#include "ppc-tdep.h"
-/* round2 rounds x up to the nearest multiple of s assuming that s is a
- power of 2 */
+/* Ensure that X is aligned to an S byte boundary (assuming that S is
+ a power of 2) rounding up/down where necessary. */
-#undef round2
-#define round2(x,s) ((((long) (x) - 1) & ~(long)((s)-1)) + (s))
+static ULONGEST
+align_up (ULONGEST x, int s)
+{
+ return (x + s - 1) & -s;
+}
+
+static ULONGEST
+align_down (ULONGEST x, int s)
+{
+ return (x & -s);
+}
/* Pass the arguments in either registers, or in the stack. Using the
ppc sysv ABI, the first eight words of the argument list (that might
int nargs, struct value **args, CORE_ADDR sp,
int struct_return, CORE_ADDR struct_addr)
{
- int argno;
- /* Next available general register for non-float, non-vector arguments. */
- int greg;
- /* Next available floating point register for float arguments. */
- int freg;
- /* Next available vector register for vector arguments. */
- int vreg;
- int argstkspace;
- int structstkspace;
- int argoffset;
- int structoffset;
- struct type *type;
- int len;
- char old_sp_buf[4];
- CORE_ADDR saved_sp;
struct gdbarch_tdep *tdep = gdbarch_tdep (current_gdbarch);
+ const CORE_ADDR saved_sp = read_sp ();
+ int argspace = 0; /* 0 is an initial wrong guess. */
+ int write_pass;
- greg = 3;
- freg = 1;
- vreg = 2;
- argstkspace = 0;
- structstkspace = 0;
+ /* Go through the argument list twice.
- /* If the function is returning a `struct', then the first word
- (which will be passed in r3) is used for struct return address.
- In that case we should advance one word and start from r4
- register to copy parameters. */
- if (struct_return)
- {
- regcache_raw_write_signed (regcache, tdep->ppc_gp0_regnum + greg,
- struct_addr);
- greg++;
- }
+ Pass 1: Figure out how much new stack space is required for
+ arguments and pushed values. Unlike the PowerOpen ABI, the SysV
+ ABI doesn't reserve any extra space for parameters which are put
+ in registers, but does always push structures and then pass their
+ address.
- /* Figure out how much new stack space is required for arguments
- which don't fit in registers. Unlike the PowerOpen ABI, the
- SysV ABI doesn't reserve any extra space for parameters which
- are put in registers. */
- for (argno = 0; argno < nargs; argno++)
- {
- struct value *arg = args[argno];
- type = check_typedef (VALUE_TYPE (arg));
- len = TYPE_LENGTH (type);
+ Pass 2: Replay the same computation but this time also write the
+ values out to the target. */
- if (TYPE_CODE (type) == TYPE_CODE_FLT
- && ppc_floating_point_unit_p (current_gdbarch))
+ for (write_pass = 0; write_pass < 2; write_pass++)
+ {
+ int argno;
+ /* Next available floating point register for float and double
+ arguments. */
+ int freg = 1;
+ /* Next available general register for non-float, non-vector
+ arguments. */
+ int greg = 3;
+ /* Next available vector register for vector arguments. */
+ int vreg = 2;
+ /* Arguments start above the "LR save word" and "Back chain". */
+ int argoffset = 2 * tdep->wordsize;
+ /* Structures start after the arguments. */
+ int structoffset = argoffset + argspace;
+
+ /* If the function is returning a `struct', then the first word
+ (which will be passed in r3) is used for struct return
+ address. In that case we should advance one word and start
+ from r4 register to copy parameters. */
+ if (struct_return)
{
- if (freg <= 8)
- freg++;
- else
- {
- /* SysV ABI converts floats to doubles when placed in
- memory and requires 8 byte alignment */
- if (argstkspace & 0x4)
- argstkspace += 4;
- argstkspace += 8;
- }
+ if (write_pass)
+ regcache_cooked_write_signed (regcache,
+ tdep->ppc_gp0_regnum + greg,
+ struct_addr);
+ greg++;
}
- else if (len == 8
- && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */
- || (!ppc_floating_point_unit_p (current_gdbarch)
- && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */
+
+ for (argno = 0; argno < nargs; argno++)
{
- if (greg > 9)
+ struct value *arg = args[argno];
+ struct type *type = check_typedef (VALUE_TYPE (arg));
+ int len = TYPE_LENGTH (type);
+ char *val = VALUE_CONTENTS (arg);
+
+ if (TYPE_CODE (type) == TYPE_CODE_FLT
+ && ppc_floating_point_unit_p (current_gdbarch)
+ && len <= 8)
{
- greg = 11;
- if (argstkspace & 0x4)
- argstkspace += 4;
- argstkspace += 8;
- }
- else
- {
- if ((greg & 1) == 0)
- greg++;
- greg += 2;
- }
- }
- else if (!TYPE_VECTOR (type))
- {
- if (len > 4
- || TYPE_CODE (type) == TYPE_CODE_STRUCT
- || TYPE_CODE (type) == TYPE_CODE_UNION)
- {
- /* Rounding to the nearest multiple of 8 may not be necessary,
- but it is safe. Particularly since we don't know the
- field types of the structure */
- structstkspace += round2 (len, 8);
- }
- if (greg <= 10)
- greg++;
- else
- argstkspace += 4;
- }
- else
- {
- if (len == 16
- && TYPE_CODE (type) == TYPE_CODE_ARRAY
- && TYPE_VECTOR (type))
- {
- if (vreg <= 13)
- vreg++;
+ /* Floating point value converted to "double" then
+ passed in an FP register, when the registers run out,
+ 8 byte aligned stack is used. */
+ if (freg <= 8)
+ {
+ if (write_pass)
+ {
+ /* Always store the floating point value using
+ the register's floating-point format. */
+ char regval[MAX_REGISTER_SIZE];
+ struct type *regtype
+ = register_type (gdbarch, FP0_REGNUM + freg);
+ convert_typed_floating (val, type, regval, regtype);
+ regcache_cooked_write (regcache, FP0_REGNUM + freg,
+ regval);
+ }
+ freg++;
+ }
else
{
- /* Vector arguments must be aligned to 16 bytes on
- the stack. */
- argstkspace += round2 (argstkspace, 16);
- argstkspace += 16;
+ /* SysV ABI converts floats to doubles before
+ writing them to an 8 byte aligned stack location. */
+ argoffset = align_up (argoffset, 8);
+ if (write_pass)
+ {
+ char memval[8];
+ struct type *memtype;
+ switch (TARGET_BYTE_ORDER)
+ {
+ case BFD_ENDIAN_BIG:
+ memtype = builtin_type_ieee_double_big;
+ break;
+ case BFD_ENDIAN_LITTLE:
+ memtype = builtin_type_ieee_double_little;
+ break;
+ default:
+ internal_error (__FILE__, __LINE__, "bad switch");
+ }
+ convert_typed_floating (val, type, memval, memtype);
+ write_memory (sp + argoffset, val, len);
+ }
+ argoffset += 8;
}
}
- else if (len == 8
- && TYPE_CODE (type) == TYPE_CODE_ARRAY
- && TYPE_VECTOR (type))
- {
- if (greg <= 10)
- greg++;
- else
- {
- /* Vector arguments must be aligned to 8 bytes on
- the stack. */
- argstkspace += round2 (argstkspace, 8);
- argstkspace += 8;
- }
- }
- }
- }
-
- /* Get current SP location */
- saved_sp = read_sp ();
-
- sp -= argstkspace + structstkspace;
-
- /* Allocate space for backchain and callee's saved lr */
- sp -= 8;
-
- /* Make sure that we maintain 16 byte alignment */
- sp &= ~0x0f;
-
- /* Update %sp before proceeding any further. */
- regcache_raw_write_signed (regcache, SP_REGNUM, sp);
-
- /* write the backchain */
- store_unsigned_integer (old_sp_buf, 4, saved_sp);
- write_memory (sp, old_sp_buf, 4);
-
- argoffset = 8;
- structoffset = argoffset + argstkspace;
- freg = 1;
- greg = 3;
- vreg = 2;
-
- /* Fill in r3 with the return structure, if any */
- if (struct_return)
- {
- write_register (tdep->ppc_gp0_regnum + greg, struct_addr);
- greg++;
- }
-
- /* Now fill in the registers and stack... */
- for (argno = 0; argno < nargs; argno++)
- {
- struct value *arg = args[argno];
- char *val = VALUE_CONTENTS (arg);
- type = check_typedef (VALUE_TYPE (arg));
- len = TYPE_LENGTH (type);
-
- if (TYPE_CODE (type) == TYPE_CODE_FLT
- && ppc_floating_point_unit_p (current_gdbarch))
- {
- if (freg <= 8)
+ else if (len == 8
+ && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */
+ || (!ppc_floating_point_unit_p (current_gdbarch)
+ && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */
{
- ULONGEST regval;
- if (len > 8)
- printf_unfiltered (
- "Fatal Error: a floating point parameter #%d with a size > 8 is found!\n", argno);
- regval = extract_unsigned_integer (val, len);
- write_register (FP0_REGNUM + freg, regval);
- freg++;
- }
- else
- {
- /* SysV ABI converts floats to doubles when placed in
- memory and requires 8 byte alignment */
- /* FIXME: Convert floats to doubles */
- if (argoffset & 0x4)
- argoffset += 4;
- write_memory (sp + argoffset, val, len);
- argoffset += 8;
- }
- }
- else if (len == 8
- && (TYPE_CODE (type) == TYPE_CODE_INT /* long long */
- || (!ppc_floating_point_unit_p (current_gdbarch)
- && TYPE_CODE (type) == TYPE_CODE_FLT))) /* double */
- {
- if (greg > 9)
- {
- greg = 11;
- if (argoffset & 0x4)
- argoffset += 4;
- write_memory (sp + argoffset, val, len);
- argoffset += 8;
- }
- else
- {
- ULONGEST regval;
- if ((greg & 1) == 0)
- greg++;
- regval = extract_unsigned_integer (val, 4);
- write_register (tdep->ppc_gp0_regnum + greg, regval);
- regval = extract_unsigned_integer (val + 4, 4);
- write_register (tdep->ppc_gp0_regnum + greg + 1, regval);
- greg += 2;
- }
- }
- else if (!TYPE_VECTOR (type))
- {
- char val_buf[4];
- if (len > 4
- || TYPE_CODE (type) == TYPE_CODE_STRUCT
- || TYPE_CODE (type) == TYPE_CODE_UNION)
- {
- write_memory (sp + structoffset, val, len);
- store_unsigned_integer (val_buf, 4, sp + structoffset);
- structoffset += round2 (len, 8);
- }
- else
- {
- memset (val_buf, 0, 4);
- memcpy (val_buf, val, len);
- }
- if (greg <= 10)
- {
- ULONGEST regval = extract_unsigned_integer (val_buf, 4);
- write_register (tdep->ppc_gp0_regnum + greg, regval);
- greg++;
- }
- else
- {
- write_memory (sp + argoffset, val_buf, 4);
- argoffset += 4;
+ /* "long long" or "double" passed in an odd/even
+ register pair with the low addressed word in the odd
+ register and the high addressed word in the even
+ register, or when the registers run out an 8 byte
+ aligned stack location. */
+ if (greg > 9)
+ {
+ /* Just in case GREG was 10. */
+ greg = 11;
+ argoffset = align_up (argoffset, 8);
+ if (write_pass)
+ write_memory (sp + argoffset, val, len);
+ argoffset += 8;
+ }
+ else if (tdep->wordsize == 8)
+ {
+ if (write_pass)
+ regcache_cooked_write (regcache,
+ tdep->ppc_gp0_regnum + greg,
+ val);
+ greg += 1;
+ }
+ else
+ {
+ /* Must start on an odd register - r3/r4 etc. */
+ if ((greg & 1) == 0)
+ greg++;
+ if (write_pass)
+ {
+ regcache_cooked_write (regcache,
+ tdep->ppc_gp0_regnum + greg + 0,
+ val + 0);
+ regcache_cooked_write (regcache,
+ tdep->ppc_gp0_regnum + greg + 1,
+ val + 4);
+ }
+ greg += 2;
+ }
}
- }
- else
- {
- if (len == 16
- && TYPE_CODE (type) == TYPE_CODE_ARRAY
- && TYPE_VECTOR (type))
+ else if (len == 16
+ && TYPE_CODE (type) == TYPE_CODE_ARRAY
+ && TYPE_VECTOR (type)
+ && tdep->ppc_vr0_regnum >= 0)
{
- char *v_val_buf = alloca (16);
- memset (v_val_buf, 0, 16);
- memcpy (v_val_buf, val, len);
+ /* Vector parameter passed in an Altivec register, or
+ when that runs out, 16 byte aligned stack location. */
if (vreg <= 13)
{
- regcache_cooked_write (current_regcache,
- tdep->ppc_vr0_regnum + vreg,
- v_val_buf);
+ if (write_pass)
+ regcache_cooked_write (current_regcache,
+ tdep->ppc_vr0_regnum + vreg,
+ val);
vreg++;
}
else
{
- write_memory (sp + argoffset, v_val_buf, 16);
+ argoffset = align_up (argoffset, 16);
+ if (write_pass)
+ write_memory (sp + argoffset, val, 16);
argoffset += 16;
}
}
else if (len == 8
&& TYPE_CODE (type) == TYPE_CODE_ARRAY
- && TYPE_VECTOR (type))
+ && TYPE_VECTOR (type)
+ && tdep->ppc_ev0_regnum >= 0)
{
- char *v_val_buf = alloca (8);
- memset (v_val_buf, 0, 8);
- memcpy (v_val_buf, val, len);
+ /* Vector parameter passed in an e500 register, or when
+ that runs out, 8 byte aligned stack location. Note
+ that since e500 vector and general purpose registers
+ both map onto the same underlying register set, a
+ "greg" and not a "vreg" is consumed here. A cooked
+ write stores the value in the correct locations
+ within the raw register cache. */
if (greg <= 10)
{
- regcache_cooked_write (current_regcache,
- tdep->ppc_ev0_regnum + greg,
- v_val_buf);
+ if (write_pass)
+ regcache_cooked_write (current_regcache,
+ tdep->ppc_ev0_regnum + greg,
+ val);
greg++;
}
else
{
- write_memory (sp + argoffset, v_val_buf, 8);
+ argoffset = align_up (argoffset, 8);
+ if (write_pass)
+ write_memory (sp + argoffset, val, 8);
argoffset += 8;
}
}
- }
+ else
+ {
+ /* Reduce the parameter down to something that fits in a
+ "word". */
+ char word[MAX_REGISTER_SIZE];
+ memset (word, 0, MAX_REGISTER_SIZE);
+ if (len > tdep->wordsize
+ || TYPE_CODE (type) == TYPE_CODE_STRUCT
+ || TYPE_CODE (type) == TYPE_CODE_UNION)
+ {
+ /* Structs and large values are put on an 8 byte
+ aligned stack ... */
+ structoffset = align_up (structoffset, 8);
+ if (write_pass)
+ write_memory (sp + structoffset, val, len);
+ /* ... and then a "word" pointing to that address is
+ passed as the parameter. */
+ store_unsigned_integer (word, tdep->wordsize,
+ sp + structoffset);
+ structoffset += len;
+ }
+ else if (TYPE_CODE (type) == TYPE_CODE_INT)
+ /* Sign or zero extend the "int" into a "word". */
+ store_unsigned_integer (word, tdep->wordsize,
+ unpack_long (type, val));
+ else
+ /* Always goes in the low address. */
+ memcpy (word, val, len);
+ /* Store that "word" in a register, or on the stack.
+ The words have "4" byte alignment. */
+ if (greg <= 10)
+ {
+ if (write_pass)
+ regcache_cooked_write (regcache,
+ tdep->ppc_gp0_regnum + greg,
+ word);
+ greg++;
+ }
+ else
+ {
+ argoffset = align_up (argoffset, tdep->wordsize);
+ if (write_pass)
+ write_memory (sp + argoffset, word, tdep->wordsize);
+ argoffset += tdep->wordsize;
+ }
+ }
+ }
+
+ /* Compute the actual stack space requirements. */
+ if (!write_pass)
+ {
+ /* Remember the amount of space needed by the arguments. */
+ argspace = argoffset;
+ /* Allocate space for both the arguments and the structures. */
+ sp -= (argoffset + structoffset);
+ /* Ensure that the stack is still 16 byte aligned. */
+ sp = align_down (sp, 16);
+ }
}
+ /* Update %sp. */
+ regcache_cooked_write_signed (regcache, SP_REGNUM, sp);
+
+ /* Write the backchain (it occupies WORDSIZED bytes). */
+ write_memory_signed_integer (sp, tdep->wordsize, saved_sp);
+
/* Point the inferior function call's return address at the dummy's
breakpoint. */
- regcache_raw_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);
+ regcache_cooked_write_signed (regcache, tdep->ppc_lr_regnum, bp_addr);
- target_store_registers (-1);
return sp;
}
projects / deliverable / binutils-gdb.git / commitdiff
