libgcc/config/arm/bpabi.S

   1 /* Miscellaneous BPABI functions.
   2
   3    Copyright (C) 2003-2019 Free Software Foundation, Inc.
   4    Contributed by CodeSourcery, LLC.
   5
   6    This file is free software; you can redistribute it and/or modify it
   7    under the terms of the GNU General Public License as published by the
   8    Free Software Foundation; either version 3, or (at your option) any
   9    later version.
  10
  11    This file is distributed in the hope that it will be useful, but
  12    WITHOUT ANY WARRANTY; without even the implied warranty of
  13    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  14    General Public License for more details.
  15
  16    Under Section 7 of GPL version 3, you are granted additional
  17    permissions described in the GCC Runtime Library Exception, version
  18    3.1, as published by the Free Software Foundation.
  19
  20    You should have received a copy of the GNU General Public License and
  21    a copy of the GCC Runtime Library Exception along with this program;
  22    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  23    <http://www.gnu.org/licenses/>.  */
  24
  25         .cfi_sections .debug_frame
  26
  27 #ifdef __ARM_EABI__
  28 /* Some attributes that are common to all routines in this file.  */
  29         /* Tag_ABI_align_needed: This code does not require 8-byte
  30            alignment from the caller.  */
  31         /* .eabi_attribute 24, 0  -- default setting.  */
  32         /* Tag_ABI_align_preserved: This code preserves 8-byte
  33            alignment in any callee.  */
  34         .eabi_attribute 25, 1
  35 #endif /* __ARM_EABI__ */
  36
  37 #ifdef L_aeabi_lcmp
  38
  39 ARM_FUNC_START aeabi_lcmp
  40         cmp     xxh, yyh
  41         do_it   lt
  42         movlt   r0, #-1
  43         do_it   gt
  44         movgt   r0, #1
  45         do_it   ne
  46         RETc(ne)
  47         subs    r0, xxl, yyl
  48         do_it   lo
  49         movlo   r0, #-1
  50         do_it   hi
  51         movhi   r0, #1
  52         RET
  53         FUNC_END aeabi_lcmp
  54
  55 #endif /* L_aeabi_lcmp */
  56
  57 #ifdef L_aeabi_ulcmp
  58
  59 ARM_FUNC_START aeabi_ulcmp
  60         cmp     xxh, yyh
  61         do_it   lo
  62         movlo   r0, #-1
  63         do_it   hi
  64         movhi   r0, #1
  65         do_it   ne
  66         RETc(ne)
  67         cmp     xxl, yyl
  68         do_it   lo
  69         movlo   r0, #-1
  70         do_it   hi
  71         movhi   r0, #1
  72         do_it   eq
  73         moveq   r0, #0
  74         RET
  75         FUNC_END aeabi_ulcmp
  76
  77 #endif /* L_aeabi_ulcmp */
  78
  79 .macro test_div_by_zero signed
  80 /* Tail-call to divide-by-zero handlers which may be overridden by the user,
  81    so unwinding works properly.  */
  82 #if defined(__thumb2__)
  83         cbnz    yyh, 2f
  84         cbnz    yyl, 2f
  85         cmp     xxh, #0
  86         .ifc \signed, unsigned
  87         do_it   eq
  88         cmpeq   xxl, #0
  89         do_it   ne, t
  90         movne   xxh, #0xffffffff
  91         movne   xxl, #0xffffffff
  92         .else
  93         do_it   lt, tt
  94         movlt   xxl, #0
  95         movlt   xxh, #0x80000000
  96         blt     1f
  97         do_it   eq
  98         cmpeq   xxl, #0
  99         do_it   ne, t
 100         movne   xxh, #0x7fffffff
 101         movne   xxl, #0xffffffff
 102         .endif
 103 1:
 104         b       SYM (__aeabi_ldiv0) __PLT__
 105 2:
 106 #else
 107         /* Note: Thumb-1 code calls via an ARM shim on processors which
 108            support ARM mode.  */
 109         cmp     yyh, #0
 110         cmpeq   yyl, #0
 111         bne     2f
 112         cmp     xxh, #0
 113         .ifc \signed, unsigned
 114         cmpeq   xxl, #0
 115         movne   xxh, #0xffffffff
 116         movne   xxl, #0xffffffff
 117         .else
 118         movlt   xxh, #0x80000000
 119         movlt   xxl, #0
 120         blt     1f
 121         cmpeq   xxl, #0
 122         movne   xxh, #0x7fffffff
 123         movne   xxl, #0xffffffff
 124         .endif
 125 1:
 126         b       SYM (__aeabi_ldiv0) __PLT__
 127 2:
 128 #endif
 129 .endm
 130
 131 /* we can use STRD/LDRD on v5TE and later, and any Thumb-2 architecture. */
 132 #if (defined(__ARM_EABI__)                                            \
 133      && (defined(__thumb2__)                                          \
 134          || (__ARM_ARCH >= 5 && defined(__TARGET_FEATURE_DSP))))
 135 #define CAN_USE_LDRD 1
 136 #else
 137 #define CAN_USE_LDRD 0
 138 #endif
 139
 140 /* set up stack from for call to __udivmoddi4. At the end of the macro the
 141    stack is arranged as follows:
 142                 sp+12   / space for remainder
 143                 sp+8    \ (written by __udivmoddi4)
 144                 sp+4    lr
 145                 sp+0    sp+8 [rp (remainder pointer) argument for __udivmoddi4]
 146
 147  */
 148 .macro push_for_divide fname
 149 #if defined(__thumb2__) && CAN_USE_LDRD
 150         sub     ip, sp, #8
 151         strd    ip, lr, [sp, #-16]!
 152 #else
 153         sub     sp, sp, #8
 154         do_push {sp, lr}
 155 #endif
 156         .cfi_adjust_cfa_offset 16
 157         .cfi_offset 14, -12
 158 .endm
 159
 160 /* restore stack */
 161 .macro pop_for_divide
 162         ldr     lr, [sp, #4]
 163 #if CAN_USE_LDRD
 164         ldrd    r2, r3, [sp, #8]
 165         add     sp, sp, #16
 166 #else
 167         add     sp, sp, #8
 168         do_pop  {r2, r3}
 169 #endif
 170         .cfi_restore 14
 171         .cfi_adjust_cfa_offset 0
 172 .endm
 173
 174 #ifdef L_aeabi_ldivmod
 175
 176 /* Perform 64 bit signed division.
 177    Inputs:
 178         r0:r1   numerator
 179         r2:r3   denominator
 180    Outputs:
 181         r0:r1   quotient
 182         r2:r3   remainder
 183  */
 184 ARM_FUNC_START aeabi_ldivmod
 185         .cfi_startproc
 186         test_div_by_zero        signed
 187
 188         push_for_divide __aeabi_ldivmod
 189         cmp     xxh, #0
 190         blt     1f
 191         cmp     yyh, #0
 192         blt     2f
 193         /* arguments in (r0:r1), (r2:r3) and *sp */
 194         bl      SYM(__udivmoddi4) __PLT__
 195         .cfi_remember_state
 196         pop_for_divide
 197         RET
 198
 199 1: /* xxh:xxl is negative */
 200         .cfi_restore_state
 201         negs    xxl, xxl
 202         sbc     xxh, xxh, xxh, lsl #1   /* Thumb-2 has no RSC, so use X - 2X */
 203         cmp     yyh, #0
 204         blt     3f
 205         /* arguments in (r0:r1), (r2:r3) and *sp */
 206         bl      SYM(__udivmoddi4) __PLT__
 207         .cfi_remember_state
 208         pop_for_divide
 209         negs    xxl, xxl
 210         sbc     xxh, xxh, xxh, lsl #1   /* Thumb-2 has no RSC, so use X - 2X */
 211         negs    yyl, yyl
 212         sbc     yyh, yyh, yyh, lsl #1   /* Thumb-2 has no RSC, so use X - 2X */
 213         RET
 214
 215 2: /* only yyh:yyl is negative */
 216         .cfi_restore_state
 217         negs    yyl, yyl
 218         sbc     yyh, yyh, yyh, lsl #1   /* Thumb-2 has no RSC, so use X - 2X */
 219         /* arguments in (r0:r1), (r2:r3) and *sp */
 220         bl      SYM(__udivmoddi4) __PLT__
 221         .cfi_remember_state
 222         pop_for_divide
 223         negs    xxl, xxl
 224         sbc     xxh, xxh, xxh, lsl #1   /* Thumb-2 has no RSC, so use X - 2X */
 225         RET
 226
 227 3: /* both xxh:xxl and yyh:yyl are negative */
 228         .cfi_restore_state
 229         negs    yyl, yyl
 230         sbc     yyh, yyh, yyh, lsl #1   /* Thumb-2 has no RSC, so use X - 2X */
 231         /* arguments in (r0:r1), (r2:r3) and *sp */
 232         bl      SYM(__udivmoddi4) __PLT__
 233         pop_for_divide
 234         negs    yyl, yyl
 235         sbc     yyh, yyh, yyh, lsl #1   /* Thumb-2 has no RSC, so use X - 2X */
 236         RET
 237
 238         .cfi_endproc
 239
 240 #endif /* L_aeabi_ldivmod */
 241
 242 #ifdef L_aeabi_uldivmod
 243
 244 /* Perform 64 bit signed division.
 245    Inputs:
 246         r0:r1   numerator
 247         r2:r3   denominator
 248    Outputs:
 249         r0:r1   quotient
 250         r2:r3   remainder
 251  */
 252 ARM_FUNC_START aeabi_uldivmod
 253         .cfi_startproc
 254         test_div_by_zero        unsigned
 255
 256         push_for_divide __aeabi_uldivmod
 257         /* arguments in (r0:r1), (r2:r3) and *sp */
 258         bl      SYM(__udivmoddi4) __PLT__
 259         pop_for_divide
 260         RET
 261         .cfi_endproc
 262
 263 #endif /* L_aeabi_divmod */
 264