libgcc/config/arm/bpabi-v6m.S

   1 /* Miscellaneous BPABI functions.  Thumb-1 implementation, suitable for ARMv4T,
   2    ARMv6-M and ARMv8-M Baseline like ISA variants.
   3
   4    Copyright (C) 2006-2024 Free Software Foundation, Inc.
   5    Contributed by CodeSourcery.
   6
   7    This file is free software; you can redistribute it and/or modify it
   8    under the terms of the GNU General Public License as published by the
   9    Free Software Foundation; either version 3, or (at your option) any
  10    later version.
  11
  12    This file is distributed in the hope that it will be useful, but
  13    WITHOUT ANY WARRANTY; without even the implied warranty of
  14    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15    General Public License for more details.
  16
  17    Under Section 7 of GPL version 3, you are granted additional
  18    permissions described in the GCC Runtime Library Exception, version
  19    3.1, as published by the Free Software Foundation.
  20
  21    You should have received a copy of the GNU General Public License and
  22    a copy of the GCC Runtime Library Exception along with this program;
  23    see the files COPYING3 and COPYING.RUNTIME respectively.  If not, see
  24    <http://www.gnu.org/licenses/>.  */
  25
  26 #ifdef __ARM_EABI__
  27 /* Some attributes that are common to all routines in this file.  */
  28         /* Tag_ABI_align_needed: This code does not require 8-byte
  29            alignment from the caller.  */
  30         /* .eabi_attribute 24, 0  -- default setting.  */
  31         /* Tag_ABI_align_preserved: This code preserves 8-byte
  32            alignment in any callee.  */
  33         .eabi_attribute 25, 1
  34 #endif /* __ARM_EABI__ */
  35
  36 #ifdef L_aeabi_lcmp
  37
  38 FUNC_START aeabi_lcmp
  39         cmp     xxh, yyh
  40         beq     1f
  41         bgt     2f
  42         movs    r0, #1
  43         negs    r0, r0
  44         RET
  45 2:
  46         movs    r0, #1
  47         RET
  48 1:
  49         subs    r0, xxl, yyl
  50         beq     1f
  51         bhi     2f
  52         movs    r0, #1
  53         negs    r0, r0
  54         RET
  55 2:
  56         movs    r0, #1
  57 1:
  58         RET
  59         FUNC_END aeabi_lcmp
  60
  61 #endif /* L_aeabi_lcmp */
  62
  63 #ifdef L_aeabi_ulcmp
  64
  65 FUNC_START aeabi_ulcmp
  66         cmp     xxh, yyh
  67         bne     1f
  68         subs    r0, xxl, yyl
  69         beq     2f
  70 1:
  71         bcs     1f
  72         movs    r0, #1
  73         negs    r0, r0
  74         RET
  75 1:
  76         movs    r0, #1
  77 2:
  78         RET
  79         FUNC_END aeabi_ulcmp
  80
  81 #endif /* L_aeabi_ulcmp */
  82
  83 .macro test_div_by_zero signed
  84         cmp     yyh, #0
  85         bne     7f
  86         cmp     yyl, #0
  87         bne     7f
  88         cmp     xxh, #0
  89         .ifc    \signed, unsigned
  90         bne     2f
  91         cmp     xxl, #0
  92 2:
  93         beq     3f
  94         movs    xxh, #0
  95         mvns    xxh, xxh                @ 0xffffffff
  96         movs    xxl, xxh
  97 3:
  98         .else
  99         blt     6f
 100         bgt     4f
 101         cmp     xxl, #0
 102         beq     5f
 103 4:      movs    xxl, #0
 104         mvns    xxl, xxl                @ 0xffffffff
 105         lsrs    xxh, xxl, #1            @ 0x7fffffff
 106         b       5f
 107 6:      movs    xxh, #0x80
 108         lsls    xxh, xxh, #24           @ 0x80000000
 109         movs    xxl, #0
 110 5:
 111         .endif
 112         @ tailcalls are tricky on v6-m.
 113         push    {r0, r1, r2}
 114         ldr     r0, 1f
 115         adr     r1, 1f
 116         adds    r0, r1
 117         str     r0, [sp, #8]
 118         @ We know we are not on armv4t, so pop pc is safe.
 119         pop     {r0, r1, pc}
 120         .align  2
 121 1:
 122         .word   __aeabi_ldiv0 - 1b
 123 7:
 124 .endm
 125
 126 #ifdef L_aeabi_ldivmod
 127
 128 FUNC_START aeabi_ldivmod
 129         test_div_by_zero signed
 130
 131         push    {r0, r1}
 132         mov     r0, sp
 133         push    {r0, lr}
 134         ldr     r0, [sp, #8]
 135         bl      SYM(__gnu_ldivmod_helper)
 136         ldr     r3, [sp, #4]
 137         mov     lr, r3
 138         add     sp, sp, #8
 139         pop     {r2, r3}
 140         RET
 141         FUNC_END aeabi_ldivmod
 142
 143 #endif /* L_aeabi_ldivmod */
 144
 145 #ifdef L_aeabi_uldivmod
 146
 147 FUNC_START aeabi_uldivmod
 148         test_div_by_zero unsigned
 149
 150         push    {r0, r1}
 151         mov     r0, sp
 152         push    {r0, lr}
 153         ldr     r0, [sp, #8]
 154         bl      SYM(__udivmoddi4)
 155         ldr     r3, [sp, #4]
 156         mov     lr, r3
 157         add     sp, sp, #8
 158         pop     {r2, r3}
 159         RET
 160         FUNC_END aeabi_uldivmod
 161
 162 #endif /* L_aeabi_uldivmod */
 163
 164 #ifdef L_arm_addsubsf3
 165
 166 FUNC_START aeabi_frsub
 167
 168       push      {r4, lr}
 169       movs      r4, #1
 170       lsls      r4, #31
 171       eors      r0, r0, r4
 172       bl        __aeabi_fadd
 173       pop       {r4, pc}
 174
 175       FUNC_END aeabi_frsub
 176
 177 #endif /* L_arm_addsubsf3 */
 178
 179 #ifdef L_arm_cmpsf2
 180
 181 FUNC_START aeabi_cfrcmple
 182
 183         mov     ip, r0
 184         movs    r0, r1
 185         mov     r1, ip
 186         b       6f
 187
 188 FUNC_START aeabi_cfcmpeq
 189 FUNC_ALIAS aeabi_cfcmple aeabi_cfcmpeq
 190
 191         @ The status-returning routines are required to preserve all
 192         @ registers except ip, lr, and cpsr.
 193 6:      push    {r0, r1, r2, r3, r4, lr}
 194         bl      __lesf2
 195         @ Set the Z flag correctly, and the C flag unconditionally.
 196         cmp     r0, #0
 197         @ Clear the C flag if the return value was -1, indicating
 198         @ that the first operand was smaller than the second.
 199         bmi     1f
 200         movs    r1, #0
 201         cmn     r0, r1
 202 1:
 203         pop     {r0, r1, r2, r3, r4, pc}
 204
 205         FUNC_END aeabi_cfcmple
 206         FUNC_END aeabi_cfcmpeq
 207         FUNC_END aeabi_cfrcmple
 208
 209 FUNC_START      aeabi_fcmpeq
 210
 211         push    {r4, lr}
 212         bl      __eqsf2
 213         negs    r0, r0
 214         adds    r0, r0, #1
 215         pop     {r4, pc}
 216
 217         FUNC_END aeabi_fcmpeq
 218
 219 .macro COMPARISON cond, helper, mode=sf2
 220 FUNC_START      aeabi_fcmp\cond
 221
 222         push    {r4, lr}
 223         bl      __\helper\mode
 224         cmp     r0, #0
 225         b\cond  1f
 226         movs    r0, #0
 227         pop     {r4, pc}
 228 1:
 229         movs    r0, #1
 230         pop     {r4, pc}
 231
 232         FUNC_END aeabi_fcmp\cond
 233 .endm
 234
 235 COMPARISON lt, le
 236 COMPARISON le, le
 237 COMPARISON gt, ge
 238 COMPARISON ge, ge
 239
 240 #endif /* L_arm_cmpsf2 */
 241
 242 #ifdef L_arm_addsubdf3
 243
 244 FUNC_START aeabi_drsub
 245
 246       push      {r4, lr}
 247       movs      r4, #1
 248       lsls      r4, #31
 249       eors      xxh, xxh, r4
 250       bl        __aeabi_dadd
 251       pop       {r4, pc}
 252
 253       FUNC_END aeabi_drsub
 254
 255 #endif /* L_arm_addsubdf3 */
 256
 257 #ifdef L_arm_cmpdf2
 258
 259 FUNC_START aeabi_cdrcmple
 260
 261         mov     ip, r0
 262         movs    r0, r2
 263         mov     r2, ip
 264         mov     ip, r1
 265         movs    r1, r3
 266         mov     r3, ip
 267         b       6f
 268
 269 FUNC_START aeabi_cdcmpeq
 270 FUNC_ALIAS aeabi_cdcmple aeabi_cdcmpeq
 271
 272         @ The status-returning routines are required to preserve all
 273         @ registers except ip, lr, and cpsr.
 274 6:      push    {r0, r1, r2, r3, r4, lr}
 275         bl      __ledf2
 276         @ Set the Z flag correctly, and the C flag unconditionally.
 277         cmp     r0, #0
 278         @ Clear the C flag if the return value was -1, indicating
 279         @ that the first operand was smaller than the second.
 280         bmi     1f
 281         movs    r1, #0
 282         cmn     r0, r1
 283 1:
 284         pop     {r0, r1, r2, r3, r4, pc}
 285
 286         FUNC_END aeabi_cdcmple
 287         FUNC_END aeabi_cdcmpeq
 288         FUNC_END aeabi_cdrcmple
 289
 290 FUNC_START      aeabi_dcmpeq
 291
 292         push    {r4, lr}
 293         bl      __eqdf2
 294         negs    r0, r0
 295         adds    r0, r0, #1
 296         pop     {r4, pc}
 297
 298         FUNC_END aeabi_dcmpeq
 299
 300 .macro COMPARISON cond, helper, mode=df2
 301 FUNC_START      aeabi_dcmp\cond
 302
 303         push    {r4, lr}
 304         bl      __\helper\mode
 305         cmp     r0, #0
 306         b\cond  1f
 307         movs    r0, #0
 308         pop     {r4, pc}
 309 1:
 310         movs    r0, #1
 311         pop     {r4, pc}
 312
 313         FUNC_END aeabi_dcmp\cond
 314 .endm
 315
 316 COMPARISON lt, le
 317 COMPARISON le, le
 318 COMPARISON gt, ge
 319 COMPARISON ge, ge
 320
 321 #endif /* L_arm_cmpdf2 */