[ARM] Optional -mthumb for Thumb only targets

2016-11-18  Terry Guo  <terry.guo@arm.com>
            Thomas Preud'homme  <thomas.preudhomme@arm.com>

    gcc/
    * common/config/arm/arm-common.c (arm_target_thumb_only): New function.
    * config/arm/arm-opts.h: Include arm-flags.h.
    (struct arm_arch_core_flag): Define.
    (arm_arch_core_flags): Define.
    * config/arm/arm-protos.h: Include arm-flags.h
    (FL_NONE, FL_ANY, FL_CO_PROC, FL_ARCH3M, FL_MODE26, FL_MODE32,
    FL_ARCH4, FL_ARCH5, FL_THUMB, FL_LDSCHED, FL_STRONG, FL_ARCH5E,
    FL_XSCALE, FL_ARCH6, FL_VFPV2, FL_WBUF, FL_ARCH6K, FL_THUMB2, FL_NOTM,
    FL_THUMB_DIV, FL_VFPV3, FL_NEON, FL_ARCH7EM, FL_ARCH7, FL_ARM_DIV,
    FL_ARCH8, FL_CRC32, FL_SMALLMUL, FL_NO_VOLATILE_CE, FL_IWMMXT,
    FL_IWMMXT2, FL_ARCH6KZ, FL2_ARCH8_1, FL2_ARCH8_2, FL2_FP16INST,
    FL_TUNE, FL_FOR_ARCH2, FL_FOR_ARCH3, FL_FOR_ARCH3M, FL_FOR_ARCH4,
    FL_FOR_ARCH4T, FL_FOR_ARCH5, FL_FOR_ARCH5T, FL_FOR_ARCH5E,
    FL_FOR_ARCH5TE, FL_FOR_ARCH5TEJ, FL_FOR_ARCH6, FL_FOR_ARCH6J,
    FL_FOR_ARCH6K, FL_FOR_ARCH6Z, FL_FOR_ARCH6ZK, FL_FOR_ARCH6KZ,
    FL_FOR_ARCH6T2, FL_FOR_ARCH6M, FL_FOR_ARCH7, FL_FOR_ARCH7A,
    FL_FOR_ARCH7VE, FL_FOR_ARCH7R, FL_FOR_ARCH7M, FL_FOR_ARCH7EM,
    FL_FOR_ARCH8A, FL2_FOR_ARCH8_1A, FL2_FOR_ARCH8_2A, FL_FOR_ARCH8M_BASE,
    FL_FOR_ARCH8M_MAIN, arm_feature_set, ARM_FSET_MAKE,
    ARM_FSET_MAKE_CPU1, ARM_FSET_MAKE_CPU2, ARM_FSET_CPU1, ARM_FSET_CPU2,
    ARM_FSET_EMPTY, ARM_FSET_ANY, ARM_FSET_HAS_CPU1, ARM_FSET_HAS_CPU2,
    ARM_FSET_HAS_CPU, ARM_FSET_ADD_CPU1, ARM_FSET_ADD_CPU2,
    ARM_FSET_DEL_CPU1, ARM_FSET_DEL_CPU2, ARM_FSET_UNION, ARM_FSET_INTER,
    ARM_FSET_XOR, ARM_FSET_EXCLUDE, ARM_FSET_IS_EMPTY,
    ARM_FSET_CPU_SUBSET): Move to ...
    * config/arm/arm-flags.h: This new file.
    * config/arm/arm.h (TARGET_MODE_SPEC_FUNCTIONS): Define.
    (EXTRA_SPEC_FUNCTIONS): Add TARGET_MODE_SPEC_FUNCTIONS to its value.
    (TARGET_MODE_SPECS): Define.
    (DRIVER_SELF_SPECS): Add TARGET_MODE_SPECS to its value.

    gcc/testsuite/
    * gcc.target/arm/optional_thumb-1.c: New test.
    * gcc.target/arm/optional_thumb-2.c: New test.
    * gcc.target/arm/optional_thumb-3.c: New test.

From-SVN: r242597

1 files changed, 23 insertions, 0 deletions

diff --git a/gcc/common/config/arm/arm-common.c b/gcc/common/config/arm/arm-common.c
index f3b674339a5..473417a2e5f 100644
--- a/gcc/common/config/arm/arm-common.c
+++ b/gcc/common/config/arm/arm-common.c
@@ -98,6 +98,29 @@ arm_rewrite_mcpu (int argc, const char **argv)
   return arm_rewrite_selected_cpu (argv[argc - 1]);
 }
 
+/* Called by the driver to check whether the target denoted by current
+   command line options is a Thumb-only target.  ARGV is an array of
+   -march and -mcpu values (ie. it contains the rhs after the equal
+   sign) and we use the last one of them to make a decision.  The
+   number of elements in ARGV is given in ARGC.  */
+const char *
+arm_target_thumb_only (int argc, const char **argv)
+{
+  unsigned int opt;
+
+  if (argc)
+    {
+      for (opt = 0; opt < (ARRAY_SIZE (arm_arch_core_flags)); opt++)
+	if ((strcmp (argv[argc - 1], arm_arch_core_flags[opt].name) == 0)
+	    && !ARM_FSET_HAS_CPU1(arm_arch_core_flags[opt].flags, FL_NOTM))
+	  return "-mthumb";
+
+      return NULL;
+    }
+  else
+    return NULL;
+}
+
 #undef ARM_CPU_NAME_LENGTH