Add s390x support

This adds support for building the Rust compiler and standard
library for s390x-linux, allowing a full cross-bootstrap sequence
to complete.  This includes:

- Makefile/configure changes to allow native s390x builds
- Full Rust compiler support for the s390x C ABI
  (only the non-vector ABI is supported at this point)
- Port of the standard library to s390x
- Update the liblibc submodule to a version including s390x support
- Testsuite fixes to allow clean "make check" on s390x

Caveats:

- Resets base cpu to "z10" to bring support in sync with the default
  behaviour of other compilers on the platforms.  (Usually, upstream
  supports all older processors; a distribution build may then chose
  to require a more recent base version.)  (Also, using zEC12 causes
  failures in the valgrind tests since valgrind doesn't fully support
  this CPU yet.)

- z13 vector ABI is not yet supported.  To ensure compatible code
  generation, the -vector feature is passed to LLVM.  Note that this
  means that even when compiling for z13, no vector instructions
  will be used.  In the future, support for the vector ABI should be
  added (this will require common code support for different ABIs
  that need different data_layout strings on the same platform).

- Two test cases are (temporarily) ignored on s390x to allow passing
  the test suite.  The underlying issues still need to be fixed:
  * debuginfo/simd.rs fails because of incorrect debug information.
    This seems to be a LLVM bug (also seen with C code).
  * run-pass/union/union-basic.rs simply seems to be incorrect for
    all big-endian platforms.

Signed-off-by: Ulrich Weigand <ulrich.weigand@de.ibm.com>

26 files changed, 252 insertions, 13 deletions

diff --git a/configure b/configure
index 71fb164f891..792a1ed9c3c 100755
--- a/configure
+++ b/configure
@@ -524,6 +524,10 @@ case $CFG_CPUTYPE in
         CFG_CPUTYPE=powerpc64le
         ;;
 
+    s390x)
+        CFG_CPUTYPE=s390x
+        ;;
+
     x86_64 | x86-64 | x64 | amd64)
         CFG_CPUTYPE=x86_64
         ;;
diff --git a/mk/cfg/s390x-unknown-linux-gnu.mk b/mk/cfg/s390x-unknown-linux-gnu.mk
index 34aee77ae21..eb1cb2329c4 100644
--- a/mk/cfg/s390x-unknown-linux-gnu.mk
+++ b/mk/cfg/s390x-unknown-linux-gnu.mk
@@ -1 +1,24 @@
-# rustbuild-only target
+# s390x-unknown-linux-gnu configuration
+CROSS_PREFIX_s390x-unknown-linux-gnu=s390x-linux-gnu-
+CC_s390x-unknown-linux-gnu=$(CC)
+CXX_s390x-unknown-linux-gnu=$(CXX)
+CPP_s390x-unknown-linux-gnu=$(CPP)
+AR_s390x-unknown-linux-gnu=$(AR)
+CFG_LIB_NAME_s390x-unknown-linux-gnu=lib$(1).so
+CFG_STATIC_LIB_NAME_s390x-unknown-linux-gnu=lib$(1).a
+CFG_LIB_GLOB_s390x-unknown-linux-gnu=lib$(1)-*.so
+CFG_LIB_DSYM_GLOB_s390x-unknown-linux-gnu=lib$(1)-*.dylib.dSYM
+CFG_CFLAGS_s390x-unknown-linux-gnu := -m64 $(CFLAGS)
+CFG_GCCISH_CFLAGS_s390x-unknown-linux-gnu :=  -g -fPIC -m64 $(CFLAGS)
+CFG_GCCISH_CXXFLAGS_s390x-unknown-linux-gnu := -fno-rtti $(CXXFLAGS)
+CFG_GCCISH_LINK_FLAGS_s390x-unknown-linux-gnu := -shared -fPIC -ldl -pthread  -lrt -g -m64
+CFG_GCCISH_DEF_FLAG_s390x-unknown-linux-gnu := -Wl,--export-dynamic,--dynamic-list=
+CFG_LLC_FLAGS_s390x-unknown-linux-gnu :=
+CFG_INSTALL_NAME_s390x-unknown-linux-gnu =
+CFG_EXE_SUFFIX_s390x-unknown-linux-gnu =
+CFG_WINDOWSY_s390x-unknown-linux-gnu :=
+CFG_UNIXY_s390x-unknown-linux-gnu := 1
+CFG_LDPATH_s390x-unknown-linux-gnu :=
+CFG_RUN_s390x-unknown-linux-gnu=$(2)
+CFG_RUN_TARG_s390x-unknown-linux-gnu=$(call CFG_RUN_s390x-unknown-linux-gnu,,$(2))
+CFG_GNU_TRIPLE_s390x-unknown-linux-gnu := s390x-unknown-linux-gnu
diff --git a/src/liballoc_jemalloc/lib.rs b/src/liballoc_jemalloc/lib.rs
index aae0528e42c..5bbf1c35e0d 100644
--- a/src/liballoc_jemalloc/lib.rs
+++ b/src/liballoc_jemalloc/lib.rs
@@ -78,7 +78,8 @@ const MIN_ALIGN: usize = 8;
               target_arch = "x86_64",
               target_arch = "aarch64",
               target_arch = "powerpc64",
-              target_arch = "mips64")))]
+              target_arch = "mips64",
+              target_arch = "s390x")))]
 const MIN_ALIGN: usize = 16;
 
 // MALLOCX_ALIGN(a) macro
diff --git a/src/liballoc_system/lib.rs b/src/liballoc_system/lib.rs
index 2c0c6d068ca..01407d1acd2 100644
--- a/src/liballoc_system/lib.rs
+++ b/src/liballoc_system/lib.rs
@@ -33,7 +33,8 @@
 const MIN_ALIGN: usize = 8;
 #[cfg(all(any(target_arch = "x86_64",
               target_arch = "aarch64",
-              target_arch = "mips64")))]
+              target_arch = "mips64",
+              target_arch = "s390x")))]
 const MIN_ALIGN: usize = 16;
 
 #[no_mangle]
diff --git a/src/liblibc b/src/liblibc
-Subproject 49d64cae0699ed9d9ed84810d737a26b0b519da
+Subproject d4f6a19c55a03e3f9f6fb7377911b37ed807eb6
diff --git a/src/libpanic_unwind/gcc.rs b/src/libpanic_unwind/gcc.rs
index c2e8eccbd22..33b24fbaa26 100644
--- a/src/libpanic_unwind/gcc.rs
+++ b/src/libpanic_unwind/gcc.rs
@@ -130,6 +130,9 @@ const UNWIND_DATA_REG: (i32, i32) = (4, 5); // A0, A1
 #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
 const UNWIND_DATA_REG: (i32, i32) = (3, 4); // R3, R4 / X3, X4
 
+#[cfg(target_arch = "s390x")]
+const UNWIND_DATA_REG: (i32, i32) = (6, 7); // R6, R7
+
 // The following code is based on GCC's C and C++ personality routines.  For reference, see:
 // https://github.com/gcc-mirror/gcc/blob/master/libstdc++-v3/libsupc++/eh_personality.cc
 // https://github.com/gcc-mirror/gcc/blob/trunk/libgcc/unwind-c.c
diff --git a/src/librustc_back/target/s390x_unknown_linux_gnu.rs b/src/librustc_back/target/s390x_unknown_linux_gnu.rs
index 895d33d8d75..79f2d290e37 100644
--- a/src/librustc_back/target/s390x_unknown_linux_gnu.rs
+++ b/src/librustc_back/target/s390x_unknown_linux_gnu.rs
@@ -12,8 +12,12 @@ use target::{Target, TargetResult};
 
 pub fn target() -> TargetResult {
     let mut base = super::linux_base::opts();
-    // NOTE(zEC12) matches C toolchain
-    base.cpu = "zEC12".to_string();
+    // z10 is the oldest CPU supported by LLVM
+    base.cpu = "z10".to_string();
+    // FIXME: The data_layout string below and the ABI implementation in
+    // cabi_s390x.rs are for now hard-coded to assume the no-vector ABI.
+    // Pass the -vector feature string to LLVM to respect this assumption.
+    base.features = "-vector".to_string();
     base.max_atomic_width = 64;
 
     Ok(Target {
diff --git a/src/librustc_trans/abi.rs b/src/librustc_trans/abi.rs
index 42289ec094f..1a6c34b55af 100644
--- a/src/librustc_trans/abi.rs
+++ b/src/librustc_trans/abi.rs
@@ -20,6 +20,7 @@ use cabi_arm;
 use cabi_aarch64;
 use cabi_powerpc;
 use cabi_powerpc64;
+use cabi_s390x;
 use cabi_mips;
 use cabi_mips64;
 use cabi_asmjs;
@@ -301,6 +302,9 @@ impl FnType {
         let win_x64_gnu = target.target_os == "windows"
                        && target.arch == "x86_64"
                        && target.target_env == "gnu";
+        let linux_s390x = target.target_os == "linux"
+                       && target.arch == "s390x"
+                       && target.target_env == "gnu";
         let rust_abi = match abi {
             RustIntrinsic | PlatformIntrinsic | Rust | RustCall => true,
             _ => false
@@ -326,7 +330,9 @@ impl FnType {
                 if llsize_of_real(ccx, arg.ty) == 0 {
                     // For some forsaken reason, x86_64-pc-windows-gnu
                     // doesn't ignore zero-sized struct arguments.
-                    if is_return || rust_abi || !win_x64_gnu {
+                    // The same is true for s390x-unknown-linux-gnu.
+                    if is_return || rust_abi ||
+                       (!win_x64_gnu && !linux_s390x) {
                         arg.ignore();
                     }
                 }
@@ -511,6 +517,7 @@ impl FnType {
             "mips64" => cabi_mips64::compute_abi_info(ccx, self),
             "powerpc" => cabi_powerpc::compute_abi_info(ccx, self),
             "powerpc64" => cabi_powerpc64::compute_abi_info(ccx, self),
+            "s390x" => cabi_s390x::compute_abi_info(ccx, self),
             "asmjs" => cabi_asmjs::compute_abi_info(ccx, self),
             a => ccx.sess().fatal(&format!("unrecognized arch \"{}\" in target specification", a))
         }
diff --git a/src/librustc_trans/cabi_s390x.rs b/src/librustc_trans/cabi_s390x.rs
new file mode 100644
index 00000000000..19404b667e1
--- /dev/null
+++ b/src/librustc_trans/cabi_s390x.rs
@@ -0,0 +1,150 @@
+// Copyright 2016 The Rust Project Developers. See the COPYRIGHT
+// file at the top-level directory of this distribution and at
+// http://rust-lang.org/COPYRIGHT.
+//
+// Licensed under the Apache License, Version 2.0 <LICENSE-APACHE or
+// http://www.apache.org/licenses/LICENSE-2.0> or the MIT license
+// <LICENSE-MIT or http://opensource.org/licenses/MIT>, at your
+// option. This file may not be copied, modified, or distributed
+// except according to those terms.
+
+// FIXME: The assumes we're using the non-vector ABI, i.e. compiling
+// for a pre-z13 machine or using -mno-vx.
+
+use llvm::{Integer, Pointer, Float, Double, Struct, Array, Vector};
+use abi::{FnType, ArgType};
+use context::CrateContext;
+use type_::Type;
+
+use std::cmp;
+
+fn align_up_to(off: usize, a: usize) -> usize {
+    return (off + a - 1) / a * a;
+}
+
+fn align(off: usize, ty: Type) -> usize {
+    let a = ty_align(ty);
+    return align_up_to(off, a);
+}
+
+fn ty_align(ty: Type) -> usize {
+    match ty.kind() {
+        Integer => ((ty.int_width() as usize) + 7) / 8,
+        Pointer => 8,
+        Float => 4,
+        Double => 8,
+        Struct => {
+            if ty.is_packed() {
+                1
+            } else {
+                let str_tys = ty.field_types();
+                str_tys.iter().fold(1, |a, t| cmp::max(a, ty_align(*t)))
+            }
+        }
+        Array => {
+            let elt = ty.element_type();
+            ty_align(elt)
+        }
+        Vector => ty_size(ty),
+        _ => bug!("ty_align: unhandled type")
+    }
+}
+
+fn ty_size(ty: Type) -> usize {
+    match ty.kind() {
+        Integer => ((ty.int_width() as usize) + 7) / 8,
+        Pointer => 8,
+        Float => 4,
+        Double => 8,
+        Struct => {
+            if ty.is_packed() {
+                let str_tys = ty.field_types();
+                str_tys.iter().fold(0, |s, t| s + ty_size(*t))
+            } else {
+                let str_tys = ty.field_types();
+                let size = str_tys.iter().fold(0, |s, t| align(s, *t) + ty_size(*t));
+                align(size, ty)
+            }
+        }
+        Array => {
+            let len = ty.array_length();
+            let elt = ty.element_type();
+            let eltsz = ty_size(elt);
+            len * eltsz
+        }
+        Vector => {
+            let len = ty.vector_length();
+            let elt = ty.element_type();
+            let eltsz = ty_size(elt);
+            len * eltsz
+        }
+        _ => bug!("ty_size: unhandled type")
+    }
+}
+
+fn classify_ret_ty(ccx: &CrateContext, ret: &mut ArgType) {
+    if is_reg_ty(ret.ty) {
+        ret.extend_integer_width_to(64);
+    } else {
+        ret.make_indirect(ccx);
+    }
+}
+
+fn classify_arg_ty(ccx: &CrateContext, arg: &mut ArgType) {
+    if arg.ty.kind() == Struct {
+        fn is_single_fp_element(tys: &[Type]) -> bool {
+            if tys.len() != 1 {
+                return false;
+            }
+            match tys[0].kind() {
+                Float | Double => true,
+                Struct => is_single_fp_element(&tys[0].field_types()),
+                _ => false
+            }
+        }
+
+        if is_single_fp_element(&arg.ty.field_types()) {
+            match ty_size(arg.ty) {
+                4 => arg.cast = Some(Type::f32(ccx)),
+                8 => arg.cast = Some(Type::f64(ccx)),
+                _ => arg.make_indirect(ccx)
+            }
+        } else {
+            match ty_size(arg.ty) {
+                1 => arg.cast = Some(Type::i8(ccx)),
+                2 => arg.cast = Some(Type::i16(ccx)),
+                4 => arg.cast = Some(Type::i32(ccx)),
+                8 => arg.cast = Some(Type::i64(ccx)),
+                _ => arg.make_indirect(ccx)
+            }
+        }
+        return;
+    }
+
+    if is_reg_ty(arg.ty) {
+        arg.extend_integer_width_to(64);
+    } else {
+        arg.make_indirect(ccx);
+    }
+}
+
+fn is_reg_ty(ty: Type) -> bool {
+    match ty.kind() {
+        Integer
+        | Pointer
+        | Float
+        | Double => ty_size(ty) <= 8,
+        _ => false
+    }
+}
+
+pub fn compute_abi_info(ccx: &CrateContext, fty: &mut FnType) {
+    if !fty.ret.is_ignore() {
+        classify_ret_ty(ccx, &mut fty.ret);
+    }
+
+    for arg in &mut fty.args {
+        if arg.is_ignore() { continue; }
+        classify_arg_ty(ccx, arg);
+    }
+}
diff --git a/src/librustc_trans/lib.rs b/src/librustc_trans/lib.rs
index 6f5bac840a1..3e60369acbf 100644
--- a/src/librustc_trans/lib.rs
+++ b/src/librustc_trans/lib.rs
@@ -102,6 +102,7 @@ mod cabi_mips;
 mod cabi_mips64;
 mod cabi_powerpc;
 mod cabi_powerpc64;
+mod cabi_s390x;
 mod cabi_x86;
 mod cabi_x86_64;
 mod cabi_x86_win64;
diff --git a/src/libstd/env.rs b/src/libstd/env.rs
index 9fcc3a80b98..63bf051c9bc 100644
--- a/src/libstd/env.rs
+++ b/src/libstd/env.rs
@@ -662,6 +662,7 @@ pub mod consts {
     /// - mips64
     /// - powerpc
     /// - powerpc64
+    /// - s390x
     #[stable(feature = "env", since = "1.0.0")]
     pub const ARCH: &'static str = super::arch::ARCH;
 
@@ -942,6 +943,11 @@ mod arch {
     pub const ARCH: &'static str = "powerpc64";
 }
 
+#[cfg(target_arch = "s390x")]
+mod arch {
+    pub const ARCH: &'static str = "s390x";
+}
+
 #[cfg(target_arch = "le32")]
 mod arch {
     pub const ARCH: &'static str = "le32";
diff --git a/src/libstd/os/linux/raw.rs b/src/libstd/os/linux/raw.rs
index 0f62877500b..1c19e58818d 100644
--- a/src/libstd/os/linux/raw.rs
+++ b/src/libstd/os/linux/raw.rs
@@ -160,6 +160,11 @@ mod arch {
     pub use libc::{off_t, ino_t, nlink_t, blksize_t, blkcnt_t, stat, time_t};
 }
 
+#[cfg(target_arch = "s390x")]
+mod arch {
+    pub use libc::{off_t, ino_t, nlink_t, blksize_t, blkcnt_t, stat, time_t};
+}
+
 #[cfg(target_arch = "aarch64")]
 mod arch {
     use os::raw::{c_long, c_int};
diff --git a/src/libstd/os/raw.rs b/src/libstd/os/raw.rs
index 55d8ad17460..6c5c1b90a4a 100644
--- a/src/libstd/os/raw.rs
+++ b/src/libstd/os/raw.rs
@@ -17,14 +17,16 @@
           all(target_os = "linux", any(target_arch = "aarch64",
                                        target_arch = "arm",
                                        target_arch = "powerpc",
-                                       target_arch = "powerpc64"))))]
+                                       target_arch = "powerpc64",
+                                       target_arch = "s390x"))))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_char = u8;
 #[cfg(not(any(target_os = "android",
               target_os = "emscripten",
               all(target_os = "linux", any(target_arch = "aarch64",
                                            target_arch = "arm",
                                            target_arch = "powerpc",
-                                           target_arch = "powerpc64")))))]
+                                           target_arch = "powerpc64",
+                                           target_arch = "s390x")))))]
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_char = i8;
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_schar = i8;
 #[stable(feature = "raw_os", since = "1.1.0")] pub type c_uchar = u8;
diff --git a/src/libstd/sys/unix/rand.rs b/src/libstd/sys/unix/rand.rs
index e4ca8344ee2..6b50ca9bcdf 100644
--- a/src/libstd/sys/unix/rand.rs
+++ b/src/libstd/sys/unix/rand.rs
@@ -45,7 +45,8 @@ mod imp {
                   target_arch = "arm",
                   target_arch = "aarch64",
                   target_arch = "powerpc",
-                  target_arch = "powerpc64")))]
+                  target_arch = "powerpc64",
+                  target_arch = "s390x")))]
     fn getrandom(buf: &mut [u8]) -> libc::c_long {
         #[cfg(target_arch = "x86_64")]
         const NR_GETRANDOM: libc::c_long = 318;
@@ -53,6 +54,8 @@ mod imp {
         const NR_GETRANDOM: libc::c_long = 355;
         #[cfg(target_arch = "arm")]
         const NR_GETRANDOM: libc::c_long = 384;
+        #[cfg(target_arch = "s390x")]
+        const NR_GETRANDOM: libc::c_long = 349;
         #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
         const NR_GETRANDOM: libc::c_long = 359;
         #[cfg(target_arch = "aarch64")]
@@ -71,7 +74,8 @@ mod imp {
                       target_arch = "arm",
                       target_arch = "aarch64",
                       target_arch = "powerpc",
-                      target_arch = "powerpc64"))))]
+                      target_arch = "powerpc64",
+                      target_arch = "s390x"))))]
     fn getrandom(_buf: &mut [u8]) -> libc::c_long { -1 }
 
     fn getrandom_fill_bytes(v: &mut [u8]) {
@@ -110,7 +114,8 @@ mod imp {
                   target_arch = "arm",
                   target_arch = "aarch64",
                   target_arch = "powerpc",
-                  target_arch = "powerpc64")))]
+                  target_arch = "powerpc64",
+                  target_arch = "s390x")))]
     fn is_getrandom_available() -> bool {
         use sync::atomic::{AtomicBool, Ordering};
         use sync::Once;
@@ -139,7 +144,8 @@ mod imp {
                       target_arch = "arm",
                       target_arch = "aarch64",
                       target_arch = "powerpc",
-                      target_arch = "powerpc64"))))]
+                      target_arch = "powerpc64",
+                      target_arch = "s390x"))))]
     fn is_getrandom_available() -> bool { false }
 
     pub struct OsRng {
diff --git a/src/libunwind/libunwind.rs b/src/libunwind/libunwind.rs
index 8292a684178..3900ba65293 100644
--- a/src/libunwind/libunwind.rs
+++ b/src/libunwind/libunwind.rs
@@ -62,6 +62,9 @@ pub const unwinder_private_data_size: usize = 2;
 #[cfg(any(target_arch = "powerpc", target_arch = "powerpc64"))]
 pub const unwinder_private_data_size: usize = 2;
 
+#[cfg(target_arch = "s390x")]
+pub const unwinder_private_data_size: usize = 2;
+
 #[cfg(target_arch = "asmjs")]
 pub const unwinder_private_data_size: usize = 20;
 
diff --git a/src/test/compile-fail/asm-bad-clobber.rs b/src/test/compile-fail/asm-bad-clobber.rs
index 714343a372d..85832ddefe2 100644
--- a/src/test/compile-fail/asm-bad-clobber.rs
+++ b/src/test/compile-fail/asm-bad-clobber.rs
@@ -11,6 +11,7 @@
 // ignore-android
 // ignore-arm
 // ignore-aarch64
+// ignore-s390x
 
 #![feature(asm, rustc_attrs)]
 
diff --git a/src/test/compile-fail/asm-in-bad-modifier.rs b/src/test/compile-fail/asm-in-bad-modifier.rs
index 3cb608a9c5e..a4d076fc90d 100644
--- a/src/test/compile-fail/asm-in-bad-modifier.rs
+++ b/src/test/compile-fail/asm-in-bad-modifier.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-s390x
+
 #![feature(asm)]
 
 fn foo(x: isize) { println!("{}", x); }
diff --git a/src/test/compile-fail/asm-misplaced-option.rs b/src/test/compile-fail/asm-misplaced-option.rs
index 1020a5ba8a4..fbfc20f8d04 100644
--- a/src/test/compile-fail/asm-misplaced-option.rs
+++ b/src/test/compile-fail/asm-misplaced-option.rs
@@ -11,6 +11,7 @@
 // ignore-android
 // ignore-arm
 // ignore-aarch64
+// ignore-s390x
 
 #![feature(asm, rustc_attrs)]
 
diff --git a/src/test/compile-fail/asm-out-assign-imm.rs b/src/test/compile-fail/asm-out-assign-imm.rs
index 0541faa0213..1329959fe49 100644
--- a/src/test/compile-fail/asm-out-assign-imm.rs
+++ b/src/test/compile-fail/asm-out-assign-imm.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-s390x
+
 #![feature(asm)]
 
 fn foo(x: isize) { println!("{}", x); }
diff --git a/src/test/compile-fail/asm-out-no-modifier.rs b/src/test/compile-fail/asm-out-no-modifier.rs
index 9cf43bebe65..d610f9e3440 100644
--- a/src/test/compile-fail/asm-out-no-modifier.rs
+++ b/src/test/compile-fail/asm-out-no-modifier.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-s390x
+
 #![feature(asm)]
 
 fn foo(x: isize) { println!("{}", x); }
diff --git a/src/test/compile-fail/asm-out-read-uninit.rs b/src/test/compile-fail/asm-out-read-uninit.rs
index 5e71a2c731d..360f89dda9c 100644
--- a/src/test/compile-fail/asm-out-read-uninit.rs
+++ b/src/test/compile-fail/asm-out-read-uninit.rs
@@ -8,6 +8,8 @@
 // option. This file may not be copied, modified, or distributed
 // except according to those terms.
 
+// ignore-s390x
+
 #![feature(asm)]
 
 fn foo(x: isize) { println!("{}", x); }
diff --git a/src/test/debuginfo/simd.rs b/src/test/debuginfo/simd.rs
index 620e1a73b4d..80ac901b60f 100644
--- a/src/test/debuginfo/simd.rs
+++ b/src/test/debuginfo/simd.rs
@@ -12,6 +12,11 @@
 // ignore-lldb
 // ignore-tidy-linelength
 
+// FIXME: LLVM generates invalid debug info for variables requiring
+// dynamic stack realignment, which is the case on s390x for vector
+// types with with non-vector ABI.
+// ignore-s390x
+
 // compile-flags:-g
 // gdb-command:run
 
diff --git a/src/test/run-make/atomic-lock-free/Makefile b/src/test/run-make/atomic-lock-free/Makefile
index 78e7bb23137..e2ccbe2ad14 100644
--- a/src/test/run-make/atomic-lock-free/Makefile
+++ b/src/test/run-make/atomic-lock-free/Makefile
@@ -27,4 +27,6 @@ ifeq ($(UNAME),Linux)
 	nm "$(TMPDIR)/libatomic_lock_free.rlib" | grep -vq __atomic_fetch_add
 	$(RUSTC) --target=powerpc64le-unknown-linux-gnu atomic_lock_free.rs
 	nm "$(TMPDIR)/libatomic_lock_free.rlib" | grep -vq __atomic_fetch_add
+	$(RUSTC) --target=s390x-unknown-linux-gnu atomic_lock_free.rs
+	nm "$(TMPDIR)/libatomic_lock_free.rlib" | grep -vq __atomic_fetch_add
 endif
diff --git a/src/test/run-pass/conditional-compile-arch.rs b/src/test/run-pass/conditional-compile-arch.rs
index 44971e9252e..368ffe6e713 100644
--- a/src/test/run-pass/conditional-compile-arch.rs
+++ b/src/test/run-pass/conditional-compile-arch.rs
@@ -25,5 +25,8 @@ pub fn main() { }
 #[cfg(target_arch = "powerpc64")]
 pub fn main() { }
 
+#[cfg(target_arch = "s390x")]
+pub fn main() { }
+
 #[cfg(target_arch = "asmjs")]
 pub fn main() { }
diff --git a/src/test/run-pass/union/union-basic.rs b/src/test/run-pass/union/union-basic.rs
index d23af4b41b7..dc14c12b6a2 100644
--- a/src/test/run-pass/union/union-basic.rs
+++ b/src/test/run-pass/union/union-basic.rs
@@ -10,6 +10,9 @@
 
 // aux-build:union.rs
 
+// FIXME: This test case makes little-endian assumptions.
+// ignore-s390x
+
 #![feature(untagged_unions)]
 
 extern crate union;
diff --git a/src/tools/compiletest/src/util.rs b/src/tools/compiletest/src/util.rs
index d2872a0a2b7..2db53947d88 100644
--- a/src/tools/compiletest/src/util.rs
+++ b/src/tools/compiletest/src/util.rs
@@ -38,7 +38,7 @@ const ARCH_TABLE: &'static [(&'static str, &'static str)] = &[("aarch64", "aarch
                                                               ("msp430", "msp430"),
                                                               ("powerpc", "powerpc"),
                                                               ("powerpc64", "powerpc64"),
-                                                              ("s390x", "systemz"),
+                                                              ("s390x", "s390x"),
                                                               ("sparc", "sparc"),
                                                               ("x86_64", "x86_64"),
                                                               ("xcore", "xcore"),