Index: llvm/lib/IR/DebugInfo.cpp
===================================================================
--- llvm/lib/IR/DebugInfo.cpp
+++ llvm/lib/IR/DebugInfo.cpp
@@ -1843,26 +1843,35 @@
   assert(ID && "Store instruction must have DIAssignID metadata");
   (void)ID;
 
+  const uint64_t StoreStartBit = Info.OffsetInBits;
+  const uint64_t StoreEndBit = Info.OffsetInBits + Info.SizeInBits;
+
+  uint64_t FragStartBit = StoreStartBit;
+  uint64_t FragEndBit = StoreEndBit;
+
   bool StoreToWholeVariable = Info.StoreToWholeAlloca;
   if (auto Size = VarRec.Var->getSizeInBits()) {
-    // Discard stores to bits outside this variable. NOTE: trackAssignments
-    // doesn't understand base expressions yet, so all variables that reach
-    // here are guaranteed to start at offset 0 in the alloca.
-    // TODO: Could we truncate the fragment expression instead of discarding
-    // the assignment?
-    if (Info.OffsetInBits + Info.SizeInBits > *Size)
+    // NOTE: trackAssignments doesn't understand base expressions yet, so all
+    // variables that reach here are guaranteed to start at offset 0 in the
+    // alloca.
+    const uint64_t VarStartBit = 0;
+    const uint64_t VarEndBit = *Size;
+
+    FragStartBit = std::max(FragStartBit, VarStartBit);
+    FragEndBit = std::min(FragEndBit, VarEndBit);
+
+    // Discard stores to bits outside this variable.
+    if (FragStartBit >= FragEndBit)
       return nullptr;
-    // FIXME: As noted above - only variables at offset 0 are handled
-    // currently.
-    StoreToWholeVariable = Info.OffsetInBits == /*VarOffsetInAlloca*/ 0 &&
-                           Info.SizeInBits == *Size;
+
+    StoreToWholeVariable = FragStartBit <= VarStartBit && FragEndBit >= *Size;
   }
 
   DIExpression *Expr =
       DIExpression::get(StoreLikeInst.getContext(), std::nullopt);
   if (!StoreToWholeVariable) {
-    auto R = DIExpression::createFragmentExpression(Expr, Info.OffsetInBits,
-                                                    Info.SizeInBits);
+    auto R = DIExpression::createFragmentExpression(Expr, FragStartBit,
+                                                    FragEndBit - FragStartBit);
     assert(R.has_value() && "failed to create fragment expression");
     Expr = *R;
   }
Index: llvm/test/DebugInfo/Generic/assignment-tracking/declare-to-assign/structured-bindings.ll
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/Generic/assignment-tracking/declare-to-assign/structured-bindings.ll
@@ -0,0 +1,81 @@
+; RUN: opt -passes=declare-to-assign -S %s -o - | FileCheck %s
+
+;; Check assignment tracking debug info for structured bindings. FIXME only
+;; variables at offset 0 in the backing alloca are currently tracked with the
+;; feature.
+
+;; struct two { int a, b; };
+;; two get();
+;; int fun() {
+;;   auto [a,b] = get();
+;;   return a * b;
+;; }
+
+; CHECK: %0 = alloca %struct.two, align 4, !DIAssignID ![[ID1:[0-9]+]]
+; CHECK-NEXT: llvm.dbg.assign(metadata i1 undef, metadata ![[AGGR:[0-9]+]], metadata !DIExpression(), metadata ![[ID1]], metadata ptr %0, metadata !DIExpression())
+; CHECK-NEXT: llvm.dbg.assign(metadata i1 undef, metadata ![[A:[0-9]+]], metadata !DIExpression(), metadata ![[ID1]], metadata ptr %0, metadata !DIExpression())
+; CHECK-NEXT: llvm.dbg.declare(metadata ptr %0, metadata ![[B:[0-9]+]], metadata !DIExpression(DW_OP_plus_uconst, 4))
+
+; CHECK: store i64 %call, ptr %0, align 4,{{.*}}, !DIAssignID ![[ID2:[0-9]+]]
+; CHECK-NEXT: llvm.dbg.assign(metadata i64 %call, metadata ![[AGGR]], metadata !DIExpression(), metadata ![[ID2]], metadata ptr %0, metadata !DIExpression())
+; CHECK-NEXT: llvm.dbg.assign(metadata i64 %call, metadata ![[A]], metadata !DIExpression(), metadata ![[ID2]], metadata ptr %0, metadata !DIExpression())
+
+; CHECK: ![[AGGR]] = !DILocalVariable(scope:
+; CHECK: ![[A]] = !DILocalVariable(name: "a", scope:
+; CHECK: ![[B]] = !DILocalVariable(name: "b", scope:
+
+%struct.two = type { i32, i32 }
+
+define dso_local noundef i32 @_Z3funv() #0 !dbg !10 {
+entry:
+  %0 = alloca %struct.two, align 4
+  call void @llvm.dbg.declare(metadata ptr %0, metadata !15, metadata !DIExpression()), !dbg !16
+  call void @llvm.dbg.declare(metadata ptr %0, metadata !17, metadata !DIExpression(DW_OP_plus_uconst, 4)), !dbg !18
+  call void @llvm.dbg.declare(metadata ptr %0, metadata !19, metadata !DIExpression()), !dbg !24
+  %call = call i64 @_Z3getv(), !dbg !25
+  store i64 %call, ptr %0, align 4, !dbg !25
+  %a = getelementptr inbounds %struct.two, ptr %0, i32 0, i32 0, !dbg !16
+  %1 = load i32, ptr %a, align 4, !dbg !26
+  %b = getelementptr inbounds %struct.two, ptr %0, i32 0, i32 1, !dbg !18
+  %2 = load i32, ptr %b, align 4, !dbg !27
+  %mul = mul nsw i32 %1, %2, !dbg !28
+  ret i32 %mul, !dbg !29
+}
+
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+declare i64 @_Z3getv()
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5, !6, !7, !8}
+!llvm.ident = !{!9}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 17.0.0)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "/")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 4}
+!5 = !{i32 8, !"PIC Level", i32 2}
+!6 = !{i32 7, !"PIE Level", i32 2}
+!7 = !{i32 7, !"uwtable", i32 2}
+!8 = !{i32 7, !"frame-pointer", i32 2}
+!9 = !{!"clang version 17.0.0)"}
+!10 = distinct !DISubprogram(name: "fun", linkageName: "_Z3funv", scope: !1, file: !1, line: 3, type: !11, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !14)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!13}
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !{}
+!15 = !DILocalVariable(name: "a", scope: !10, file: !1, line: 4, type: !13)
+!16 = !DILocation(line: 4, column: 9, scope: !10)
+!17 = !DILocalVariable(name: "b", scope: !10, file: !1, line: 4, type: !13)
+!18 = !DILocation(line: 4, column: 11, scope: !10)
+!19 = !DILocalVariable(scope: !10, file: !1, line: 4, type: !20)
+!20 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "two", file: !1, line: 1, size: 64, flags: DIFlagTypePassByValue, elements: !21, identifier: "_ZTS3two")
+!21 = !{!22, !23}
+!22 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !20, file: !1, line: 1, baseType: !13, size: 32)
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !20, file: !1, line: 1, baseType: !13, size: 32, offset: 32)
+!24 = !DILocation(line: 4, column: 8, scope: !10)
+!25 = !DILocation(line: 4, column: 16, scope: !10)
+!26 = !DILocation(line: 5, column: 10, scope: !10)
+!27 = !DILocation(line: 5, column: 14, scope: !10)
+!28 = !DILocation(line: 5, column: 12, scope: !10)
+!29 = !DILocation(line: 5, column: 3, scope: !10)
Index: llvm/test/DebugInfo/Generic/assignment-tracking/declare-to-assign/var-not-alloca-sized.ll
===================================================================
--- /dev/null
+++ llvm/test/DebugInfo/Generic/assignment-tracking/declare-to-assign/var-not-alloca-sized.ll
@@ -0,0 +1,69 @@
+; RUN: opt -passes=declare-to-assign -S %s -o - | FileCheck %s
+
+;; The variable doesn't fill the whole alloca which has a range of different
+;; sized stores to it, overlapping (or not) the variable in various ways. Check
+;; the fragment info looks right when converting the dbg.declare to
+;; dbg.assigns.
+;;
+;; Check directives written inline.
+
+%struct.two = type { i32, i32 }
+
+define dso_local noundef i32 @_Z3funv() #0 !dbg !10 {
+entry:
+  %0 = alloca [4 x i16], align 4
+  call void @llvm.dbg.declare(metadata ptr %0, metadata !15, metadata !DIExpression()), !dbg !16
+; CHECK: %0 = alloca [4 x i16], align 4, !DIAssignID ![[ID1:[0-9]+]]
+; CHECK-NEXT: llvm.dbg.assign(metadata i1 undef, metadata ![[#]], metadata !DIExpression(), metadata ![[ID1]], metadata ptr %0, metadata !DIExpression())
+  %a = getelementptr inbounds [4 x i16], ptr %0, i32 0, i32 0
+  %a.5 = getelementptr inbounds [4 x i16], ptr %0, i32 0, i32 1
+  %b = getelementptr inbounds [4 x i16], ptr %0, i32 0, i32 2
+  store i64 1, ptr %a, align 4
+; CHECK: store i64 1, ptr %a, align 4, !DIAssignID ![[ID2:[0-9]+]]
+; CHECK-NEXT: llvm.dbg.assign(metadata i64 1, metadata ![[#]], metadata !DIExpression(), metadata ![[ID2]], metadata ptr %a, metadata !DIExpression())
+  store i64 2, ptr %b, align 4
+;; %b is outside the variable bounds, no debug intrinsic needed.
+  store i16 3, ptr %a.5, align 4
+; CHECK: store i16 3, ptr %a.5, align 4, !DIAssignID ![[ID3:[0-9]+]]
+; CHECK-NEXT: llvm.dbg.assign(metadata i16 3, metadata ![[#]], metadata !DIExpression(DW_OP_LLVM_fragment, 16, 16), metadata ![[ID3]], metadata ptr %a.5, metadata !DIExpression())
+  store i32 4, ptr %a.5, align 4
+; CHECK: store i32 4, ptr %a.5, align 4, !DIAssignID ![[ID4:[0-9]+]]
+; CHECK-NEXT: llvm.dbg.assign(metadata i32 4, metadata ![[#]], metadata !DIExpression(DW_OP_LLVM_fragment, 16, 16), metadata ![[ID4]], metadata ptr %a.5, metadata !DIExpression())
+  store i32 5, ptr %a, align 4
+; CHECK: store i32 5, ptr %a, align 4, !DIAssignID ![[ID5:[0-9]+]]
+; CHECK-NEXT: llvm.dbg.assign(metadata i32 5, metadata ![[#]], metadata !DIExpression(), metadata ![[ID5]], metadata ptr %a, metadata !DIExpression())
+  ret i32 0
+}
+
+declare void @llvm.dbg.declare(metadata, metadata, metadata)
+declare i64 @_Z3getv()
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!2, !3, !4, !5, !6, !7, !8}
+!llvm.ident = !{!9}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "clang version 17.0.0)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "test.cpp", directory: "/")
+!2 = !{i32 7, !"Dwarf Version", i32 5}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !{i32 1, !"wchar_size", i32 4}
+!5 = !{i32 8, !"PIC Level", i32 2}
+!6 = !{i32 7, !"PIE Level", i32 2}
+!7 = !{i32 7, !"uwtable", i32 2}
+!8 = !{i32 7, !"frame-pointer", i32 2}
+!9 = !{!"clang version 17.0.0)"}
+!10 = distinct !DISubprogram(name: "fun", linkageName: "_Z3funv", scope: !1, file: !1, line: 3, type: !11, scopeLine: 3, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !14)
+!11 = !DISubroutineType(types: !12)
+!12 = !{!13}
+!13 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!14 = !{}
+!15 = !DILocalVariable(name: "a", scope: !10, file: !1, line: 4, type: !13)
+!16 = !DILocation(line: 4, column: 9, scope: !10)
+!17 = !DILocalVariable(name: "b", scope: !10, file: !1, line: 4, type: !13)
+!18 = !DILocation(line: 4, column: 11, scope: !10)
+!19 = !DILocalVariable(scope: !10, file: !1, line: 4, type: !20)
+!20 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "two", file: !1, line: 1, size: 64, flags: DIFlagTypePassByValue, elements: !21, identifier: "_ZTS3two")
+!21 = !{!22, !23}
+!22 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !20, file: !1, line: 1, baseType: !13, size: 32)
+!23 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !20, file: !1, line: 1, baseType: !13, size: 32, offset: 32)
+!25 = !DILocation(line: 4, column: 16, scope: !10)