Index: clang/docs/ClangFormatStyleOptions.rst
===================================================================
--- clang/docs/ClangFormatStyleOptions.rst
+++ clang/docs/ClangFormatStyleOptions.rst
@@ -1899,7 +1899,18 @@
   * ``BS_Custom`` (in configuration: ``Custom``)
     Configure each individual brace in `BraceWrapping`.
 
+**BreakBeforeInlineASMColon** (``bool``)
+  If ``true``, colons in ASM parameters will be placed after line breaks.
 
+  .. code-block:: c
+
+     true:
+      asm volatile("string",
+                   :
+                   : val);
+
+     false:
+      asm volatile("string", : : val);
 
 **BreakBeforeConceptDeclarations** (``bool``)
   If ``true``, concept will be placed on a new line.
Index: clang/include/clang/Format/Format.h
===================================================================
--- clang/include/clang/Format/Format.h
+++ clang/include/clang/Format/Format.h
@@ -1685,6 +1685,18 @@
   /// \endcode
   bool BreakBeforeConceptDeclarations;
 
+  /// If ``true``, colons in ASM parameters will be placed after line breaks.
+  /// \code
+  ///    true:
+  ///    asm volatile("string",
+  ///                 :
+  ///                 : val);
+  ///
+  ///    false:
+  ///    asm volatile("string", : : val);
+  /// \endcode
+  bool BreakBeforeInlineASMColon;
+
   /// If ``true``, ternary operators will be placed after line breaks.
   /// \code
   ///    true:
@@ -3184,6 +3196,7 @@
            BreakBeforeBinaryOperators == R.BreakBeforeBinaryOperators &&
            BreakBeforeBraces == R.BreakBeforeBraces &&
            BreakBeforeConceptDeclarations == R.BreakBeforeConceptDeclarations &&
+           BreakBeforeInlineASMColon == R.BreakBeforeInlineASMColon &&
            BreakBeforeTernaryOperators == R.BreakBeforeTernaryOperators &&
            BreakConstructorInitializers == R.BreakConstructorInitializers &&
            CompactNamespaces == R.CompactNamespaces &&
Index: clang/lib/Format/Format.cpp
===================================================================
--- clang/lib/Format/Format.cpp
+++ clang/lib/Format/Format.cpp
@@ -554,6 +554,9 @@
         Style.BreakInheritanceList == FormatStyle::BILS_BeforeColon)
       Style.BreakInheritanceList = FormatStyle::BILS_BeforeComma;
 
+    IO.mapOptional("BreakBeforeInlineASMColon",
+                   Style.BreakBeforeInlineASMColon);
+
     IO.mapOptional("BreakBeforeTernaryOperators",
                    Style.BreakBeforeTernaryOperators);
 
@@ -940,6 +943,7 @@
   LLVMStyle.BinPackParameters = true;
   LLVMStyle.BreakBeforeBinaryOperators = FormatStyle::BOS_None;
   LLVMStyle.BreakBeforeConceptDeclarations = true;
+  LLVMStyle.BreakBeforeInlineASMColon = false;
   LLVMStyle.BreakBeforeTernaryOperators = true;
   LLVMStyle.BreakBeforeBraces = FormatStyle::BS_Attach;
   LLVMStyle.BraceWrapping = {/*AfterCaseLabel=*/false,
Index: clang/lib/Format/TokenAnnotator.cpp
===================================================================
--- clang/lib/Format/TokenAnnotator.cpp
+++ clang/lib/Format/TokenAnnotator.cpp
@@ -3514,6 +3514,9 @@
   const FormatToken &Left = *Right.Previous;
   if (Right.NewlinesBefore > 1 && Style.MaxEmptyLinesToKeep > 0)
     return true;
+  if (Line.startsWith(tok::kw_asm) && Right.is(TT_InlineASMColon) &&
+      Style.BreakBeforeInlineASMColon)
+    return true;
 
   if (Style.isCSharp()) {
     if (Right.is(TT_CSharpNamedArgumentColon) ||
Index: clang/unittests/Format/FormatTest.cpp
===================================================================
--- clang/unittests/Format/FormatTest.cpp
+++ clang/unittests/Format/FormatTest.cpp
@@ -5069,6 +5069,26 @@
             format(Input, Style));
 }
 
+TEST_F(FormatTest, BreakBeforeInlineASMColon) {
+  FormatStyle Style = getLLVMStyle();
+
+  Style.BreakBeforeInlineASMColon = false;
+  verifyFormat("asm volatile(\"string\", : : val);",
+               Style);
+  verifyFormat("asm volatile(\"string\", : val1 : val2);",
+               Style);
+
+  Style.BreakBeforeInlineASMColon = true;
+  verifyFormat("asm volatile(\"string\",\n"
+               "             :\n"
+               "             : val);",
+               Style);
+  verifyFormat("asm volatile(\"string\",\n"
+               "             : val1\n"
+               "             : val2);",
+               Style);
+}
+
 TEST_F(FormatTest, BreakConstructorInitializersAfterColon) {
   FormatStyle Style = getLLVMStyle();
   Style.BreakConstructorInitializers = FormatStyle::BCIS_AfterColon;