[llvm-branch-commits] [llvm] llvm-reduce: Handle the addrspacecast nonnull flag (PR #217907)

[Matt Arsenault via llvm-branch-commits]

https://github.com/arsenm created https://github.com/llvm/llvm-project/pull/217907

Co-authored-by: Claude (Claude-Opus-4.8) <noreply at anthropic.com>

>From 16e4e6e824cd5a8a00ec1ba13f01a66531956c03 Mon Sep 17 00:00:00 2001
From: Matt Arsenault <Matthew.Arsenault at amd.com>
Date: Thu, 20 Aug 2026 22:00:37 +0200
Subject: [PATCH] llvm-reduce: Handle the addrspacecast nonnull flag

Co-authored-by: Claude (Claude-Opus-4.8) <noreply at anthropic.com>
---
 llvm/test/tools/llvm-reduce/reduce-flags.ll   | 24 +++++++++++++++++++
 llvm/tools/llvm-reduce/ReducerWorkItem.cpp    |  3 +++
 .../deltas/ReduceInstructionFlags.cpp         |  3 +++
 3 files changed, 30 insertions(+)

diff --git a/llvm/test/tools/llvm-reduce/reduce-flags.ll b/llvm/test/tools/llvm-reduce/reduce-flags.ll
index f220fc429c89e..dd7610f583533 100644
--- a/llvm/test/tools/llvm-reduce/reduce-flags.ll
+++ b/llvm/test/tools/llvm-reduce/reduce-flags.ll
@@ -288,3 +288,27 @@ define i1 @icmp_samesign_keep(i32 %a) {
   %op = icmp samesign ult i32 %a, 10
   ret i1 %op
 }
+
+; CHECK-LABEL: @addrspacecast_nonnull_drop(
+; INTERESTING: = addrspacecast
+; RESULT: addrspacecast ptr addrspace(1) %a to ptr
+define ptr @addrspacecast_nonnull_drop(ptr addrspace(1) %a) {
+  %op = addrspacecast nonnull ptr addrspace(1) %a to ptr
+  ret ptr %op
+}
+
+; CHECK-LABEL: @addrspacecast_nonnull_keep(
+; INTERESTING: = addrspacecast nonnull
+; RESULT: addrspacecast nonnull ptr addrspace(1) %a to ptr
+define ptr @addrspacecast_nonnull_keep(ptr addrspace(1) %a) {
+  %op = addrspacecast nonnull ptr addrspace(1) %a to ptr
+  ret ptr %op
+}
+
+; CHECK-LABEL: @addrspacecast_nonnull_vector_keep(
+; INTERESTING: = addrspacecast nonnull
+; RESULT: addrspacecast nonnull <2 x ptr addrspace(1)> %a to <2 x ptr>
+define <2 x ptr> @addrspacecast_nonnull_vector_keep(<2 x ptr addrspace(1)> %a) {
+  %op = addrspacecast nonnull <2 x ptr addrspace(1)> %a to <2 x ptr>
+  ret <2 x ptr> %op
+}
diff --git a/llvm/tools/llvm-reduce/ReducerWorkItem.cpp b/llvm/tools/llvm-reduce/ReducerWorkItem.cpp
index fa4da7a073f1e..9be05aafc865d 100644
--- a/llvm/tools/llvm-reduce/ReducerWorkItem.cpp
+++ b/llvm/tools/llvm-reduce/ReducerWorkItem.cpp
@@ -681,6 +681,9 @@ static uint64_t computeIRComplexityScoreImpl(const Function &F) {
       } else if (const auto *PDI = dyn_cast<PossiblyDisjointInst>(&I)) {
         if (PDI->isDisjoint())
           ++Score;
+      } else if (const auto *ASC = dyn_cast<AddrSpaceCastInst>(&I)) {
+        if (ASC->hasNonNull())
+          ++Score;
       } else if (const auto *GEP = dyn_cast<GEPOperator>(&I)) {
         if (GEP->isInBounds())
           ++Score;
diff --git a/llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp b/llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp
index 2937550bfec75..300747b4c5312 100644
--- a/llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp
+++ b/llvm/tools/llvm-reduce/deltas/ReduceInstructionFlags.cpp
@@ -45,6 +45,9 @@ void llvm::reduceInstructionFlagsDeltaPass(Oracle &O,
       } else if (auto *ICmp = dyn_cast<ICmpInst>(&I)) {
         if (ICmp->hasSameSign() && !O.shouldKeep())
           ICmp->setSameSign(false);
+      } else if (auto *ASC = dyn_cast<AddrSpaceCastInst>(&I)) {
+        if (ASC->hasNonNull() && !O.shouldKeep())
+          ASC->setNonNull(false);
       } else if (auto *GEP = dyn_cast<GetElementPtrInst>(&I)) {
         GEPNoWrapFlags NW = GEP->getNoWrapFlags();
         if (NW.isInBounds() && !O.shouldKeep())