From 4d819d0ef5da350adef2dba9219144e434fc939a Mon Sep 17 00:00:00 2001 From: Jim Blandy Date: Tue, 1 Jul 2003 00:05:37 +0000 Subject: [PATCH] Patch from IBM (authors unspecified, probably Ulrich Weigand and Gerhard Tonn) for argument passing on the S/390 and S/390x: * s390-tdep.c (S390_STACK_FRAME_OVERHEAD): This is always space for 16 registers, and then 32 more bytes. (S390_STACK_PARAMETER_ALIGNMENT, S390_NUM_FP_PARAMETER_REGISTERS): New macros. (is_double_arg): The s390x doesn't handle DOUBLE_ARGS specially. Move up in the file, since it's now used by is_simple_arg. (is_simple_arg): Don't assume registers are four bytes long. Exclude all double arguments. Extended floats are not simple args. (is_power_of_two): New function. (pass_by_copy_ref): Call is_power_of_two, and check that the length fits in a register, rather than listing all the acceptable sizes. Extended floats are not passed by reference. (s390_push_arguments): Don't assume registers are four bytes long. Reserve an argument register to point to the buffer for structures returned by value. Use S390_NUM_FP_PARAMETER_REGISTERS and S390_STACK_FRAME_OVERHEAD. --- gdb/ChangeLog | 22 +++++++++++++ gdb/s390-tdep.c | 88 +++++++++++++++++++++++++++++-------------------- 2 files changed, 74 insertions(+), 36 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index c64b83ceb5e..d082c459ad1 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,25 @@ +2003-06-30 Jim Blandy + + Patch from IBM (authors unspecified, probably Ulrich Weigand and + Gerhard Tonn) for argument passing on the S/390 and S/390x: + * s390-tdep.c (S390_STACK_FRAME_OVERHEAD): This is always space + for 16 registers, and then 32 more bytes. + (S390_STACK_PARAMETER_ALIGNMENT, S390_NUM_FP_PARAMETER_REGISTERS): + New macros. + (is_double_arg): The s390x doesn't handle DOUBLE_ARGS specially. + Move up in the file, since it's now used by is_simple_arg. + (is_simple_arg): Don't assume registers are four bytes long. + Exclude all double arguments. Extended floats are not simple + args. + (is_power_of_two): New function. + (pass_by_copy_ref): Call is_power_of_two, and check that the + length fits in a register, rather than listing all the acceptable + sizes. Extended floats are not passed by reference. + (s390_push_arguments): Don't assume registers are four bytes long. + Reserve an argument register to point to the buffer for structures + returned by value. Use S390_NUM_FP_PARAMETER_REGISTERS and + S390_STACK_FRAME_OVERHEAD. + 2003-06-30 Andreas Schwab * utils.c (internal_vproblem): Use xvasprintf, not xasprintf, to diff --git a/gdb/s390-tdep.c b/gdb/s390-tdep.c index 87ddef0de16..9ef9837452f 100644 --- a/gdb/s390-tdep.c +++ b/gdb/s390-tdep.c @@ -93,7 +93,9 @@ s390_register_byte (int reg_nr) #define S390X_SIGREGS_FP0_OFFSET (216) #define S390_UC_MCONTEXT_OFFSET (256) #define S390X_UC_MCONTEXT_OFFSET (344) -#define S390_STACK_FRAME_OVERHEAD (GDB_TARGET_IS_ESAME ? 160:96) +#define S390_STACK_FRAME_OVERHEAD 16*DEPRECATED_REGISTER_SIZE+32 +#define S390_STACK_PARAMETER_ALIGNMENT DEPRECATED_REGISTER_SIZE +#define S390_NUM_FP_PARAMETER_REGISTERS (GDB_TARGET_IS_ESAME ? 4:2) #define S390_SIGNAL_FRAMESIZE (GDB_TARGET_IS_ESAME ? 160:96) #define s390_NR_sigreturn 119 #define s390_NR_rt_sigreturn 173 @@ -1331,7 +1333,7 @@ is_struct_like (struct type *type) You'd think this would just be floats, doubles, long doubles, etc. But as an odd quirk, not mentioned in the ABI, GCC passes float and double singletons as if they were a plain float, double, etc. (The - corresponding union types are handled normally.) So we exclude + corresponding union types are handled normally.) So we include those types here. *shrug* */ static int is_float_like (struct type *type) @@ -1354,6 +1356,25 @@ is_double_or_float (struct type *type) } +/* Return non-zero if TYPE is a `DOUBLE_ARG', as defined by the + parameter passing conventions described in the "GNU/Linux for S/390 + ELF Application Binary Interface Supplement". Return zero + otherwise. */ +static int +is_double_arg (struct type *type) +{ + unsigned length = TYPE_LENGTH (type); + + /* The s390x ABI doesn't handle DOUBLE_ARGS specially. */ + if (GDB_TARGET_IS_ESAME) + return 0; + + return ((is_integer_like (type) + || is_struct_like (type)) + && length == 8); +} + + /* Return non-zero if TYPE is considered a `SIMPLE_ARG', as defined by the parameter passing conventions described in the "GNU/Linux for S/390 ELF Application Binary Interface Supplement". Return zero @@ -1365,13 +1386,18 @@ is_simple_arg (struct type *type) /* This is almost a direct translation of the ABI's language, except that we have to exclude 8-byte structs; those are DOUBLE_ARGs. */ - return ((is_integer_like (type) && length <= 4) + return ((is_integer_like (type) && length <= DEPRECATED_REGISTER_SIZE) || is_pointer_like (type) - || (is_struct_like (type) && length != 8) - || (is_float_like (type) && length == 16)); + || (is_struct_like (type) && !is_double_arg (type))); } +static int +is_power_of_two (unsigned int n) +{ + return ((n & (n - 1)) == 0); +} + /* Return non-zero if TYPE should be passed as a pointer to a copy, zero otherwise. TYPE must be a SIMPLE_ARG, as recognized by `is_simple_arg'. */ @@ -1380,8 +1406,8 @@ pass_by_copy_ref (struct type *type) { unsigned length = TYPE_LENGTH (type); - return ((is_struct_like (type) && length != 1 && length != 2 && length != 4) - || (is_float_like (type) && length == 16)); + return (is_struct_like (type) + && !(is_power_of_two (length) && length <= DEPRECATED_REGISTER_SIZE)); } @@ -1404,21 +1430,6 @@ extend_simple_arg (struct value *arg) } -/* Return non-zero if TYPE is a `DOUBLE_ARG', as defined by the - parameter passing conventions described in the "GNU/Linux for S/390 - ELF Application Binary Interface Supplement". Return zero - otherwise. */ -static int -is_double_arg (struct type *type) -{ - unsigned length = TYPE_LENGTH (type); - - return ((is_integer_like (type) - || is_struct_like (type)) - && length == 8); -} - - /* Round ADDR up to the next N-byte boundary. N must be a power of two. */ static CORE_ADDR @@ -1538,9 +1549,9 @@ s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp, sp = round_down (sp, alignment_of (type)); - /* SIMPLE_ARG values get extended to 32 bits. Assume every - argument is. */ - if (length < 4) length = 4; + /* SIMPLE_ARG values get extended to DEPRECATED_REGISTER_SIZE bytes. + Assume every argument is. */ + if (length < DEPRECATED_REGISTER_SIZE) length = DEPRECATED_REGISTER_SIZE; sp -= length; } } @@ -1561,13 +1572,17 @@ s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp, int gr = 2; CORE_ADDR starg = sp; + /* A struct is returned using general register 2 */ + if (struct_return) + gr++; + for (i = 0; i < nargs; i++) { struct value *arg = args[i]; struct type *type = VALUE_TYPE (arg); if (is_double_or_float (type) - && fr <= 2) + && fr <= S390_NUM_FP_PARAMETER_REGISTERS * 2 - 2) { /* When we store a single-precision value in an FP register, it occupies the leftmost bits. */ @@ -1594,7 +1609,7 @@ s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp, deprecated_write_register_gen (S390_GP0_REGNUM + gr, VALUE_CONTENTS (arg)); deprecated_write_register_gen (S390_GP0_REGNUM + gr + 1, - VALUE_CONTENTS (arg) + 4); + VALUE_CONTENTS (arg) + DEPRECATED_REGISTER_SIZE); gr += 2; } else @@ -1610,9 +1625,9 @@ s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp, if (is_simple_arg (type)) { - /* Simple args are always either extended to 32 bits, - or pointers. */ - starg = round_up (starg, 4); + /* Simple args are always extended to + DEPRECATED_REGISTER_SIZE bytes. */ + starg = round_up (starg, DEPRECATED_REGISTER_SIZE); /* Do we need to pass a pointer to our copy of this argument? */ @@ -1620,18 +1635,19 @@ s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp, write_memory_signed_integer (starg, pointer_size, copy_addr[i]); else - /* Simple args are always extended to 32 bits. */ - write_memory_signed_integer (starg, 4, + /* Simple args are always extended to + DEPRECATED_REGISTER_SIZE bytes. */ + write_memory_signed_integer (starg, DEPRECATED_REGISTER_SIZE, extend_simple_arg (arg)); - starg += 4; + starg += DEPRECATED_REGISTER_SIZE; } else { /* You'd think we should say: starg = round_up (starg, alignment_of (type)); Unfortunately, GCC seems to simply align the stack on - a four-byte boundary, even when passing doubles. */ - starg = round_up (starg, 4); + a four/eight-byte boundary, even when passing doubles. */ + starg = round_up (starg, S390_STACK_PARAMETER_ALIGNMENT); write_memory (starg, VALUE_CONTENTS (arg), length); starg += length; } @@ -1642,7 +1658,7 @@ s390_push_arguments (int nargs, struct value **args, CORE_ADDR sp, /* Allocate the standard frame areas: the register save area, the word reserved for the compiler (which seems kind of meaningless), and the back chain pointer. */ - sp -= 96; + sp -= S390_STACK_FRAME_OVERHEAD; /* Write the back chain pointer into the first word of the stack frame. This will help us get backtraces from within functions -- 2.30.2