Merge pull request #31049 from aschwaighofer/irgen_fix_initial_offset_not_fixed_heap_layout

IRGen: Use the header size for the initial offset in non fixed heap l…

Author: aschwaighofer

lib/IRGen/GenHeap.cpp

@@ -285,7 +285,7 @@ static llvm::Value *calcInitOffset(swift::irgen::IRGenFunction &IGF,
                                    const swift::irgen::HeapLayout &layout) {
   llvm::Value *offset = nullptr;
   if (i == 0) {
-    auto startoffset = layout.getSize();
+    auto startoffset = layout.getHeaderSize();
     offset = llvm::ConstantInt::get(IGF.IGM.SizeTy, startoffset.getValue());
     return offset;
   }

lib/IRGen/StructLayout.cpp

@@ -70,6 +70,7 @@ StructLayout::StructLayout(IRGenModule &IGM,
     assert(!builder.empty() == requiresHeapHeader(layoutKind));
     MinimumAlign = Alignment(1);
     MinimumSize = Size(0);
+    headerSize = builder.getHeaderSize();
     SpareBits.clear();
     IsFixedLayout = true;
     IsKnownPOD = IsPOD;
@@ -79,6 +80,7 @@ StructLayout::StructLayout(IRGenModule &IGM,
   } else {
     MinimumAlign = builder.getAlignment();
     MinimumSize = builder.getSize();
+    headerSize = builder.getHeaderSize();
     SpareBits = builder.getSpareBits();
     IsFixedLayout = builder.isFixedLayout();
     IsKnownPOD = builder.isPOD();
@@ -186,13 +188,15 @@ void StructLayoutBuilder::addHeapHeader() {
   CurSize = IGM.RefCountedStructSize;
   CurAlignment = IGM.getPointerAlignment();
   StructFields.push_back(IGM.RefCountedStructTy);
+  headerSize = CurSize;
 }
 
 void StructLayoutBuilder::addNSObjectHeader() {
   assert(StructFields.empty() && "adding heap header at a non-zero offset");
   CurSize = IGM.getPointerSize();
   CurAlignment = IGM.getPointerAlignment();
   StructFields.push_back(IGM.ObjCClassPtrTy);
+  headerSize = CurSize;
 }
 
 bool StructLayoutBuilder::addFields(llvm::MutableArrayRef<ElementLayout> elts,

lib/IRGen/StructLayout.h

@@ -253,6 +253,7 @@ class StructLayoutBuilder {
   IRGenModule &IGM;
   SmallVector<llvm::Type*, 8> StructFields;
   Size CurSize = Size(0);
+  Size headerSize = Size(0);
 private:
   Alignment CurAlignment = Alignment(1);
   SmallVector<SpareBitVector, 8> CurSpareBits;
@@ -314,6 +315,9 @@ class StructLayoutBuilder {
   /// Return the size of the structure built so far.
   Size getSize() const { return CurSize; }
 
+  // Return the size of the header.
+  Size getHeaderSize() const { return headerSize; }
+
   /// Return the alignment of the structure built so far.
   Alignment getAlignment() const { return CurAlignment; }
 
@@ -350,6 +354,9 @@ class StructLayout {
 
   /// The statically-known minimum bound on the size.
   Size MinimumSize;
+
+  /// The size of a header if present.
+  Size headerSize;
 
   /// The statically-known spare bit mask.
   SpareBitVector SpareBits;
@@ -386,6 +393,7 @@ class StructLayout {
                ArrayRef<ElementLayout> elements)
     : MinimumAlign(builder.getAlignment()),
       MinimumSize(builder.getSize()),
+      headerSize(builder.getHeaderSize()),
       SpareBits(builder.getSpareBits()),
       IsFixedLayout(builder.isFixedLayout()),
       IsKnownPOD(builder.isPOD()),
@@ -401,6 +409,7 @@ class StructLayout {
 
   llvm::Type *getType() const { return Ty; }
   Size getSize() const { return MinimumSize; }
+  Size getHeaderSize() const { return headerSize; }
   Alignment getAlignment() const { return MinimumAlign; }
   const SpareBitVector &getSpareBits() const { return SpareBits; }
   SpareBitVector &getSpareBits() { return SpareBits; }

test/IRGen/partial_apply.sil

@@ -1,9 +1,12 @@
-// RUN: %target-swift-frontend %s -emit-ir | %FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-%target-ptrsize
+// RUN: %empty-directory(%t)
+// RUN: %target-swift-frontend -emit-module -enable-library-evolution -emit-module-path=%t/resilient_struct.swiftmodule -module-name=resilient_struct %S/../Inputs/resilient_struct.swift
+// RUN: %target-swift-frontend -I %t -emit-ir %s | %FileCheck %s --check-prefix=CHECK --check-prefix=CHECK-%target-ptrsize
 
 // REQUIRES: CPU=x86_64
 
 import Builtin
 import Swift
+import resilient_struct
 
 class SwiftClass {}
 sil_vtable SwiftClass {}
@@ -738,3 +741,29 @@ bb0(%x : $*SwiftClassPair):
   %t = tuple()
   return %t : $()
 }
+
+sil public_external @closure : $@convention(thin) (@in_guaranteed ResilientInt, @guaranteed SwiftClass) -> ()
+
+// Make sure that we use the heap header size (16) for the initial offset.
+// CHECK-LABEL: define{{.*}} swiftcc void @test_initial_offset(%swift.opaque* noalias nocapture %0, %T13partial_apply10SwiftClassC* %1)
+// CHECK:   [[T0:%.*]] = call swiftcc %swift.metadata_response @"$s16resilient_struct12ResilientIntVMa"
+// CHECK:   [[MD:%.*]] = extractvalue %swift.metadata_response [[T0]], 0
+// CHECK:   [[CAST:%.*]] = bitcast %swift.type* [[MD]] to i8***
+// CHECK:   [[VWT_PTR:%.*]] = getelementptr inbounds i8**, i8*** [[CAST]], i64 -1
+// CHECK:   [[VWT_TMP:%.*]] = load i8**, i8*** [[VWT_PTR]]
+// CHECK:   [[VWT:%.*]] = bitcast i8** [[VWT_TMP]] to %swift.vwtable*
+// CHECK:   [[FLAGS_PTR:%.*]] = getelementptr inbounds %swift.vwtable, %swift.vwtable* [[VWT]], i32 0, i32 10
+// CHECK:   [[FLAGS:%.*]] = load i32, i32* [[FLAGS_PTR]]
+// CHECK:   [[FLAGS2:%.*]] = zext i32 [[FLAGS]] to i64
+// CHECK:   [[ALIGNMASK:%.*]] = and i64 [[FLAGS2]], 255
+// CHECK:   = xor i64 [[ALIGNMASK]], -1
+// CHECK:   = add i64 16, [[ALIGNMASK]]
+
+sil @test_initial_offset : $@convention(thin) (@in_guaranteed ResilientInt, @guaranteed SwiftClass) -> () {
+bb0(%x : $*ResilientInt, %y : $SwiftClass):
+  %f = function_ref @closure : $@convention(thin) (@in_guaranteed ResilientInt, @guaranteed SwiftClass) -> ()
+  %p = partial_apply [callee_guaranteed] %f(%x, %y) : $@convention(thin) (@in_guaranteed ResilientInt, @guaranteed SwiftClass) -> ()
+  release_value %p : $@callee_guaranteed () ->()
+  %t = tuple()
+  return %t : $()
+}