commit 9b3a8400aeb43ad9ce0c753dc8fecac9db304da3 Author: Olivier Hainque Date: Tue Mar 22 18:37:27 2016 +0100 initial port from 4.9 diff --git a/gcc/alias.c b/gcc/alias.c index 753e1af..09a709f 100644 --- a/gcc/alias.c +++ b/gcc/alias.c @@ -3241,9 +3241,12 @@ init_alias_analysis (void) insn chain until after reload has completed. Thus, there is no sense wasting time checking if INSN is in the prologue/epilogue until after reload has completed. */ - bool could_be_prologue_epilogue = ((targetm.have_prologue () - || targetm.have_epilogue ()) - && reload_completed); + + bool could_be_prologue = (targetm.have_prologue () + && reload_completed); + + bool could_be_epilogue = (targetm.have_epilogue () + && reload_completed); pass = 0; do @@ -3283,8 +3286,19 @@ init_alias_analysis (void) { rtx note, set; - if (could_be_prologue_epilogue - && prologue_epilogue_contains (insn)) + /* Skip prologue instructions threaded onto the insn chain + after reload, which bring nothing of interest to alias + analysis within the function's body. */ + if (could_be_prologue + && prologue_contains (insn)) + continue; + + /* Likewise for epilogue instructions, except for possible + needs within the epilogue sequence itself. */ + if (could_be_epilogue + && epilogue_contains (insn) + && (!targetm.epilogue_aliases () + || RTX_FRAME_RELATED_P (insn))) continue; /* If this insn has a noalias note, process it, Otherwise, diff --git a/gcc/config/rs6000/rs6000.c b/gcc/config/rs6000/rs6000.c index fd4b7cc..cf5ca42 100644 --- a/gcc/config/rs6000/rs6000.c +++ b/gcc/config/rs6000/rs6000.c @@ -1712,6 +1712,11 @@ static const struct attribute_spec rs6000_attribute_table[] = #define TARGET_ASM_OUTPUT_DWARF_DTPREL rs6000_output_dwarf_dtprel #endif +/* Our stack_tie mechanism requires visibility on intermediate + base register computations in the epilogue. */ +#undef TARGET_EPILOGUE_ALIASES +#define TARGET_EPILOGUE_ALIASES hook_bool_void_true + /* Use a 32-bit anchor range. This leads to sequences like: addis tmp,anchor,high diff --git a/gcc/doc/tm.texi b/gcc/doc/tm.texi index 745910f..20c17f6 100644 --- a/gcc/doc/tm.texi +++ b/gcc/doc/tm.texi @@ -11289,6 +11289,16 @@ or when the back end is in a partially-initialized state. outside of any function scope. @end deftypefn +@deftypefn {Target Hook} bool TARGET_EPILOGUE_ALIASES (void) +This target hook should return @code{true} if the target needs +alias analysis to look into operations performed by epilogue instructions +*not* marked @code{RTX_FRAME_RELATED_P}. +This needs only be redefined by targets which use precise memory references +with specially assigned alias sets instead of a strong blockage to prevent +the move of register restores past the stack frame release. +Default return value is @code{false}. +@end deftypefn + @defmac TARGET_OBJECT_SUFFIX Define this macro to be a C string representing the suffix for object files on your target machine. If you do not define this macro, GCC will diff --git a/gcc/doc/tm.texi.in b/gcc/doc/tm.texi.in index f31c763..b4b6b1a 100644 --- a/gcc/doc/tm.texi.in +++ b/gcc/doc/tm.texi.in @@ -8039,6 +8039,8 @@ to by @var{ce_info}. @hook TARGET_SET_CURRENT_FUNCTION +@hook TARGET_EPILOGUE_ALIASES + @defmac TARGET_OBJECT_SUFFIX Define this macro to be a C string representing the suffix for object files on your target machine. If you do not define this macro, GCC will diff --git a/gcc/function.c b/gcc/function.c index 1ac8e26..f025f21 100644 --- a/gcc/function.c +++ b/gcc/function.c @@ -5743,14 +5743,28 @@ contains (const_rtx insn, hash_table *hash) return hash->find (const_cast (insn)) != NULL; } -int +/* Whether INSN is part of the function's prologue sequence. */ + +bool +prologue_contains (const_rtx insn) +{ + return contains (insn, prologue_insn_hash); +} + +/* Whether INSN is part of the function's epilogue sequence. */ + +bool +epilogue_contains (const_rtx insn) +{ + return contains (insn, epilogue_insn_hash); +} + +/* Whether INSN is part of the function's prologue or epilogue sequence. */ + +bool prologue_epilogue_contains (const_rtx insn) { - if (contains (insn, prologue_insn_hash)) - return 1; - if (contains (insn, epilogue_insn_hash)) - return 1; - return 0; + return prologue_contains (insn) || epilogue_contains (insn); } /* Insert use of return register before the end of BB. */ diff --git a/gcc/function.h b/gcc/function.h index 501ef68..81d9e50 100644 --- a/gcc/function.h +++ b/gcc/function.h @@ -628,7 +628,9 @@ extern void clobber_return_register (void); extern void expand_function_end (void); extern rtx get_arg_pointer_save_area (void); extern void maybe_copy_prologue_epilogue_insn (rtx, rtx); -extern int prologue_epilogue_contains (const_rtx); +extern bool prologue_contains (const_rtx); +extern bool epilogue_contains (const_rtx); +extern bool prologue_epilogue_contains (const_rtx); extern void emit_return_into_block (bool simple_p, basic_block bb); extern void set_return_jump_label (rtx_insn *); extern bool active_insn_between (rtx_insn *head, rtx_insn *tail); diff --git a/gcc/target.def b/gcc/target.def index 20f2b32..9276858 100644 --- a/gcc/target.def +++ b/gcc/target.def @@ -3417,6 +3417,19 @@ move would be greater than that of a library call.", enum by_pieces_operation op, bool speed_p), default_use_by_pieces_infrastructure_p) +/* Return true if a function must have and use a frame pointer. */ +DEFHOOK +(epilogue_aliases, + "This target hook should return @code{true} if the target needs\n" + "alias analysis to look into operations performed by epilogue instructions\n" + "*not* marked @code{RTX_FRAME_RELATED_P}.\n" + "This needs only be redefined by targets which use precise memory references\n" + "with specially assigned alias sets instead of a strong blockage to prevent\n" + "the move of register restores past the stack frame release.\n" + "Default return value is @code{false}.", + bool, (void), + hook_bool_void_false) + DEFHOOK (optab_supported_p, "Return true if the optimizers should use optab @var{op} with\n\