[RemoveDIs] Fix DPValue hoisting in hoistSuccIdenticalTerminatorToSwitchOrIf

[OCHyams]

Follow up to #79476 - that patch added a call to hoistLockstepIdenticalDPValues which hoists identical DPValues in lockstep, matching dbg intrinsic hoisting behaviour. The code deleted in this patch, which unconditionally hoists DPValues, should have been deleted in that patch.

Update test with --try-experimental-debuginfo-iterators to check the behaviour.

Follow up to #79476 - that change introduces a call to hoistLockstepIdenticalDPValues

[llvmbot]

@llvm/pr-subscribers-llvm-transforms

Author: Orlando Cazalet-Hyams (OCHyams)

Changes

Follow up to #79476 - that patch added a call to hoistLockstepIdenticalDPValues which hoists identical DPValues in lockstep, matching dbg intrinsic hoisting behaviour. The code deleted in this patch, which unconditionally hoists DPValues, should have been deleted in that patch.

Update test with --try-experimental-debuginfo-iterators to check the behaviour.

Follow up to #79476 - that change introduces a call to hoistLockstepIdenticalDPValues

---

Full diff: https://github.com/llvm/llvm-project/pull/80822.diff

2 Files Affected:

• (modified) llvm/lib/Transforms/Utils/SimplifyCFG.cpp (-5)
• (modified) llvm/test/Transforms/SimplifyCFG/X86/sink-common-code.ll (+2)

diff --git a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
index f5b398cae04ed..7424fe31945dc 100644
--- a/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
+++ b/llvm/lib/Transforms/Utils/SimplifyCFG.cpp
@@ -1842,11 +1842,6 @@ bool SimplifyCFGOpt::hoistSuccIdenticalTerminatorToSwitchOrIf(
   Locs.push_back(I1->getDebugLoc());
   for (auto *OtherSuccTI : OtherSuccTIs)
     Locs.push_back(OtherSuccTI->getDebugLoc());
-  // Also clone DPValues from the existing terminator, and all others (to
-  // duplicate existing hoisting behaviour).
-  NT->cloneDebugInfoFrom(I1);
-  for (Instruction *OtherSuccTI : OtherSuccTIs)
-    NT->cloneDebugInfoFrom(OtherSuccTI);
   NT->setDebugLoc(DILocation::getMergedLocations(Locs));
 
   // PHIs created below will adopt NT's merged DebugLoc.
diff --git a/llvm/test/Transforms/SimplifyCFG/X86/sink-common-code.ll b/llvm/test/Transforms/SimplifyCFG/X86/sink-common-code.ll
index 26107965a1a8b..630c71df0536f 100644
--- a/llvm/test/Transforms/SimplifyCFG/X86/sink-common-code.ll
+++ b/llvm/test/Transforms/SimplifyCFG/X86/sink-common-code.ll
@@ -1,6 +1,8 @@
 ; NOTE: Assertions have been autogenerated by utils/update_test_checks.py
 ; RUN: opt < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -sink-common-insts -S | FileCheck %s
+; RUN: opt --try-experimental-debuginfo-iterators < %s -passes=simplifycfg -simplifycfg-require-and-preserve-domtree=1 -sink-common-insts -S | FileCheck %s
 ; RUN: opt < %s -passes='simplifycfg<sink-common-insts>' -S | FileCheck %s
+; RUN: opt --try-experimental-debuginfo-iterators < %s -passes='simplifycfg<sink-common-insts>' -S | FileCheck %s
 
 target datalayout = "e-p:64:64:64-i1:8:8-i8:8:8-i16:16:16-i32:32:32-i64:64:64-f32:32:32-f64:64:64-v64:64:64-v128:128:128-a0:0:64-s0:64:64-f80:128:128-n8:16:32:64"
 target triple = "x86_64-pc-linux-gnu"

[jmorse]

LGTM, thanks for patching.