Initial creation of sourceware repositorygdb-4_18-branchpoint

1 files changed, 564 insertions, 0 deletions

diff --git a/gdb/config/rs6000/tm-rs6000.h b/gdb/config/rs6000/tm-rs6000.h
new file mode 100644
index 0000000..52beec1
--- /dev/null
+++ b/gdb/config/rs6000/tm-rs6000.h
@@ -0,0 +1,564 @@
+/* Parameters for target execution on an RS6000, for GDB, the GNU debugger.
+   Copyright 1986, 1987, 1989, 1991, 1992, 1993, 1994, 1997
+   Free Software Foundation, Inc.
+   Contributed by IBM Corporation.
+
+This file is part of GDB.
+
+This program is free software; you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation; either version 2 of the License, or
+(at your option) any later version.
+
+This program is distributed in the hope that it will be useful,
+but WITHOUT ANY WARRANTY; without even the implied warranty of
+MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+GNU General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program; if not, write to the Free Software
+Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
+
+#ifdef __STDC__		/* Forward decls for prototypes */
+struct frame_info;
+struct type;
+struct value;
+#endif
+
+/* Minimum possible text address in AIX */
+
+#define TEXT_SEGMENT_BASE	0x10000000
+
+/* Load segment of a given pc value. */
+
+#define	PC_LOAD_SEGMENT(PC)	pc_load_segment_name(PC)
+extern char *pc_load_segment_name PARAMS ((CORE_ADDR));
+
+/* AIX cc seems to get this right.  */
+
+#define BELIEVE_PCC_PROMOTION 1
+
+/* return true if a given `pc' value is in `call dummy' function. */
+/* FIXME: This just checks for the end of the stack, which is broken
+   for things like stepping through gcc nested function stubs.  */
+#define	PC_IN_CALL_DUMMY(STOP_PC, STOP_SP, STOP_FRAME_ADDR)	\
+	(STOP_SP < STOP_PC && STOP_PC < STACK_END_ADDR)
+
+#if 0
+extern unsigned int text_start, data_start;
+extern char *corefile;
+#endif
+extern int inferior_pid;
+
+/* We are missing register descriptions in the system header files. Sigh! */
+
+struct regs {
+	int	gregs [32];		/* general purpose registers */
+	int	pc;			/* program conter	*/
+	int	ps;			/* processor status, or machine state */
+};
+
+struct fp_status {
+	double	fpregs [32];		/* floating GP registers */
+};
+
+
+/* To be used by skip_prologue. */
+
+struct rs6000_framedata {
+  int	offset;				/* total size of frame --- the distance
+					   by which we decrement sp to allocate
+					   the frame */
+  int	saved_gpr;			/* smallest # of saved gpr */
+  int	saved_fpr;			/* smallest # of saved fpr */
+  int	alloca_reg;			/* alloca register number (frame ptr) */
+  char	frameless;			/* true if frameless functions. */
+  char	nosavedpc;			/* true if pc not saved. */
+  int	gpr_offset;			/* offset of saved gprs from prev sp */
+  int	fpr_offset;			/* offset of saved fprs from prev sp */
+  int	lr_offset;			/* offset of saved lr */
+  int	cr_offset;			/* offset of saved cr */
+};
+
+/* Define the byte order of the machine.  */
+
+#define TARGET_BYTE_ORDER_DEFAULT	BIG_ENDIAN
+
+/* AIX's assembler doesn't grok dollar signs in identifiers.
+   So we use dots instead.  This item must be coordinated with G++. */
+#undef CPLUS_MARKER
+#define CPLUS_MARKER '.'
+
+/* Offset from address of function to start of its code.
+   Zero on most machines.  */
+
+#define FUNCTION_START_OFFSET 0
+
+/* Advance PC across any function entry prologue instructions
+   to reach some "real" code.  */
+
+#define SKIP_PROLOGUE(pc)						\
+do {									\
+  struct rs6000_framedata _frame;					\
+  pc = skip_prologue (pc, &_frame);					\
+} while (0)
+
+extern CORE_ADDR skip_prologue PARAMS((CORE_ADDR, struct rs6000_framedata *));
+
+
+/* If PC is in some function-call trampoline code, return the PC
+   where the function itself actually starts.  If not, return NULL.  */
+
+#define	SKIP_TRAMPOLINE_CODE(pc)	skip_trampoline_code (pc)
+extern CORE_ADDR skip_trampoline_code PARAMS ((CORE_ADDR));
+
+/* Number of trap signals we need to skip over, once the inferior process
+   starts running. */
+
+#define	START_INFERIOR_TRAPS_EXPECTED	2
+
+/* AIX has a couple of strange returns from wait().  */
+
+#define CHILD_SPECIAL_WAITSTATUS(ourstatus, hoststatus) ( \
+  /* "stop after load" status.  */ \
+  (hoststatus) == 0x57c ? (ourstatus)->kind = TARGET_WAITKIND_LOADED, 1 : \
+  \
+  /* signal 0. I have no idea why wait(2) returns with this status word.  */ \
+  /* It looks harmless. */ \
+  (hoststatus) == 0x7f ? (ourstatus)->kind = TARGET_WAITKIND_SPURIOUS, 1 : \
+  \
+  /* A normal waitstatus.  Let the usual macros deal with it.  */ \
+  0)
+
+/* In xcoff, we cannot process line numbers when we see them. This is
+   mainly because we don't know the boundaries of the include files. So,
+   we postpone that, and then enter and sort(?) the whole line table at
+   once, when we are closing the current symbol table in end_symtab(). */
+
+#define	PROCESS_LINENUMBER_HOOK()	aix_process_linenos ()
+extern void aix_process_linenos PARAMS ((void));
+   
+/* Immediately after a function call, return the saved pc.
+   Can't go through the frames for this because on some machines
+   the new frame is not set up until the new function executes
+   some instructions.  */
+
+#define	SAVED_PC_AFTER_CALL(frame) read_register (LR_REGNUM)
+
+/* Address of end of stack space.  */
+
+#define STACK_END_ADDR 0x2ff80000
+
+/* Stack grows downward.  */
+
+#define INNER_THAN(lhs,rhs) ((lhs) < (rhs))
+
+/* This is how arguments pushed onto stack or passed in registers.
+   Stack must be aligned on 64-bit boundaries when synthesizing
+   function calls.  We don't need STACK_ALIGN, PUSH_ARGUMENTS will
+   handle it. */
+
+#define	PUSH_ARGUMENTS(nargs, args, sp, struct_return, struct_addr) \
+  sp = push_arguments((nargs), (args), (sp), (struct_return), (struct_addr))
+extern CORE_ADDR push_arguments PARAMS ((int, struct value **, CORE_ADDR,
+					 int, CORE_ADDR));
+
+/* BREAKPOINT_FROM_PC uses the program counter value to determine the
+   breakpoint that should be used */
+extern breakpoint_from_pc_fn rs6000_breakpoint_from_pc;
+#define BREAKPOINT_FROM_PC(pcptr, lenptr) rs6000_breakpoint_from_pc (pcptr, lenptr)
+
+/* Amount PC must be decremented by after a breakpoint.
+   This is often the number of bytes in BREAKPOINT
+   but not always.  */
+
+#define DECR_PC_AFTER_BREAK 0
+
+/* Say how long (ordinary) registers are.  This is a piece of bogosity
+   used in push_word and a few other places; REGISTER_RAW_SIZE is the
+   real way to know how big a register is.  */
+#define REGISTER_SIZE 4
+
+
+/* Return the name of register number REG.  This may return "" to
+   indicate a register number that's not used on this variant.
+   (Register numbers may be sparse for consistency between variants.)  */
+#define REGISTER_NAME(reg) (rs6000_register_name(reg))
+extern char *rs6000_register_name (int reg);
+
+/* Number of machine registers */
+#define NUM_REGS 183
+
+/* Register numbers of various important registers.
+   Note that some of these values are "real" register numbers,
+   and correspond to the general registers of the machine,
+   and some are "phony" register numbers which are too large
+   to be actual register numbers as far as the user is concerned
+   but do serve to get the desired values when passed to read_register.  */
+
+#define FP_REGNUM 1		/* Contains address of executing stack frame */
+#define SP_REGNUM 1		/* Contains address of top of stack */
+#define	TOC_REGNUM 2		/* TOC register */
+#define FP0_REGNUM 32		/* Floating point register 0 */
+#define	GP0_REGNUM 0		/* GPR register 0 */
+#define FP0_REGNUM 32		/* FPR (Floating point) register 0 */
+#define FPLAST_REGNUM 63	/* Last floating point register */  
+
+/* Special purpose registers... */
+/* P.S. keep these in the same order as in /usr/mstsave.h `mstsave'
+   structure, for easier processing */
+
+#define PC_REGNUM 64		/* Program counter (instruction address %iar)*/
+#define PS_REGNUM 65		/* Processor (or machine) status (%msr) */
+#define	CR_REGNUM 66		/* Condition register */
+#define	LR_REGNUM 67		/* Link register */
+#define	CTR_REGNUM 68		/* Count register */
+#define	XER_REGNUM 69		/* Fixed point exception registers */
+#define	MQ_REGNUM 70		/* Multiply/quotient register */
+
+/* These #defines are used to parse core files and talk to ptrace, so they
+   must remain fixed.  */
+#define	FIRST_UISA_SP_REGNUM 64	/* first special register number */
+#define LAST_UISA_SP_REGNUM  70	/* last special register number */
+
+/* This is the offset in REG_NAMES at which the `set processor'
+   command starts plugging in its names.  */
+#define FIRST_VARIANT_REGISTER 66
+
+/* Total amount of space needed to store our copies of the machine's
+   register state, the array `registers'.
+	     32 4-byte gpr's
+	     32 8-byte fpr's
+	     7  4-byte UISA special purpose registers, 
+	     16 4-byte segment registers,
+	     32 4-byte standard OEA special-purpose registers,
+   and up to 64 4-byte non-standard OEA special purpose regs.
+   total: (+ (* 32 4) (* 32 8) (* 7 4) (* 16 4) (* 32 4) (* 64 4)) 860 bytes
+   Keep some extra space for now, in case to add more. */
+#define REGISTER_BYTES 880
+
+
+/* Index within `registers' of the first byte of the space for
+   register N.  */
+
+#define REGISTER_BYTE(N)  \
+ (								\
+  ((N) > FPLAST_REGNUM) ? ((((N) - FPLAST_REGNUM -1) * 4) + 384)\
+  :((N) >= FP0_REGNUM) ? ((((N) - FP0_REGNUM) * 8) + 128)	\
+  :((N) * 4) )
+
+/* Number of bytes of storage in the actual machine representation
+   for register N. */
+/* Note that the unsigned cast here forces the result of the
+   subtraction to very high positive values if N < FP0_REGNUM */
+
+#define REGISTER_RAW_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
+
+/* Number of bytes of storage in the program's representation
+   for register N.  On the RS6000, all regs are 4 bytes
+   except the floating point regs which are 8-byte doubles.  */
+
+#define REGISTER_VIRTUAL_SIZE(N) (((unsigned)(N) - FP0_REGNUM) < 32 ? 8 : 4)
+
+/* Largest value REGISTER_RAW_SIZE can have.  */
+
+#define MAX_REGISTER_RAW_SIZE 8
+
+/* Largest value REGISTER_VIRTUAL_SIZE can have.  */
+
+#define MAX_REGISTER_VIRTUAL_SIZE 8
+
+/* convert a dbx stab register number (from `r' declaration) to a gdb REGNUM */
+
+#define STAB_REG_TO_REGNUM(value)	(value)
+
+/* Nonzero if register N requires conversion
+   from raw format to virtual format.
+   The register format for rs6000 floating point registers is always
+   double, we need a conversion if the memory format is float.  */
+
+#define REGISTER_CONVERTIBLE(N) ((N) >= FP0_REGNUM && (N) <= FPLAST_REGNUM)
+
+/* Convert data from raw format for register REGNUM in buffer FROM
+   to virtual format with type TYPE in buffer TO.  */
+
+#define REGISTER_CONVERT_TO_VIRTUAL(REGNUM,TYPE,FROM,TO) \
+{ \
+  if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \
+    { \
+      double val = extract_floating ((FROM), REGISTER_RAW_SIZE (REGNUM)); \
+      store_floating ((TO), TYPE_LENGTH (TYPE), val); \
+    } \
+  else \
+    memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \
+}
+
+/* Convert data from virtual format with type TYPE in buffer FROM
+   to raw format for register REGNUM in buffer TO.  */
+
+#define REGISTER_CONVERT_TO_RAW(TYPE,REGNUM,FROM,TO)	\
+{ \
+  if (TYPE_LENGTH (TYPE) != REGISTER_RAW_SIZE (REGNUM)) \
+    { \
+      double val = extract_floating ((FROM), TYPE_LENGTH (TYPE)); \
+      store_floating ((TO), REGISTER_RAW_SIZE (REGNUM), val); \
+    } \
+  else \
+    memcpy ((TO), (FROM), REGISTER_RAW_SIZE (REGNUM)); \
+}
+
+/* Return the GDB type object for the "standard" data type
+   of data in register N.  */
+
+#define REGISTER_VIRTUAL_TYPE(N) \
+ (((unsigned)(N) - FP0_REGNUM) < 32 ? builtin_type_double : builtin_type_int)
+
+/* Store the address of the place in which to copy the structure the
+   subroutine will return.  This is called from call_function. */
+/* in RS6000, struct return addresses are passed as an extra parameter in r3.
+   In function return, callee is not responsible of returning this address back.
+   Since gdb needs to find it, we will store in a designated variable
+   `rs6000_struct_return_address'. */
+
+extern CORE_ADDR rs6000_struct_return_address;
+
+#define STORE_STRUCT_RETURN(ADDR, SP)	\
+  { write_register (3, (ADDR));		\
+    rs6000_struct_return_address = (ADDR); }
+
+/* Extract from an array REGBUF containing the (raw) register state
+   a function return value of type TYPE, and copy that, in virtual format,
+   into VALBUF.  */
+
+/* #define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
+  memcpy (VALBUF, REGBUF, TYPE_LENGTH (TYPE)) */
+
+#define EXTRACT_RETURN_VALUE(TYPE,REGBUF,VALBUF) \
+  extract_return_value(TYPE,REGBUF,VALBUF)
+extern void extract_return_value PARAMS ((struct type *, char [], char *));
+
+/* Write into appropriate registers a function return value
+   of type TYPE, given in virtual format.  */
+
+#define STORE_RETURN_VALUE(TYPE,VALBUF) \
+  {									\
+    if (TYPE_CODE (TYPE) == TYPE_CODE_FLT)				\
+									\
+     /* Floating point values are returned starting from FPR1 and up.	\
+	Say a double_double_double type could be returned in		\
+	FPR1/FPR2/FPR3 triple. */					\
+									\
+      write_register_bytes (REGISTER_BYTE (FP0_REGNUM+1), (VALBUF),	\
+						TYPE_LENGTH (TYPE));	\
+    else								\
+      /* Everything else is returned in GPR3 and up. */			\
+      write_register_bytes (REGISTER_BYTE (GP0_REGNUM+3), (VALBUF),	\
+						TYPE_LENGTH (TYPE));	\
+  }
+
+
+/* Extract from an array REGBUF containing the (raw) register state
+   the address in which a function should return its structure value,
+   as a CORE_ADDR (or an expression that can be used as one).  */
+
+#define EXTRACT_STRUCT_VALUE_ADDRESS(REGBUF)	rs6000_struct_return_address
+
+/* Describe the pointer in each stack frame to the previous stack frame
+   (its caller).  */
+
+/* FRAME_CHAIN takes a frame's nominal address
+   and produces the frame's chain-pointer. */
+
+/* In the case of the RS6000, the frame's nominal address
+   is the address of a 4-byte word containing the calling frame's address.  */
+
+#define FRAME_CHAIN(thisframe) rs6000_frame_chain (thisframe)
+CORE_ADDR rs6000_frame_chain PARAMS ((struct frame_info *));
+
+/* Define other aspects of the stack frame.  */
+
+/* A macro that tells us whether the function invocation represented
+   by FI does not have a frame on the stack associated with it.  If it
+   does not, FRAMELESS is set to 1, else 0.  */
+
+#define FRAMELESS_FUNCTION_INVOCATION(FI, FRAMELESS) \
+  FRAMELESS = frameless_function_invocation (FI)
+
+extern int frameless_function_invocation PARAMS((struct frame_info *));
+
+#define INIT_FRAME_PC_FIRST(fromleaf, prev) \
+  prev->pc = (fromleaf ? SAVED_PC_AFTER_CALL (prev->next) : \
+	      prev->next ? FRAME_SAVED_PC (prev->next) : read_pc ());
+#define INIT_FRAME_PC(fromleaf, prev) /* nothing */
+extern void rs6000_init_extra_frame_info (int fromleaf, struct frame_info *);
+#define	INIT_EXTRA_FRAME_INFO(fromleaf, fi) rs6000_init_extra_frame_info (fromleaf, fi)
+
+/* If the kernel has to deliver a signal, it pushes a sigcontext
+   structure on the stack and then calls the signal handler, passing
+   the address of the sigcontext in an argument register. Usually
+   the signal handler doesn't save this register, so we have to
+   access the sigcontext structure via an offset from the signal handler
+   frame.
+   The following constants were determined by experimentation on AIX 3.2.  */
+#define SIG_FRAME_PC_OFFSET 96
+#define SIG_FRAME_LR_OFFSET 108
+#define SIG_FRAME_FP_OFFSET 284
+
+/* Default offset from SP where the LR is stored */
+#define	DEFAULT_LR_SAVE 8
+
+/* Return saved PC from a frame */
+#define FRAME_SAVED_PC(FRAME)  frame_saved_pc (FRAME)
+
+extern unsigned long frame_saved_pc PARAMS ((struct frame_info *));
+
+extern CORE_ADDR rs6000_frame_args_address PARAMS ((struct frame_info *));
+#define FRAME_ARGS_ADDRESS(FI) rs6000_frame_args_address (FI)
+
+#define FRAME_LOCALS_ADDRESS(FI)	FRAME_ARGS_ADDRESS(FI)
+
+
+/* Set VAL to the number of args passed to frame described by FI.
+   Can set VAL to -1, meaning no way to tell.  */
+
+/* We can't tell how many args there are
+   now that the C compiler delays popping them.  */
+
+#define FRAME_NUM_ARGS(val,fi) (val = -1)
+
+/* Return number of bytes at start of arglist that are not really args.  */
+
+#define FRAME_ARGS_SKIP 8	/* Not sure on this. FIXMEmgo */
+
+/* Put here the code to store, into a struct frame_saved_regs,
+   the addresses of the saved registers of frame described by FRAME_INFO.
+   This includes special registers such as pc and fp saved in special
+   ways in the stack frame.  sp is even more special:
+   the address we return for it IS the sp for the next frame.  */
+/* In the following implementation for RS6000, we did *not* save sp. I am
+   not sure if it will be needed. The following macro takes care of gpr's
+   and fpr's only. */
+
+extern void rs6000_frame_init_saved_regs PARAMS ((struct frame_info *));
+#define FRAME_INIT_SAVED_REGS(FI) rs6000_frame_init_saved_regs (FI)
+
+/* Things needed for making the inferior call functions.  */
+
+/* Push an empty stack frame, to record the current PC, etc.  */
+/* Change these names into rs6k_{push, pop}_frame(). FIXMEmgo. */
+
+#define PUSH_DUMMY_FRAME	push_dummy_frame ()
+extern void push_dummy_frame PARAMS ((void));
+
+/* Discard from the stack the innermost frame, 
+   restoring all saved registers.  */
+
+#define POP_FRAME	pop_frame ()
+extern void pop_frame PARAMS ((void));
+
+/* This sequence of words is the instructions:
+
+	mflr	r0		// 0x7c0802a6
+				// save fpr's
+	stfd	r?, num(r1)	// 0xd8010000 there should be 32 of this??
+				// save gpr's
+	stm	r0, num(r1)	// 0xbc010000
+	stu	r1, num(r1)	// 0x94210000
+
+	// the function we want to branch might be in a different load 
+	// segment. reset the toc register. Note that the actual toc address
+	// will be fix by fix_call_dummy () along with function address.
+
+	st	r2, 0x14(r1)	// 0x90410014 save toc register
+	liu	r2, 0x1234	// 0x3c401234 reset a new toc value 0x12345678
+	oril	r2, r2,0x5678   // 0x60425678	
+
+				// load absolute address 0x12345678 to r0
+	liu	r0, 0x1234	// 0x3c001234
+	oril	r0, r0,0x5678	// 0x60005678
+	mtctr	r0		// 0x7c0903a6 ctr <- r0
+	bctrl			// 0x4e800421 jump subroutine 0x12345678 (%ctr)
+	cror	0xf, 0xf, 0xf	// 0x4def7b82
+	brpt			// 0x7d821008, breakpoint
+	cror	0xf, 0xf, 0xf	// 0x4def7b82 (for 8 byte alignment)
+
+
+  We actually start executing by saving the toc register first, since the pushing 
+  of the registers is done by PUSH_DUMMY_FRAME.  If this were real code,
+  the arguments for the function called by the `bctrl' would be pushed
+  between the `stu' and the `bctrl', and we could allow it to execute through.
+  But the arguments have to be pushed by GDB after the PUSH_DUMMY_FRAME is done,
+  and we cannot allow to push the registers again.
+*/
+	
+#define CALL_DUMMY {0x7c0802a6, 0xd8010000, 0xbc010000, 0x94210000, \
+		    0x90410014, 0x3c401234, 0x60425678,		    \
+		    0x3c001234, 0x60005678, 0x7c0903a6, 0x4e800421, \
+		    0x4def7b82, 0x7d821008, 0x4def7b82 }
+
+
+/* keep this as multiple of 8 (%sp requires 8 byte alignment) */
+#define CALL_DUMMY_LENGTH 56
+
+#define CALL_DUMMY_START_OFFSET 16
+
+/* Insert the specified number of args and function address into a
+   call sequence of the above form stored at DUMMYNAME.  */
+
+#define FIX_CALL_DUMMY(dummyname, pc, fun, nargs, args, type, gcc_p) \
+  rs6000_fix_call_dummy (dummyname, pc, fun, nargs, args, type, gcc_p)
+extern void rs6000_fix_call_dummy PARAMS ((char *, CORE_ADDR, CORE_ADDR,
+					   int, struct value **,
+					   struct type *, int));
+
+/* Hook in rs6000-tdep.c for determining the TOC address when
+   calling functions in the inferior.  */
+extern CORE_ADDR (*find_toc_address_hook) PARAMS ((CORE_ADDR));
+
+/* xcoffread.c provides a function to determine the TOC offset
+   for a given object file.
+   It is used under native AIX configurations for determining the
+   TOC address when calling functions in the inferior.  */
+#ifdef __STDC__
+struct objfile;
+#endif
+extern CORE_ADDR get_toc_offset PARAMS ((struct objfile *));
+
+/* Usually a function pointer's representation is simply the address
+   of the function. On the RS/6000 however, a function pointer is
+   represented by a pointer to a TOC entry. This TOC entry contains
+   three words, the first word is the address of the function, the
+   second word is the TOC pointer (r2), and the third word is the
+   static chain value.  Throughout GDB it is currently assumed that a
+   function pointer contains the address of the function, which is not
+   easy to fix.  In addition, the conversion of a function address to
+   a function pointer would require allocation of a TOC entry in the
+   inferior's memory space, with all its drawbacks.  To be able to
+   call C++ virtual methods in the inferior (which are called via
+   function pointers), find_function_addr uses this macro to get the
+   function address from a function pointer.  */
+
+#define CONVERT_FROM_FUNC_PTR_ADDR(ADDR) \
+  (is_magic_function_pointer (ADDR) ? read_memory_integer (ADDR, 4) : (ADDR))
+extern int is_magic_function_pointer PARAMS ((CORE_ADDR));
+
+/* Flag for machine-specific stuff in shared files.  FIXME */
+#define IBM6000_TARGET
+
+/* RS6000/AIX does not support PT_STEP.  Has to be simulated.  */
+
+#define SOFTWARE_SINGLE_STEP_P 1
+extern void rs6000_software_single_step PARAMS ((unsigned int, int));
+#define SOFTWARE_SINGLE_STEP(sig,bp_p) rs6000_software_single_step (sig, bp_p)
+
+/* If the current gcc for for this target does not produce correct debugging
+   information for float parameters, both prototyped and unprototyped, then
+   define this macro.  This forces gdb to  always assume that floats are
+   passed as doubles and then converted in the callee.
+
+   For the PowerPC, it appears that the debug info marks the parameters as
+   floats regardless of whether the function is prototyped, but the actual
+   values are always passed in as doubles.  Thus by setting this to 1, both
+   types of calls will work. */
+
+#define COERCE_FLOAT_TO_DOUBLE 1