diff -Nru llvm-toolchain-13-13.0.0/debian/changelog llvm-toolchain-13-13.0.0/debian/changelog
--- llvm-toolchain-13-13.0.0/debian/changelog	2021-10-03 20:38:18.000000000 +0000
+++ llvm-toolchain-13-13.0.0/debian/changelog	2021-12-01 10:49:29.000000000 +0000
@@ -1,3 +1,9 @@
+llvm-toolchain-13 (1:13.0.0-2+v3) impish; urgency=medium
+
+  * Default to x86-64-v3 on amd64.
+
+ -- Matthias Klose <doko@ubuntu.com>  Wed, 01 Dec 2021 11:49:29 +0100
+
 llvm-toolchain-13 (1:13.0.0-2) unstable; urgency=medium
 
   * Fix the libclang detection in cmake
diff -Nru llvm-toolchain-13-13.0.0/debian/patches/clang-default-x86-64-v2.diff llvm-toolchain-13-13.0.0/debian/patches/clang-default-x86-64-v2.diff
--- llvm-toolchain-13-13.0.0/debian/patches/clang-default-x86-64-v2.diff	1970-01-01 00:00:00.000000000 +0000
+++ llvm-toolchain-13-13.0.0/debian/patches/clang-default-x86-64-v2.diff	2021-04-15 11:34:40.000000000 +0000
@@ -0,0 +1,11 @@
+--- a/clang/lib/Driver/ToolChains/Arch/X86.cpp
++++ b/clang/lib/Driver/ToolChains/Arch/X86.cpp
+@@ -91,7 +91,7 @@ std::string x86::getX86TargetCPU(const A
+ 
+   // Everything else goes to x86-64 in 64-bit mode.
+   if (Is64Bit)
+-    return "x86-64";
++    return "x86-64-v2";
+ 
+   switch (Triple.getOS()) {
+   case llvm::Triple::NetBSD:
diff -Nru llvm-toolchain-13-13.0.0/debian/patches/clang-default-x86-64-v3.diff llvm-toolchain-13-13.0.0/debian/patches/clang-default-x86-64-v3.diff
--- llvm-toolchain-13-13.0.0/debian/patches/clang-default-x86-64-v3.diff	1970-01-01 00:00:00.000000000 +0000
+++ llvm-toolchain-13-13.0.0/debian/patches/clang-default-x86-64-v3.diff	2021-04-15 11:34:40.000000000 +0000
@@ -0,0 +1,11 @@
+--- a/clang/lib/Driver/ToolChains/Arch/X86.cpp
++++ b/clang/lib/Driver/ToolChains/Arch/X86.cpp
+@@ -91,7 +91,7 @@ std::string x86::getX86TargetCPU(const A
+ 
+   // Everything else goes to x86-64 in 64-bit mode.
+   if (Is64Bit)
+-    return "x86-64";
++    return "x86-64-v3";
+ 
+   switch (Triple.getOS()) {
+   case llvm::Triple::NetBSD:
diff -Nru llvm-toolchain-13-13.0.0/debian/patches/series llvm-toolchain-13-13.0.0/debian/patches/series
--- llvm-toolchain-13-13.0.0/debian/patches/series	2021-09-18 17:29:58.000000000 +0000
+++ llvm-toolchain-13-13.0.0/debian/patches/series	2021-12-01 10:49:29.000000000 +0000
@@ -144,3 +144,6 @@
 
 libclc-llvm-spirv.diff
 omp-riscv64.patch
+
+#clang-default-x86-64-v2.diff
+clang-default-x86-64-v3.diff