[LSR] Do not consider uses in lifetime intrinsics

llvm/lib/Transforms/Scalar/LoopStrengthReduce.cpp

@@ -3790,6 +3790,11 @@ LSRInstance::CollectLoopInvariantFixupsAndFormulae() {
             continue;
         }
 
+        // Do not consider uses inside lifetime intrinsics. These are not
+        // actually materialized.
+        if (UserInst->isLifetimeStartOrEnd())
+          continue;
+
         std::pair<size_t, Immediate> P =
             getUse(S, LSRUse::Basic, MemAccessTy());
         size_t LUIdx = P.first;

llvm/test/Transforms/LoopStrengthReduce/X86/lifetime-use.ll

@@ -0,0 +1,59 @@
+; NOTE: Assertions have been autogenerated by utils/update_test_checks.py UTC_ARGS: --version 5
+; RUN: opt -S -passes=loop-reduce -mtriple=x86_64-unknown-linux-gnu < %s | FileCheck %s
+
+define void @test(ptr %p, i64 %idx) {
+; CHECK-LABEL: define void @test(
+; CHECK-SAME: ptr [[P:%.*]], i64 [[IDX:%.*]]) {
+; CHECK-NEXT:  [[ENTRY:.*]]:
+; CHECK-NEXT:    [[ALLOCA:%.*]] = alloca [4 x [4 x i32]], align 16
+; CHECK-NEXT:    call void @llvm.lifetime.start.p0(i64 64, ptr [[ALLOCA]])
+; CHECK-NEXT:    [[TMP0:%.*]] = shl i64 [[IDX]], 6
+; CHECK-NEXT:    [[TMP1:%.*]] = add nuw nsw i64 [[TMP0]], 48
+; CHECK-NEXT:    [[SCEVGEP:%.*]] = getelementptr i8, ptr [[P]], i64 [[TMP1]]
+; CHECK-NEXT:    [[SCEVGEP3:%.*]] = getelementptr nuw i8, ptr [[ALLOCA]], i64 48
+; CHECK-NEXT:    br label %[[LOOP:.*]]
+; CHECK:       [[LOOP]]:
+; CHECK-NEXT:    [[LSR_IV:%.*]] = phi i64 [ [[LSR_IV_NEXT:%.*]], %[[LOOP]] ], [ -8, %[[ENTRY]] ]
+; CHECK-NEXT:    [[TMP2:%.*]] = shl nsw i64 [[LSR_IV]], 2
+; CHECK-NEXT:    [[SCEVGEP8:%.*]] = getelementptr i8, ptr [[P]], i64 [[TMP2]]
+; CHECK-NEXT:    [[SCEVGEP9:%.*]] = getelementptr i8, ptr [[SCEVGEP8]], i64 32
+; CHECK-NEXT:    [[TMP3:%.*]] = load i32, ptr [[SCEVGEP9]], align 4
+; CHECK-NEXT:    [[SCEVGEP6:%.*]] = getelementptr i8, ptr [[P]], i64 [[LSR_IV]]
+; CHECK-NEXT:    [[SCEVGEP7:%.*]] = getelementptr i8, ptr [[SCEVGEP6]], i64 8
+; CHECK-NEXT:    [[TMP4:%.*]] = load i32, ptr [[SCEVGEP7]], align 4
+; CHECK-NEXT:    [[SCEVGEP4:%.*]] = getelementptr i8, ptr [[SCEVGEP3]], i64 [[LSR_IV]]
+; CHECK-NEXT:    [[SCEVGEP5:%.*]] = getelementptr i8, ptr [[SCEVGEP4]], i64 8
+; CHECK-NEXT:    [[TMP5:%.*]] = load i32, ptr [[SCEVGEP5]], align 4
+; CHECK-NEXT:    [[SCEVGEP1:%.*]] = getelementptr i8, ptr [[SCEVGEP]], i64 [[LSR_IV]]
+; CHECK-NEXT:    [[SCEVGEP2:%.*]] = getelementptr i8, ptr [[SCEVGEP1]], i64 8
+; CHECK-NEXT:    [[TMP6:%.*]] = load i32, ptr [[SCEVGEP2]], align 4
+; CHECK-NEXT:    [[LSR_IV_NEXT]] = add nsw i64 [[LSR_IV]], 4
+; CHECK-NEXT:    [[EXITCOND_NOT:%.*]] = icmp eq i64 [[LSR_IV_NEXT]], 0
+; CHECK-NEXT:    br i1 [[EXITCOND_NOT]], label %[[EXIT:.*]], label %[[LOOP]]
+; CHECK:       [[EXIT]]:
+; CHECK-NEXT:    call void @llvm.lifetime.end.p0(i64 64, ptr [[ALLOCA]])
+; CHECK-NEXT:    ret void
+;
+entry:
+  %alloca = alloca [4 x [4 x i32]], align 16
+  call void @llvm.lifetime.start.p0(i64 64, ptr %alloca)
+  br label %loop
+
+loop:
+  %indvars.iv = phi i64 [ 0, %entry ], [ %indvars.iv.next, %loop ]
+  %gep1 = getelementptr [4 x [12 x [4 x [4 x i32]]]], ptr %p, i64 0, i64 0, i64 0, i64 %indvars.iv, i64 0
+  %0 = load i32, ptr %gep1, align 4
+  %gep2 = getelementptr [6 x [4 x [4 x i32]]], ptr %p, i64 0, i64 0, i64 0, i64 %indvars.iv
+  %1 = load i32, ptr %gep2, align 4
+  %gep3 = getelementptr [4 x [4 x i32]], ptr %alloca, i64 0, i64 3, i64 %indvars.iv
+  %2 = load i32, ptr %gep3, align 4
+  %gep4 = getelementptr [6 x [4 x [4 x i32]]], ptr %p, i64 0, i64 %idx, i64 3, i64 %indvars.iv
+  %3 = load i32, ptr %gep4, align 4
+  %indvars.iv.next = add i64 %indvars.iv, 1
+  %exitcond.not = icmp eq i64 %indvars.iv, 1
+  br i1 %exitcond.not, label %exit, label %loop
+
+exit:
+  call void @llvm.lifetime.end.p0(i64 64, ptr %alloca)
+  ret void
+}