diff --git a/build.zig b/build.zig
index bbc0c57b80..0466b79bf2 100644
--- a/build.zig
+++ b/build.zig
@@ -576,6 +576,7 @@ pub fn build(b: *std.Build) !void {
         enable_macos_sdk,
         enable_ios_sdk,
         enable_symlinks_windows,
+        skip_translate_c,
     ));
     test_step.dependOn(tests.addCAbiTests(b, .{
         .test_target_filters = test_target_filters,
diff --git a/ci/loongarch64-linux-debug.sh b/ci/loongarch64-linux-debug.sh
new file mode 100755
index 0000000000..f233fb6f77
--- /dev/null
+++ b/ci/loongarch64-linux-debug.sh
@@ -0,0 +1,71 @@
+#!/bin/sh
+
+# Requires cmake ninja-build
+
+set -x
+set -e
+
+ARCH="$(uname -m)"
+TARGET="$ARCH-linux-musl"
+MCPU="baseline"
+CACHE_BASENAME="zig+llvm+lld+clang-$TARGET-0.16.0-dev.157+7fdd60df1"
+PREFIX="$HOME/deps/$CACHE_BASENAME"
+ZIG="$PREFIX/bin/zig"
+
+# Make the `zig version` number consistent.
+# This will affect the cmake command below.
+git fetch --unshallow || true
+git fetch --tags
+
+# Override the cache directories because they won't actually help other CI runs
+# which will be testing alternate versions of zig, and ultimately would just
+# fill up space on the hard drive for no reason.
+export ZIG_GLOBAL_CACHE_DIR="$PWD/zig-global-cache"
+export ZIG_LOCAL_CACHE_DIR="$PWD/zig-local-cache"
+
+mkdir build-debug
+cd build-debug
+
+export CC="$ZIG cc -target $TARGET -mcpu=$MCPU"
+export CXX="$ZIG c++ -target $TARGET -mcpu=$MCPU"
+
+cmake .. \
+  -DCMAKE_INSTALL_PREFIX="stage3-debug" \
+  -DCMAKE_PREFIX_PATH="$PREFIX" \
+  -DCMAKE_BUILD_TYPE=Debug \
+  -DZIG_TARGET_TRIPLE="$TARGET" \
+  -DZIG_TARGET_MCPU="$MCPU" \
+  -DZIG_STATIC=ON \
+  -DZIG_NO_LIB=ON \
+  -GNinja \
+  -DCMAKE_C_LINKER_DEPFILE_SUPPORTED=FALSE \
+  -DCMAKE_CXX_LINKER_DEPFILE_SUPPORTED=FALSE
+# https://github.com/ziglang/zig/issues/22213
+
+# Now cmake will use zig as the C/C++ compiler. We reset the environment variables
+# so that installation and testing do not get affected by them.
+unset CC
+unset CXX
+
+ninja install
+
+# No -fqemu and -fwasmtime here as they're covered by the x86_64-linux scripts.
+stage3-debug/bin/zig build test \
+  --maxrss 60129542144 \
+  -Dstatic-llvm \
+  -Dskip-non-native \
+  -Dtarget=native-native-musl \
+  --search-prefix "$PREFIX" \
+  --zig-lib-dir "$PWD/../lib" \
+  -Dno-langref \
+  -Dskip-translate-c
+
+stage3-debug/bin/zig build \
+  --prefix stage4-debug \
+  -Denable-llvm \
+  -Dno-lib \
+  -Dtarget=$TARGET \
+  -Duse-zig-libcxx \
+  -Dversion-string="$(stage3-debug/bin/zig version)"
+
+stage4-debug/bin/zig test ../test/behavior.zig
diff --git a/ci/loongarch64-linux-release.sh b/ci/loongarch64-linux-release.sh
new file mode 100755
index 0000000000..2020449181
--- /dev/null
+++ b/ci/loongarch64-linux-release.sh
@@ -0,0 +1,77 @@
+#!/bin/sh
+
+# Requires cmake ninja-build
+
+set -x
+set -e
+
+ARCH="$(uname -m)"
+TARGET="$ARCH-linux-musl"
+MCPU="baseline"
+CACHE_BASENAME="zig+llvm+lld+clang-$TARGET-0.16.0-dev.157+7fdd60df1"
+PREFIX="$HOME/deps/$CACHE_BASENAME"
+ZIG="$PREFIX/bin/zig"
+
+# Make the `zig version` number consistent.
+# This will affect the cmake command below.
+git fetch --unshallow || true
+git fetch --tags
+
+# Override the cache directories because they won't actually help other CI runs
+# which will be testing alternate versions of zig, and ultimately would just
+# fill up space on the hard drive for no reason.
+export ZIG_GLOBAL_CACHE_DIR="$PWD/zig-global-cache"
+export ZIG_LOCAL_CACHE_DIR="$PWD/zig-local-cache"
+
+mkdir build-release
+cd build-release
+
+export CC="$ZIG cc -target $TARGET -mcpu=$MCPU"
+export CXX="$ZIG c++ -target $TARGET -mcpu=$MCPU"
+
+cmake .. \
+  -DCMAKE_INSTALL_PREFIX="stage3-release" \
+  -DCMAKE_PREFIX_PATH="$PREFIX" \
+  -DCMAKE_BUILD_TYPE=Release \
+  -DZIG_TARGET_TRIPLE="$TARGET" \
+  -DZIG_TARGET_MCPU="$MCPU" \
+  -DZIG_STATIC=ON \
+  -DZIG_NO_LIB=ON \
+  -GNinja \
+  -DCMAKE_C_LINKER_DEPFILE_SUPPORTED=FALSE \
+  -DCMAKE_CXX_LINKER_DEPFILE_SUPPORTED=FALSE
+# https://github.com/ziglang/zig/issues/22213
+
+# Now cmake will use zig as the C/C++ compiler. We reset the environment variables
+# so that installation and testing do not get affected by them.
+unset CC
+unset CXX
+
+ninja install
+
+# No -fqemu and -fwasmtime here as they're covered by the x86_64-linux scripts.
+stage3-release/bin/zig build test \
+  --maxrss 60129542144 \
+  -Dstatic-llvm \
+  -Dskip-non-native \
+  -Dtarget=native-native-musl \
+  --search-prefix "$PREFIX" \
+  --zig-lib-dir "$PWD/../lib" \
+  -Dno-langref \
+  -Dskip-translate-c
+
+# Ensure that stage3 and stage4 are byte-for-byte identical.
+stage3-release/bin/zig build \
+  --prefix stage4-release \
+  -Denable-llvm \
+  -Dno-lib \
+  -Doptimize=ReleaseFast \
+  -Dstrip \
+  -Dtarget=$TARGET \
+  -Duse-zig-libcxx \
+  -Dversion-string="$(stage3-release/bin/zig version)"
+
+# diff returns an error code if the files differ.
+echo "If the following command fails, it means nondeterminism has been"
+echo "introduced, making stage3 and stage4 no longer byte-for-byte identical."
+diff stage3-release/bin/zig stage4-release/bin/zig
diff --git a/doc/langref/runtime_shrExact_overflow.zig b/doc/langref/runtime_shrExact_overflow.zig
index 1350e9da75..98da0dde11 100644
--- a/doc/langref/runtime_shrExact_overflow.zig
+++ b/doc/langref/runtime_shrExact_overflow.zig
@@ -7,7 +7,7 @@ pub fn main() void {
     const y = @shrExact(x, 2);
     std.debug.print("value: {}\n", .{y});
 
-    if (builtin.cpu.arch.isRISCV() and builtin.zig_backend == .stage2_llvm) @panic("https://github.com/ziglang/zig/issues/24304");
+    if ((builtin.cpu.arch.isRISCV() or builtin.cpu.arch.isLoongArch()) and builtin.zig_backend == .stage2_llvm) @panic("https://github.com/ziglang/zig/issues/24304");
 }
 
 // exe=fail
diff --git a/lib/std/Target.zig b/lib/std/Target.zig
index 60f0b2e304..5773faa5f2 100644
--- a/lib/std/Target.zig
+++ b/lib/std/Target.zig
@@ -1903,7 +1903,7 @@ pub const Cpu = struct {
                 .csky => &csky.cpu.ck810, // gcc/clang do not have a generic csky model.
                 .hexagon => &hexagon.cpu.hexagonv68, // gcc/clang do not have a generic hexagon model.
                 .lanai => &lanai.cpu.v11, // clang does not have a generic lanai model.
-                .loongarch64 => &loongarch.cpu.loongarch64,
+                .loongarch64 => &loongarch.cpu.la64v1_0,
                 .m68k => &m68k.cpu.M68000,
                 .mips, .mipsel => &mips.cpu.mips32r2,
                 .mips64, .mips64el => &mips.cpu.mips64r2,
diff --git a/lib/std/Target/loongarch.zig b/lib/std/Target/loongarch.zig
index e87e4e95d1..251e202daf 100644
--- a/lib/std/Target/loongarch.zig
+++ b/lib/std/Target/loongarch.zig
@@ -159,11 +159,6 @@ pub const all_features = blk: {
 };
 
 pub const cpu = struct {
-    pub const generic: CpuModel = .{
-        .name = "generic",
-        .llvm_name = "generic",
-        .features = featureSet(&[_]Feature{}),
-    };
     pub const generic_la32: CpuModel = .{
         .name = "generic_la32",
         .llvm_name = "generic-la32",
@@ -191,6 +186,30 @@ pub const cpu = struct {
             .ual,
         }),
     };
+    pub const la64v1_0: CpuModel = .{
+        .name = "la64v1_0",
+        .llvm_name = null,
+        .features = featureSet(&[_]Feature{
+            .@"64bit",
+            .lsx,
+            .ual,
+        }),
+    };
+    pub const la64v1_1: CpuModel = .{
+        .name = "la64v1_1",
+        .llvm_name = null,
+        .features = featureSet(&[_]Feature{
+            .@"64bit",
+            .div32,
+            .frecipe,
+            .lam_bh,
+            .lamcas,
+            .ld_seq_sa,
+            .lsx,
+            .scq,
+            .ual,
+        }),
+    };
     pub const la664: CpuModel = .{
         .name = "la664",
         .llvm_name = "la664",
@@ -208,13 +227,4 @@ pub const cpu = struct {
             .ual,
         }),
     };
-    pub const loongarch64: CpuModel = .{
-        .name = "loongarch64",
-        .llvm_name = "loongarch64",
-        .features = featureSet(&[_]Feature{
-            .@"64bit",
-            .d,
-            .ual,
-        }),
-    };
 };
diff --git a/lib/std/crypto/ml_kem.zig b/lib/std/crypto/ml_kem.zig
index c7ad23d3e2..0a8e73f785 100644
--- a/lib/std/crypto/ml_kem.zig
+++ b/lib/std/crypto/ml_kem.zig
@@ -1722,14 +1722,20 @@ test "Test happy flow" {
 // Code to test NIST Known Answer Tests (KAT), see PQCgenKAT.c.
 
 test "NIST KAT test d00.Kyber512" {
+    if (comptime builtin.cpu.has(.loongarch, .lsx)) return error.SkipZigTest;
+
     try testNistKat(d00.Kyber512, "e9c2bd37133fcb40772f81559f14b1f58dccd1c816701be9ba6214d43baf4547");
 }
 
 test "NIST KAT test d00.Kyber1024" {
+    if (comptime builtin.cpu.has(.loongarch, .lsx)) return error.SkipZigTest;
+
     try testNistKat(d00.Kyber1024, "89248f2f33f7f4f7051729111f3049c409a933ec904aedadf035f30fa5646cd5");
 }
 
 test "NIST KAT test d00.Kyber768" {
+    if (comptime builtin.cpu.has(.loongarch, .lsx)) return error.SkipZigTest;
+
     try testNistKat(d00.Kyber768, "a1e122cad3c24bc51622e4c242d8b8acbcd3f618fee4220400605ca8f9ea02c2");
 }
 
diff --git a/lib/std/math/modf.zig b/lib/std/math/modf.zig
index 870b4e6f6b..60680cf831 100644
--- a/lib/std/math/modf.zig
+++ b/lib/std/math/modf.zig
@@ -87,6 +87,7 @@ fn ModfTests(comptime T: type) type {
         test "vector" {
             if (builtin.os.tag == .macos and builtin.cpu.arch == .aarch64) return error.SkipZigTest;
             if (builtin.cpu.arch == .s390x) return error.SkipZigTest;
+            if (comptime builtin.cpu.has(.loongarch, .lsx)) return error.SkipZigTest; // https://github.com/llvm/llvm-project/issues/159529
 
             const widths = [_]comptime_int{ 1, 2, 3, 4, 8, 16 };
 
diff --git a/lib/std/mem.zig b/lib/std/mem.zig
index 3013af36f6..128ac695cf 100644
--- a/lib/std/mem.zig
+++ b/lib/std/mem.zig
@@ -4534,7 +4534,8 @@ pub fn doNotOptimizeAway(val: anytype) void {
             } else doNotOptimizeAway(&val);
         },
         .float => {
-            if ((t.float.bits == 32 or t.float.bits == 64) and builtin.zig_backend != .stage2_c) {
+            // https://github.com/llvm/llvm-project/issues/159200
+            if ((t.float.bits == 32 or t.float.bits == 64) and builtin.zig_backend != .stage2_c and !builtin.cpu.arch.isLoongArch()) {
                 asm volatile (""
                     :
                     : [_] "rm" (val),
diff --git a/lib/std/zig/system.zig b/lib/std/zig/system.zig
index 549f365321..b2116c1a74 100644
--- a/lib/std/zig/system.zig
+++ b/lib/std/zig/system.zig
@@ -468,9 +468,8 @@ fn detectNativeCpuAndFeatures(cpu_arch: Target.Cpu.Arch, os: Target.Os, query: T
     // although it is a runtime value, is guaranteed to be one of the architectures in the set
     // of the respective switch prong.
     switch (builtin.cpu.arch) {
-        .x86_64, .x86 => {
-            return @import("system/x86.zig").detectNativeCpuAndFeatures(cpu_arch, os, query);
-        },
+        .loongarch32, .loongarch64 => return @import("system/loongarch.zig").detectNativeCpuAndFeatures(cpu_arch, os, query),
+        .x86_64, .x86 => return @import("system/x86.zig").detectNativeCpuAndFeatures(cpu_arch, os, query),
         else => {},
     }
 
diff --git a/lib/std/zig/system/loongarch.zig b/lib/std/zig/system/loongarch.zig
new file mode 100644
index 0000000000..cdeeb10564
--- /dev/null
+++ b/lib/std/zig/system/loongarch.zig
@@ -0,0 +1,48 @@
+const builtin = @import("builtin");
+const std = @import("std");
+
+pub fn detectNativeCpuAndFeatures(
+    arch: std.Target.Cpu.Arch,
+    os: std.Target.Os,
+    query: std.Target.Query,
+) ?std.Target.Cpu {
+    _ = os;
+    _ = query;
+
+    // Clearly this code could do better in the future by actually querying specific CPU features
+    // with the cpucfg instruction like on x86. But with the small number of well-known LoongArch
+    // models that exist at the moment, simply checking the PRID is plenty.
+    var cpu: std.Target.Cpu = .{
+        .arch = arch,
+        .model = switch (cpucfg(0) & 0xf000) {
+            else => return null,
+            0xc000 => &std.Target.loongarch.cpu.la464,
+            0xd000 => &std.Target.loongarch.cpu.la664,
+        },
+        .features = .empty,
+    };
+
+    cpu.features.addFeatureSet(cpu.model.features);
+    cpu.features.populateDependencies(cpu.arch.allFeaturesList());
+
+    return cpu;
+}
+
+/// This is a workaround for the C backend until zig has the ability to put
+/// C code in inline assembly.
+extern fn zig_loongarch_cpucfg(word: u32, result: *u32) callconv(.c) void;
+
+fn cpucfg(word: u32) u32 {
+    var result: u32 = undefined;
+
+    if (builtin.zig_backend == .stage2_c) {
+        zig_loongarch_cpucfg(word, &result);
+    } else {
+        asm ("cpucfg %[result], %[word]"
+            : [result] "=r" (result),
+            : [word] "r" (word),
+        );
+    }
+
+    return result;
+}
diff --git a/lib/zig.h b/lib/zig.h
index b9d4645ca2..5c96b4bea0 100644
--- a/lib/zig.h
+++ b/lib/zig.h
@@ -4195,7 +4195,17 @@ static inline void* zig_x86_64_windows_teb(void) {
 
 #endif
 
-#if defined(zig_x86)
+#if defined(zig_loongarch)
+
+static inline void zig_loongarch_cpucfg(uint32_t word, uint32_t* result) {
+#if defined(zig_gnuc_asm)
+    __asm__("cpucfg %[result], %[word]" : [result] "=r" (result) : [word] "r" (word));
+#else
+    *result = 0;
+#endif
+}
+
+#elif defined(zig_x86)
 
 static inline void zig_x86_cpuid(uint32_t leaf_id, uint32_t subid, uint32_t* eax, uint32_t* ebx, uint32_t* ecx, uint32_t* edx) {
 #if defined(zig_msvc)
@@ -4206,7 +4216,7 @@ static inline void zig_x86_cpuid(uint32_t leaf_id, uint32_t subid, uint32_t* eax
     *ecx = (uint32_t)cpu_info[2];
     *edx = (uint32_t)cpu_info[3];
 #elif defined(zig_gnuc_asm)
-    __asm__("cpuid" : "=a"(*eax), "=b"(*ebx), "=c"(*ecx), "=d"(*edx) : "a"(leaf_id), "c"(subid));
+    __asm__("cpuid" : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx) : "a" (leaf_id), "c" (subid));
 #else
     *eax = 0;
     *ebx = 0;
@@ -4221,7 +4231,7 @@ static inline uint32_t zig_x86_get_xcr0(void) {
 #elif defined(zig_gnuc_asm)
     uint32_t eax;
     uint32_t edx;
-    __asm__("xgetbv" : "=a"(eax), "=d"(edx) : "c"(0));
+    __asm__("xgetbv" : "=a" (eax), "=d" (edx) : "c" (0));
     return eax;
 #else
     *eax = 0;
diff --git a/stage1/zig.h b/stage1/zig.h
index b9d4645ca2..5c96b4bea0 100644
--- a/stage1/zig.h
+++ b/stage1/zig.h
@@ -4195,7 +4195,17 @@ static inline void* zig_x86_64_windows_teb(void) {
 
 #endif
 
-#if defined(zig_x86)
+#if defined(zig_loongarch)
+
+static inline void zig_loongarch_cpucfg(uint32_t word, uint32_t* result) {
+#if defined(zig_gnuc_asm)
+    __asm__("cpucfg %[result], %[word]" : [result] "=r" (result) : [word] "r" (word));
+#else
+    *result = 0;
+#endif
+}
+
+#elif defined(zig_x86)
 
 static inline void zig_x86_cpuid(uint32_t leaf_id, uint32_t subid, uint32_t* eax, uint32_t* ebx, uint32_t* ecx, uint32_t* edx) {
 #if defined(zig_msvc)
@@ -4206,7 +4216,7 @@ static inline void zig_x86_cpuid(uint32_t leaf_id, uint32_t subid, uint32_t* eax
     *ecx = (uint32_t)cpu_info[2];
     *edx = (uint32_t)cpu_info[3];
 #elif defined(zig_gnuc_asm)
-    __asm__("cpuid" : "=a"(*eax), "=b"(*ebx), "=c"(*ecx), "=d"(*edx) : "a"(leaf_id), "c"(subid));
+    __asm__("cpuid" : "=a" (*eax), "=b" (*ebx), "=c" (*ecx), "=d" (*edx) : "a" (leaf_id), "c" (subid));
 #else
     *eax = 0;
     *ebx = 0;
@@ -4221,7 +4231,7 @@ static inline uint32_t zig_x86_get_xcr0(void) {
 #elif defined(zig_gnuc_asm)
     uint32_t eax;
     uint32_t edx;
-    __asm__("xgetbv" : "=a"(eax), "=d"(edx) : "c"(0));
+    __asm__("xgetbv" : "=a" (eax), "=d" (edx) : "c" (0));
     return eax;
 #else
     *eax = 0;
diff --git a/stage1/zig1.wasm b/stage1/zig1.wasm
index ef46d39da4..1660c5a926 100644
Binary files a/stage1/zig1.wasm and b/stage1/zig1.wasm differ
diff --git a/test/behavior/asm.zig b/test/behavior/asm.zig
index dae2f579c0..ebfd5bb235 100644
--- a/test/behavior/asm.zig
+++ b/test/behavior/asm.zig
@@ -67,6 +67,7 @@ test "alternative constraints" {
     if (builtin.zig_backend == .stage2_sparc64) return error.SkipZigTest; // TODO
     if (builtin.zig_backend == .stage2_spirv) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_riscv64) return error.SkipZigTest;
+    if (builtin.zig_backend == .stage2_llvm and builtin.cpu.arch.isLoongArch()) return error.SkipZigTest; // https://github.com/llvm/llvm-project/issues/159200
 
     if (builtin.zig_backend == .stage2_c and builtin.os.tag == .windows) return error.SkipZigTest; // MSVC doesn't support inline assembly
 
diff --git a/test/behavior/math.zig b/test/behavior/math.zig
index 679c94a78e..914c47ba69 100644
--- a/test/behavior/math.zig
+++ b/test/behavior/math.zig
@@ -111,6 +111,8 @@ test "@clz vectors" {
 }
 
 fn testClzVectors() !void {
+    if (comptime builtin.cpu.has(.loongarch, .lsx)) return error.SkipZigTest; // https://github.com/llvm/llvm-project/issues/159529
+
     const Vu4 = @Vector(64, u4);
     const Vu8 = @Vector(64, u8);
     const Vu128 = @Vector(64, u128);
@@ -197,6 +199,8 @@ test "@ctz vectors" {
 }
 
 fn testCtzVectors() !void {
+    if (comptime builtin.cpu.has(.loongarch, .lsx)) return error.SkipZigTest; // https://github.com/llvm/llvm-project/issues/159529
+
     const Vu4 = @Vector(64, u4);
     const Vu8 = @Vector(64, u8);
     @setEvalBranchQuota(10_000);
diff --git a/test/c_abi/main.zig b/test/c_abi/main.zig
index 49a9ab99c2..a6f692601a 100644
--- a/test/c_abi/main.zig
+++ b/test/c_abi/main.zig
@@ -1135,6 +1135,7 @@ extern fn c_ret_medium_vec() MediumVec;
 test "medium simd vector" {
     if (builtin.zig_backend == .stage2_x86_64 and !comptime builtin.cpu.has(.x86, .avx)) return error.SkipZigTest;
     if (builtin.cpu.arch.isPowerPC64()) return error.SkipZigTest;
+    if (builtin.cpu.arch.isLoongArch()) return error.SkipZigTest;
 
     c_medium_vec(.{ 1, 2, 3, 4 });
 
@@ -1155,6 +1156,7 @@ test "big simd vector" {
 
     if (builtin.cpu.arch.isMIPS64() and builtin.mode != .Debug) return error.SkipZigTest;
     if (builtin.cpu.arch.isPowerPC64()) return error.SkipZigTest;
+    if (builtin.cpu.arch.isLoongArch()) return error.SkipZigTest;
     if (builtin.zig_backend == .stage2_llvm and builtin.cpu.arch == .x86_64 and builtin.os.tag == .macos and builtin.mode != .Debug) return error.SkipZigTest;
 
     c_big_vec(.{ 1, 2, 3, 4, 5, 6, 7, 8 });
diff --git a/test/src/StackTrace.zig b/test/src/StackTrace.zig
index d956e27cd7..061df37e3a 100644
--- a/test/src/StackTrace.zig
+++ b/test/src/StackTrace.zig
@@ -15,6 +15,7 @@ const Config = struct {
 
     const PerMode = struct {
         expect: []const u8,
+        exclude_arch: []const std.Target.Cpu.Arch = &.{},
         exclude_os: []const std.Target.Os.Tag = &.{},
         error_tracing: ?bool = null,
     };
@@ -59,6 +60,7 @@ fn addExpect(
     use_llvm: bool,
     mode_config: Config.PerMode,
 ) void {
+    for (mode_config.exclude_arch) |tag| if (tag == builtin.cpu.arch) return;
     for (mode_config.exclude_os) |tag| if (tag == builtin.os.tag) return;
 
     const b = self.b;
diff --git a/test/stack_traces.zig b/test/stack_traces.zig
index 40a6168297..9e815e032f 100644
--- a/test/stack_traces.zig
+++ b/test/stack_traces.zig
@@ -792,6 +792,16 @@ pub fn addCases(cases: *tests.StackTracesContext) void {
         \\}
         ,
         .Debug = .{
+            // std.debug.sys_can_stack_trace
+            .exclude_arch = &.{
+                .loongarch32,
+                .loongarch64,
+                .mips,
+                .mipsel,
+                .mips64,
+                .mips64el,
+                .s390x,
+            },
             .exclude_os = &.{
                 .openbsd, // integer overflow
                 .windows, // TODO intermittent failures
diff --git a/test/standalone/build.zig b/test/standalone/build.zig
index cf08c9b182..b284f25483 100644
--- a/test/standalone/build.zig
+++ b/test/standalone/build.zig
@@ -9,6 +9,7 @@ pub fn build(b: *std.Build) void {
     const enable_macos_sdk = b.option(bool, "enable_macos_sdk", "Run tests requiring presence of macOS SDK and frameworks") orelse enable_ios_sdk;
     const enable_symlinks_windows = b.option(bool, "enable_symlinks_windows", "Run tests requiring presence of symlinks on Windows") orelse false;
     const omit_symlinks = builtin.os.tag == .windows and !enable_symlinks_windows;
+    const skip_translate_c = b.option(bool, "skip_translate_c", "Test suite skips translate-c tests") orelse false;
 
     const simple_skip_debug = b.option(bool, "simple_skip_debug", "Simple tests skip debug builds") orelse false;
     const simple_skip_release_safe = b.option(bool, "simple_skip_release_safe", "Simple tests skip release-safe builds") orelse false;
@@ -20,6 +21,7 @@ pub fn build(b: *std.Build) void {
         .skip_release_safe = simple_skip_release_safe,
         .skip_release_fast = simple_skip_release_fast,
         .skip_release_small = simple_skip_release_small,
+        .skip_translate_c = skip_translate_c,
     });
     const simple_dep_step = simple_dep.builder.default_step;
     simple_dep_step.name = "standalone_test_cases.simple";
@@ -97,9 +99,12 @@ pub fn build(b: *std.Build) void {
                     pkg.build_zig.requires_macos_sdk;
                 const requires_symlinks = @hasDecl(pkg.build_zig, "requires_symlinks") and
                     pkg.build_zig.requires_symlinks;
+                const requires_translate_c = @hasDecl(pkg.build_zig, "requires_translate_c") and
+                    pkg.build_zig.requires_translate_c;
                 if ((requires_symlinks and omit_symlinks) or
                     (requires_macos_sdk and !enable_macos_sdk) or
-                    (requires_ios_sdk and !enable_ios_sdk))
+                    (requires_ios_sdk and !enable_ios_sdk) or
+                    (requires_translate_c and skip_translate_c))
                 {
                     continue :add_dep_steps;
                 }
diff --git a/test/standalone/dep_lazypath/build.zig b/test/standalone/dep_lazypath/build.zig
index 01b4be8fd4..9649a02500 100644
--- a/test/standalone/dep_lazypath/build.zig
+++ b/test/standalone/dep_lazypath/build.zig
@@ -1,5 +1,7 @@
 const std = @import("std");
 
+pub const requires_translate_c = true;
+
 pub fn build(b: *std.Build) void {
     const test_step = b.step("test", "Test it");
     b.default_step = test_step;
diff --git a/test/standalone/glibc_compat/build.zig b/test/standalone/glibc_compat/build.zig
index 6c2c924cae..fd3bbaf084 100644
--- a/test/standalone/glibc_compat/build.zig
+++ b/test/standalone/glibc_compat/build.zig
@@ -1,6 +1,8 @@
 const std = @import("std");
 const builtin = @import("builtin");
 
+pub const requires_translate_c = true;
+
 // To run executables linked against a specific glibc version, the
 // run-time glibc version needs to be new enough.  Check the host's glibc
 // version.  Note that this does not allow for translation/vm/emulation
diff --git a/test/standalone/issue_794/build.zig b/test/standalone/issue_794/build.zig
index 0f3f0a16f7..b0afe51bf4 100644
--- a/test/standalone/issue_794/build.zig
+++ b/test/standalone/issue_794/build.zig
@@ -1,5 +1,7 @@
 const std = @import("std");
 
+pub const requires_translate_c = true;
+
 pub fn build(b: *std.Build) void {
     const test_step = b.step("test", "Test it");
     b.default_step = test_step;
diff --git a/test/standalone/simple/build.zig b/test/standalone/simple/build.zig
index 5bd76a3540..dbfca21f83 100644
--- a/test/standalone/simple/build.zig
+++ b/test/standalone/simple/build.zig
@@ -9,6 +9,7 @@ pub fn build(b: *std.Build) void {
     const skip_release_safe = b.option(bool, "skip_release_safe", "Skip release-safe builds") orelse false;
     const skip_release_fast = b.option(bool, "skip_release_fast", "Skip release-fast builds") orelse false;
     const skip_release_small = b.option(bool, "skip_release_small", "Skip release-small builds") orelse false;
+    const skip_translate_c = b.option(bool, "skip_translate_c", "Test suite skips translate-c tests") orelse false;
 
     var optimize_modes_buf: [4]std.builtin.OptimizeMode = undefined;
     var optimize_modes_len: usize = 0;
@@ -36,6 +37,7 @@ pub fn build(b: *std.Build) void {
             if (case.os_filter) |os_tag| {
                 if (os_tag != builtin.os.tag) continue;
             }
+            if (case.uses_translate_c and skip_translate_c) continue;
 
             const resolved_target = b.resolveTargetQuery(case.target);
 
@@ -82,6 +84,7 @@ const Case = struct {
     is_exe: bool = true,
     /// Run only on this OS.
     os_filter: ?std.Target.Os.Tag = null,
+    uses_translate_c: bool = false,
 };
 
 const cases = [_]Case{
@@ -93,6 +96,7 @@ const cases = [_]Case{
         .src_path = "hello_world/hello_libc.zig",
         .link_libc = true,
         .all_modes = true,
+        .uses_translate_c = true,
     },
     .{
         .src_path = "cat/main.zig",
@@ -108,7 +112,10 @@ const cases = [_]Case{
             .os_tag = .freestanding,
         },
     },
-    .{ .src_path = "issue_12471/main.zig" },
+    .{
+        .src_path = "issue_12471/main.zig",
+        .uses_translate_c = true,
+    },
     .{ .src_path = "guess_number/main.zig" },
     .{ .src_path = "main_return_error/error_u8.zig" },
     .{ .src_path = "main_return_error/error_u8_non_zero.zig" },
diff --git a/test/standalone/simple/hello_world/hello_libc.zig b/test/standalone/simple/hello_world/hello_libc.zig
index 992afd736e..994ca31b8e 100644
--- a/test/standalone/simple/hello_world/hello_libc.zig
+++ b/test/standalone/simple/hello_world/hello_libc.zig
@@ -1,15 +1,11 @@
-const c = @cImport({
-    // See https://github.com/ziglang/zig/issues/515
-    @cDefine("_NO_CRT_STDIO_INLINE", "1");
-    @cInclude("stdio.h");
-    @cInclude("string.h");
-});
+extern fn printf(format: [*:0]const u8, ...) c_int;
+extern fn strlen(str: [*:0]const u8) usize;
 
 const msg = "Hello, world!\n";
 
 pub export fn main(argc: c_int, argv: **u8) c_int {
     _ = argv;
     _ = argc;
-    if (c.printf(msg) != @as(c_int, @intCast(c.strlen(msg)))) return -1;
+    if (printf(msg) != @as(c_int, @intCast(strlen(msg)))) return -1;
     return 0;
 }
diff --git a/test/standalone/static_c_lib/foo.zig b/test/standalone/static_c_lib/foo.zig
index da02875408..2ff5fadb95 100644
--- a/test/standalone/static_c_lib/foo.zig
+++ b/test/standalone/static_c_lib/foo.zig
@@ -1,12 +1,14 @@
 const std = @import("std");
 const expect = std.testing.expect;
-const c = @cImport(@cInclude("foo.h"));
+
+extern fn add(a: u32, b: u32) u32;
+extern var foo: u32;
 
 test "C add" {
-    const result = c.add(1, 2);
+    const result = add(1, 2);
     try expect(result == 3);
 }
 
 test "C extern variable" {
-    try expect(c.foo == 12345);
+    try expect(foo == 12345);
 }
diff --git a/test/tests.zig b/test/tests.zig
index 5b80ec5b0b..8bcdce7aad 100644
--- a/test/tests.zig
+++ b/test/tests.zig
@@ -419,8 +419,6 @@ const test_targets = blk: {
                 .os_tag = .linux,
                 .abi = .none,
             },
-            // https://github.com/ziglang/zig/issues/21646
-            .skip_modules = &.{"std"},
         },
         .{
             .target = .{
@@ -429,8 +427,6 @@ const test_targets = blk: {
                 .abi = .musl,
             },
             .link_libc = true,
-            // https://github.com/ziglang/zig/issues/21646
-            .skip_modules = &.{"std"},
         },
         .{
             .target = .{
@@ -440,8 +436,6 @@ const test_targets = blk: {
             },
             .linkage = .dynamic,
             .link_libc = true,
-            // https://github.com/ziglang/zig/issues/21646
-            .skip_modules = &.{"std"},
             .extra_target = true,
         },
         .{
@@ -451,8 +445,6 @@ const test_targets = blk: {
                 .abi = .gnu,
             },
             .link_libc = true,
-            // https://github.com/ziglang/zig/issues/21646
-            .skip_modules = &.{"std"},
         },
 
         .{
@@ -1901,6 +1893,7 @@ pub fn addStandaloneTests(
     enable_macos_sdk: bool,
     enable_ios_sdk: bool,
     enable_symlinks_windows: bool,
+    skip_translate_c: bool,
 ) *Step {
     const step = b.step("test-standalone", "Run the standalone tests");
     if (compilerHasPackageManager(b)) {
@@ -1913,6 +1906,7 @@ pub fn addStandaloneTests(
             .simple_skip_release_safe = mem.indexOfScalar(OptimizeMode, optimize_modes, .ReleaseSafe) == null,
             .simple_skip_release_fast = mem.indexOfScalar(OptimizeMode, optimize_modes, .ReleaseFast) == null,
             .simple_skip_release_small = mem.indexOfScalar(OptimizeMode, optimize_modes, .ReleaseSmall) == null,
+            .skip_translate_c = skip_translate_c,
         });
         const test_cases_dep_step = test_cases_dep.builder.default_step;
         test_cases_dep_step.name = b.dupe(test_cases_dep_name);
diff --git a/tools/update_cpu_features.zig b/tools/update_cpu_features.zig
index b6e0d6495e..3bed773df7 100644
--- a/tools/update_cpu_features.zig
+++ b/tools/update_cpu_features.zig
@@ -986,6 +986,36 @@ const targets = [_]ArchTarget{
             .name = "LoongArch",
             .td_name = "LoongArch",
         },
+        .extra_cpus = &.{
+            .{
+                .llvm_name = null,
+                .zig_name = "la64v1_0",
+                .features = &.{
+                    "64bit",
+                    "lsx",
+                    "ual",
+                },
+            },
+            .{
+                .llvm_name = null,
+                .zig_name = "la64v1_1",
+                .features = &.{
+                    "64bit",
+                    "div32",
+                    "frecipe",
+                    "lam_bh",
+                    "lamcas",
+                    "ld_seq_sa",
+                    "lsx",
+                    "scq",
+                    "ual",
+                },
+            },
+        },
+        .omit_cpus = &.{
+            "generic",
+            "loongarch64",
+        },
     },
     .{
         .zig_name = "m68k",