re PR target/50457 (SH2A atomic functions)
authorOleg Endo <olegendo@gcc.gnu.org>
Mon, 1 Oct 2012 08:34:02 +0000 (08:34 +0000)
committerOleg Endo <olegendo@gcc.gnu.org>
Mon, 1 Oct 2012 08:34:02 +0000 (08:34 +0000)
PR target/50457
* config/sh/sh.opt (matomic-model): New option.
(msoft-atomic): Mark as deprecated and alias to matomic-model=soft-gusa.
(mhard-atomic): Delete.
* config/sh/predicates.md (gbr_displacement): New predicate.
* config/sh/sh-protos.h (sh_atomic_model): New struct.
(selected_atomic_model): New declaration.
(TARGET_ATOMIC_ANY, TARGET_ATOMIC_STRICT, TARGET_ATOMIC_SOFT_GUSA,
TARGET_ATOMIC_HARD_LLCS, TARGET_ATOMIC_SOFT_TCB,
TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX, TARGET_ATOMIC_SOFT_IMASK):
New macros.
* config/sh/linux.h (SUBTARGET_OVERRIDE_OPTIONS): Adapt setting to
default atomic model.
* config/sh/sh.c (selected_atomic_model_): New global variable.
(selected_atomic_model, parse_validate_atomic_model_option): New
functions.
(sh_option_override): Replace atomic selection checks with call to
parse_validate_atomic_model_option.
* config/sh/sh.h (TARGET_ANY_ATOMIC, UNSUPPORTED_ATOMIC_OPTIONS,
UNSUPPORTED_HARD_ATOMIC_CPU): Delete.
(DRIVER_SELF_SPECS): Remove atomic checks.
config/sh/sync.md: Update documentation comments.
(atomic_compare_and_swap<mode>, atomic_exchange<mode>,
atomic_fetch_<fetchop_name><mode>, atomic_fetch_nand<mode>,
atomic_<fetchop_name>_fetch<mode>, atomic_nand_fetch<mode>): Use
TARGET_ATOMIC_ANY as condition.  Add TARGET_ATOMIC_STRICT check for
SH4A case.  Handle new TARGET_ATOMIC_SOFT_TCB and
TARGET_ATOMIC_SOFT_IMASK cases.
(atomic_test_and_set): Handle new TARGET_ATOMIC_SOFT_TCB and
TARGET_ATOMIC_SOFT_IMASK cases.
(atomic_compare_and_swapsi_hard, atomic_exchangesi_hard,
atomic_fetch_<fetchop_name>si_hard, atomic_fetch_nandsi_hard,
atomic_<fetchop_name>_fetchsi_hard, atomic_nand_fetchsi_hard):
Add TARGET_ATOMIC_STRICT check.
(atomic_compare_and_swap<mode>_hard, atomic_exchange<mode>_hard,
atomic_fetch_<fetchop_name><mode>_hard, atomic_fetch_nand<mode>_hard,
atomic_<fetchop_name>_fetch<mode>_hard, atomic_nand_fetch<mode>_hard,
atomic_test_and_set_hard): Use TARGET_ATOMIC_HARD_LLCS condition.
(atomic_compare_and_swap<mode>_soft, atomic_exchange<mode>_soft,
atomic_fetch_<fetchop_name><mode>_soft, atomic_fetch_nand<mode>_soft,
atomic_<fetchop_name>_fetch<mode>_soft, atomic_nand_fetch<mode>_soft,
atomic_test_and_set_soft): Append _gusa to the insn names and use
TARGET_ATOMIC_SOFT_GUSA as condition.
(atomic_compare_and_swap<mode>_soft_tcb, atomic_exchange<mode>_soft_tcb,
atomic_fetch_<fetchop_name><mode>_soft_tcb,
atomic_fetch_nand<mode>_soft_tcb,
atomic_<fetchop_name>_fetch<mode>_soft_tcb,
atomic_nand_fetch<mode>_soft_tcb, atomic_test_and_set_soft_tcb):
New insns.
(atomic_compare_and_swap<mode>_soft_imask,
atomic_exchange<mode>_soft_imask,
atomic_fetch_<fetchop_name><mode>_soft_imask,
atomic_fetch_nand<mode>_soft_imask,
atomic_<fetchop_name>_fetch<mode>_soft_imask,
atomic_nand_fetch<mode>_soft_imask, atomic_test_and_set_soft_imask):
New insns.
* doc/invoke.texi (SH Options): Document new matomic-model option.
Remove msoft-atomic and mhard-atomic options.

From-SVN: r191899

gcc/ChangeLog
gcc/config/sh/linux.h
gcc/config/sh/predicates.md
gcc/config/sh/sh-protos.h
gcc/config/sh/sh.c
gcc/config/sh/sh.h
gcc/config/sh/sh.opt
gcc/config/sh/sync.md
gcc/doc/invoke.texi

index 06020e86a17e801d5161982e27d35688e9730fb1..2acf70a3077a3390cc485a8df38cdf88bbc438b6 100644 (file)
@@ -1,3 +1,64 @@
+2012-10-01  Oleg Endo  <olegendo@gcc.gnu.org>
+
+       PR target/50457
+       * config/sh/sh.opt (matomic-model): New option.
+       (msoft-atomic): Mark as deprecated and alias to matomic-model=soft-gusa.
+       (mhard-atomic): Delete.
+       * config/sh/predicates.md (gbr_displacement): New predicate.
+       * config/sh/sh-protos.h (sh_atomic_model): New struct.
+       (selected_atomic_model): New declaration.
+       (TARGET_ATOMIC_ANY, TARGET_ATOMIC_STRICT, TARGET_ATOMIC_SOFT_GUSA,
+       TARGET_ATOMIC_HARD_LLCS, TARGET_ATOMIC_SOFT_TCB,
+       TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX, TARGET_ATOMIC_SOFT_IMASK):
+       New macros.
+       * config/sh/linux.h (SUBTARGET_OVERRIDE_OPTIONS): Adapt setting to
+       default atomic model.
+       * config/sh/sh.c (selected_atomic_model_): New global variable.
+       (selected_atomic_model, parse_validate_atomic_model_option): New
+       functions.
+       (sh_option_override): Replace atomic selection checks with call to
+       parse_validate_atomic_model_option.
+       * config/sh/sh.h (TARGET_ANY_ATOMIC, UNSUPPORTED_ATOMIC_OPTIONS,
+       UNSUPPORTED_HARD_ATOMIC_CPU): Delete.
+       (DRIVER_SELF_SPECS): Remove atomic checks.
+       config/sh/sync.md: Update documentation comments.
+       (atomic_compare_and_swap<mode>, atomic_exchange<mode>,
+       atomic_fetch_<fetchop_name><mode>, atomic_fetch_nand<mode>,
+       atomic_<fetchop_name>_fetch<mode>, atomic_nand_fetch<mode>): Use
+       TARGET_ATOMIC_ANY as condition.  Add TARGET_ATOMIC_STRICT check for
+       SH4A case.  Handle new TARGET_ATOMIC_SOFT_TCB and
+       TARGET_ATOMIC_SOFT_IMASK cases.
+       (atomic_test_and_set): Handle new TARGET_ATOMIC_SOFT_TCB and
+       TARGET_ATOMIC_SOFT_IMASK cases.
+       (atomic_compare_and_swapsi_hard, atomic_exchangesi_hard,
+       atomic_fetch_<fetchop_name>si_hard, atomic_fetch_nandsi_hard,
+       atomic_<fetchop_name>_fetchsi_hard, atomic_nand_fetchsi_hard):
+       Add TARGET_ATOMIC_STRICT check.
+       (atomic_compare_and_swap<mode>_hard, atomic_exchange<mode>_hard,
+       atomic_fetch_<fetchop_name><mode>_hard, atomic_fetch_nand<mode>_hard,
+       atomic_<fetchop_name>_fetch<mode>_hard, atomic_nand_fetch<mode>_hard,
+       atomic_test_and_set_hard): Use TARGET_ATOMIC_HARD_LLCS condition.
+       (atomic_compare_and_swap<mode>_soft, atomic_exchange<mode>_soft,
+       atomic_fetch_<fetchop_name><mode>_soft, atomic_fetch_nand<mode>_soft,
+       atomic_<fetchop_name>_fetch<mode>_soft, atomic_nand_fetch<mode>_soft,
+       atomic_test_and_set_soft): Append _gusa to the insn names and use
+       TARGET_ATOMIC_SOFT_GUSA as condition.
+       (atomic_compare_and_swap<mode>_soft_tcb, atomic_exchange<mode>_soft_tcb,
+       atomic_fetch_<fetchop_name><mode>_soft_tcb,
+       atomic_fetch_nand<mode>_soft_tcb,
+       atomic_<fetchop_name>_fetch<mode>_soft_tcb,
+       atomic_nand_fetch<mode>_soft_tcb, atomic_test_and_set_soft_tcb):
+       New insns.
+       (atomic_compare_and_swap<mode>_soft_imask,
+       atomic_exchange<mode>_soft_imask,
+       atomic_fetch_<fetchop_name><mode>_soft_imask,
+       atomic_fetch_nand<mode>_soft_imask,
+       atomic_<fetchop_name>_fetch<mode>_soft_imask,
+       atomic_nand_fetch<mode>_soft_imask, atomic_test_and_set_soft_imask):
+       New insns.
+       * doc/invoke.texi (SH Options): Document new matomic-model option.
+       Remove msoft-atomic and mhard-atomic options.
+
 2012-10-01  Andreas Krebbel  <Andreas.Krebbel@de.ibm.com>
 
        PR target/54746
index 904a7823bf2a7616df845ec39c9a53ff219b11af..e3fec2f542d303096ff98f492dfaab362b6b065f 100644 (file)
@@ -138,11 +138,16 @@ along with GCC; see the file COPYING3.  If not see
 #define TARGET_INIT_LIBFUNCS  sh_init_sync_libfuncs
 
 #undef SUBTARGET_OVERRIDE_OPTIONS
-#define SUBTARGET_OVERRIDE_OPTIONS                     \
-  do                                                   \
-    {                                                  \
-      /* Defaulting to -msoft-atomic.  */              \
-      if (global_options_set.x_TARGET_SOFT_ATOMIC == 0)        \
-       TARGET_SOFT_ATOMIC = 1;                         \
-    }                                                  \
+#define SUBTARGET_OVERRIDE_OPTIONS                                     \
+  do                                                                   \
+    {                                                                  \
+      /* Set default atomic model if it hasn't been specified.  */     \
+      if (global_options_set.x_sh_atomic_model_str == 0)               \
+       {                                                               \
+         if (TARGET_SH3)                                               \
+           sh_atomic_model_str = "soft-gusa";                          \
+         else if (TARGET_SH1)                                          \
+           sh_atomic_model_str = "soft-imask";                         \
+       }                                                               \
+    }                                                                  \
   while (0)
index 93a33bf2544b06cf64d2f6c4cbaed84466d3c2d6..05ad85808bbf3fca92573f6a3625c981083808df 100644 (file)
 
   return false;
 })
+
+;; A predicate that determines whether a given constant is a valid
+;; displacement for a gbr load/store of the specified mode.
+(define_predicate "gbr_displacement"
+  (match_code "const_int")
+{
+  const int mode_sz = GET_MODE_SIZE (mode);
+  const int move_sz = mode_sz > GET_MODE_SIZE (SImode)
+                               ? GET_MODE_SIZE (SImode)
+                               : mode_sz;
+  int max_disp = 255 * move_sz;
+  if (mode_sz > move_sz)
+    max_disp -= mode_sz - move_sz;
+
+  return INTVAL (op) >= 0 && INTVAL (op) <= max_disp;
+})
index 827b1b48819433ad9c1d63de306191a75faf6211..135a5c43a9d370c50e4ded4cb20d551f863ffe91 100644 (file)
@@ -37,6 +37,51 @@ enum sh_function_kind {
   SFUNC_STATIC
 };
 
+/* Atomic model.  */
+struct sh_atomic_model
+{
+  enum enum_type
+  {
+    none = 0,
+    soft_gusa,
+    hard_llcs,
+    soft_tcb,
+    soft_imask,
+
+    num_models
+  };
+
+  /*  If strict is set, disallow mixing of different models, as it would
+      happen on SH4A.  */
+  bool strict;
+  enum_type type;
+  int tcb_gbr_offset;
+};
+
+extern const sh_atomic_model& selected_atomic_model (void);
+
+/* Shortcuts to check the currently selected atomic model.  */
+#define TARGET_ATOMIC_ANY \
+  selected_atomic_model ().type != sh_atomic_model::none
+
+#define TARGET_ATOMIC_STRICT \
+  selected_atomic_model ().strict
+
+#define TARGET_ATOMIC_SOFT_GUSA \
+  selected_atomic_model ().type == sh_atomic_model::soft_gusa
+
+#define TARGET_ATOMIC_HARD_LLCS \
+  selected_atomic_model ().type == sh_atomic_model::hard_llcs
+
+#define TARGET_ATOMIC_SOFT_TCB \
+  selected_atomic_model ().type == sh_atomic_model::soft_tcb
+
+#define TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX \
+  GEN_INT (selected_atomic_model ().tcb_gbr_offset)
+
+#define TARGET_ATOMIC_SOFT_IMASK \
+  selected_atomic_model ().type == sh_atomic_model::soft_imask
+
 #ifdef RTX_CODE
 extern rtx sh_fsca_sf2int (void);
 extern rtx sh_fsca_int2sf (void);
index fd7879910dc0f837ad9b176c59174d5d819198e3..ebfacbbcfe04af745c94db9e3f14ef8e579f4881 100644 (file)
@@ -62,6 +62,8 @@ along with GCC; see the file COPYING3.  If not see
 #include "tm-constrs.h"
 #include "opts.h"
 
+#include <sstream>
+#include <vector>
 #include <algorithm>
 
 int code_for_indirect_jump_scratch = CODE_FOR_indirect_jump_scratch;
@@ -596,6 +598,110 @@ static const struct attribute_spec sh_attribute_table[] =
 
 struct gcc_target targetm = TARGET_INITIALIZER;
 \f
+
+/* Information on the currently selected atomic model.
+   This is initialized in sh_option_override.  */
+static sh_atomic_model selected_atomic_model_;
+
+const sh_atomic_model&
+selected_atomic_model (void)
+{
+  return selected_atomic_model_;
+}
+
+static sh_atomic_model
+parse_validate_atomic_model_option (const char* str)
+{
+  const char* model_names[sh_atomic_model::num_models];
+  model_names[sh_atomic_model::none] = "none";
+  model_names[sh_atomic_model::soft_gusa] = "soft-gusa";
+  model_names[sh_atomic_model::hard_llcs] = "hard-llcs";
+  model_names[sh_atomic_model::soft_tcb] = "soft-tcb";
+  model_names[sh_atomic_model::soft_imask] = "soft-imask";
+
+  sh_atomic_model ret;
+  ret.type = sh_atomic_model::none;
+  ret.strict = false;
+  ret.tcb_gbr_offset = -1;
+
+  /* Handle empty string as 'none'.  */
+  if (str == NULL || *str == '\0')
+    return ret;
+
+#define err_ret(...) do { error (__VA_ARGS__); return ret; } while (0)
+
+  std::vector<std::string> tokens;
+  for (std::stringstream ss (str); ss.good (); )
+  {
+    tokens.push_back (std::string ());
+    std::getline (ss, tokens.back (), ',');
+  }
+
+  if (tokens.empty ())
+    err_ret ("invalid atomic model option");
+
+  /* The first token must be the atomic model name.  */
+  {
+    for (size_t i = 0; i < sh_atomic_model::num_models; ++i)
+      if (tokens.front () == model_names[i])
+       {
+         ret.type = (sh_atomic_model::enum_type)i;
+         goto got_mode_name;
+       }
+
+    err_ret ("invalid atomic model name \"%s\"", tokens.front ().c_str ());
+got_mode_name:;
+  }
+
+  /* Go through the remaining tokens.  */
+  for (size_t i = 1; i < tokens.size (); ++i)
+    {
+      if (tokens[i] == "strict")
+       ret.strict = true;
+      else if (tokens[i].find ("gbr-offset=") == 0)
+       {
+         std::string offset_str = tokens[i].substr (strlen ("gbr-offset="));
+         ret.tcb_gbr_offset = integral_argument (offset_str.c_str ());
+         if (offset_str.empty () || ret.tcb_gbr_offset == -1)
+           err_ret ("could not parse gbr-offset value \"%s\" in atomic model "
+                    "option", offset_str.c_str ());
+       }
+      else
+       err_ret ("unknown parameter \"%s\" in atomic model option",
+                tokens[i].c_str ());
+    }
+
+  /* Check that the selection makes sense.  */
+  if (TARGET_SHMEDIA && ret.type != sh_atomic_model::none)
+    err_ret ("atomic operations are not supported on SHmedia");
+
+  if (ret.type == sh_atomic_model::soft_gusa && !TARGET_SH3)
+    err_ret ("atomic model %s is only available on SH3 and SH4 targets",
+            model_names[ret.type]);
+
+  if (ret.type == sh_atomic_model::hard_llcs && !TARGET_SH4A)
+    err_ret ("atomic model %s is only available on SH4A targets",
+            model_names[ret.type]);
+
+  if (ret.type == sh_atomic_model::soft_tcb && ret.tcb_gbr_offset == -1)
+    err_ret ("atomic model %s requires gbr-offset parameter", 
+            model_names[ret.type]);
+
+  if (ret.type == sh_atomic_model::soft_tcb
+      && (ret.tcb_gbr_offset < 0 || ret.tcb_gbr_offset > 1020
+          || (ret.tcb_gbr_offset & 3) != 0))
+    err_ret ("invalid gbr-offset value \"%d\" for atomic model %s; it must be "
+            "a multiple of 4 in the range 0-1020", ret.tcb_gbr_offset,
+            model_names[ret.type]);
+
+  if (ret.type == sh_atomic_model::soft_imask && TARGET_USERMODE)
+    err_ret ("cannot use atomic model %s in user mode", model_names[ret.type]);
+
+  return ret;
+
+#undef err_ret
+}
+
 /* Implement TARGET_OPTION_OVERRIDE macro.  Validate and override 
    various options, and do some machine dependent initialization.  */
 static void
@@ -907,12 +1013,10 @@ sh_option_override (void)
   if (flag_strict_volatile_bitfields < 0 && abi_version_at_least(2))
     flag_strict_volatile_bitfields = 1;
 
-  /* Make sure that only one atomic mode is selected and that the selection
-     is valid for the current target CPU.  */
-  if (TARGET_SOFT_ATOMIC && TARGET_HARD_ATOMIC)
-    error ("-msoft-atomic and -mhard-atomic cannot be used at the same time");
-  if (TARGET_HARD_ATOMIC && ! TARGET_SH4A_ARCH)
-    error ("-mhard-atomic is only available for SH4A targets");
+  /* Parse atomic model option and make sure it is valid for the current
+     target CPU.  */
+  selected_atomic_model_
+    = parse_validate_atomic_model_option (sh_atomic_model_str);
 }
 \f
 /* Print the operand address in x to the stream.  */
index d72379022bbd6d8d64f7eea5731962563c19ec8a..546cb6fd3cb200f32e41ed38625199234d0c8ad8 100644 (file)
@@ -172,9 +172,6 @@ do { \
   (TARGET_SH1 && ! TARGET_SH2E && ! TARGET_SH5 \
    && ! (TARGET_HITACHI || sh_attr_renesas_p (FUN_DECL)))
 
-/* Nonzero if either soft or hard atomics are enabled.  */
-#define TARGET_ANY_ATOMIC (TARGET_SOFT_ATOMIC | TARGET_HARD_ATOMIC)
-
 #ifndef TARGET_CPU_DEFAULT
 #define TARGET_CPU_DEFAULT SELECT_SH1
 #define SUPPORT_SH1 1
@@ -436,20 +433,8 @@ do { \
 "%{m2a*:%eSH2a does not support little-endian}}"
 #endif
 
-#define UNSUPPORTED_ATOMIC_OPTIONS \
-"%{msoft-atomic:%{mhard-atomic:%e-msoft-atomic and -mhard-atomic cannot be \
-used at the same time}}"
-
-#if TARGET_CPU_DEFAULT & MASK_SH4A
-#define UNSUPPORTED_HARD_ATOMIC_CPU ""
-#else
-#define UNSUPPORTED_HARD_ATOMIC_CPU \
-"%{!m4a*:%{mhard-atomic:%e-mhard-atomic is only available for SH4A targets}}"
-#endif
-
 #undef DRIVER_SELF_SPECS
-#define DRIVER_SELF_SPECS UNSUPPORTED_SH2A, UNSUPPORTED_ATOMIC_OPTIONS,\
-                         UNSUPPORTED_HARD_ATOMIC_CPU
+#define DRIVER_SELF_SPECS UNSUPPORTED_SH2A
 
 #define ASSEMBLER_DIALECT assembler_dialect
 
index cb01810619bb89cd366e10d41d391987541395f1..df9df6d3e1244a60aa1b7705fa570be44d7522ac 100644 (file)
@@ -320,12 +320,12 @@ Target Mask(HITACHI)
 Follow Renesas (formerly Hitachi) / SuperH calling conventions
 
 msoft-atomic
-Target Report Var(TARGET_SOFT_ATOMIC)
-Use gUSA software atomic sequences
+Target Undocumented Alias(matomic-model=, soft-gusa, none)
+Deprecated.  Use -matomic= instead to select the atomic model
 
-mhard-atomic
-Target Report Var(TARGET_HARD_ATOMIC)
-Use hardware atomic sequences
+matomic-model=
+Target Report RejectNegative Joined Var(sh_atomic_model_str)
+Specify the model for atomic operations
 
 mtas
 Target Report RejectNegative Var(TARGET_ENABLE_TAS)
index aa87c57c765335d7daba29a3678592a89a1845cb..6cd982c79b1eebe5d36efc8753480568374bf06a 100644 (file)
 ;; Atomic integer operations for the Renesas / SuperH SH CPUs.
 ;;
 ;; On SH CPUs atomic integer operations can be done either in 'software' or
-;; in 'hardware', where true hardware support was introduced with the SH4A.
-;; In addition to that all SH CPUs support the 'tas.b' instruction, which
-;; can be optionally used to implement the 'atomic_test_and_set' builtin.
+;; in 'hardware' in various styles.  True hardware support was introduced
+;; with the SH4A.  Some SH2A dual-core models (e.g. SH7205) also come with
+;; 'semaphore' hardware registers, but these are currently unsupported.
+;; All SH CPUs support the 'tas.b' instruction, which can be optionally used
+;; to implement the 'atomic_test_and_set' builtin.
+;; The following atomic options and models are supported.
 ;;
 ;; tas.b atomic_test_and_set (-mtas)
 ;;
@@ -37,7 +40,7 @@
 ;; other atomic operations.
 ;;
 ;;
-;; Hardware Atomics (-mhard-atomic, SH4A only)
+;; Hardware Atomics (-matomic-model=hard-llcs; SH4A only)
 ;;
 ;; Hardware atomics implement all atomic operations using the 'movli.l' and
 ;; 'movco.l' instructions that are availble on SH4A.  On multi-core hardware
@@ -48,7 +51,7 @@
 ;; larger code.
 ;;
 ;;
-;; Software Atomics (-msoft-atomic)
+;; gUSA Software Atomics (-matomic-model=soft-gusa; SH3*, SH4* only)
 ;;
 ;; On single-core systems there can only be one execution context running
 ;; at a given point in time.  This allows the usage of rewindable atomic
@@ -68,9 +71,8 @@
 ;;       interrupted_pc = atomic_entrypoint;
 ;;
 ;; This method is also known as gUSA ("g" User Space Atomicity) and the
-;; Linux kernel for SH3/SH4 implements support for such software
-;; atomic sequences.  However, it can also be implemented in freestanding
-;; environments.
+;; Linux kernel for SH3/SH4 implements support for such software atomic
+;; sequences.  It can also be implemented in freestanding environments.
 ;;
 ;; For this the following atomic sequence ABI is used.
 ;;
 ;; For correct operation the atomic sequences must not be rewound after
 ;; they have passed the write-back instruction.
 ;;
+;; This is model works only on SH3* and SH4* because the stack pointer (r15)
+;; is set to an invalid pointer temporarily.  SH1* and SH2* CPUs will try
+;; to push SR and PC registers on the stack when an interrupt / exception
+;; occurs, and thus require the stack pointer (r15) always to be valid.
+;;
+;;
+;; TCB Software Atomics (-matomic-model=soft-tcb)
+;;
+;; This model is a variation of the gUSA model.  The concept of rewindable
+;; atomic sequences is the same, but it does not use the stack pointer (r15)
+;; for signaling the 'is in atomic sequence' condition.  Instead, a variable
+;; in the thread control block (TCB) is set to hold the exit point of the
+;; atomic sequence.  This assumes that the GBR is used as a thread pointer
+;; register.  The offset of the variable in the TCB to be used must be
+;; specified with an additional option 'gbr-offset', such as:
+;;     -matomic-model=soft-tcb,gbr-offset=4
+;;
+;; For this model the following atomic sequence ABI is used.
+;; 
+;; @(#x,gbr) == 0:  Execution context is not in an atomic sequence.
+;;
+;; @(#x,gbr) != 0:  Execution context is in an atomic sequence.  In this
+;;                 case the following applies:
+;;
+;;                 @(#x,gbr):  PC of the first instruction after the atomic
+;;                             write-back instruction (exit point).
+;;
+;;                 r1:         Negative byte length of the atomic sequence.
+;;                             The entry point PC of the sequence can be
+;;                             determined by doing @(#x,gbr) + r1
+;;
+;; Note: #x is the user specified gbr-offset.
+;;
+;;
+;; Interrupt-Flipping Software Atomics (-matomic-model=soft-imask)
+;;
+;; This model achieves atomicity by temporarily disabling interrupts for
+;; the duration of the atomic sequence.  This works only when the program
+;; runs in privileged mode but does not require any support from the
+;; interrupt / exception handling code.  There is no particular ABI.
+;; To disable interrupts the SR.IMASK bits are set to '1111'.
+;; This method is not as efficient as the other software atomic models,
+;; since loading and storing SR (in order to flip interrupts on / off)
+;; requires using multi-cycle instructions.  Moreover, it can potentially
+;; increase the interrupt latency which might be important for hard-realtime
+;; applications.
+;;
+;;
+;; Compatibility Notes
+;;
+;; On single-core SH4A CPUs software atomic aware interrupt / exception code
+;; is actually compatible with user code that utilizes hardware atomics.
+;; Since SImode hardware atomic sequences are more compact on SH4A they are
+;; always used, regardless of the selected atomic model.  This atomic model
+;; mixing can be disabled by setting the 'strict' flag, like:
+;;     -matomic-model=soft-gusa,strict
+;;
+;; The software atomic models are generally compatible with each other,
+;; but the interrupt / exception handling code has to support both gUSA and
+;; TCB models.
+;;
 ;; The current atomic support is limited to QImode, HImode and SImode 
 ;; atomic operations.  DImode operations could also be implemented but
 ;; would require some ABI modifications to support multiple-instruction
 ;; write-back.  This is because SH1/SH2/SH3/SH4 does not have a DImode
 ;; store instruction.  DImode stores must be split into two SImode stores.
-;;
-;; On single-core SH4A CPUs software atomic aware interrupt / exception code
-;; is actually compatible with user code that utilizes hardware atomics.
-;; Since SImode hardware atomic sequences are more compact on SH4A they are
-;; always used, regardless of the selected atomic mode.
 
 (define_c_enum "unspec" [
   UNSPEC_ATOMIC
    (match_operand:SI 5 "const_int_operand" "")         ;; is_weak
    (match_operand:SI 6 "const_int_operand" "")         ;; success model
    (match_operand:SI 7 "const_int_operand" "")]                ;; failure model
-  "TARGET_ANY_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_ANY"
 {
   rtx addr = force_reg (Pmode, XEXP (operands[2], 0));
   rtx old_val = gen_lowpart (SImode, operands[1]);
   rtx new_val = operands[4];
   rtx atomic_insn;
 
-  if (TARGET_HARD_ATOMIC || (TARGET_SH4A_ARCH && <MODE>mode == SImode))
+  if (TARGET_ATOMIC_HARD_LLCS
+      || (TARGET_SH4A_ARCH && <MODE>mode == SImode && !TARGET_ATOMIC_STRICT))
     atomic_insn = gen_atomic_compare_and_swap<mode>_hard (old_val, addr,
                                                          exp_val, new_val);
+  else if (TARGET_ATOMIC_SOFT_GUSA)
+    atomic_insn = gen_atomic_compare_and_swap<mode>_soft_gusa (old_val, addr,
+                     exp_val, new_val);
+  else if (TARGET_ATOMIC_SOFT_TCB)
+    atomic_insn = gen_atomic_compare_and_swap<mode>_soft_tcb (old_val, addr,
+                     exp_val, new_val, TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX);
+  else if (TARGET_ATOMIC_SOFT_IMASK)
+    atomic_insn = gen_atomic_compare_and_swap<mode>_soft_imask (old_val, addr,
+                     exp_val, new_val);
   else
-    atomic_insn = gen_atomic_compare_and_swap<mode>_soft (old_val, addr,
-                                                         exp_val, new_val);
+    FAIL;
+
   emit_insn (atomic_insn);
 
   if (<MODE>mode == QImode)
    (set (reg:SI T_REG)
        (unspec_volatile:SI [(const_int 0)] UNSPECV_CMPXCHG_3))
    (clobber (reg:SI R0_REG))]
-  "TARGET_ANY_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS
+   || (TARGET_SH4A_ARCH && TARGET_ATOMIC_ANY && !TARGET_ATOMIC_STRICT)"
 {
   return "\r0: movli.l @%1,r0"         "\n"
         "      cmp/eq  %2,r0"          "\n"
    (clobber (match_scratch:SI 4 "=&r"))
    (clobber (match_scratch:SI 5 "=&r"))
    (clobber (match_scratch:SI 6 "=1"))]
-  "TARGET_HARD_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS"
 {
   return "\r   mov     #-4,%5"                 "\n"
         "      <i124extend_insn>       %2,%4"  "\n"
 }
   [(set_attr "length" "30")])
 
-(define_insn "atomic_compare_and_swap<mode>_soft"
+(define_insn "atomic_compare_and_swap<mode>_soft_gusa"
   [(set (match_operand:SI 0 "register_operand" "=&u")
        (unspec_volatile:SI
          [(mem:QIHISI (match_operand:SI 1 "register_operand" "u"))
    (clobber (match_scratch:SI 4 "=&u"))
    (clobber (reg:SI R0_REG))
    (clobber (reg:SI R1_REG))]
-  "TARGET_SOFT_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_SOFT_GUSA"
 {
   return "\r   mova    1f,r0"                  "\n"
         "      <i124extend_insn>       %2,%4"  "\n"
 }
   [(set_attr "length" "20")])
 
+(define_insn "atomic_compare_and_swap<mode>_soft_tcb"
+  [(set (match_operand:SI 0 "register_operand" "=&r")
+       (unspec_volatile:SI
+         [(mem:QIHISI (match_operand:SI 1 "register_operand" "r"))
+          (match_operand:QIHISI 2 "register_operand" "r")
+          (match_operand:QIHISI 3 "register_operand" "r")]
+         UNSPECV_CMPXCHG_1))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec_volatile:QIHISI [(const_int 0)] UNSPECV_CMPXCHG_2))
+   (set (reg:SI T_REG)
+       (unspec_volatile:SI [(const_int 0)] UNSPECV_CMPXCHG_3))
+   (use (match_operand:SI 4 "gbr_displacement"))
+   (clobber (match_scratch:SI 5 "=&r"))
+   (clobber (reg:SI R0_REG))
+   (clobber (reg:SI R1_REG))]
+  "TARGET_ATOMIC_SOFT_TCB"
+{
+  return "\r   mova    1f,r0"                  "\n"
+        "      .align 2"                       "\n"
+        "      <i124extend_insn>       %2,%5"  "\n"
+        "      mov     #(0f-1f),r1"            "\n"
+        "      mov.l   r0,@(%O4,gbr)"          "\n"
+        "0:    mov.<bwl>       @%1,%0"         "\n"
+        "      mov     #0,r0"                  "\n"
+        "      cmp/eq  %0,%5"                  "\n"
+        "      bf      1f"                     "\n"
+        "      mov.<bwl>       %3,@%1"         "\n"
+        "1:    mov.l   r0,@(%O4,gbr)";
+}
+  [(set_attr "length" "22")])
+
+(define_insn "atomic_compare_and_swap<mode>_soft_imask"
+  [(set (match_operand:SI 0 "register_operand" "=&z")
+       (unspec_volatile:SI
+         [(mem:QIHISI (match_operand:SI 1 "register_operand" "r"))
+          (match_operand:QIHISI 2 "register_operand" "r")
+          (match_operand:QIHISI 3 "register_operand" "r")]
+         UNSPECV_CMPXCHG_1))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec_volatile:QIHISI [(const_int 0)] UNSPECV_CMPXCHG_2))
+   (set (reg:SI T_REG)
+       (unspec_volatile:SI [(const_int 0)] UNSPECV_CMPXCHG_3))
+   (clobber (match_scratch:SI 4 "=&r"))
+   (clobber (match_scratch:SI 5 "=&r"))]
+  "TARGET_ATOMIC_SOFT_IMASK"
+{
+  /* The comparison result is supposed to be in T_REG.
+     Notice that restoring SR will overwrite the T_REG.  We handle this by
+     rotating the T_REG into the saved SR before restoring SR.  On SH2A we
+     can do one insn shorter by using the bst insn.  */
+  if (!TARGET_SH2A)
+    return "\r stc     sr,%0"                  "\n"
+          "    <i124extend_insn>       %2,%4"  "\n"
+          "    mov     %0,%5"                  "\n"
+          "    or      #0xF0,%0"               "\n"
+          "    shlr    %5"                     "\n"
+          "    ldc     %0,sr"                  "\n"
+          "    mov.<bwl>       @%1,%0"         "\n"
+          "    cmp/eq  %4,%0"                  "\n"
+          "    bf      1f"                     "\n"
+          "    mov.<bwl>       %3,@%1"         "\n"
+          "1:  rotcl   %5"                     "\n"
+          "    ldc     %5,sr";
+  else
+    return "\r stc     sr,%0"                  "\n"
+          "    <i124extend_insn>       %2,%4"  "\n"
+          "    mov     %0,%5"                  "\n"
+          "    or      #0xF0,%0"               "\n"
+          "    ldc     %0,sr"                  "\n"
+          "    mov.<bwl>       @%1,%0"         "\n"
+          "    cmp/eq  %4,%0"                  "\n"
+          "    bst     #0,%5"                  "\n"
+          "    bf      1f"                     "\n"
+          "    mov.<bwl>       %3,@%1"         "\n"
+          "1:  ldc     %5,sr";
+}
+  [(set (attr "length") (if_then_else (match_test "!TARGET_SH2A")
+                                     (const_string "24")
+                                     (const_string "22")))])
+
 ;;------------------------------------------------------------------------------
 ;; read - write - return old value
 
    (match_operand:QIHISI 1 "memory_operand" "")                ;; memory
    (match_operand:QIHISI 2 "atomic_arith_operand" "")  ;; newval input
    (match_operand:SI 3 "const_int_operand" "")]                ;; memory model
-  "TARGET_ANY_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_ANY"
 {
   rtx addr = force_reg (Pmode, XEXP (operands[1], 0));
   rtx val = operands[2];
   rtx atomic_insn;
 
-  if (TARGET_HARD_ATOMIC || (TARGET_SH4A_ARCH && <MODE>mode == SImode))
+  if (TARGET_ATOMIC_HARD_LLCS
+      || (TARGET_SH4A_ARCH && <MODE>mode == SImode && !TARGET_ATOMIC_STRICT))
     atomic_insn = gen_atomic_exchange<mode>_hard (operands[0], addr, val);
+  else if (TARGET_ATOMIC_SOFT_GUSA)
+    atomic_insn = gen_atomic_exchange<mode>_soft_gusa (operands[0], addr, val);
+  else if (TARGET_ATOMIC_SOFT_TCB)
+    atomic_insn = gen_atomic_exchange<mode>_soft_tcb (operands[0], addr, val,
+                     TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX);
+  else if (TARGET_ATOMIC_SOFT_IMASK)
+    atomic_insn = gen_atomic_exchange<mode>_soft_imask (operands[0], addr, val);
   else
-    atomic_insn = gen_atomic_exchange<mode>_soft (operands[0], addr, val);
+    FAIL;
 
   emit_insn (atomic_insn);
 
        (unspec:SI
          [(match_operand:SI 2 "arith_operand" "rI08")] UNSPEC_ATOMIC))
    (clobber (reg:SI R0_REG))]
-  "TARGET_ANY_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS
+   || (TARGET_SH4A_ARCH && TARGET_ATOMIC_ANY && !TARGET_ATOMIC_STRICT)"
 {
   return "\r0: movli.l @%1,r0"         "\n"
         "      mov     r0,%0"          "\n"
    (clobber (reg:SI R0_REG))
    (clobber (match_scratch:SI 3 "=&r"))
    (clobber (match_scratch:SI 4 "=1"))]
-  "TARGET_HARD_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS"
 {
   return "\r   mov     #-4,%3"                 "\n"
         "      and     %1,%3"                  "\n"
 }
   [(set_attr "length" "24")])
 
-(define_insn "atomic_exchange<mode>_soft"
+(define_insn "atomic_exchange<mode>_soft_gusa"
   [(set (match_operand:QIHISI 0 "register_operand" "=&u")
        (mem:QIHISI (match_operand:SI 1 "register_operand" "u")))
    (set (mem:QIHISI (match_dup 1))
          [(match_operand:QIHISI 2 "register_operand" "u")] UNSPEC_ATOMIC))
    (clobber (reg:SI R0_REG))
    (clobber (reg:SI R1_REG))]
-  "TARGET_SOFT_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_SOFT_GUSA"
 {
   return "\r   mova    1f,r0"                  "\n"
         "      .align 2"                       "\n"
 }
   [(set_attr "length" "14")])
 
+(define_insn "atomic_exchange<mode>_soft_tcb"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&r")
+       (mem:QIHISI (match_operand:SI 1 "register_operand" "r")))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(match_operand:QIHISI 2 "register_operand" "r")] UNSPEC_ATOMIC))
+   (clobber (reg:SI R0_REG))
+   (clobber (reg:SI R1_REG))
+   (use (match_operand:SI 3 "gbr_displacement"))]
+  "TARGET_ATOMIC_SOFT_TCB"
+{
+  return "\r   mova    1f,r0"                  "\n"
+        "      mov     #(0f-1f),r1"            "\n"
+        "      .align 2"                       "\n"
+        "      mov.l   r0,@(%O3,gbr)"          "\n"
+        "0:    mov.<bwl>       @%1,%0"         "\n"
+        "      mov     #0,r0"                  "\n"
+        "      mov.<bwl>       %2,@%1"         "\n"
+        "1:    mov.l   r0,@(%O3,gbr)";
+}
+  [(set_attr "length" "16")])
+
+(define_insn "atomic_exchange<mode>_soft_imask"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&z")
+       (mem:QIHISI (match_operand:SI 1 "register_operand" "r")))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(match_operand:QIHISI 2 "register_operand" "r")] UNSPEC_ATOMIC))
+   (clobber (match_scratch:SI 3 "=&r"))]
+  "TARGET_ATOMIC_SOFT_IMASK"
+{
+  return "\r   stc     sr,%0"                  "\n"
+        "      mov     %0,%3"                  "\n"
+        "      or      #0xF0,%0"               "\n"
+        "      ldc     %0,sr"                  "\n"
+        "      mov.<bwl>       @%1,%0"         "\n"
+        "      mov.<bwl>       %2,@%1"         "\n"
+        "      ldc     %3,sr";
+}
+  [(set_attr "length" "14")])
+
 ;;------------------------------------------------------------------------------
 ;; read - add|sub|or|and|xor|nand - write - return old value
 
             (match_operand:QIHISI 2 "<fetchop_predicate>" ""))]
          UNSPEC_ATOMIC))
    (match_operand:SI 3 "const_int_operand" "")]
-  "TARGET_ANY_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_ANY"
 {
   rtx addr = force_reg (Pmode, XEXP (operands[1], 0));
   rtx atomic_insn;
 
-  if (TARGET_HARD_ATOMIC || (TARGET_SH4A_ARCH && <MODE>mode == SImode))
+  if (TARGET_ATOMIC_HARD_LLCS
+      || (TARGET_SH4A_ARCH && <MODE>mode == SImode && !TARGET_ATOMIC_STRICT))
     atomic_insn = gen_atomic_fetch_<fetchop_name><mode>_hard (operands[0], addr,
                                                              operands[2]);
+  else if (TARGET_ATOMIC_SOFT_GUSA)
+    atomic_insn = gen_atomic_fetch_<fetchop_name><mode>_soft_gusa (operands[0],
+                     addr, operands[2]);
+  else if (TARGET_ATOMIC_SOFT_TCB)
+    atomic_insn = gen_atomic_fetch_<fetchop_name><mode>_soft_tcb (operands[0],
+                     addr, operands[2], TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX);
+  else if (TARGET_ATOMIC_SOFT_IMASK)
+    atomic_insn = gen_atomic_fetch_<fetchop_name><mode>_soft_imask (operands[0],
+                     addr, operands[2]);
   else
-    atomic_insn = gen_atomic_fetch_<fetchop_name><mode>_soft (operands[0],
-                                                             addr,
-                                                             operands[2]);
+    FAIL;
+
   emit_insn (atomic_insn);
 
   if (<MODE>mode == QImode)
             (match_operand:SI 2 "<fetchop_predicate>" "<fetchop_constraint>"))]
          UNSPEC_ATOMIC))
    (clobber (reg:SI R0_REG))]
-  "TARGET_ANY_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS
+   || (TARGET_SH4A_ARCH && TARGET_ATOMIC_ANY && !TARGET_ATOMIC_STRICT)"
 {
   return "\r0: movli.l @%1,r0"         "\n"
         "      mov     r0,%0"          "\n"
    (clobber (reg:SI R0_REG))
    (clobber (match_scratch:SI 3 "=&r"))
    (clobber (match_scratch:SI 4 "=1"))]
-  "TARGET_HARD_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS"
 {
   return "\r   mov     #-4,%3"                 "\n"
         "      and     %1,%3"                  "\n"
 }
   [(set_attr "length" "28")])
 
-(define_insn "atomic_fetch_<fetchop_name><mode>_soft"
+(define_insn "atomic_fetch_<fetchop_name><mode>_soft_gusa"
   [(set (match_operand:QIHISI 0 "register_operand" "=&u")
        (mem:QIHISI (match_operand:SI 1 "register_operand" "u")))
    (set (mem:QIHISI (match_dup 1))
    (clobber (match_scratch:QIHISI 3 "=&u"))
    (clobber (reg:SI R0_REG))
    (clobber (reg:SI R1_REG))]
-  "TARGET_SOFT_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_SOFT_GUSA"
 {
   return "\r   mova    1f,r0"                  "\n"
         "      .align 2"                       "\n"
 }
   [(set_attr "length" "18")])
 
+(define_insn "atomic_fetch_<fetchop_name><mode>_soft_tcb"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&r")
+       (mem:QIHISI (match_operand:SI 1 "register_operand" "r")))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(FETCHOP:QIHISI (mem:QIHISI (match_dup 1))
+            (match_operand:QIHISI 2 "register_operand" "r"))]
+         UNSPEC_ATOMIC))
+   (use (match_operand:SI 3 "gbr_displacement"))
+   (clobber (match_scratch:QIHISI 4 "=&r"))
+   (clobber (reg:SI R0_REG))
+   (clobber (reg:SI R1_REG))]
+  "TARGET_ATOMIC_SOFT_TCB"
+{
+  return "\r   mova    1f,r0"                  "\n"
+        "      mov     #(0f-1f),r1"            "\n"
+        "      .align 2"                       "\n"
+        "      mov.l   r0,@(%O3,gbr)"          "\n"
+        "0:    mov.<bwl>       @%1,%0"         "\n"
+        "      mov     #0,r0"                  "\n"
+        "      mov     %0,%4"                  "\n"
+        "      <fetchop_name>  %2,%4"          "\n"
+        "      mov.<bwl>       %4,@%1"         "\n"
+        "1:    mov.l   r0,@(%O3,gbr)";
+}
+  [(set_attr "length" "20")])
+
+(define_insn "atomic_fetch_<fetchop_name><mode>_soft_imask"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&z")
+       (mem:QIHISI (match_operand:SI 1 "register_operand" "r")))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(FETCHOP:QIHISI (mem:QIHISI (match_dup 1))
+            (match_operand:QIHISI 2 "register_operand" "r"))]
+         UNSPEC_ATOMIC))
+   (clobber (match_scratch:QIHISI 3 "=&r"))
+   (clobber (match_scratch:SI 4 "=&r"))]
+  "TARGET_ATOMIC_SOFT_IMASK"
+{
+  return "\r   stc     sr,%0"                  "\n"
+        "      mov     %0,%4"                  "\n"
+        "      or      #0xF0,%0"               "\n"
+        "      ldc     %0,sr"                  "\n"
+        "      mov.<bwl>       @%1,%0"         "\n"
+        "      mov     %0,%3"                  "\n"
+        "      <fetchop_name>  %2,%3"          "\n"
+        "      mov.<bwl>       %3,@%1"         "\n"
+        "      ldc     %4,sr";
+}
+  [(set_attr "length" "18")])
+
 (define_expand "atomic_fetch_nand<mode>"
   [(set (match_operand:QIHISI 0 "register_operand" "")
        (match_operand:QIHISI 1 "memory_operand" ""))
                       (match_operand:QIHISI 2 "atomic_logical_operand" "")))]
          UNSPEC_ATOMIC))
    (match_operand:SI 3 "const_int_operand" "")]
-  "TARGET_ANY_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_ANY"
 {
   rtx addr = force_reg (Pmode, XEXP (operands[1], 0));
   rtx atomic_insn;
 
-  if (TARGET_HARD_ATOMIC || (TARGET_SH4A_ARCH && <MODE>mode == SImode))
+  if (TARGET_ATOMIC_HARD_LLCS
+      || (TARGET_SH4A_ARCH && <MODE>mode == SImode && !TARGET_ATOMIC_STRICT))
     atomic_insn = gen_atomic_fetch_nand<mode>_hard (operands[0], addr,
                                                    operands[2]);
+  else if (TARGET_ATOMIC_SOFT_GUSA)
+    atomic_insn = gen_atomic_fetch_nand<mode>_soft_gusa (operands[0], addr,
+                                                        operands[2]);
+  else if (TARGET_ATOMIC_SOFT_TCB)
+    atomic_insn = gen_atomic_fetch_nand<mode>_soft_tcb (operands[0], addr,
+                     operands[2], TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX);
+  else if (TARGET_ATOMIC_SOFT_IMASK)
+    atomic_insn = gen_atomic_fetch_nand<mode>_soft_imask (operands[0], addr,
+                                                         operands[2]);
   else
-    atomic_insn = gen_atomic_fetch_nand<mode>_soft (operands[0], addr,
-                                                   operands[2]);
+    FAIL;
 
   emit_insn (atomic_insn);
 
                   (match_operand:SI 2 "logical_operand" "rK08")))]
          UNSPEC_ATOMIC))
    (clobber (reg:SI R0_REG))]
-  "TARGET_ANY_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS
+   || (TARGET_SH4A_ARCH && TARGET_ATOMIC_ANY && !TARGET_ATOMIC_STRICT)"
 {
   return "\r0: movli.l @%1,r0"         "\n"
         "      mov     r0,%0"          "\n"
    (clobber (reg:SI R0_REG))
    (clobber (match_scratch:SI 3 "=&r"))
    (clobber (match_scratch:SI 4 "=1"))]
-  "TARGET_HARD_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS"
 {
   return "\r   mov     #-4,%3"                 "\n"
         "      and     %1,%3"                  "\n"
 }
   [(set_attr "length" "30")])
 
-(define_insn "atomic_fetch_nand<mode>_soft"
+(define_insn "atomic_fetch_nand<mode>_soft_gusa"
   [(set (match_operand:QIHISI 0 "register_operand" "=&u")
        (mem:QIHISI (match_operand:SI 1 "register_operand" "u")))
    (set (mem:QIHISI (match_dup 1))
    (clobber (match_scratch:QIHISI 3 "=&u"))
    (clobber (reg:SI R0_REG))
    (clobber (reg:SI R1_REG))]
-  "TARGET_SOFT_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_SOFT_GUSA"
 {
   return "\r   mova    1f,r0"                  "\n"
         "      mov     r15,r1"                 "\n"
 }
   [(set_attr "length" "20")])
 
+(define_insn "atomic_fetch_nand<mode>_soft_tcb"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&r")
+       (mem:QIHISI (match_operand:SI 1 "register_operand" "r")))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(not:QIHISI (and:QIHISI (mem:QIHISI (match_dup 1))
+            (match_operand:QIHISI 2 "register_operand" "r")))]
+         UNSPEC_ATOMIC))
+   (use (match_operand:SI 3 "gbr_displacement"))
+   (clobber (match_scratch:QIHISI 4 "=&r"))
+   (clobber (reg:SI R0_REG))
+   (clobber (reg:SI R1_REG))]
+  "TARGET_ATOMIC_SOFT_TCB"
+{
+  return "\r   mova    1f,r0"                  "\n"
+        "      .align 2"                       "\n"
+        "      mov     #(0f-1f),r1"            "\n"
+        "      mov.l   r0,@(%O3,gbr)"          "\n"
+        "0:    mov.<bwl>       @%1,%0"         "\n"
+        "      mov     #0,r0"                  "\n"
+        "      mov     %2,%4"                  "\n"
+        "      and     %0,%4"                  "\n"
+        "      not     %4,%4"                  "\n"
+        "      mov.<bwl>       %4,@%1"         "\n"
+        "1:    mov.l   r0,@(%O3,gbr)";
+}
+  [(set_attr "length" "22")])
+
+(define_insn "atomic_fetch_nand<mode>_soft_imask"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&z")
+       (mem:QIHISI (match_operand:SI 1 "register_operand" "r")))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(not:QIHISI (and:QIHISI (mem:QIHISI (match_dup 1))
+            (match_operand:QIHISI 2 "register_operand" "r")))]
+         UNSPEC_ATOMIC))
+   (clobber (match_scratch:QIHISI 3 "=&r"))
+   (clobber (match_scratch:SI 4 "=&r"))]
+  "TARGET_ATOMIC_SOFT_IMASK"
+{
+  return "\r   stc     sr,%0"                  "\n"
+        "      mov     %0,%4"                  "\n"
+        "      or      #0xF0,%0"               "\n"
+        "      ldc     %0,sr"                  "\n"
+        "      mov.<bwl>       @%1,%0"         "\n"
+        "      mov     %2,%3"                  "\n"
+        "      and     %0,%3"                  "\n"
+        "      not     %3,%3"                  "\n"
+        "      mov.<bwl>       %3,@%1"         "\n"
+        "      stc     %4,sr";
+}
+  [(set_attr "length" "20")])
+
 ;;------------------------------------------------------------------------------
 ;; read - add|sub|or|and|xor|nand - write - return new value
 
          [(FETCHOP:QIHISI (match_dup 1) (match_dup 2))]
          UNSPEC_ATOMIC))
    (match_operand:SI 3 "const_int_operand" "")]
-  "TARGET_ANY_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_ANY"
 {
   rtx addr = force_reg (Pmode, XEXP (operands[1], 0));
   rtx atomic_insn;
 
-  if (TARGET_HARD_ATOMIC || (TARGET_SH4A_ARCH && <MODE>mode == SImode))
+  if (TARGET_ATOMIC_HARD_LLCS
+      || (TARGET_SH4A_ARCH && <MODE>mode == SImode && !TARGET_ATOMIC_STRICT))
     atomic_insn = gen_atomic_<fetchop_name>_fetch<mode>_hard (operands[0], addr,
                                                              operands[2]);
+  else if (TARGET_ATOMIC_SOFT_GUSA)
+    atomic_insn = gen_atomic_<fetchop_name>_fetch<mode>_soft_gusa (operands[0],
+                     addr, operands[2]);
+  else if (TARGET_ATOMIC_SOFT_TCB)
+    atomic_insn = gen_atomic_<fetchop_name>_fetch<mode>_soft_tcb (operands[0],
+                     addr, operands[2], TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX);
+  else if (TARGET_ATOMIC_SOFT_IMASK)
+    atomic_insn = gen_atomic_<fetchop_name>_fetch<mode>_soft_imask (operands[0],
+                     addr, operands[2]);
   else
-    atomic_insn = gen_atomic_<fetchop_name>_fetch<mode>_soft (operands[0], addr,
-                                                             operands[2]);
+    FAIL;
+
   emit_insn (atomic_insn);
 
   if (<MODE>mode == QImode)
        (unspec:SI
          [(FETCHOP:SI (mem:SI (match_dup 1)) (match_dup 2))]
          UNSPEC_ATOMIC))]
-  "TARGET_ANY_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS
+   || (TARGET_SH4A_ARCH && TARGET_ATOMIC_ANY && !TARGET_ATOMIC_STRICT)"
 {
   return "\r0: movli.l @%1,%0"         "\n"
         "      <fetchop_name>  %2,%0"  "\n"
        (unspec:QIHI
          [(FETCHOP:QIHI (mem:QIHI (match_dup 1)) (match_dup 2))]
          UNSPEC_ATOMIC))
-
    (clobber (reg:SI R0_REG))
    (clobber (match_scratch:SI 3 "=&r"))
    (clobber (match_scratch:SI 4 "=1"))]
-  "TARGET_HARD_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS"
 {
   return "\r   mov     #-4,%3"                 "\n"
         "      and     %1,%3"                  "\n"
 }
   [(set_attr "length" "28")])
 
-(define_insn "atomic_<fetchop_name>_fetch<mode>_soft"
+(define_insn "atomic_<fetchop_name>_fetch<mode>_soft_gusa"
   [(set (match_operand:QIHISI 0 "register_operand" "=&u")
        (FETCHOP:QIHISI
          (mem:QIHISI (match_operand:SI 1 "register_operand" "u"))
          UNSPEC_ATOMIC))
    (clobber (reg:SI R0_REG))
    (clobber (reg:SI R1_REG))]
-  "TARGET_SOFT_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_SOFT_GUSA"
 {
   return "\r   mova    1f,r0"                  "\n"
         "      mov     r15,r1"                 "\n"
 }
   [(set_attr "length" "16")])
 
+(define_insn "atomic_<fetchop_name>_fetch<mode>_soft_tcb"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&r")
+       (FETCHOP:QIHISI
+         (mem:QIHISI (match_operand:SI 1 "register_operand" "r"))
+         (match_operand:QIHISI 2 "register_operand" "r")))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(FETCHOP:QIHISI (mem:QIHISI (match_dup 1)) (match_dup 2))]
+         UNSPEC_ATOMIC))
+   (clobber (reg:SI R0_REG))
+   (clobber (reg:SI R1_REG))
+   (use (match_operand:SI 3 "gbr_displacement"))]
+  "TARGET_ATOMIC_SOFT_TCB"
+{
+  return "\r   mova    1f,r0"                  "\n"
+        "      .align 2"                       "\n"
+        "      mov     #(0f-1f),r1"            "\n"
+        "      mov.l   r0,@(%O3,gbr)"          "\n"
+        "0:    mov.<bwl>       @%1,%0"         "\n"
+        "      mov     #0,r0"                  "\n"
+        "      <fetchop_name>  %2,%0"          "\n"
+        "      mov.<bwl>       %0,@%1"         "\n"
+        "1:    mov.l   r0,@(%O3,gbr)";
+}
+  [(set_attr "length" "18")])
+
+(define_insn "atomic_<fetchop_name>_fetch<mode>_soft_imask"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&z")
+       (FETCHOP:QIHISI
+         (mem:QIHISI (match_operand:SI 1 "register_operand" "r"))
+         (match_operand:QIHISI 2 "register_operand" "r")))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(FETCHOP:QIHISI (mem:QIHISI (match_dup 1)) (match_dup 2))]
+         UNSPEC_ATOMIC))
+   (clobber (match_scratch:SI 3 "=&r"))]
+  "TARGET_ATOMIC_SOFT_IMASK"
+{
+  return "\r   stc     sr,%0"                  "\n"
+        "      mov     %0,%3"                  "\n"
+        "      or      #0xF0,%0"               "\n"
+        "      ldc     %0,sr"                  "\n"
+        "      mov.<bwl>       @%1,%0"         "\n"
+        "      <fetchop_name>  %2,%0"          "\n"
+        "      mov.<bwl>       %0,@%1"         "\n"
+        "      ldc     %3,sr";
+}
+  [(set_attr "length" "16")])
+
 (define_expand "atomic_nand_fetch<mode>"
   [(set (match_operand:QIHISI 0 "register_operand" "")
        (not:QIHISI (and:QIHISI
          [(not:QIHISI (and:QIHISI (match_dup 1) (match_dup 2)))]
          UNSPEC_ATOMIC))
    (match_operand:SI 3 "const_int_operand" "")]
-  "TARGET_ANY_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_ANY"
 {
   rtx addr = force_reg (Pmode, XEXP (operands[1], 0));
   rtx atomic_insn;
 
-  if (TARGET_HARD_ATOMIC || (TARGET_SH4A_ARCH && <MODE>mode == SImode))
+  if (TARGET_ATOMIC_HARD_LLCS
+      || (TARGET_SH4A_ARCH && <MODE>mode == SImode && !TARGET_ATOMIC_STRICT))
     atomic_insn = gen_atomic_nand_fetch<mode>_hard (operands[0], addr,
                                                    operands[2]);
+  else if (TARGET_ATOMIC_SOFT_GUSA)
+    atomic_insn = gen_atomic_nand_fetch<mode>_soft_gusa (operands[0], addr,
+                                                        operands[2]);
+  else if (TARGET_ATOMIC_SOFT_TCB)
+    atomic_insn = gen_atomic_nand_fetch<mode>_soft_tcb (operands[0], addr,
+                     operands[2], TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX);
+  else if (TARGET_ATOMIC_SOFT_IMASK)
+    atomic_insn = gen_atomic_nand_fetch<mode>_soft_imask (operands[0], addr,
+                                                         operands[2]);
   else
-    atomic_insn = gen_atomic_nand_fetch<mode>_soft (operands[0], addr,
-                                                   operands[2]);
+    FAIL;
+
   emit_insn (atomic_insn);
 
   if (<MODE>mode == QImode)
        (unspec:SI
          [(not:SI (and:SI (mem:SI (match_dup 1)) (match_dup 2)))]
          UNSPEC_ATOMIC))]
-  "TARGET_ANY_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS
+   || (TARGET_SH4A_ARCH && TARGET_ATOMIC_ANY && !TARGET_ATOMIC_STRICT)"
 {
   return "\r0: movli.l @%1,%0"         "\n"
         "      and     %2,%0"          "\n"
    (clobber (reg:SI R0_REG))
    (clobber (match_scratch:SI 3 "=&r"))
    (clobber (match_scratch:SI 4 "=1"))]
-  "TARGET_HARD_ATOMIC && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS"
 {
   return "\r   mov     #-4,%3"                 "\n"
         "      and     %1,%3"                  "\n"
 }
   [(set_attr "length" "28")])
 
-(define_insn "atomic_nand_fetch<mode>_soft"
+(define_insn "atomic_nand_fetch<mode>_soft_gusa"
   [(set (match_operand:QIHISI 0 "register_operand" "=&u")
        (not:QIHISI (and:QIHISI
          (mem:QIHISI (match_operand:SI 1 "register_operand" "u"))
          UNSPEC_ATOMIC))
    (clobber (reg:SI R0_REG))
    (clobber (reg:SI R1_REG))]
-  "TARGET_SOFT_ATOMIC && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_SOFT_GUSA"
 {
   return "\r   mova    1f,r0"                  "\n"
         "      .align 2"                       "\n"
 }
   [(set_attr "length" "18")])
 
+(define_insn "atomic_nand_fetch<mode>_soft_tcb"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&r")
+       (not:QIHISI (and:QIHISI
+         (mem:QIHISI (match_operand:SI 1 "register_operand" "r"))
+         (match_operand:QIHISI 2 "register_operand" "r"))))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(not:QIHISI (and:QIHISI (mem:QIHISI (match_dup 1)) (match_dup 2)))]
+         UNSPEC_ATOMIC))
+   (clobber (reg:SI R0_REG))
+   (clobber (reg:SI R1_REG))
+   (use (match_operand:SI 3 "gbr_displacement"))]
+  "TARGET_ATOMIC_SOFT_TCB"
+{
+  return "\r   mova    1f,r0"                  "\n"
+        "      mov     #(0f-1f),r1"            "\n"
+        "      .align 2"                       "\n"
+        "      mov.l   r0,@(%O3,gbr)"          "\n"
+        "0:    mov.<bwl>       @%1,%0"         "\n"
+        "      mov     #0,r0"                  "\n"
+        "      and     %2,%0"                  "\n"
+        "      not     %0,%0"                  "\n"
+        "      mov.<bwl>       %0,@%1"         "\n"
+        "1:    mov.l   r0,@(%O3,gbr)";
+}
+  [(set_attr "length" "20")])
+
+(define_insn "atomic_nand_fetch<mode>_soft_imask"
+  [(set (match_operand:QIHISI 0 "register_operand" "=&z")
+       (not:QIHISI (and:QIHISI
+         (mem:QIHISI (match_operand:SI 1 "register_operand" "r"))
+         (match_operand:QIHISI 2 "register_operand" "r"))))
+   (set (mem:QIHISI (match_dup 1))
+       (unspec:QIHISI
+         [(not:QIHISI (and:QIHISI (mem:QIHISI (match_dup 1)) (match_dup 2)))]
+         UNSPEC_ATOMIC))
+   (clobber (match_scratch:SI 3 "=&r"))]
+  "TARGET_ATOMIC_SOFT_IMASK"
+{
+  return "\r   stc     sr,%0"                  "\n"
+        "      mov     %0,%3"                  "\n"
+        "      or      #0xF0,%0"               "\n"
+        "      ldc     %0,sr"                  "\n"
+        "      mov.<bwl>       @%1,%0"         "\n"
+        "      and     %2,%0"                  "\n"
+        "      not     %0,%0"                  "\n"
+        "      mov.<bwl>       %0,@%1"         "\n"
+        "      ldc     %3,sr";
+}
+  [(set_attr "length" "18")])
+
 ;;------------------------------------------------------------------------------
 ;; read - test against zero - or with 0x80 - write - return test result
 
   [(match_operand:SI 0 "register_operand" "")          ;; bool result output
    (match_operand:QI 1 "memory_operand" "")            ;; memory
    (match_operand:SI 2 "const_int_operand" "")]                ;; model
-  "(TARGET_ANY_ATOMIC || TARGET_ENABLE_TAS) && !TARGET_SHMEDIA"
+  "(TARGET_ATOMIC_ANY || TARGET_ENABLE_TAS) && !TARGET_SHMEDIA"
 {
   rtx addr = force_reg (Pmode, XEXP (operands[1], 0));
 
       rtx val = gen_int_mode (targetm.atomic_test_and_set_trueval, QImode);
       val = force_reg (QImode, val);
 
-      if (TARGET_HARD_ATOMIC)
+      if (TARGET_ATOMIC_HARD_LLCS)
          emit_insn (gen_atomic_test_and_set_hard (addr, val));
+      else if (TARGET_ATOMIC_SOFT_GUSA)
+         emit_insn (gen_atomic_test_and_set_soft_gusa (addr, val));
+      else if (TARGET_ATOMIC_SOFT_TCB)
+         emit_insn (gen_atomic_test_and_set_soft_tcb (addr, val,
+                        TARGET_ATOMIC_SOFT_TCB_GBR_OFFSET_RTX));
+      else if (TARGET_ATOMIC_SOFT_IMASK)
+         emit_insn (gen_atomic_test_and_set_soft_imask (addr, val));
       else
-         emit_insn (gen_atomic_test_and_set_soft (addr, val));
+       FAIL;
     }
 
   /* The result of the test op is the inverse of what we are
   "tas.b       @%0"
   [(set_attr "insn_class" "co_group")])
 
-(define_insn "atomic_test_and_set_soft"
+(define_insn "atomic_test_and_set_soft_gusa"
   [(set (reg:SI T_REG)
        (eq:SI (mem:QI (match_operand:SI 0 "register_operand" "u"))
               (const_int 0)))
    (clobber (match_scratch:QI 2 "=&u"))
    (clobber (reg:SI R0_REG))
    (clobber (reg:SI R1_REG))]
-  "TARGET_SOFT_ATOMIC && !TARGET_ENABLE_TAS && !TARGET_SHMEDIA"
+  "TARGET_ATOMIC_SOFT_GUSA && !TARGET_ENABLE_TAS"
 {
   return "\r   mova    1f,r0"          "\n"
         "      .align 2"               "\n"
 }
   [(set_attr "length" "16")])
 
+(define_insn "atomic_test_and_set_soft_tcb"
+  [(set (reg:SI T_REG)
+       (eq:SI (mem:QI (match_operand:SI 0 "register_operand" "r"))
+              (const_int 0)))
+   (set (mem:QI (match_dup 0))
+       (unspec:QI [(match_operand:QI 1 "register_operand" "r")] UNSPEC_ATOMIC))
+   (use (match_operand:SI 2 "gbr_displacement"))
+   (clobber (match_scratch:QI 3 "=&r"))
+   (clobber (reg:SI R0_REG))
+   (clobber (reg:SI R1_REG))]
+  "TARGET_ATOMIC_SOFT_TCB && !TARGET_ENABLE_TAS"
+{
+  return "\r   mova    1f,r0"          "\n"
+        "      mov     #(0f-1f),r1"    "\n"
+        "      .align 2"               "\n"
+        "      mov.l   r0,@(%O2,gbr)"  "\n"
+        "0:    mov.b   @%0,%3"         "\n"
+        "      mov     #0,r0"          "\n"
+        "      mov.b   %1,@%0"         "\n"
+        "1:    mov.l   r0,@(%O2,gbr)"  "\n"
+        "      tst     %3,%3";
+}
+  [(set_attr "length" "18")])
+
+(define_insn "atomic_test_and_set_soft_imask"
+  [(set (reg:SI T_REG)
+       (eq:SI (mem:QI (match_operand:SI 0 "register_operand" "r"))
+              (const_int 0)))
+   (set (mem:QI (match_dup 0))
+       (unspec:QI [(match_operand:QI 1 "register_operand" "r")] UNSPEC_ATOMIC))
+   (clobber (match_scratch:SI 2 "=&r"))
+   (clobber (reg:SI R0_REG))]
+  "TARGET_ATOMIC_SOFT_IMASK && !TARGET_ENABLE_TAS"
+{
+  return "\r   stc     sr,r0"          "\n"
+        "      mov     r0,%2"          "\n"
+        "      or      #0xF0,r0"       "\n"
+        "      ldc     r0,sr"          "\n"
+        "      mov.b   @%0,r0"         "\n"
+        "      mov.b   %1,@%0"         "\n"
+        "      stc     %2,sr"          "\n"
+        "      tst     r0,r0";
+}
+  [(set_attr "length" "16")])
+
 (define_insn "atomic_test_and_set_hard"
   [(set (reg:SI T_REG)
        (eq:SI (mem:QI (match_operand:SI 0 "register_operand" "r"))
    (clobber (match_scratch:SI 2 "=&r"))
    (clobber (match_scratch:SI 3 "=&r"))
    (clobber (match_scratch:SI 4 "=0"))]
-  "TARGET_HARD_ATOMIC && !TARGET_ENABLE_TAS && TARGET_SH4A_ARCH"
+  "TARGET_ATOMIC_HARD_LLCS && !TARGET_ENABLE_TAS"
 {
   return "\r   mov     #-4,%2"         "\n"
         "      and     %0,%2"          "\n"
index 205faa7015e09a1fe1df467708ae630c6de2fe18..7578ddac93b1ea6bb09d38b433997710db61ad77 100644 (file)
@@ -893,7 +893,8 @@ See RS/6000 and PowerPC Options.
 -mspace -mprefergot  -musermode -multcost=@var{number} -mdiv=@var{strategy} @gol
 -mdivsi3_libfunc=@var{name} -mfixed-range=@var{register-range} @gol
 -mindexed-addressing -mgettrcost=@var{number} -mpt-fixed @gol
--maccumulate-outgoing-args -minvalid-symbols -msoft-atomic -mhard-atomic @gol
+-maccumulate-outgoing-args -minvalid-symbols @gol
+-matomic-model=@var{atomic-model} @gol
 -mbranch-cost=@var{num} -mzdcbranch -mno-zdcbranch -mcbranchdi -mcmpeqdi @gol
 -mfused-madd -mno-fused-madd -mfsca -mno-fsca -mfsrra -mno-fsrra @gol
 -mpretend-cmove -mtas}
@@ -18297,26 +18298,67 @@ Dump instruction size and location in the assembly code.
 This option is deprecated.  It pads structures to multiple of 4 bytes,
 which is incompatible with the SH ABI@.
 
-@item -msoft-atomic
-@opindex msoft-atomic
+@item -matomic-model=@var{model}
+@opindex matomic-model=@var{model}
+Sets the model of atomic operations and additional parameters as a comma
+separated list.  For details on the atomic built-in functions see
+@ref{__atomic Builtins}.  The following models and parameters are supported:
+
+@table @samp
+
+@item none
+Disable compiler generated atomic sequences and emit library calls for atomic
+operations.  This is the default if the target is not @code{sh-*-linux*}.
+
+@item soft-gusa
 Generate GNU/Linux compatible gUSA software atomic sequences for the atomic
-built-in functions.  The generated atomic sequences require support from the 
-interrupt / exception handling code of the system and are only suitable for
-single-core systems.  They will not operate correctly on multi-core systems.
-This option is enabled by default when the target is @code{sh-*-linux*}.
-When the target is SH4A, this option will also partially utilize the hardware
-atomic instructions @code{movli.l} and @code{movco.l} to create more
-efficient code.
-For details on the atomic built-in functions see @ref{__atomic Builtins}.
-
-@item -mhard-atomic
-@opindex hard-atomic
-Generate hardware atomic sequences for the atomic built-in functions.  This
-is only available on SH4A and is suitable for multi-core systems.  Code
-compiled with this option will also be compatible with gUSA aware
-interrupt / exception handling systems.  In contrast to the
-@option{-msoft-atomic} option this will only use the instructions
-@code{movli.l} and @code{movco.l} to create atomic sequences.
+built-in functions.  The generated atomic sequences require additional support
+from the interrupt/exception handling code of the system and are only suitable
+for SH3* and SH4* single-core systems.  This option is enabled by default when
+the target is @code{sh-*-linux*} and SH3* or SH4*.  When the target is SH4A,
+this option will also partially utilize the hardware atomic instructions
+@code{movli.l} and @code{movco.l} to create more efficient code, unless
+@samp{strict} is specified.  
+
+@item soft-tcb
+Generate software atomic sequences that use a variable in the thread control
+block.  This is a variation of the gUSA sequences which can also be used on
+SH1* and SH2* targets.  The generated atomic sequences require additional
+support from the interrupt/exception handling code of the system and are only
+suitable for single-core systems.  When using this model, the @samp{gbr-offset=}
+parameter has to be specified as well.
+
+@item soft-imask
+Generate software atomic sequences that temporarily disable interrupts by
+setting @code{SR.IMASK = 1111}.  This model works only when the program runs
+in privileged mode and is only suitable for single-core systems.  Additional
+support from the interrupt/exception handling code of the system is not
+required.  This model is enabled by default when the target is
+@code{sh-*-linux*} and SH1* or SH2*.
+
+@item hard-llcs
+Generate hardware atomic sequences using the @code{movli.l} and @code{movco.l}
+instructions only.  This is only available on SH4A and is suitable for
+multi-core systems.  Since the hardware instructions support only 32 bit atomic
+variables access to 8 or 16 bit variables is emulated with 32 bit accesses.
+Code compiled with this option will also be compatible with other software
+atomic model interrupt/exception handling systems if executed on an SH4A
+system.  Additional support from the interrupt/exception handling code of the
+system is not required for this model.
+
+@item gbr-offset=
+This parameter specifies the offset in bytes of the variable in the thread
+control block structure that should be used by the generated atomic sequences
+when the @samp{soft-tcb} model has been selected.  For other models this
+parameter is ignored.  The specified value must be an integer multiple of four
+and in the range 0-1020.
+
+@item strict
+This parameter prevents mixed usage of multiple atomic models, even though they
+would be compatible, and will make the compiler generate atomic sequences of the
+specified model only.
+
+@end table
 
 @item -mtas
 @opindex mtas