[SelectionDAG] Handle IntToPtr constants in dbg.value

The function `handleDebugValue` has custom logic to handle certain kinds
constants, namely integers, floats and null pointers. However, it does
not handle constant pointers created from IntToPtr ConstantExpressions.
This patch addresses the issue by replacing the Constant with its
integer operand.

A similar bug was addressed for GlobalISel in D130642.

Reviewed By: aprantl, #debug-info

Differential Revision: https://reviews.llvm.org/D130908

diff --git a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
index 2239148..40b3f68 100644 (file)
--- a/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
+++ b/llvm/lib/CodeGen/SelectionDAG/SelectionDAGBuilder.cpp
@@ -1344,6 +1344,13 @@ bool SelectionDAGBuilder::handleDebugValue(ArrayRef<const Value *> Values,
       continue;
     }
 
+    // Look through IntToPtr constants.
+    if (auto *CE = dyn_cast<ConstantExpr>(V))
+      if (CE->getOpcode() == Instruction::IntToPtr) {
+        LocationOps.emplace_back(SDDbgOperand::fromConst(CE->getOperand(0)));
+        continue;
+      }
+
     // If the Value is a frame index, we can create a FrameIndex debug value
     // without relying on the DAG at all.
     if (const AllocaInst *AI = dyn_cast<AllocaInst>(V)) {

diff --git a/llvm/test/CodeGen/AArch64/inttoptr_debug_value.ll b/llvm/test/CodeGen/AArch64/inttoptr_debug_value.ll
new file mode 100644 (file)
index 0000000..5ff5292
--- /dev/null
+++ b/llvm/test/CodeGen/AArch64/inttoptr_debug_value.ll
@@ -0,0 +1,25 @@
+; RUN: llc -o - --print-after-isel %s 2>&1 | FileCheck %s
+
+target triple = "arm64-apple-ios13.4.0"
+define void @foo() !dbg !6 {
+  ; CHECK: DBG_VALUE 42, $noreg, !"myvar", !DIExpression()
+  call void @llvm.dbg.value(metadata ptr inttoptr (i64 42 to ptr), metadata !9, metadata !DIExpression()), !dbg !11
+  ret void
+}
+
+declare void @llvm.dbg.value(metadata, metadata, metadata)
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!5}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C, file: !1, producer: "debugify", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2)
+!1 = !DIFile(filename: "t.ll", directory: "/")
+!2 = !{}
+!5 = !{i32 4, !"Debug Info Version", i32 3}
+!6 = distinct !DISubprogram(name: "foo", linkageName: "foo", scope: null, file: !1, line: 1, type: !7, scopeLine: 1, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !8)
+!7 = !DISubroutineType(types: !2)
+!8 = !{!9}
+!9 = !DILocalVariable(name: "myvar", scope: !6, file: !1, line: 1, type: !10)
+!10 = !DIBasicType(name: "ty64", size: 64, encoding: DW_ATE_unsigned)
+!11 = !DILocation(line: 1, column: 1, scope: !6)
+!12 = !DILocation(line: 2, column: 1, scope: !6)