(useType));
-            howToReturnStruct = SPK_PrimitiveType;
-        }
-        else if (!lowering->byIntegerCallConv)
-        {
-            assert(lowering->numLoweredElements == 2);
-            howToReturnStruct = SPK_ByValue;
-            useType           = TYP_STRUCT;
+            if (lowering->numLoweredElements == 1)
+            {
+                useType = JITtype2varType(lowering->loweredElements[0]);
+                assert(varTypeIsFloating(useType));
+                howToReturnStruct = SPK_PrimitiveType;
+            }
+            else
+            {
+                assert(lowering->numLoweredElements == 2);
+                howToReturnStruct = SPK_ByValue;
+                useType           = TYP_STRUCT;
+            }
         }
     }
 

diff --git a/src/coreclr/jit/targetriscv64.cpp b/src/coreclr/jit/targetriscv64.cpp
@@ -73,17 +73,19 @@ ABIPassingInformation RiscV64Classifier::Classify(Compiler*    comp,
         else if (!structLayout->IsBlockLayout())
         {
             lowering = comp->GetFpStructLowering(structLayout->GetClassHandle());
-            assert((lowering->numLoweredElements > 0) == !lowering->byIntegerCallConv);
-            assert(lowering->numLoweredElements <= 2);
-            INDEBUG(unsigned debugIntFields = 0;)
-            for (size_t i = 0; i < lowering->numLoweredElements; ++i)
+            if (!lowering->byIntegerCallConv)
             {
-                var_types type = JITtype2varType(lowering->loweredElements[i]);
-                floatFields += (unsigned)varTypeIsFloating(type);
-                INDEBUG(debugIntFields += (unsigned)varTypeIsIntegralOrI(type);)
+                assert((lowering->numLoweredElements == 1) || (lowering->numLoweredElements == 2));
+                INDEBUG(unsigned debugIntFields = 0;)
+                for (size_t i = 0; i < lowering->numLoweredElements; ++i)
+                {
+                    var_types type = JITtype2varType(lowering->loweredElements[i]);
+                    floatFields += (unsigned)varTypeIsFloating(type);
+                    INDEBUG(debugIntFields += (unsigned)varTypeIsIntegralOrI(type);)
+                }
+                intFields = lowering->numLoweredElements - floatFields;
+                assert(debugIntFields == intFields);
             }
-            intFields = lowering->numLoweredElements - floatFields;
-            assert(debugIntFields == intFields);
         }
     }
     else

diff --git a/src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs b/src/coreclr/tools/Common/JitInterface/CorInfoImpl.cs
@@ -3460,12 +3460,10 @@ private void getFpStructLowering(CORINFO_CLASS_STRUCT_* structHnd, ref CORINFO_F
                 HandleToObject(structHnd), _compilation.TypeSystemContext.Target.Architecture);
             if (info.flags != FpStruct.UseIntCallConv)
             {
-                lowering = new CORINFO_FPSTRUCT_LOWERING {
-                    byIntegerCallConv = false,
-                    numLoweredElements = ((info.flags & FpStruct.OnlyOne) != 0) ? 1 : 2,
-                };
+                lowering.byIntegerCallConv = false;
                 lowering.Offsets[0] = info.offset1st;
                 lowering.Offsets[1] = info.offset2nd;
+                lowering.numLoweredElements = ((info.flags & FpStruct.OnlyOne) != 0) ? 1 : 2;
 
                 if ((info.flags & (FpStruct.BothFloat | FpStruct.FloatInt | FpStruct.OnlyOne)) != 0)
                     lowering.LoweredElements[0] = (info.SizeShift1st() == 3) ? CorInfoType.CORINFO_TYPE_DOUBLE : CorInfoType.CORINFO_TYPE_FLOAT;
@@ -3488,7 +3486,7 @@ private void getFpStructLowering(CORINFO_CLASS_STRUCT_* structHnd, ref CORINFO_F
             }
             else
             {
-                lowering = new CORINFO_FPSTRUCT_LOWERING{ byIntegerCallConv = true };
+                lowering.byIntegerCallConv = true;
             }
         }
 

diff --git a/src/coreclr/tools/superpmi/superpmi-shared/methodcontext.cpp b/src/coreclr/tools/superpmi/superpmi-shared/methodcontext.cpp
@@ -6337,9 +6337,12 @@ void MethodContext::dmpGetSwiftLowering(
 {
     printf("GetSwiftLowering key structHnd-%016" PRIX64 ", value byReference-%u numLoweredElements-%u", key,
         value.byReference, value.numLoweredElements);
-    for (size_t i = 0; i < value.numLoweredElements; i++)
+    if (!value.byReference)
     {
-        printf(" [%zu] %u", i, value.loweredElements[i]);
+        for (size_t i = 0; i < value.numLoweredElements; i++)
+        {
+            printf(" [%zu] %u", i, value.loweredElements[i]);
+        }
     }
 }
 void MethodContext::repGetSwiftLowering(CORINFO_CLASS_HANDLE structHnd, CORINFO_SWIFT_LOWERING* pLowering)
@@ -6387,9 +6390,12 @@ void MethodContext::dmpGetFpStructLowering(
 {
     printf("GetFpStructLowering key structHnd-%016" PRIX64 ", value byIntegerCallConv-%u numLoweredElements-%u", key,
         value.byIntegerCallConv, value.numLoweredElements);
-    for (size_t i = 0; i < value.numLoweredElements; i++)
+    if (!value.byIntegerCallConv)
     {
-        printf(" [%zu] %u", i, value.loweredElements[i]);
+        for (size_t i = 0; i < value.numLoweredElements; i++)
+        {
+            printf(" [%zu] %u", i, value.loweredElements[i]);
+        }
     }
 }
 void MethodContext::repGetFpStructLowering(CORINFO_CLASS_HANDLE structHnd, CORINFO_FPSTRUCT_LOWERING* pLowering)

diff --git a/src/coreclr/vm/jitinterface.cpp b/src/coreclr/vm/jitinterface.cpp
@@ -9535,11 +9535,10 @@ void CEEInfo::getFpStructLowering(CORINFO_CLASS_HANDLE structHnd, CORINFO_FPSTRU
     FpStructInRegistersInfo info = MethodTable::GetFpStructInRegistersInfo(TypeHandle(structHnd));
     if (info.flags != FpStruct::UseIntCallConv)
     {
-        *pLowering = {
-            .byIntegerCallConv = false,
-            .offsets = { info.offset1st, info.offset2nd },
-            .numLoweredElements = (info.flags & FpStruct::OnlyOne) ? 1ul : 2ul,
-        };
+        pLowering->byIntegerCallConv = false;
+        pLowering->offsets[0] = info.offset1st;
+        pLowering->offsets[1] = info.offset2nd;
+        pLowering->numLoweredElements = (info.flags & FpStruct::OnlyOne) ? 1ul : 2ul;
 
         if (info.flags & (FpStruct::BothFloat | FpStruct::FloatInt | FpStruct::OnlyOne))
             pLowering->loweredElements[0] = (info.SizeShift1st() == 3) ? CORINFO_TYPE_DOUBLE : CORINFO_TYPE_FLOAT;
@@ -9562,7 +9561,7 @@ void CEEInfo::getFpStructLowering(CORINFO_CLASS_HANDLE structHnd, CORINFO_FPSTRU
     }
     else
     {
-        *pLowering = { .byIntegerCallConv = true };
+        pLowering->byIntegerCallConv = true;
     }
 #endif // TARGET_RISCV64 || TARGET_LOONGARCH64