diff --git a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
--- a/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
+++ b/llvm/lib/Transforms/Instrumentation/AddressSanitizer.cpp
@@ -2931,6 +2931,8 @@
                                          size_t Begin, size_t End,
                                          IRBuilder<> &IRB, Value *ShadowBase) {
   assert(ShadowMask.size() == ShadowBytes.size());
+  const size_t MaxHoleSize =
+      std::min<size_t>(sizeof(uint64_t), ASan.LongSize / 8);
   size_t Done = Begin;
   for (size_t i = Begin, j = Begin + 1; i < End; i = j++) {
     if (!ShadowMask[i]) {
@@ -2945,6 +2947,20 @@
     for (; j < End && ShadowMask[j] && Val == ShadowBytes[j]; ++j) {
     }
 
+    // Special case for zero value: allow a few consecutive zeros in the middle
+    // of the mask. It avoids splitting the buffer into many inlined chunks.
+    if (!Val) {
+      size_t HoleSize = 0;
+      for (; j < End && !ShadowBytes[j] && HoleSize <= MaxHoleSize; ++j) {
+        if (!ShadowMask[j])
+          HoleSize++;
+        else
+          HoleSize = 0;
+      }
+      // Ignore trailing zeros in the mask.
+      j -= HoleSize;
+    }
+
     if (j - i >= ClMaxInlinePoisoningSize) {
       copyToShadowInline(ShadowMask, ShadowBytes, Done, i, IRB, ShadowBase);
       IRB.CreateCall(AsanSetShadowFunc[Val],
diff --git a/llvm/test/Instrumentation/AddressSanitizer/asan-optimize-inline-poisoning.ll b/llvm/test/Instrumentation/AddressSanitizer/asan-optimize-inline-poisoning.ll
new file mode 100644
--- /dev/null
+++ b/llvm/test/Instrumentation/AddressSanitizer/asan-optimize-inline-poisoning.ll
@@ -0,0 +1,63 @@
+; RUN: opt < %s  -passes=asan -asan-max-inline-poisoning-size=8 -S | FileCheck %s --check-prefix=CHECK
+
+target datalayout = "e-m:w-p270:32:32-p271:32:32-p272:64:64-i64:64-f80:128-n8:16:32:64-S128"
+target triple = "x86_64-pc-windows-msvc19.20.0"
+
+%struct.S = type { ptr, ptr }
+
+define void @allocas() sanitize_address {
+; CHECK-LABEL: void @allocas()
+entry:
+  %agg.tmp = alloca %struct.S, align 8
+  %agg.tmp1 = alloca %struct.S, align 8
+  %agg.tmp2 = alloca %struct.S, align 8
+  %agg.tmp3 = alloca %struct.S, align 8
+  %agg.tmp4 = alloca %struct.S, align 8
+  %agg.tmp5 = alloca %struct.S, align 8
+  %agg.tmp6 = alloca %struct.S, align 8
+  %agg.tmp7 = alloca %struct.S, align 8
+  %agg.tmp8 = alloca %struct.S, align 8
+  %agg.tmp9 = alloca %struct.S, align 8
+  %agg.tmp10 = alloca %struct.S, align 8
+  %agg.tmp11 = alloca %struct.S, align 8
+  %agg.tmp12 = alloca %struct.S, align 8
+  %agg.tmp13 = alloca %struct.S, align 8
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp)
+  call void @use_copy(ptr noundef nonnull %agg.tmp)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp1)
+  call void @use_copy(ptr noundef nonnull %agg.tmp1)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp2)
+  call void @use_copy(ptr noundef nonnull %agg.tmp2)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp3)
+  call void @use_copy(ptr noundef nonnull %agg.tmp3)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp4)
+  call void @use_copy(ptr noundef nonnull %agg.tmp4)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp5)
+  call void @use_copy(ptr noundef nonnull %agg.tmp5)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp6)
+  call void @use_copy(ptr noundef nonnull %agg.tmp6)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp7)
+  call void @use_copy(ptr noundef nonnull %agg.tmp7)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp8)
+  call void @use_copy(ptr noundef nonnull %agg.tmp8)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp9)
+  call void @use_copy(ptr noundef nonnull %agg.tmp9)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp10)
+  call void @use_copy(ptr noundef nonnull %agg.tmp10)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp11)
+  call void @use_copy(ptr noundef nonnull %agg.tmp11)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp12)
+  call void @use_copy(ptr noundef nonnull %agg.tmp12)
+  call void @get(ptr nonnull sret(%struct.S) align 8 %agg.tmp13)
+  call void @use_copy(ptr noundef nonnull %agg.tmp13)
+  br label %return
+return:
+; CHECK: return:
+; CHECK: call void @__asan_set_shadow_f5(i64 %{{.*}}, i64 64)
+; CHECK: call void @__asan_set_shadow_00(i64 %{{.*}}, i64 60)
+; CHECK: ret void
+  ret void
+}
+
+declare void @use_copy(ptr noundef)
+declare void @get(ptr sret(%struct.S) align 8, ...)