MIPS: Only use .set mips* assembler directives when necessary

There are a few .set mips* assembler directives used in the MIPS specific
sysdep code that force an instruction to be assembled for a specific ISA.
The reason for these is to allow an instruction to be encoded when it might
not be supported in the current ISA (when the code is run the Linux kernel
will trap and emulate any unsupported instructions).  Unfortunately forcing
a specific ISA means that when assembling for a newer ISA, where the
instruction has a different encoding, the wrong encoding will be used.

        * sysdeps/mips/bits/atomic.h [_MIPS_SIM == _ABIO32] (MIPS_PUSH_MIPS2):
        Only use .set mips2 if the current ISA is below mips2.
        * sysdeps/mips/sys/tas.h [_MIPS_SIM == _ABIO32] (_test_and_set):
        Likewise.
        * sysdeps/mips/nptl/tls.h (READ_THREAD_POINTER): Only use .set
        mips32r2 if the current ISA is below mips32r2.
        * sysdeps/mips/tls-macros.h (TLS_RDHWR): New define.
        (TLS_IE): Updated to use the TLD_RDHWR macro.
        (TLS_LE): Likewise.
        * sysdeps/unix/mips/sysdep.h (__mips_isa_rev): Moved out of #ifdef
        __ASSEMBLER__ condition.

diff --git a/ChangeLog b/ChangeLog
index 7316777d55829e0a8117a724b7f50802374579d3..f36e17460dc83dadcf14297c1aea1bc5ee04f03a 100644 (file)
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,17 @@
+2015-09-08  Andrew Bennett  <andrew.bennett@imgtec.com>
+
+       * sysdeps/mips/bits/atomic.h [_MIPS_SIM == _ABIO32] (MIPS_PUSH_MIPS2):
+       Only use .set mips2 if the current ISA is below mips2.
+       * sysdeps/mips/sys/tas.h [_MIPS_SIM == _ABIO32] (_test_and_set):
+       Likewise.
+       * sysdeps/mips/nptl/tls.h (READ_THREAD_POINTER): Only use .set
+       mips32r2 if the current ISA is below mips32r2.
+       * sysdeps/mips/tls-macros.h (TLS_RDHWR): New define.
+       (TLS_IE): Updated to use the TLD_RDHWR macro.
+       (TLS_LE): Likewise.
+       * sysdeps/unix/mips/sysdep.h (__mips_isa_rev): Moved out of #ifdef
+       __ASSEMBLER__ condition.
+
 2015-09-08  Samuel Thibault  <samuel.thibault@ens-lyon.org>
 
        Fix parallel build of before-compile targets.

diff --git a/sysdeps/mips/bits/atomic.h b/sysdeps/mips/bits/atomic.h
index a39188160ba71467d0a88bcc8a4353d641f9981e..375448957cf5aebb6360e83e45716d58c650ed64 100644 (file)
--- a/sysdeps/mips/bits/atomic.h
+++ b/sysdeps/mips/bits/atomic.h
@@ -38,7 +38,7 @@ typedef uintptr_t uatomicptr_t;
 typedef intmax_t atomic_max_t;
 typedef uintmax_t uatomic_max_t;
 
-#if _MIPS_SIM == _ABIO32
+#if _MIPS_SIM == _ABIO32 && __mips < 2
 #define MIPS_PUSH_MIPS2 ".set  mips2\n\t"
 #else
 #define MIPS_PUSH_MIPS2

diff --git a/sysdeps/mips/nptl/tls.h b/sysdeps/mips/nptl/tls.h
index ef1145779df47816bb7d6e501c77d853d61ce0fa..e69c3970df91a0aa3763b9f0410a4a3c34d2d7c6 100644 (file)
--- a/sysdeps/mips/nptl/tls.h
+++ b/sysdeps/mips/nptl/tls.h
@@ -25,6 +25,8 @@
 # include <stdbool.h>
 # include <stddef.h>
 # include <stdint.h>
+/* Get system call information.  */
+# include <sysdep.h>
 
 /* Type for the dtv.  */
 typedef union dtv
@@ -42,29 +44,37 @@ typedef union dtv
 # define READ_THREAD_POINTER() (__builtin_thread_pointer ())
 #else
 /* Note: rd must be $v1 to be ABI-conformant.  */
-# define READ_THREAD_POINTER() \
-    ({ void *__result;                                                       \
-       asm volatile (".set\tpush\n\t.set\tmips32r2\n\t"                              \
-                    "rdhwr\t%0, $29\n\t.set\tpop" : "=v" (__result));        \
-       __result; })
+# if __mips_isa_rev >= 2
+#  define READ_THREAD_POINTER() \
+     ({ void *__result;                                                              \
+        asm volatile ("rdhwr\t%0, $29" : "=v" (__result));                   \
+        __result; })
+# else
+#  define READ_THREAD_POINTER() \
+     ({ void *__result;                                                              \
+        asm volatile (".set\tpush\n\t.set\tmips32r2\n\t"                             \
+                     "rdhwr\t%0, $29\n\t.set\tpop" : "=v" (__result));       \
+        __result; })
+# endif
 #endif
 
 #else /* __ASSEMBLER__ */
 # include <tcb-offsets.h>
 
-# define READ_THREAD_POINTER(rd) \
-       .set    push;                                                         \
-       .set    mips32r2;                                                     \
-       rdhwr   rd, $29;                                                      \
-       .set    pop
+# if __mips_isa_rev >= 2
+#  define READ_THREAD_POINTER(rd) rdhwr        rd, $29
+# else
+#  define READ_THREAD_POINTER(rd) \
+        .set   push;                                                         \
+        .set   mips32r2;                                                     \
+        rdhwr  rd, $29;                                                      \
+        .set   pop
+# endif
 #endif /* __ASSEMBLER__ */
 
 
 #ifndef __ASSEMBLER__
 
-/* Get system call information.  */
-# include <sysdep.h>
-
 /* The TP points to the start of the thread blocks.  */
 # define TLS_DTV_AT_TP 1
 # define TLS_TCB_AT_TP 0

diff --git a/sysdeps/mips/sys/tas.h b/sysdeps/mips/sys/tas.h
index e14b5f04c17eb02b808ef4caf96f1eb137821f3e..2820ff6f058d4f30eba434f1c8121c5efcdc2ce3 100644 (file)
--- a/sysdeps/mips/sys/tas.h
+++ b/sysdeps/mips/sys/tas.h
@@ -41,7 +41,7 @@ __NTH (_test_and_set (int *__p, int __v))
   __asm__ __volatile__
     ("/* Inline test and set */\n"
      ".set     push\n\t"
-#if _MIPS_SIM == _ABIO32
+#if _MIPS_SIM == _ABIO32 && __mips < 2
      ".set     mips2\n\t"
 #endif
      "sync\n\t"

diff --git a/sysdeps/mips/tls-macros.h b/sysdeps/mips/tls-macros.h
index 3e87e42ea1eb689a4651b35f2fbc996ceab3c390..a6fdfbc0ad29255c5253bd83bf087284af3665dc 100644 (file)
--- a/sysdeps/mips/tls-macros.h
+++ b/sysdeps/mips/tls-macros.h
@@ -2,6 +2,7 @@
 
 #include <sys/cdefs.h>
 #include <sys/asm.h>
+#include <sysdep.h>
 
 #define __STRING2(X) __STRING(X)
 #define ADDU __STRING2(PTR_ADDU)
@@ -38,6 +39,14 @@
 # define UNLOAD_GP
 #endif
 
+# if __mips_isa_rev >= 2
+#  define TLS_RDHWR "rdhwr\t%0,$29"
+# else
+#  define TLS_RDHWR                                    \
+         ".set push\n\t.set mips32r2\n\t"              \
+         "rdhwr\t%0,$29\n\t.set pop"
+#endif
+
 #ifndef __mips16
 # define TLS_GD(x)                                     \
   ({ void *__result, *__tmp;                           \
@@ -60,8 +69,7 @@
      __result; })
 # define TLS_IE(x)                                     \
   ({ void *__result, *__tmp;                           \
-     asm (".set push\n\t.set mips32r2\n\t"             \
-         "rdhwr\t%0,$29\n\t.set pop"                   \
+     asm (TLS_RDHWR                                    \
          : "=v" (__result));                           \
      asm (LOAD_GP LW " $3,%%gottprel(" #x ")($28)\n\t" \
          ADDU " %0,%0,$3"                              \
@@ -71,8 +79,7 @@
      __result; })
 # define TLS_LE(x)                                     \
   ({ void *__result;                                   \
-     asm (".set push\n\t.set mips32r2\n\t"             \
-         "rdhwr\t%0,$29\n\t.set pop"                   \
+     asm (TLS_RDHWR                                    \
          : "=v" (__result));                           \
      asm ("lui $3,%%tprel_hi(" #x ")\n\t"              \
          "addiu $3,$3,%%tprel_lo(" #x ")\n\t"          \

diff --git a/sysdeps/unix/mips/sysdep.h b/sysdeps/unix/mips/sysdep.h
index 4fd58f75c7fcb28b8f6e108c26d2b65601a0506d..08595cc980ffbafda6709701437101b15af259f9 100644 (file)
--- a/sysdeps/unix/mips/sysdep.h
+++ b/sysdeps/unix/mips/sysdep.h
@@ -19,6 +19,10 @@
 #include <sgidefs.h>
 #include <sysdeps/unix/sysdep.h>
 
+#ifndef __mips_isa_rev
+# define __mips_isa_rev 0
+#endif
+
 #ifdef __ASSEMBLER__
 
 #include <regdef.h>
@@ -78,8 +82,4 @@
 # define L(label) .L ## label
 #endif
 
-#ifndef __mips_isa_rev
-# define __mips_isa_rev 0
-#endif
-
 #endif