+++ /dev/null
-/* -----------------------------------------------------------------------------
- *
- * (c) The GHC Team, 1998-2004
- *
- * Code to perform updates.
- *
- * This file is written in a subset of C--, extended with various
- * features specific to GHC. It is compiled by GHC directly. For the
- * syntax of .cmm files, see the parser in ghc/compiler/cmm/CmmParse.y.
- *
- * ---------------------------------------------------------------------------*/
-
-#include "Cmm.h"
-#include "Updates.h"
-#include "StgLdvProf.h"
-
-/*
- The update frame return address must be *polymorphic*, that means
- we have to cope with both vectored and non-vectored returns. This
- is done by putting the return vector right before the info table, and
- having a standard direct return address after the info table (pointed
- to by the return address itself, as usual).
-
- Each entry in the vector table points to a specialised entry code fragment
- that knows how to return after doing the update. It would be possible to
- use a single generic piece of code that simply entered the return value
- to return, but it's quicker this way. The direct return code of course
- just does another direct return when it's finished.
-*/
-
-/* on entry to the update code
- (1) R1 points to the closure being returned
- (2) Sp points to the update frame
-*/
-
-/* The update fragment has been tuned so as to generate good
- code with gcc, which accounts for some of the strangeness in the
- way it is written.
-
- In particular, the JMP_(ret) bit is passed down and pinned on the
- end of each branch (there end up being two major branches in the
- code), since we don't mind duplicating this jump.
-*/
-
-#define UPD_FRAME_ENTRY_TEMPLATE(label,ind_info,ret) \
- label \
- { \
- W_ updatee; \
- \
- updatee = StgUpdateFrame_updatee(Sp); \
- \
- /* remove the update frame from the stack */ \
- Sp = Sp + SIZEOF_StgUpdateFrame; \
- \
- /* ToDo: it might be a PAP, so we should check... */ \
- TICK_UPD_CON_IN_NEW(sizeW_fromITBL(%GET_STD_INFO(updatee))); \
- \
- UPD_SPEC_IND(updatee, ind_info, R1, jump (ret)); \
- }
-
-UPD_FRAME_ENTRY_TEMPLATE(stg_upd_frame_0_ret,stg_IND_0_info,%RET_VEC(Sp(0),0))
-UPD_FRAME_ENTRY_TEMPLATE(stg_upd_frame_1_ret,stg_IND_1_info,%RET_VEC(Sp(0),1))
-UPD_FRAME_ENTRY_TEMPLATE(stg_upd_frame_2_ret,stg_IND_2_info,%RET_VEC(Sp(0),2))
-UPD_FRAME_ENTRY_TEMPLATE(stg_upd_frame_3_ret,stg_IND_3_info,%RET_VEC(Sp(0),3))
-UPD_FRAME_ENTRY_TEMPLATE(stg_upd_frame_4_ret,stg_IND_4_info,%RET_VEC(Sp(0),4))
-UPD_FRAME_ENTRY_TEMPLATE(stg_upd_frame_5_ret,stg_IND_5_info,%RET_VEC(Sp(0),5))
-UPD_FRAME_ENTRY_TEMPLATE(stg_upd_frame_6_ret,stg_IND_6_info,%RET_VEC(Sp(0),6))
-UPD_FRAME_ENTRY_TEMPLATE(stg_upd_frame_7_ret,stg_IND_7_info,%RET_VEC(Sp(0),7))
-
-#if MAX_VECTORED_RTN > 8
-#error MAX_VECTORED_RTN has changed: please modify stg_upd_frame too.
-#endif
-
-/*
- Make sure this table is big enough to handle the maximum vectored
- return size!
- */
-
-#if defined(PROFILING)
-#define UPD_FRAME_BITMAP 3
-#define UPD_FRAME_WORDS 3
-#else
-#define UPD_FRAME_BITMAP 0
-#define UPD_FRAME_WORDS 1
-#endif
-
-/* this bitmap indicates that the first word of an update frame is a
- * non-pointer - this is the update frame link. (for profiling,
- * there's a cost-centre-stack in there too).
- */
-
-INFO_TABLE_RET( stg_upd_frame,
- UPD_FRAME_WORDS, UPD_FRAME_BITMAP, UPDATE_FRAME,
- stg_upd_frame_0_ret,
- stg_upd_frame_1_ret,
- stg_upd_frame_2_ret,
- stg_upd_frame_3_ret,
- stg_upd_frame_4_ret,
- stg_upd_frame_5_ret,
- stg_upd_frame_6_ret,
- stg_upd_frame_7_ret
- )
-UPD_FRAME_ENTRY_TEMPLATE(,stg_IND_direct_info,%ENTRY_CODE(Sp(0)))
-
-
-INFO_TABLE_RET( stg_marked_upd_frame,
- UPD_FRAME_WORDS, UPD_FRAME_BITMAP, UPDATE_FRAME,
- stg_upd_frame_0_ret,
- stg_upd_frame_1_ret,
- stg_upd_frame_2_ret,
- stg_upd_frame_3_ret,
- stg_upd_frame_4_ret,
- stg_upd_frame_5_ret,
- stg_upd_frame_6_ret,
- stg_upd_frame_7_ret
- )
-UPD_FRAME_ENTRY_TEMPLATE(,stg_IND_direct_info,%ENTRY_CODE(Sp(0)))
-
-/*-----------------------------------------------------------------------------
- Seq frames
-
- We don't have a primitive seq# operator: it is just a 'case'
- expression whose scrutinee has either a polymorphic or function type
- (constructor types can be handled by normal 'case' expressions).
-
- To handle a polymorphic/function typed seq, we push a SEQ frame on
- the stack. This is a polymorphic activation record that just pops
- itself and returns (in a non-vectored way) when entered. The
- purpose of the SEQ frame is to avoid having to make a polymorphic return
- point for each polymorphic case expression.
-
- Another way of looking at it: the SEQ frame turns a vectored return
- into a direct one.
- -------------------------------------------------------------------------- */
-
-#if MAX_VECTORED_RTN > 8
-#error MAX_VECTORED_RTN has changed: please modify stg_seq_frame too.
-#endif
-
-INFO_TABLE_RET( stg_seq_frame, 0/* words */, 0/* bitmap */, RET_SMALL,
- RET_LBL(stg_seq_frame), /* 0 */
- RET_LBL(stg_seq_frame), /* 1 */
- RET_LBL(stg_seq_frame), /* 2 */
- RET_LBL(stg_seq_frame), /* 3 */
- RET_LBL(stg_seq_frame), /* 4 */
- RET_LBL(stg_seq_frame), /* 5 */
- RET_LBL(stg_seq_frame), /* 6 */
- RET_LBL(stg_seq_frame) /* 7 */
- )
-{
- Sp_adj(1);
- jump %ENTRY_CODE(Sp(0));
-}
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