diff --git a/.gitmodules b/.gitmodules
index f9bd42edab3f..97a0c0c54cf9 100644
--- a/.gitmodules
+++ b/.gitmodules
@@ -29,7 +29,7 @@
 [submodule "src/llvm-project"]
 	path = src/llvm-project
 	url = https://github.com/rust-lang/llvm-project.git
-	branch = rustc/19.1-2024-12-03
+	branch = rustc/20.1-2025-02-13
 	shallow = true
 [submodule "src/doc/embedded-book"]
 	path = src/doc/embedded-book
diff --git a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
index a6b2384f2d7b..7eb11f9e6087 100644
--- a/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
+++ b/compiler/rustc_llvm/llvm-wrapper/PassWrapper.cpp
@@ -22,6 +22,7 @@
 #include "llvm/Passes/StandardInstrumentations.h"
 #include "llvm/Support/CBindingWrapping.h"
 #include "llvm/Support/FileSystem.h"
+#include "llvm/Support/Program.h"
 #include "llvm/Support/TimeProfiler.h"
 #include "llvm/Support/VirtualFileSystem.h"
 #include "llvm/Target/TargetMachine.h"
@@ -472,16 +473,19 @@ extern "C" LLVMTargetMachineRef LLVMRustCreateTargetMachine(
     assert(ArgsCstrBuff[ArgsCstrBuffLen - 1] == '\0');
     auto Arg0 = std::string(ArgsCstrBuff);
     buffer_offset = Arg0.size() + 1;
-    auto ArgsCppStr = std::string(ArgsCstrBuff + buffer_offset,
-                                  ArgsCstrBuffLen - buffer_offset);
-    auto i = 0;
-    while (i != std::string::npos) {
-      i = ArgsCppStr.find('\0', i + 1);
-      if (i != std::string::npos)
-        ArgsCppStr.replace(i, 1, " ");
+
+    std::string CommandlineArgs;
+    raw_string_ostream OS(CommandlineArgs);
+    ListSeparator LS(" ");
+    for (StringRef Arg : split(StringRef(ArgsCstrBuff + buffer_offset,
+                                         ArgsCstrBuffLen - buffer_offset),
+                               '\0')) {
+      OS << LS;
+      sys::printArg(OS, Arg, /*Quote=*/true);
     }
+    OS.flush();
     Options.MCOptions.Argv0 = Arg0;
-    Options.MCOptions.CommandlineArgs = ArgsCppStr;
+    Options.MCOptions.CommandlineArgs = CommandlineArgs;
 #else
     int buffer_offset = 0;
     assert(ArgsCstrBuff[ArgsCstrBuffLen - 1] == '\0');
diff --git a/src/ci/docker/host-x86_64/dist-loongarch64-linux/loongarch64-unknown-linux-gnu.defconfig b/src/ci/docker/host-x86_64/dist-loongarch64-linux/loongarch64-unknown-linux-gnu.defconfig
index 576f3631cd53..aa33f72268e4 100644
--- a/src/ci/docker/host-x86_64/dist-loongarch64-linux/loongarch64-unknown-linux-gnu.defconfig
+++ b/src/ci/docker/host-x86_64/dist-loongarch64-linux/loongarch64-unknown-linux-gnu.defconfig
@@ -7,6 +7,8 @@ CT_ARCH_LOONGARCH=y
 # CT_DEMULTILIB is not set
 CT_ARCH_USE_MMU=y
 CT_ARCH_ARCH="loongarch64"
+CT_TARGET_CFLAGS="-mcmodel=medium"
+CT_TARGET_LDFLAGS="-mcmodel=medium"
 CT_KERNEL_LINUX=y
 CT_LINUX_V_5_19=y
 CT_GLIBC_V_2_36=y
diff --git a/src/ci/docker/host-x86_64/dist-loongarch64-musl/loongarch64-unknown-linux-musl.defconfig b/src/ci/docker/host-x86_64/dist-loongarch64-musl/loongarch64-unknown-linux-musl.defconfig
index 3ab676ed9717..3ccbc583c1bd 100644
--- a/src/ci/docker/host-x86_64/dist-loongarch64-musl/loongarch64-unknown-linux-musl.defconfig
+++ b/src/ci/docker/host-x86_64/dist-loongarch64-musl/loongarch64-unknown-linux-musl.defconfig
@@ -7,6 +7,8 @@ CT_ARCH_LOONGARCH=y
 # CT_DEMULTILIB is not set
 CT_ARCH_USE_MMU=y
 CT_ARCH_ARCH="loongarch64"
+CT_TARGET_CFLAGS="-mcmodel=medium"
+CT_TARGET_LDFLAGS="-mcmodel=medium"
 CT_KERNEL_LINUX=y
 CT_LINUX_V_5_19=y
 CT_LIBC_MUSL=y
diff --git a/src/llvm-project b/src/llvm-project
index 7e8c93c87c61..92e80685d0d5 160000
--- a/src/llvm-project
+++ b/src/llvm-project
@@ -1 +1 @@
-Subproject commit 7e8c93c87c611f21d9bd95100563392f4c18bfe7
+Subproject commit 92e80685d0d5dcea3ccf321995c43b72338639c6