From 656552edc693e2bb4abc9258399c39d190fce2b3 Mon Sep 17 00:00:00 2001
From: Emma Pilkington <Emma.Pilkington@amd.com>
Date: Mon, 15 Jul 2024 16:10:10 -0400
Subject: [PATCH] [InstCombine] Skip addrspacecast when lowering dbg.declare

Change-Id: I99e4fc3dedad09c038b026bd62e316ccdfab82dc
---
 llvm/lib/Transforms/Utils/Local.cpp           |  5 +++
 .../heterogeneous-poison-lower-dbg-declare.ll | 35 ++++++++++++++++---
 2 files changed, 36 insertions(+), 4 deletions(-)

diff --git a/llvm/lib/Transforms/Utils/Local.cpp b/llvm/lib/Transforms/Utils/Local.cpp
index b92e016fe05ed3..4dee0227b1f379 100644
--- a/llvm/lib/Transforms/Utils/Local.cpp
+++ b/llvm/lib/Transforms/Utils/Local.cpp
@@ -2136,6 +2136,11 @@ bool llvm::LowerDbgDeclare(Function &F) {
         } else if (BitCastInst *BI = dyn_cast<BitCastInst>(U)) {
           if (BI->getType()->isPointerTy())
             WorkList.push_back(BI);
+        } else if (auto *ASC = dyn_cast<AddrSpaceCastInst>(U)) {
+          // Only look through addrspacecasts if the declare uses new
+          // expressions (to avoid a difference with upstream).
+          if (DDI->getExpression()->holdsNewElements())
+            WorkList.push_back(ASC);
         }
       }
     }
diff --git a/llvm/test/Transforms/InstCombine/heterogeneous-poison-lower-dbg-declare.ll b/llvm/test/Transforms/InstCombine/heterogeneous-poison-lower-dbg-declare.ll
index 9aaca0c4603b67..8b87e7b4abb1a2 100644
--- a/llvm/test/Transforms/InstCombine/heterogeneous-poison-lower-dbg-declare.ll
+++ b/llvm/test/Transforms/InstCombine/heterogeneous-poison-lower-dbg-declare.ll
@@ -1,6 +1,5 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 4
-; RUN: opt -passes='instcombine' -S --experimental-debuginfo-iterators=true  < %s | FileCheck %s
-; RUN: opt -passes='instcombine' -S --experimental-debuginfo-iterators=false < %s | FileCheck %s
+; RUN: opt -passes='instcombine' -S < %s | FileCheck %s
 
 target datalayout = "e-m:e-p270:32:32-p271:32:32-p272:64:64-i64:64-i128:128-f80:128-n8:16:32:64-S128"
 target triple = "x86_64-unknown-linux-gnu"
@@ -20,14 +19,31 @@ define i32 @foo() !dbg !5 {
 ;
 entry:
   %var = alloca i32, align 4
-  tail call void @llvm.dbg.declare(metadata ptr %var, metadata !11, metadata !DIExpression(DIOpArg(0, ptr), DIOpDeref(i32))), !dbg !12
+  #dbg_declare(ptr %var, !11, !DIExpression(DIOpArg(0, ptr), DIOpDeref(i32)), !12)
   store i32 42, ptr %var, align 4
   call void @escape(ptr %var)
   %0 = load i32, ptr %var, align 4
   ret i32 %0
 }
 
-declare void @llvm.dbg.declare(metadata, metadata, metadata)
+define void @bar() !dbg !15 {
+; CHECK-LABEL: define void @bar(
+; CHECK-SAME: ) !dbg [[DBG13:![0-9]+]] {
+; CHECK-NEXT:    [[VAR:%.*]] = alloca i32, align 4, addrspace(5)
+; CHECK-NEXT:    [[VAR_ASCAST:%.*]] = addrspacecast ptr addrspace(5) [[VAR]] to ptr
+; CHECK-NEXT:      #dbg_value(i32 42, [[META15:![0-9]+]], !DIExpression(DIOpArg(0, i32)), [[META16:![0-9]+]])
+; CHECK-NEXT:    store i32 42, ptr [[VAR_ASCAST]], align 4
+; CHECK-NEXT:      #dbg_value(ptr addrspace(5) [[VAR]], [[META15]], !DIExpression(DIOpArg(0, ptr addrspace(5)), DIOpDeref(i32)), [[META16]])
+; CHECK-NEXT:    call void @escape(ptr nonnull [[VAR_ASCAST]])
+; CHECK-NEXT:    ret void
+;
+  %var = alloca i32, align 4, addrspace(5)
+  %var.ascast = addrspacecast ptr addrspace(5) %var to ptr
+  #dbg_declare(ptr addrspace(5) %var, !17, !DIExpression(DIOpArg(0, ptr addrspace(5)), DIOpDeref(i32)), !18)
+  store i32 42, ptr %var.ascast, align 4
+  call void @escape(ptr %var.ascast)
+  ret void
+}
 
 declare void @escape(ptr)
 
@@ -48,6 +64,13 @@ declare void @escape(ptr)
 !10 = !{!11}
 !11 = !DILocalVariable(name: "var", scope: !5, file: !6, line: 5, type: !9)
 !12 = !DILocation(line: 1, column: 1, scope: !5)
+!13 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !9, size: 64)
+!14 = !DILocalVariable(name: "ptr", scope: !5, file: !6, line: 5, type: !13)
+!15 = distinct !DISubprogram(name: "bar", scope: !6, file: !6, line: 4, type: !7, scopeLine: 4, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !16)
+!16 = !{!17}
+!17 = !DILocalVariable(name: "var", scope: !15, file: !6, line: 5, type: !9)
+!18 = !DILocation(line: 1, column: 1, scope: !15)
+
 ;.
 ; CHECK: [[META0:![0-9]+]] = distinct !DICompileUnit(language: DW_LANG_C11, file: [[META1:![0-9]+]], producer: "clang 19.0.0", isOptimized: true, runtimeVersion: 0, emissionKind: FullDebug, splitDebugInlining: false, nameTableKind: None)
 ; CHECK: [[META1]] = !DIFile(filename: "t.c", directory: {{.*}})
@@ -59,4 +82,8 @@ declare void @escape(ptr)
 ; CHECK: [[META10]] = !{[[META11]]}
 ; CHECK: [[META11]] = !DILocalVariable(name: "var", scope: [[DBG5]], file: [[META6]], line: 5, type: [[META9]])
 ; CHECK: [[META12]] = !DILocation(line: 0, scope: [[DBG5]])
+; CHECK: [[DBG13]] = distinct !DISubprogram(name: "bar", scope: [[META6]], file: [[META6]], line: 4, type: [[META7]], scopeLine: 4, spFlags: DISPFlagDefinition, unit: [[META0]], retainedNodes: [[META14:![0-9]+]])
+; CHECK: [[META14]] = !{[[META15]]}
+; CHECK: [[META15]] = !DILocalVariable(name: "var", scope: [[DBG13]], file: [[META6]], line: 5, type: [[META9]])
+; CHECK: [[META16]] = !DILocation(line: 0, scope: [[DBG13]])
 ;.