compiler-rt/lib/builtins/arm/sync-ops.h

   1 //===-- sync-ops.h - --===//
   2 //
   3 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
   4 // See https://llvm.org/LICENSE.txt for license information.
   5 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
   6 //
   7 //===----------------------------------------------------------------------===//
   8 //
   9 // This file implements outline macros for the __sync_fetch_and_*
  10 // operations. Different instantiations will generate appropriate assembly for
  11 // ARM and Thumb-2 versions of the functions.
  12 //
  13 //===----------------------------------------------------------------------===//
  14
  15 #include "../assembly.h"
  16
  17 #if __ARM_ARCH >= 7
  18 #define DMB dmb
  19 #elif __ARM_ARCH >= 6
  20 #define DMB mcr p15, #0, r0, c7, c10, #5
  21 #else
  22 #error DMB is only supported on ARMv6+
  23 #endif
  24
  25 #define SYNC_OP_4(op)                                                          \
  26   .p2align 2;                                                                  \
  27   .syntax unified;                                                             \
  28   DEFINE_COMPILERRT_FUNCTION(__sync_fetch_and_##op)                            \
  29   DMB;                                                                         \
  30   mov r12, r0;                                                                 \
  31   LOCAL_LABEL(tryatomic_##op) : ldrex r0, [r12];                               \
  32   op(r2, r0, r1);                                                              \
  33   strex r3, r2, [r12];                                                         \
  34   cmp r3, #0;                                                                  \
  35   bne LOCAL_LABEL(tryatomic_##op);                                             \
  36   DMB;                                                                         \
  37   bx lr
  38
  39 #define SYNC_OP_8(op)                                                          \
  40   .p2align 2;                                                                  \
  41   .syntax unified;                                                             \
  42   DEFINE_COMPILERRT_FUNCTION(__sync_fetch_and_##op)                            \
  43   push {r4, r5, r6, lr};                                                       \
  44   DMB;                                                                         \
  45   mov r12, r0;                                                                 \
  46   LOCAL_LABEL(tryatomic_##op) : ldrexd r0, r1, [r12];                          \
  47   op(r4, r5, r0, r1, r2, r3);                                                  \
  48   strexd r6, r4, r5, [r12];                                                    \
  49   cmp r6, #0;                                                                  \
  50   bne LOCAL_LABEL(tryatomic_##op);                                             \
  51   DMB;                                                                         \
  52   pop { r4, r5, r6, pc }
  53
  54 #define MINMAX_4(rD, rN, rM, cmp_kind)                                         \
  55   cmp rN, rM;                                                                  \
  56   mov rD, rM;                                                                  \
  57   it cmp_kind;                                                                 \
  58   mov##cmp_kind rD, rN
  59
  60 #define MINMAX_8(rD_LO, rD_HI, rN_LO, rN_HI, rM_LO, rM_HI, cmp_kind)           \
  61   cmp rN_LO, rM_LO;                                                            \
  62   sbcs rN_HI, rM_HI;                                                           \
  63   mov rD_LO, rM_LO;                                                            \
  64   mov rD_HI, rM_HI;                                                            \
  65   itt cmp_kind;                                                                \
  66   mov##cmp_kind rD_LO, rN_LO;                                                  \
  67   mov##cmp_kind rD_HI, rN_HI