commit 0ff3e01fdc67a3842ee54224cf197e9a55f0a750

Author: Ulrich Weigand <ulrich.weigand@de.ibm.com>

Date:   Tue Feb 4 18:34:19 2014 +0100

    PowerPC64 little-endian fixes: 128-bit DFP parameters / registers

    The powerpc64le-linux ABI specifies that when a 128-bit DFP value is

    passed in a pair of floating-point registers, the first register holds

    the most-significant part of the value.  This is as opposed to the

    usual rule on little-endian systems, where the first register would

    hold the least-significant part.

    This affects two places in GDB, the read/write routines for the

    128-bit DFP pseudo-registers, and the function call / return

    sequence.  For the former, current code already distinguishes

    between big- and little-endian targets, but gets the latter

    wrong.  This is presumably because *GCC* also got it wrong,

    and GDB matches the old GCC behavior.  But GCC is now fixed:

    http://gcc.gnu.org/ml/gcc-patches/2013-11/msg02145.html

    so GDB needs to be fixed too.  (Old code shouldn't really be

    an issue since there is no code "out there" so far that uses

    dfp128 on little-endian ...)

    gdb/ChangeLog:

    	* ppc-sysv-tdep.c (ppc64_sysv_abi_push_freg): Use correct order

    	within a register pair holding a DFP 128-bit value on little-endian.

    	(ppc64_sysv_abi_return_value_base): Likewise.

    	* rs6000-tdep.c (dfp_pseudo_register_read): Likewise.

    	(dfp_pseudo_register_write): Likewise.

    gdb/testsuite/ChangeLog:

    	* gdb.arch/powerpc-d128-regs.exp: Enable on powerpc64*-*.

Index: gdb-7.6.1/gdb/ppc-sysv-tdep.c

===================================================================

--- gdb-7.6.1.orig/gdb/ppc-sysv-tdep.c

+++ gdb-7.6.1/gdb/ppc-sysv-tdep.c

@@ -1269,9 +1269,11 @@ ppc64_sysv_abi_push_freg (struct gdbarch

       if (argpos->regcache && argpos->freg <= 12)

 	{

 	  int regnum = tdep->ppc_fp0_regnum + argpos->freg;

+	  int lopart = gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG ? 8 : 0;

+	  int hipart = gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG ? 0 : 8;

-	  regcache_cooked_write (argpos->regcache, regnum, val);

-	  regcache_cooked_write (argpos->regcache, regnum + 1, val + 8);

+	  regcache_cooked_write (argpos->regcache, regnum, val + hipart);

+	  regcache_cooked_write (argpos->regcache, regnum + 1, val + lopart);

 	}

       argpos->freg += 2;

@@ -1684,16 +1686,18 @@ ppc64_sysv_abi_return_value_base (struct

       && TYPE_CODE (valtype) == TYPE_CODE_DECFLOAT)

     {

       int regnum = tdep->ppc_fp0_regnum + 2 + 2 * index;

+      int lopart = gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG ? 8 : 0;

+      int hipart = gdbarch_byte_order (gdbarch) == BFD_ENDIAN_BIG ? 0 : 8;

       if (writebuf != NULL)

 	{

-	  regcache_cooked_write (regcache, regnum, writebuf);

-	  regcache_cooked_write (regcache, regnum + 1, writebuf + 8);

+	  regcache_cooked_write (regcache, regnum, writebuf + hipart);

+	  regcache_cooked_write (regcache, regnum + 1, writebuf + lopart);

 	}

       if (readbuf != NULL)

 	{

-	  regcache_cooked_read (regcache, regnum, readbuf);

-	  regcache_cooked_read (regcache, regnum + 1, readbuf + 8);

+	  regcache_cooked_read (regcache, regnum, readbuf + hipart);

+	  regcache_cooked_read (regcache, regnum + 1, readbuf + lopart);

 	}

       return 1;

     }

Index: gdb-7.6.1/gdb/rs6000-tdep.c

===================================================================

--- gdb-7.6.1.orig/gdb/rs6000-tdep.c

+++ gdb-7.6.1/gdb/rs6000-tdep.c

@@ -2723,10 +2723,10 @@ dfp_pseudo_register_read (struct gdbarch

   else

     {

       status = regcache_raw_read (regcache, tdep->ppc_fp0_regnum +

-				  2 * reg_index + 1, buffer + 8);

+				  2 * reg_index + 1, buffer);

       if (status == REG_VALID)

 	status = regcache_raw_read (regcache, tdep->ppc_fp0_regnum +

-				    2 * reg_index, buffer);

+				    2 * reg_index, buffer + 8);

     }

   return status;

@@ -2752,9 +2752,9 @@ dfp_pseudo_register_write (struct gdbarc

   else

     {

       regcache_raw_write (regcache, tdep->ppc_fp0_regnum +

-			  2 * reg_index + 1, buffer + 8);

+			  2 * reg_index + 1, buffer);

       regcache_raw_write (regcache, tdep->ppc_fp0_regnum +

-			  2 * reg_index, buffer);

+			  2 * reg_index, buffer + 8);

     }

 }

Index: gdb-7.6.1/gdb/testsuite/gdb.arch/powerpc-d128-regs.exp

===================================================================

--- gdb-7.6.1.orig/gdb/testsuite/gdb.arch/powerpc-d128-regs.exp

+++ gdb-7.6.1/gdb/testsuite/gdb.arch/powerpc-d128-regs.exp

@@ -20,7 +20,7 @@

 # Testcase for ppc decimal128 pseudo-registers.

-if ![istarget "powerpc64-*"] then {

+if ![istarget "powerpc64*-*"] then {

     verbose "Skipping powerpc Decimal128 pseudo-registers testcase."

     return

 }