[llvm] 0ebf7b4 - IR, CodeGen: Add command line flags for dumping instruction addresses and debug locations.

[via llvm-commits]

Author: Peter Collingbourne
Date: 2025-02-27T15:45:55-08:00
New Revision: 0ebf7b473a98a7433568d0a225d8b38767bdae50

URL: https://github.com/llvm/llvm-project/commit/0ebf7b473a98a7433568d0a225d8b38767bdae50
DIFF: https://github.com/llvm/llvm-project/commit/0ebf7b473a98a7433568d0a225d8b38767bdae50.diff

LOG: IR, CodeGen: Add command line flags for dumping instruction addresses and debug locations.

As previously discussed [1], it is sometimes useful to be able to see
instruction addresses and debug locations as part of IR dumps. The
same applies to MachineInstrs which already dump debug locations but
not addresses. Therefore add some flags that can be used to enable
dumping of this information.

[1] https://discourse.llvm.org/t/small-improvement-to-llvm-debugging-experience/79914

Reviewers: rnk

Reviewed By: rnk

Pull Request: https://github.com/llvm/llvm-project/pull/127944

Added: 
    llvm/test/Other/print-inst-addrs.ll
    llvm/test/Other/print-inst-debug-locs.ll
    llvm/test/Other/print-mi-addrs.ll

Modified: 
    llvm/lib/CodeGen/MachineInstr.cpp
    llvm/lib/IR/AsmWriter.cpp

Removed: 
    


################################################################################
diff  --git a/llvm/lib/CodeGen/MachineInstr.cpp b/llvm/lib/CodeGen/MachineInstr.cpp
index 5860a76c66bff..471666568e79a 100644
--- a/llvm/lib/CodeGen/MachineInstr.cpp
+++ b/llvm/lib/CodeGen/MachineInstr.cpp
@@ -63,6 +63,10 @@
 
 using namespace llvm;
 
+static cl::opt<bool>
+    PrintMIAddrs("print-mi-addrs", cl::Hidden,
+                 cl::desc("Print addresses of MachineInstrs when dumping"));
+
 static const MachineFunction *getMFIfAvailable(const MachineInstr &MI) {
   if (const MachineBasicBlock *MBB = MI.getParent())
     if (const MachineFunction *MF = MBB->getParent())
@@ -2076,6 +2080,9 @@ void MachineInstr::print(raw_ostream &OS, ModuleSlotTracker &MST,
   }
   // TODO: DBG_LABEL
 
+  if (PrintMIAddrs)
+    OS << " ; " << this;
+
   if (AddNewLine)
     OS << '\n';
 }

diff  --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
index 11e5a9cd33260..a52c4d88ac836 100644
--- a/llvm/lib/IR/AsmWriter.cpp
+++ b/llvm/lib/IR/AsmWriter.cpp
@@ -88,6 +88,14 @@
 
 using namespace llvm;
 
+static cl::opt<bool>
+    PrintInstAddrs("print-inst-addrs", cl::Hidden,
+                   cl::desc("Print addresses of instructions when dumping"));
+
+static cl::opt<bool> PrintInstDebugLocs(
+    "print-inst-debug-locs", cl::Hidden,
+    cl::desc("Pretty print debug locations of instructions when dumping"));
+
 // Make virtual table appear in this compilation unit.
 AssemblyAnnotationWriter::~AssemblyAnnotationWriter() = default;
 
@@ -4256,6 +4264,18 @@ void AssemblyWriter::printInfoComment(const Value &V) {
   if (AnnotationWriter) {
     AnnotationWriter->printInfoComment(V, Out);
   }
+
+  if (PrintInstDebugLocs) {
+    if (auto *I = dyn_cast<Instruction>(&V)) {
+      if (I->getDebugLoc()) {
+        Out << " ; ";
+        I->getDebugLoc().print(Out);
+      }
+    }
+  }
+
+  if (PrintInstAddrs)
+    Out << " ; " << &V;
 }
 
 static void maybePrintCallAddrSpace(const Value *Operand, const Instruction *I,

diff  --git a/llvm/test/Other/print-inst-addrs.ll b/llvm/test/Other/print-inst-addrs.ll
new file mode 100644
index 0000000000000..5907b30f0f12c
--- /dev/null
+++ b/llvm/test/Other/print-inst-addrs.ll
@@ -0,0 +1,6 @@
+; RUN: opt -S -print-inst-addrs %s | FileCheck %s
+
+define void @foo() {
+  ; CHECK: ret void ; 0x
+  ret void
+}

diff  --git a/llvm/test/Other/print-inst-debug-locs.ll b/llvm/test/Other/print-inst-debug-locs.ll
new file mode 100644
index 0000000000000..93210527e27a7
--- /dev/null
+++ b/llvm/test/Other/print-inst-debug-locs.ll
@@ -0,0 +1,20 @@
+; RUN: opt -S -print-inst-debug-locs < %s | FileCheck %s
+
+define weak i32 @foo(i32 %a, i32 %b) !dbg !3 {
+entry:
+  ; CHECK: call {{.*}} ; foo.c:52
+  %sum = call i32 @fastadd(i32 %a, i32 %b), !dbg !DILocation(line: 52, scope: !3)
+  ; CHECK: ret {{.*}} ; foo.c:53
+  ret i32 %sum, !dbg !DILocation(line: 53, scope: !3)
+}
+
+declare i32 @fastadd(i32, i32)
+
+!llvm.module.flags = !{!0}
+!0 = !{i32 2, !"Debug Info Version", i32 3}
+
+!llvm.dbg.cu = !{!1}
+!1 = distinct !DICompileUnit(language: DW_LANG_C99, file: !2, emissionKind: FullDebug)
+!2 = !DIFile(filename: "foo.c", directory: "/path/to/dir")
+!3 = distinct !DISubprogram(file: !2, scope: !2, line: 51, name: "foo", type: !4, unit: !1)
+!4 = !DISubroutineType(types: !{})

diff  --git a/llvm/test/Other/print-mi-addrs.ll b/llvm/test/Other/print-mi-addrs.ll
new file mode 100644
index 0000000000000..5be006d9df282
--- /dev/null
+++ b/llvm/test/Other/print-mi-addrs.ll
@@ -0,0 +1,11 @@
+; RUN: llc -print-after=slotindexes -print-mi-addrs < %s 2>&1 | FileCheck %s
+; REQUIRES: default_triple
+
+; CHECK: IR Dump {{.*}}
+; CHECK: # Machine code for function foo{{.*}}
+
+define void @foo() {
+  ; CHECK: ; 0x
+  ret void
+}
+