[llvm] 4f32646 - [InstCombine] Retain debug information on store to null instruction (#86105)

[via llvm-commits]

Author: Abinaya Saravanan
Date: 2024-06-03T18:26:32+01:00
New Revision: 4f326468bdf9f63e562ac446210084a2997adbbd

URL: https://github.com/llvm/llvm-project/commit/4f326468bdf9f63e562ac446210084a2997adbbd
DIFF: https://github.com/llvm/llvm-project/commit/4f326468bdf9f63e562ac446210084a2997adbbd.diff

LOG: [InstCombine] Retain debug information on store to null instruction (#86105)

Call InsertNewInstWith() instead of InsertNewInstBefore() when creating
"store to null" instruction

Added: 
    llvm/test/Transforms/InstCombine/StoreToNull-DbgCheck.ll

Modified: 
    llvm/lib/Transforms/InstCombine/InstCombineInternal.h

Removed: 
    


################################################################################
diff  --git a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
index db7838bbe3c25..984f02bcccad7 100644
--- a/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
+++ b/llvm/lib/Transforms/InstCombine/InstCombineInternal.h
@@ -462,7 +462,7 @@ class LLVM_LIBRARY_VISIBILITY InstCombinerImpl final
     auto *SI = new StoreInst(ConstantInt::getTrue(Ctx),
                              PoisonValue::get(PointerType::getUnqual(Ctx)),
                              /*isVolatile*/ false, Align(1));
-    InsertNewInstBefore(SI, InsertAt->getIterator());
+    InsertNewInstWith(SI, InsertAt->getIterator());
   }
 
   /// Combiner aware instruction erasure.

diff  --git a/llvm/test/Transforms/InstCombine/StoreToNull-DbgCheck.ll b/llvm/test/Transforms/InstCombine/StoreToNull-DbgCheck.ll
new file mode 100644
index 0000000000000..dadb38820371c
--- /dev/null
+++ b/llvm/test/Transforms/InstCombine/StoreToNull-DbgCheck.ll
@@ -0,0 +1,37 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
+; Verify whether debug information is attached to the store to null/undef instruction
+; !dbg should be present at the end of "store to null" instruction
+; RUN: opt -S -passes='instcombine' < %s | FileCheck %s > /dev/null
+
+define void @_Z3foov() {
+; CHECK-LABEL: define void @_Z3foov() {
+; CHECK-NEXT:  entry:
+; CHECK-NEXT:    store i1 true, ptr poison, align 1, !dbg [[DBG4:![0-9]+]]
+; CHECK-NEXT:    ret void
+;
+
+entry:
+  tail call void null(), !dbg !4
+  ret void
+}
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: !1, producer: "Clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, globals: !2, splitDebugInlining: false, debugInfoForProfiling: true, nameTableKind: None)
+!1 = !DIFile(filename: "test_sym_mod.cpp", directory: "/workspace/asaravan/test_bugpoint")
+!2 = !{}
+!3 = !{i32 2, !"Debug Info Version", i32 3}
+!4 = !DILocation(line: 83, column: 3, scope: !5)
+!5 = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", scope: !1, file: !1, line: 77, type: !6, scopeLine: 78, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: !0, retainedNodes: !2)
+!6 = !DISubroutineType(types: !7)
+!7 = !{null}
+;.
+; CHECK: [[META0:![0-9]+]] = distinct !DICompileUnit(language: DW_LANG_C_plus_plus_14, file: [[META1:![0-9]+]], producer: "Clang", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, enums: [[META2:![0-9]+]], globals: [[META2]], splitDebugInlining: false, debugInfoForProfiling: true, nameTableKind: None)
+; CHECK: [[META1]] = !DIFile(filename: "test_sym_mod.cpp", directory: {{.*}})
+; CHECK: [[META2]] = !{}
+; CHECK: [[DBG4]] = !DILocation(line: 83, column: 3, scope: [[META5:![0-9]+]])
+; CHECK: [[META5]] = distinct !DISubprogram(name: "foo", linkageName: "_Z3foov", scope: [[META1]], file: [[META1]], line: 77, type: [[META6:![0-9]+]], scopeLine: 78, flags: DIFlagPrototyped | DIFlagAllCallsDescribed, spFlags: DISPFlagDefinition | DISPFlagOptimized, unit: [[META0]], retainedNodes: [[META2]])
+; CHECK: [[META6]] = !DISubroutineType(types: [[META7:![0-9]+]])
+; CHECK: [[META7]] = !{null}
+;.