From 90445bd31fa9fcf2b9f080b65fc5d2d3a3ca5bb0 Mon Sep 17 00:00:00 2001 From: Daniel Jacobowitz Date: Tue, 28 Jul 2009 17:30:52 +0000 Subject: [PATCH] * arm-tdep.c (enum arm_vfp_cprc_base_type, arm_vfp_cprc_unit_length, arm_vfp_cprc_reg_char, arm_vfp_cprc_sub_candidate, arm_vfp_call_candidate, arm_vfp_abi_for_function): New. (arm_push_dummy_call): Handle VFP ABI. (arm_extract_return_value, arm_store_return_value): Handle ARM_FLOAT_VFP case. (arm_return_value): Handle VFP ABI. (arm_gdbarch_init): Default fp_model based on Tag_ABI_VFP_args for EABI binaries. --- gdb/ChangeLog | 13 ++ gdb/arm-tdep.c | 360 ++++++++++++++++++++++++++++++++++++++++++++++++- 2 files changed, 367 insertions(+), 6 deletions(-) diff --git a/gdb/ChangeLog b/gdb/ChangeLog index fc1784e58b8..90056a54eb2 100644 --- a/gdb/ChangeLog +++ b/gdb/ChangeLog @@ -1,3 +1,16 @@ +2009-07-28 Joseph Myers + + * arm-tdep.c (enum arm_vfp_cprc_base_type, + arm_vfp_cprc_unit_length, arm_vfp_cprc_reg_char, + arm_vfp_cprc_sub_candidate, arm_vfp_call_candidate, + arm_vfp_abi_for_function): New. + (arm_push_dummy_call): Handle VFP ABI. + (arm_extract_return_value, arm_store_return_value): Handle + ARM_FLOAT_VFP case. + (arm_return_value): Handle VFP ABI. + (arm_gdbarch_init): Default fp_model based on Tag_ABI_VFP_args for + EABI binaries. + 2009-07-28 Daniel Jacobowitz * arch-utils.c (displaced_step_at_entry_point): Do not call diff --git a/gdb/arm-tdep.c b/gdb/arm-tdep.c index 58bdc1f0375..733318d1d90 100644 --- a/gdb/arm-tdep.c +++ b/gdb/arm-tdep.c @@ -1373,8 +1373,222 @@ arm_type_align (struct type *t) } } -/* We currently only support passing parameters in integer registers. This - conforms with GCC's default model. Several other variants exist and +/* Possible base types for a candidate for passing and returning in + VFP registers. */ + +enum arm_vfp_cprc_base_type +{ + VFP_CPRC_UNKNOWN, + VFP_CPRC_SINGLE, + VFP_CPRC_DOUBLE, + VFP_CPRC_VEC64, + VFP_CPRC_VEC128 +}; + +/* The length of one element of base type B. */ + +static unsigned +arm_vfp_cprc_unit_length (enum arm_vfp_cprc_base_type b) +{ + switch (b) + { + case VFP_CPRC_SINGLE: + return 4; + case VFP_CPRC_DOUBLE: + return 8; + case VFP_CPRC_VEC64: + return 8; + case VFP_CPRC_VEC128: + return 16; + default: + internal_error (__FILE__, __LINE__, _("Invalid VFP CPRC type: %d."), + (int) b); + } +} + +/* The character ('s', 'd' or 'q') for the type of VFP register used + for passing base type B. */ + +static int +arm_vfp_cprc_reg_char (enum arm_vfp_cprc_base_type b) +{ + switch (b) + { + case VFP_CPRC_SINGLE: + return 's'; + case VFP_CPRC_DOUBLE: + return 'd'; + case VFP_CPRC_VEC64: + return 'd'; + case VFP_CPRC_VEC128: + return 'q'; + default: + internal_error (__FILE__, __LINE__, _("Invalid VFP CPRC type: %d."), + (int) b); + } +} + +/* Determine whether T may be part of a candidate for passing and + returning in VFP registers, ignoring the limit on the total number + of components. If *BASE_TYPE is VFP_CPRC_UNKNOWN, set it to the + classification of the first valid component found; if it is not + VFP_CPRC_UNKNOWN, all components must have the same classification + as *BASE_TYPE. If it is found that T contains a type not permitted + for passing and returning in VFP registers, a type differently + classified from *BASE_TYPE, or two types differently classified + from each other, return -1, otherwise return the total number of + base-type elements found (possibly 0 in an empty structure or + array). Vectors and complex types are not currently supported, + matching the generic AAPCS support. */ + +static int +arm_vfp_cprc_sub_candidate (struct type *t, + enum arm_vfp_cprc_base_type *base_type) +{ + t = check_typedef (t); + switch (TYPE_CODE (t)) + { + case TYPE_CODE_FLT: + switch (TYPE_LENGTH (t)) + { + case 4: + if (*base_type == VFP_CPRC_UNKNOWN) + *base_type = VFP_CPRC_SINGLE; + else if (*base_type != VFP_CPRC_SINGLE) + return -1; + return 1; + + case 8: + if (*base_type == VFP_CPRC_UNKNOWN) + *base_type = VFP_CPRC_DOUBLE; + else if (*base_type != VFP_CPRC_DOUBLE) + return -1; + return 1; + + default: + return -1; + } + break; + + case TYPE_CODE_ARRAY: + { + int count; + unsigned unitlen; + count = arm_vfp_cprc_sub_candidate (TYPE_TARGET_TYPE (t), base_type); + if (count == -1) + return -1; + if (TYPE_LENGTH (t) == 0) + { + gdb_assert (count == 0); + return 0; + } + else if (count == 0) + return -1; + unitlen = arm_vfp_cprc_unit_length (*base_type); + gdb_assert ((TYPE_LENGTH (t) % unitlen) == 0); + return TYPE_LENGTH (t) / unitlen; + } + break; + + case TYPE_CODE_STRUCT: + { + int count = 0; + unsigned unitlen; + int i; + for (i = 0; i < TYPE_NFIELDS (t); i++) + { + int sub_count = arm_vfp_cprc_sub_candidate (TYPE_FIELD_TYPE (t, i), + base_type); + if (sub_count == -1) + return -1; + count += sub_count; + } + if (TYPE_LENGTH (t) == 0) + { + gdb_assert (count == 0); + return 0; + } + else if (count == 0) + return -1; + unitlen = arm_vfp_cprc_unit_length (*base_type); + if (TYPE_LENGTH (t) != unitlen * count) + return -1; + return count; + } + + case TYPE_CODE_UNION: + { + int count = 0; + unsigned unitlen; + int i; + for (i = 0; i < TYPE_NFIELDS (t); i++) + { + int sub_count = arm_vfp_cprc_sub_candidate (TYPE_FIELD_TYPE (t, i), + base_type); + if (sub_count == -1) + return -1; + count = (count > sub_count ? count : sub_count); + } + if (TYPE_LENGTH (t) == 0) + { + gdb_assert (count == 0); + return 0; + } + else if (count == 0) + return -1; + unitlen = arm_vfp_cprc_unit_length (*base_type); + if (TYPE_LENGTH (t) != unitlen * count) + return -1; + return count; + } + + default: + break; + } + + return -1; +} + +/* Determine whether T is a VFP co-processor register candidate (CPRC) + if passed to or returned from a non-variadic function with the VFP + ABI in effect. Return 1 if it is, 0 otherwise. If it is, set + *BASE_TYPE to the base type for T and *COUNT to the number of + elements of that base type before returning. */ + +static int +arm_vfp_call_candidate (struct type *t, enum arm_vfp_cprc_base_type *base_type, + int *count) +{ + enum arm_vfp_cprc_base_type b = VFP_CPRC_UNKNOWN; + int c = arm_vfp_cprc_sub_candidate (t, &b); + if (c <= 0 || c > 4) + return 0; + *base_type = b; + *count = c; + return 1; +} + +/* Return 1 if the VFP ABI should be used for passing arguments to and + returning values from a function of type FUNC_TYPE, 0 + otherwise. */ + +static int +arm_vfp_abi_for_function (struct gdbarch *gdbarch, struct type *func_type) +{ + struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + /* Variadic functions always use the base ABI. Assume that functions + without debug info are not variadic. */ + if (func_type && TYPE_VARARGS (check_typedef (func_type))) + return 0; + /* The VFP ABI is only supported as a variant of AAPCS. */ + if (tdep->arm_abi != ARM_ABI_AAPCS) + return 0; + return gdbarch_tdep (gdbarch)->fp_model == ARM_FLOAT_VFP; +} + +/* We currently only support passing parameters in integer registers, which + conforms with GCC's default model, and VFP argument passing following + the VFP variant of AAPCS. Several other variants exist and we should probably support some of them based on the selected ABI. */ static CORE_ADDR @@ -1388,6 +1602,16 @@ arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function, int argreg; int nstack; struct stack_item *si = NULL; + int use_vfp_abi; + struct type *ftype; + unsigned vfp_regs_free = (1 << 16) - 1; + + /* Determine the type of this function and whether the VFP ABI + applies. */ + ftype = check_typedef (value_type (function)); + if (TYPE_CODE (ftype) == TYPE_CODE_PTR) + ftype = check_typedef (TYPE_TARGET_TYPE (ftype)); + use_vfp_abi = arm_vfp_abi_for_function (gdbarch, ftype); /* Set the return address. For the ARM, the return breakpoint is always at BP_ADDR. */ @@ -1422,6 +1646,9 @@ arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function, enum type_code typecode; bfd_byte *val; int align; + enum arm_vfp_cprc_base_type vfp_base_type; + int vfp_base_count; + int may_use_core_reg = 1; arg_type = check_typedef (value_type (args[argnum])); len = TYPE_LENGTH (arg_type); @@ -1445,6 +1672,59 @@ arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function, align = INT_REGISTER_SIZE * 2; } + if (use_vfp_abi + && arm_vfp_call_candidate (arg_type, &vfp_base_type, + &vfp_base_count)) + { + int regno; + int unit_length; + int shift; + unsigned mask; + + /* Because this is a CPRC it cannot go in a core register or + cause a core register to be skipped for alignment. + Either it goes in VFP registers and the rest of this loop + iteration is skipped for this argument, or it goes on the + stack (and the stack alignment code is correct for this + case). */ + may_use_core_reg = 0; + + unit_length = arm_vfp_cprc_unit_length (vfp_base_type); + shift = unit_length / 4; + mask = (1 << (shift * vfp_base_count)) - 1; + for (regno = 0; regno < 16; regno += shift) + if (((vfp_regs_free >> regno) & mask) == mask) + break; + + if (regno < 16) + { + int reg_char; + int reg_scaled; + int i; + + vfp_regs_free &= ~(mask << regno); + reg_scaled = regno / shift; + reg_char = arm_vfp_cprc_reg_char (vfp_base_type); + for (i = 0; i < vfp_base_count; i++) + { + char name_buf[4]; + int regnum; + sprintf (name_buf, "%c%d", reg_char, reg_scaled + i); + regnum = user_reg_map_name_to_regnum (gdbarch, name_buf, + strlen (name_buf)); + regcache_cooked_write (regcache, regnum, + val + i * unit_length); + } + continue; + } + else + { + /* This CPRC could not go in VFP registers, so all VFP + registers are now marked as used. */ + vfp_regs_free = 0; + } + } + /* Push stack padding for dowubleword alignment. */ if (nstack & (align - 1)) { @@ -1453,7 +1733,8 @@ arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function, } /* Doubleword aligned quantities must go in even register pairs. */ - if (argreg <= ARM_LAST_ARG_REGNUM + if (may_use_core_reg + && argreg <= ARM_LAST_ARG_REGNUM && align > INT_REGISTER_SIZE && argreg & 1) argreg++; @@ -1481,7 +1762,7 @@ arm_push_dummy_call (struct gdbarch *gdbarch, struct value *function, { int partial_len = len < INT_REGISTER_SIZE ? len : INT_REGISTER_SIZE; - if (argreg <= ARM_LAST_ARG_REGNUM) + if (may_use_core_reg && argreg <= ARM_LAST_ARG_REGNUM) { /* The argument is being passed in a general purpose register. */ @@ -2315,6 +2596,9 @@ arm_extract_return_value (struct type *type, struct regcache *regs, case ARM_FLOAT_SOFT_FPA: case ARM_FLOAT_SOFT_VFP: + /* ARM_FLOAT_VFP can arise if this is a variadic function so + not using the VFP ABI code. */ + case ARM_FLOAT_VFP: regcache_cooked_read (regs, ARM_A1_REGNUM, valbuf); if (TYPE_LENGTH (type) > 4) regcache_cooked_read (regs, ARM_A1_REGNUM + 1, @@ -2501,6 +2785,9 @@ arm_store_return_value (struct type *type, struct regcache *regs, case ARM_FLOAT_SOFT_FPA: case ARM_FLOAT_SOFT_VFP: + /* ARM_FLOAT_VFP can arise if this is a variadic function so + not using the VFP ABI code. */ + case ARM_FLOAT_VFP: regcache_cooked_write (regs, ARM_A1_REGNUM, valbuf); if (TYPE_LENGTH (type) > 4) regcache_cooked_write (regs, ARM_A1_REGNUM + 1, @@ -2576,6 +2863,31 @@ arm_return_value (struct gdbarch *gdbarch, struct type *func_type, gdb_byte *readbuf, const gdb_byte *writebuf) { struct gdbarch_tdep *tdep = gdbarch_tdep (gdbarch); + enum arm_vfp_cprc_base_type vfp_base_type; + int vfp_base_count; + + if (arm_vfp_abi_for_function (gdbarch, func_type) + && arm_vfp_call_candidate (valtype, &vfp_base_type, &vfp_base_count)) + { + int reg_char = arm_vfp_cprc_reg_char (vfp_base_type); + int unit_length = arm_vfp_cprc_unit_length (vfp_base_type); + int i; + for (i = 0; i < vfp_base_count; i++) + { + char name_buf[4]; + int regnum; + sprintf (name_buf, "%c%d", reg_char, i); + regnum = user_reg_map_name_to_regnum (gdbarch, name_buf, + strlen (name_buf)); + if (writebuf) + regcache_cooked_write (regcache, regnum, + writebuf + i * unit_length); + if (readbuf) + regcache_cooked_read (regcache, regnum, + readbuf + i * unit_length); + } + return RETURN_VALUE_REGISTER_CONVENTION; + } if (TYPE_CODE (valtype) == TYPE_CODE_STRUCT || TYPE_CODE (valtype) == TYPE_CODE_UNION @@ -3151,9 +3463,45 @@ arm_gdbarch_init (struct gdbarch_info info, struct gdbarch_list *arches) case EF_ARM_EABI_VER4: case EF_ARM_EABI_VER5: arm_abi = ARM_ABI_AAPCS; - /* EABI binaries default to VFP float ordering. */ + /* EABI binaries default to VFP float ordering. + They may also contain build attributes that can + be used to identify if the VFP argument-passing + ABI is in use. */ if (fp_model == ARM_FLOAT_AUTO) - fp_model = ARM_FLOAT_SOFT_VFP; + { +#ifdef HAVE_ELF + switch (bfd_elf_get_obj_attr_int (info.abfd, + OBJ_ATTR_PROC, + Tag_ABI_VFP_args)) + { + case 0: + /* "The user intended FP parameter/result + passing to conform to AAPCS, base + variant". */ + fp_model = ARM_FLOAT_SOFT_VFP; + break; + case 1: + /* "The user intended FP parameter/result + passing to conform to AAPCS, VFP + variant". */ + fp_model = ARM_FLOAT_VFP; + break; + case 2: + /* "The user intended FP parameter/result + passing to conform to tool chain-specific + conventions" - we don't know any such + conventions, so leave it as "auto". */ + break; + default: + /* Attribute value not mentioned in the + October 2008 ABI, so leave it as + "auto". */ + break; + } +#else + fp_model = ARM_FLOAT_SOFT_VFP; +#endif + } break; default: -- 2.30.2