ghc/runtime/c-as-asm/CallWrap_C.lc

   1 %************************************************************************
   2 %*                                                                      *
   3 \section[CallWrap_C.lc]{``callWrapper'' stuff that can be written in C}
   4 %*                                                                      *
   5 %************************************************************************
   6
   7 \begin{code}
   8 #define MAIN_REG_MAP        /* These routines are all a bit special */
   9 #define CALLWRAPPER_C       /* Don't give standard declarations for wrappers */
  10 #include "rtsdefs.h"
  11 \end{code}
  12
  13 %************************************************************************
  14 %*                                                                      *
  15 \subsection[call-wrapping]{Routines to ``wrap'' special calls to C}
  16 %*                                                                      *
  17 %************************************************************************
  18
  19 In most cases, this requires some assembly-language hacking (see the
  20 discussion in @COptWraps.lh@.)
  21
  22 \begin{code}
  23 #if defined(__STG_GCC_REGS__)
  24
  25 # if defined(CALLER_SAVES_SYSTEM) || defined(CALLER_SAVES_USER)
  26 void
  27 callWrapper(STG_NO_ARGS)
  28 {
  29     MAGIC_CALL_SETUP
  30
  31     CALLER_SAVE_Base
  32     CALLER_SAVE_StkO
  33     CALLER_SAVE_R1
  34     CALLER_SAVE_R2
  35     CALLER_SAVE_R3
  36     CALLER_SAVE_R4
  37     CALLER_SAVE_R5
  38     CALLER_SAVE_R6
  39     CALLER_SAVE_R7
  40     CALLER_SAVE_R8
  41     CALLER_SAVE_FltReg1
  42     CALLER_SAVE_FltReg2
  43     CALLER_SAVE_FltReg3
  44     CALLER_SAVE_FltReg4
  45     CALLER_SAVE_DblReg1
  46     CALLER_SAVE_DblReg2
  47     CALLER_SAVE_Tag
  48     CALLER_SAVE_SpA
  49     CALLER_SAVE_SuA
  50     CALLER_SAVE_SpB
  51     CALLER_SAVE_SuB
  52     CALLER_SAVE_Hp
  53     CALLER_SAVE_HpLim
  54     CALLER_SAVE_Liveness
  55     CALLER_SAVE_Ret
  56
  57     MAGIC_CALL
  58
  59     CALLER_RESTORE_Base     /* has to be first! */
  60
  61     CALLER_RESTORE_StkO
  62     CALLER_RESTORE_R1
  63     CALLER_RESTORE_R2
  64     CALLER_RESTORE_R3
  65     CALLER_RESTORE_R4
  66     CALLER_RESTORE_R5
  67     CALLER_RESTORE_R6
  68     CALLER_RESTORE_R7
  69     CALLER_RESTORE_R8
  70     CALLER_RESTORE_FltReg1
  71     CALLER_RESTORE_FltReg2
  72     CALLER_RESTORE_FltReg3
  73     CALLER_RESTORE_FltReg4
  74     CALLER_RESTORE_DblReg1
  75     CALLER_RESTORE_DblReg2
  76     CALLER_RESTORE_Tag
  77     CALLER_RESTORE_SpA
  78     CALLER_RESTORE_SuA
  79     CALLER_RESTORE_SpB
  80     CALLER_RESTORE_SuB
  81     CALLER_RESTORE_Hp
  82     CALLER_RESTORE_HpLim
  83     CALLER_RESTORE_Liveness
  84     CALLER_RESTORE_Ret
  85
  86     /* These next two are restore-only */
  87     CALLER_RESTORE_StdUpdRetVec
  88     CALLER_RESTORE_StkStub
  89
  90     MAGIC_RETURN
  91 }
  92 # endif /* defined(CALLER_SAVES_SYSTEM) || defined(CALLER_SAVES_USER) */
  93
  94 # if defined(CALLER_SAVES_SYSTEM)
  95 void
  96 callWrapper_safe(STG_NO_ARGS)
  97 {
  98     MAGIC_CALL_SETUP
  99
 100     CALLER_SAVE_Base
 101     CALLER_SAVE_StkO
 102     CALLER_SAVE_SpA
 103     CALLER_SAVE_SuA
 104     CALLER_SAVE_SpB
 105     CALLER_SAVE_SuB
 106     CALLER_SAVE_Hp
 107     CALLER_SAVE_HpLim
 108     CALLER_SAVE_Liveness
 109     CALLER_SAVE_Ret
 110
 111     MAGIC_CALL
 112
 113     CALLER_RESTORE_Base /* has to be first! */
 114
 115     CALLER_RESTORE_StkO
 116     CALLER_RESTORE_SpA
 117     CALLER_RESTORE_SuA
 118     CALLER_RESTORE_SpB
 119     CALLER_RESTORE_SuB
 120     CALLER_RESTORE_Hp
 121     CALLER_RESTORE_HpLim
 122     CALLER_RESTORE_Liveness
 123     CALLER_RESTORE_Ret
 124
 125     /* These next two are restore-only */
 126     CALLER_RESTORE_StdUpdRetVec
 127     CALLER_RESTORE_StkStub
 128
 129     MAGIC_RETURN
 130 }
 131 # endif /* defined(CALLER_SAVES_SYSTEM) */
 132
 133 /*
 134 Nota Bene:
 135
 136 Anyone changing the definition of @callWrapper_GC@ should make
 137 appropriate changes in the compiler (absCSyn/PprAbsC.lhs :: pprCCall).
 138
 139 The reason is that \tr{_ccall_GC_} and \tr{_casm_GC_} generate code like this:
 140 \begin{verbatim}
 141    { R _ccall_result;
 142      SaveAllStgRegs();
 143      inCCallGC+=1;
 144      _ccall_result = << do the call/asm>>;
 145      inCCallGC-=1;
 146      RestoreAllStgRegs();
 147    }
 148 \end{verbatim}
 149
 150 This avoids limiting _ccall_GC_ to 6 arguments and makes it possible
 151 to implement _ccall_GC_.  (The local variable avoids the need for some
 152 of the deeper magic hidden inside @GC_SETUP@, @GC_CCALL@ and
 153 @GC_RETURN@.)
 154
 155 ADR */
 156
 157 EXTFUN(EnterNodeCode);
 158
 159 void *__temp_esp, *__temp_eax;
 160
 161 void PerformGC_wrapper PROTO((W_))          WRAPPER_NAME(PerformGC);
 162 void PerformGC_wrapper(args)
 163 W_ args;
 164 {
 165 #if i386_TARGET_ARCH
 166     void *ret_addr;
 167
 168     WRAPPER_SETUP(PerformGC,ret_addr,args)
 169 #else
 170     WRAPPER_SETUP(PerformGC, ignore_me, ignore_me)
 171 #endif
 172     PerformGC(args);
 173     WRAPPER_RETURN(0)
 174 }
 175
 176 # ifdef CONCURRENT
 177
 178 void __DISCARD__ (STG_NO_ARGS) { /*nothing*/ }
 179
 180 void StackOverflow_wrapper PROTO((W_,W_))   WRAPPER_NAME(StackOverflow);
 181 void StackOverflow_wrapper(args1,args2)
 182 W_ args1, args2;
 183 {
 184 #if i386_TARGET_ARCH
 185     void *ret_addr, *ignore_me;
 186     WRAPPER_SETUP(StackOverflow,ret_addr,ignore_me)
 187 #else
 188     WRAPPER_SETUP(StackOverflow, ignore_me, ignore_me)
 189 #endif
 190     if(StackOverflow(args1,args2)) {
 191         WRAPPER_RETURN(1)
 192     }
 193     WRAPPER_RETURN(0)
 194 }
 195
 196 void Yield_wrapper PROTO((W_))              WRAPPER_NAME(Yield);
 197 void Yield_wrapper(args)
 198 W_ args;
 199 {
 200 #if i386_TARGET_ARCH
 201     void *ret_addr, *ignore_me;
 202     WRAPPER_SETUP(Yield, ret_addr, ignore_me)
 203 #else
 204     WRAPPER_SETUP(Yield, ignore_me, ignore_me)
 205 #endif
 206     Yield(args);
 207     WRAPPER_RETURN(0)
 208 }
 209
 210 # endif
 211
 212 # ifdef GRAN
 213
 214 void PerformReschedule_wrapper PROTO((W_, W_))      WRAPPER_NAME(PerformReschedule);
 215 void PerformReschedule_wrapper(liveness, always_reenter_node)
 216   W_ liveness;
 217   W_  always_reenter_node;
 218 {
 219 #if i386_TARGET_ARCH
 220     void *ret_addr, *ignore_me;
 221     WRAPPER_SETUP(PerformReschedule, ret_addr, ignore_me)
 222 #else
 223     WRAPPER_SETUP(PerformReschedule, ignore_me, ignore_me)
 224 #endif
 225     PerformReschedule(liveness, always_reenter_node);
 226     WRAPPER_RETURN(0)
 227 }
 228
 229 # endif /* GRAN */
 230
 231 /*
 232  * In the threaded world, context switches may occur during one of these
 233  * wrapped calls, and when we come back, our stack will have been trashed.
 234  * If gcc, in all of its cleverness, tries to store any temporary values on
 235  * the stack, we need to separate the restoration function.  See the sparc
 236  * code for an example.
 237  */
 238
 239 SEPARATE_WRAPPER_RESTORE
 240
 241 #endif /* defined(__STG_GCC_REGS__) */
 242
 243 /* We can perform a runtime check that we have used @_ccall_GC_@ when
 244    appropriate using this flag. */
 245 StgInt inCCallGC = 0;
 246
 247 void
 248 checkInCCallGC()
 249 {
 250   if (inCCallGC == 0) {
 251     fprintf(stderr, "Error: entering a closure from C without using _ccall_GC_\n");
 252     EXIT(EXIT_FAILURE);
 253   }
 254 }
 255 \end{code}
 256
 257 Hack for -UGRAN setup. % HWL
 258
 259 \begin{code}
 260 #ifndef GRAN
 261 void PerformReschedule_wrapper PROTO((W_, W_));
 262 void PerformReschedule_wrapper(liveness, always_reenter_node)
 263   W_ liveness;
 264   W_  always_reenter_node;
 265 { }
 266 #endif
 267 \end{code}