| From fdaab18a65ed2529656baa64cb6169f34d7e507b Mon Sep 17 00:00:00 2001 |
| From: James Cowgill <james410@cowgill.org.uk> |
| Date: Mon, 5 Jan 2015 15:17:01 +0000 |
| Subject: [PATCH 2/3] Add support for mips64 abis in mips_retval.c |
| |
| Signed-off-by: James Cowgill <james410@cowgill.org.uk> |
| |
| Upstream-Status: Backport [from debian] |
| Signed-off-by: Hongxu Jia <hongxu.jia@windriver.com> |
| --- |
| backends/mips_retval.c | 104 ++++++++++++++++++++++++++++++++++++++++++++----- |
| 1 file changed, 94 insertions(+), 10 deletions(-) |
| |
| diff --git a/backends/mips_retval.c b/backends/mips_retval.c |
| index 33f12a7..d5c6ef0 100644 |
| --- a/backends/mips_retval.c |
| +++ b/backends/mips_retval.c |
| @@ -91,6 +91,8 @@ enum mips_abi find_mips_abi(Elf *elf) |
| default: |
| if ((elf_flags & EF_MIPS_ABI2)) |
| return MIPS_ABI_N32; |
| + else if ((ehdr->e_ident[EI_CLASS] == ELFCLASS64)) |
| + return MIPS_ABI_N64; |
| } |
| |
| /* GCC creates a pseudo-section whose name describes the ABI. */ |
| @@ -195,6 +197,57 @@ static const Dwarf_Op loc_aggregate[] = |
| }; |
| #define nloc_aggregate 1 |
| |
| +/* Test if a struct member is a float */ |
| +static int is_float_child(Dwarf_Die *childdie) |
| +{ |
| + /* Test if this is actually a struct member */ |
| + if (dwarf_tag(childdie) != DW_TAG_member) |
| + return 0; |
| + |
| + /* Get type of member */ |
| + Dwarf_Attribute attr_mem; |
| + Dwarf_Die child_type_mem; |
| + Dwarf_Die *child_typedie = |
| + dwarf_formref_die(dwarf_attr_integrate(childdie, |
| + DW_AT_type, |
| + &attr_mem), &child_type_mem); |
| + |
| + if (dwarf_tag(child_typedie) != DW_TAG_base_type) |
| + return 0; |
| + |
| + /* Get base subtype */ |
| + Dwarf_Word encoding; |
| + if (dwarf_formudata (dwarf_attr_integrate (child_typedie, |
| + DW_AT_encoding, |
| + &attr_mem), &encoding) != 0) |
| + return 0; |
| + |
| + return encoding == DW_ATE_float; |
| +} |
| + |
| +/* Returns the number of fpregs which can be returned in the given struct */ |
| +static int get_struct_fpregs(Dwarf_Die *structtypedie) |
| +{ |
| + Dwarf_Die child_mem; |
| + int fpregs = 0; |
| + |
| + /* Get first structure member */ |
| + if (dwarf_child(structtypedie, &child_mem) != 0) |
| + return 0; |
| + |
| + do |
| + { |
| + /* Ensure this register is a float */ |
| + if (!is_float_child(&child_mem)) |
| + return 0; |
| + |
| + fpregs++; |
| + } |
| + while (dwarf_siblingof (&child_mem, &child_mem) == 0); |
| + |
| + return fpregs; |
| +} |
| + |
| int |
| mips_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) |
| { |
| @@ -240,6 +293,7 @@ mips_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) |
| tag = dwarf_tag (typedie); |
| } |
| |
| + Dwarf_Word size; |
| switch (tag) |
| { |
| case -1: |
| @@ -258,8 +312,6 @@ mips_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) |
| case DW_TAG_enumeration_type: |
| case DW_TAG_pointer_type: |
| case DW_TAG_ptr_to_member_type: |
| - { |
| - Dwarf_Word size; |
| if (dwarf_formudata (dwarf_attr_integrate (typedie, DW_AT_byte_size, |
| &attr_mem), &size) != 0) |
| { |
| @@ -289,7 +341,7 @@ mips_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) |
| if (size <= 4*regsize && abi == MIPS_ABI_O32) |
| return nloc_fpregquad; |
| |
| - goto aggregate; |
| + goto large; |
| } |
| } |
| *locp = ABI_LOC(loc_intreg, regsize); |
| @@ -298,18 +350,50 @@ mips_return_value_location (Dwarf_Die *functypedie, const Dwarf_Op **locp) |
| if (size <= 2*regsize) |
| return nloc_intregpair; |
| |
| - /* Else fall through. Shouldn't happen though (at least with gcc) */ |
| - } |
| + /* Else pass in memory. Shouldn't happen though (at least with gcc) */ |
| + goto large; |
| |
| case DW_TAG_structure_type: |
| case DW_TAG_class_type: |
| case DW_TAG_union_type: |
| - case DW_TAG_array_type: |
| - aggregate: |
| - /* XXX TODO: Can't handle structure return with other ABI's yet :-/ */ |
| - if ((abi != MIPS_ABI_O32) && (abi != MIPS_ABI_O64)) |
| - return -2; |
| + /* Handle special cases for structures <= 128 bytes in newer ABIs */ |
| + if (abi == MIPS_ABI_EABI32 || abi == MIPS_ABI_EABI64 || |
| + abi == MIPS_ABI_N32 || abi == MIPS_ABI_N64) |
| + { |
| + if (dwarf_aggregate_size (typedie, &size) == 0 && size <= 16) |
| + { |
| + /* |
| + * Special case in N64 / N32 - |
| + * structures containing only floats are returned in fp regs. |
| + * Everything else is returned in integer regs. |
| + */ |
| + if (tag != DW_TAG_union_type && |
| + (abi == MIPS_ABI_N32 || abi == MIPS_ABI_N64)) |
| + { |
| + int num_fpregs = get_struct_fpregs(typedie); |
| + if (num_fpregs == 1 || num_fpregs == 2) |
| + { |
| + *locp = loc_fpreg; |
| + if (num_fpregs == 1) |
| + return nloc_fpreg; |
| + else |
| + return nloc_fpregpair; |
| + } |
| + } |
| + |
| + *locp = loc_intreg; |
| + if (size <= 8) |
| + return nloc_intreg; |
| + else |
| + return nloc_intregpair; |
| + } |
| + } |
| + |
| + /* Fallthrough to handle large types */ |
| |
| + case DW_TAG_array_type: |
| + large: |
| + /* Return large structures in memory */ |
| *locp = loc_aggregate; |
| return nloc_aggregate; |
| } |
| -- |
| 2.1.4 |
| |