From 32969c6301b01a95c52e761d785191e039a236eb Mon Sep 17 00:00:00 2001 From: denisc Date: Tue, 22 Mar 2011 19:37:35 +0000 Subject: [PATCH] * config/avr/avr-protos.h (expand_epilogue): Change prototype * config/avr/avr.h (struct machine_function): Add field sibcall_fails. * config/avr/avr.c (init_cumulative_args) (avr_function_arg_advance): Use it. * config/avr/avr.c (expand_epilogue): Add bool parameter. Handle sibcall epilogues. (TARGET_FUNCTION_OK_FOR_SIBCALL): Define to... (avr_function_ok_for_sibcall): ...this new function. (avr_lookup_function_attribute1): New static Function. (avr_naked_function_p, interrupt_function_p) (signal_function_p, avr_OS_task_function_p) (avr_OS_main_function_p): Use it. * config/avr/avr.md ("sibcall", "sibcall_value") ("sibcall_epilogue"): New expander. ("*call_insn", "*call_value_insn"): New insn. ("call_insn", "call_value_insn"): Remove ("call", "call_value", "epilogue"): Change expander to handle sibling calls. git-svn-id: svn+ssh://gcc.gnu.org/svn/gcc/trunk@171300 138bc75d-0d04-0410-961f-82ee72b054a4 --- gcc/ChangeLog | 21 ++++++ gcc/config/avr/avr-protos.h | 2 +- gcc/config/avr/avr.c | 150 ++++++++++++++++++++++++++++++++---------- gcc/config/avr/avr.h | 3 + gcc/config/avr/avr.md | 156 +++++++++++++++++++++++--------------------- 5 files changed, 221 insertions(+), 111 deletions(-) diff --git a/gcc/ChangeLog b/gcc/ChangeLog index 4706302..283a80e 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,24 @@ +2011-03-21 Georg-Johann Lay + + * config/avr/avr-protos.h (expand_epilogue): Change prototype + * config/avr/avr.h (struct machine_function): Add field sibcall_fails. + * config/avr/avr.c (init_cumulative_args) + (avr_function_arg_advance): Use it. + * config/avr/avr.c (expand_epilogue): Add bool parameter. Handle + sibcall epilogues. + (TARGET_FUNCTION_OK_FOR_SIBCALL): Define to... + (avr_function_ok_for_sibcall): ...this new function. + (avr_lookup_function_attribute1): New static Function. + (avr_naked_function_p, interrupt_function_p) + (signal_function_p, avr_OS_task_function_p) + (avr_OS_main_function_p): Use it. + * config/avr/avr.md ("sibcall", "sibcall_value") + ("sibcall_epilogue"): New expander. + ("*call_insn", "*call_value_insn"): New insn. + ("call_insn", "call_value_insn"): Remove + ("call", "call_value", "epilogue"): Change expander to handle + sibling calls. + 2011-03-21 Nick Clifton * doc/invoke.texi (Overall Options): Move closing brace to end of diff --git a/gcc/config/avr/avr-protos.h b/gcc/config/avr/avr-protos.h index 3882429..b00637e 100644 --- a/gcc/config/avr/avr-protos.h +++ b/gcc/config/avr/avr-protos.h @@ -76,7 +76,7 @@ extern const char *lshrsi3_out (rtx insn, rtx operands[], int *len); extern bool avr_rotate_bytes (rtx operands[]); extern void expand_prologue (void); -extern void expand_epilogue (void); +extern void expand_epilogue (bool); extern int avr_epilogue_uses (int regno); extern void avr_output_bld (rtx operands[], int bit_nr); diff --git a/gcc/config/avr/avr.c b/gcc/config/avr/avr.c index 9a32b97..56b216b 100644 --- a/gcc/config/avr/avr.c +++ b/gcc/config/avr/avr.c @@ -102,6 +102,7 @@ static rtx avr_function_arg (CUMULATIVE_ARGS *, enum machine_mode, static void avr_function_arg_advance (CUMULATIVE_ARGS *, enum machine_mode, const_tree, bool); static void avr_help (void); +static bool avr_function_ok_for_sibcall (tree, tree); /* Allocate registers from r25 to r8 for parameters for function calls. */ #define FIRST_CUM_REG 26 @@ -249,6 +250,9 @@ static const struct default_options avr_option_optimization_table[] = #undef TARGET_EXCEPT_UNWIND_INFO #define TARGET_EXCEPT_UNWIND_INFO sjlj_except_unwind_info +#undef TARGET_FUNCTION_OK_FOR_SIBCALL +#define TARGET_FUNCTION_OK_FOR_SIBCALL avr_function_ok_for_sibcall + struct gcc_target targetm = TARGET_INITIALIZER; static void @@ -348,17 +352,34 @@ avr_regno_reg_class (int r) return ALL_REGS; } +/* A helper for the subsequent function attribute used to dig for + attribute 'name' in a FUNCTION_DECL or FUNCTION_TYPE */ + +static inline int +avr_lookup_function_attribute1 (const_tree func, const char *name) +{ + if (FUNCTION_DECL == TREE_CODE (func)) + { + if (NULL_TREE != lookup_attribute (name, DECL_ATTRIBUTES (func))) + { + return true; + } + + func = TREE_TYPE (func); + } + + gcc_assert (TREE_CODE (func) == FUNCTION_TYPE + || TREE_CODE (func) == METHOD_TYPE); + + return NULL_TREE != lookup_attribute (name, TYPE_ATTRIBUTES (func)); +} + /* Return nonzero if FUNC is a naked function. */ static int avr_naked_function_p (tree func) { - tree a; - - gcc_assert (TREE_CODE (func) == FUNCTION_DECL); - - a = lookup_attribute ("naked", TYPE_ATTRIBUTES (TREE_TYPE (func))); - return a != NULL_TREE; + return avr_lookup_function_attribute1 (func, "naked"); } /* Return nonzero if FUNC is an interrupt function as specified @@ -367,13 +388,7 @@ avr_naked_function_p (tree func) static int interrupt_function_p (tree func) { - tree a; - - if (TREE_CODE (func) != FUNCTION_DECL) - return 0; - - a = lookup_attribute ("interrupt", DECL_ATTRIBUTES (func)); - return a != NULL_TREE; + return avr_lookup_function_attribute1 (func, "interrupt"); } /* Return nonzero if FUNC is a signal function as specified @@ -382,13 +397,7 @@ interrupt_function_p (tree func) static int signal_function_p (tree func) { - tree a; - - if (TREE_CODE (func) != FUNCTION_DECL) - return 0; - - a = lookup_attribute ("signal", DECL_ATTRIBUTES (func)); - return a != NULL_TREE; + return avr_lookup_function_attribute1 (func, "signal"); } /* Return nonzero if FUNC is a OS_task function. */ @@ -396,12 +405,7 @@ signal_function_p (tree func) static int avr_OS_task_function_p (tree func) { - tree a; - - gcc_assert (TREE_CODE (func) == FUNCTION_DECL); - - a = lookup_attribute ("OS_task", TYPE_ATTRIBUTES (TREE_TYPE (func))); - return a != NULL_TREE; + return avr_lookup_function_attribute1 (func, "OS_task"); } /* Return nonzero if FUNC is a OS_main function. */ @@ -409,12 +413,7 @@ avr_OS_task_function_p (tree func) static int avr_OS_main_function_p (tree func) { - tree a; - - gcc_assert (TREE_CODE (func) == FUNCTION_DECL); - - a = lookup_attribute ("OS_main", TYPE_ATTRIBUTES (TREE_TYPE (func))); - return a != NULL_TREE; + return avr_lookup_function_attribute1 (func, "OS_main"); } /* Return the number of hard registers to push/pop in the prologue/epilogue @@ -935,7 +934,7 @@ emit_pop_byte (unsigned regno) /* Output RTL epilogue. */ void -expand_epilogue (void) +expand_epilogue (bool sibcall_p) { int reg; int live_seq; @@ -946,6 +945,8 @@ expand_epilogue (void) /* epilogue: naked */ if (cfun->machine->is_naked) { + gcc_assert (!sibcall_p); + emit_jump_insn (gen_return ()); return; } @@ -1088,7 +1089,8 @@ expand_epilogue (void) emit_pop_byte (ZERO_REGNO); } - emit_jump_insn (gen_return ()); + if (!sibcall_p) + emit_jump_insn (gen_return ()); } } @@ -1701,6 +1703,10 @@ init_cumulative_args (CUMULATIVE_ARGS *cum, tree fntype, rtx libname, cum->regno = FIRST_CUM_REG; if (!libname && stdarg_p (fntype)) cum->nregs = 0; + + /* Assume the calle may be tail called */ + + cfun->machine->sibcall_fails = 0; } /* Returns the number of registers to allocate for a function argument. */ @@ -1748,6 +1754,23 @@ avr_function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode, cum->nregs -= bytes; cum->regno -= bytes; + /* A parameter is being passed in a call-saved register. As the original + contents of these regs has to be restored before leaving the function, + a function must not pass arguments in call-saved regs in order to get + tail-called. */ + + if (cum->regno >= 0 + && !call_used_regs[cum->regno]) + { + /* FIXME: We ship info on failing tail-call in struct machine_function. + This uses internals of calls.c:expand_call() and the way args_so_far + is used. targetm.function_ok_for_sibcall() needs to be extended to + pass &args_so_far, too. At present, CUMULATIVE_ARGS is target + dependent so that such an extension is not wanted. */ + + cfun->machine->sibcall_fails = 1; + } + if (cum->nregs <= 0) { cum->nregs = 0; @@ -1755,6 +1778,65 @@ avr_function_arg_advance (CUMULATIVE_ARGS *cum, enum machine_mode mode, } } +/* Implement `TARGET_FUNCTION_OK_FOR_SIBCALL' */ +/* Decide whether we can make a sibling call to a function. DECL is the + declaration of the function being targeted by the call and EXP is the + CALL_EXPR representing the call. */ + +static bool +avr_function_ok_for_sibcall (tree decl_callee, tree exp_callee) +{ + tree fntype_callee; + + /* Tail-calling must fail if callee-saved regs are used to pass + function args. We must not tail-call when `epilogue_restores' + is used. Unfortunately, we cannot tell at this point if that + actually will happen or not, and we cannot step back from + tail-calling. Thus, we inhibit tail-calling with -mcall-prologues. */ + + if (cfun->machine->sibcall_fails + || TARGET_CALL_PROLOGUES) + { + return false; + } + + fntype_callee = TREE_TYPE (CALL_EXPR_FN (exp_callee)); + + if (decl_callee) + { + decl_callee = TREE_TYPE (decl_callee); + } + else + { + decl_callee = fntype_callee; + + while (FUNCTION_TYPE != TREE_CODE (decl_callee) + && METHOD_TYPE != TREE_CODE (decl_callee)) + { + decl_callee = TREE_TYPE (decl_callee); + } + } + + /* Ensure that caller and callee have compatible epilogues */ + + if (interrupt_function_p (current_function_decl) + || signal_function_p (current_function_decl) + || avr_naked_function_p (decl_callee) + || avr_naked_function_p (current_function_decl) + /* FIXME: For OS_task and OS_main, we are over-conservative. + This is due to missing documentation of these attributes + and what they actually should do and should not do. */ + || (avr_OS_task_function_p (decl_callee) + != avr_OS_task_function_p (current_function_decl)) + || (avr_OS_main_function_p (decl_callee) + != avr_OS_main_function_p (current_function_decl))) + { + return false; + } + + return true; +} + /*********************************************************************** Functions for outputting various mov's for a various modes ************************************************************************/ diff --git a/gcc/config/avr/avr.h b/gcc/config/avr/avr.h index bd18aed..37fb3ed 100644 --- a/gcc/config/avr/avr.h +++ b/gcc/config/avr/avr.h @@ -826,4 +826,7 @@ struct GTY(()) machine_function /* Current function stack size. */ int stack_usage; + + /* 'true' if a callee might be tail called */ + int sibcall_fails; }; diff --git a/gcc/config/avr/avr.md b/gcc/config/avr/avr.md index 0fdee39..9c375e4 100644 --- a/gcc/config/avr/avr.md +++ b/gcc/config/avr/avr.md @@ -2646,94 +2646,91 @@ ;; call (define_expand "call" - [(call (match_operand:HI 0 "call_insn_operand" "") - (match_operand:HI 1 "general_operand" ""))] + [(parallel[(call (match_operand:HI 0 "call_insn_operand" "") + (match_operand:HI 1 "general_operand" "")) + (use (const_int 0))])] ;; Operand 1 not used on the AVR. + ;; Operand 2 is 1 for tail-call, 0 otherwise. + "" + "") + +(define_expand "sibcall" + [(parallel[(call (match_operand:HI 0 "call_insn_operand" "") + (match_operand:HI 1 "general_operand" "")) + (use (const_int 1))])] + ;; Operand 1 not used on the AVR. + ;; Operand 2 is 1 for tail-call, 0 otherwise. "" "") ;; call value (define_expand "call_value" - [(set (match_operand 0 "register_operand" "") - (call (match_operand:HI 1 "call_insn_operand" "") - (match_operand:HI 2 "general_operand" "")))] + [(parallel[(set (match_operand 0 "register_operand" "") + (call (match_operand:HI 1 "call_insn_operand" "") + (match_operand:HI 2 "general_operand" ""))) + (use (const_int 0))])] + ;; Operand 2 not used on the AVR. + ;; Operand 3 is 1 for tail-call, 0 otherwise. + "" + "") + +(define_expand "sibcall_value" + [(parallel[(set (match_operand 0 "register_operand" "") + (call (match_operand:HI 1 "call_insn_operand" "") + (match_operand:HI 2 "general_operand" ""))) + (use (const_int 1))])] ;; Operand 2 not used on the AVR. + ;; Operand 3 is 1 for tail-call, 0 otherwise. "" "") -(define_insn "call_insn" - [(call (mem:HI (match_operand:HI 0 "nonmemory_operand" "!z,*r,s,n")) - (match_operand:HI 1 "general_operand" "X,X,X,X"))] -;; We don't need in saving Z register because r30,r31 is a call used registers +(define_insn "*call_insn" + [(parallel[(call (mem:HI (match_operand:HI 0 "nonmemory_operand" "z,s,z,s")) + (match_operand:HI 1 "general_operand" "X,X,X,X")) + (use (match_operand:HI 2 "const_int_operand" "L,L,P,P"))])] ;; Operand 1 not used on the AVR. - "(register_operand (operands[0], HImode) || CONSTANT_P (operands[0]))" - "*{ - if (which_alternative==0) - return \"%!icall\"; - else if (which_alternative==1) - { - if (AVR_HAVE_MOVW) - return (AS2 (movw, r30, %0) CR_TAB - \"%!icall\"); - else - return (AS2 (mov, r30, %A0) CR_TAB - AS2 (mov, r31, %B0) CR_TAB - \"%!icall\"); - } - else if (which_alternative==2) - return AS1(%~call,%x0); - return (AS2 (ldi,r30,lo8(%0)) CR_TAB - AS2 (ldi,r31,hi8(%0)) CR_TAB - \"%!icall\"); -}" - [(set_attr "cc" "clobber,clobber,clobber,clobber") + ;; Operand 2 is 1 for tail-call, 0 otherwise. + "" + "@ + %!icall + %~call %x0 + %!ijmp + %~jmp %x0" + [(set_attr "cc" "clobber") (set_attr_alternative "length" - [(const_int 1) - (if_then_else (eq_attr "mcu_have_movw" "yes") - (const_int 2) - (const_int 3)) - (if_then_else (eq_attr "mcu_mega" "yes") - (const_int 2) - (const_int 1)) - (const_int 3)])]) - -(define_insn "call_value_insn" - [(set (match_operand 0 "register_operand" "=r,r,r,r") - (call (mem:HI (match_operand:HI 1 "nonmemory_operand" "!z,*r,s,n")) -;; We don't need in saving Z register because r30,r31 is a call used registers - (match_operand:HI 2 "general_operand" "X,X,X,X")))] + [(const_int 1) + (if_then_else (eq_attr "mcu_mega" "yes") + (const_int 2) + (const_int 1)) + (const_int 1) + (if_then_else (eq_attr "mcu_mega" "yes") + (const_int 2) + (const_int 1))])]) + +(define_insn "*call_value_insn" + [(parallel[(set (match_operand 0 "register_operand" "=r,r,r,r") + (call (mem:HI (match_operand:HI 1 "nonmemory_operand" "z,s,z,s")) + (match_operand:HI 2 "general_operand" "X,X,X,X"))) + (use (match_operand:HI 3 "const_int_operand" "L,L,P,P"))])] ;; Operand 2 not used on the AVR. - "(register_operand (operands[0], VOIDmode) || CONSTANT_P (operands[0]))" - "*{ - if (which_alternative==0) - return \"%!icall\"; - else if (which_alternative==1) - { - if (AVR_HAVE_MOVW) - return (AS2 (movw, r30, %1) CR_TAB - \"%!icall\"); - else - return (AS2 (mov, r30, %A1) CR_TAB - AS2 (mov, r31, %B1) CR_TAB - \"%!icall\"); - } - else if (which_alternative==2) - return AS1(%~call,%x1); - return (AS2 (ldi, r30, lo8(%1)) CR_TAB - AS2 (ldi, r31, hi8(%1)) CR_TAB - \"%!icall\"); -}" - [(set_attr "cc" "clobber,clobber,clobber,clobber") + ;; Operand 3 is 1 for tail-call, 0 otherwise. + "" + "@ + %!icall + %~call %x1 + %!ijmp + %~jmp %x1" + [(set_attr "cc" "clobber") (set_attr_alternative "length" - [(const_int 1) - (if_then_else (eq_attr "mcu_have_movw" "yes") - (const_int 2) - (const_int 3)) - (if_then_else (eq_attr "mcu_mega" "yes") - (const_int 2) - (const_int 1)) - (const_int 3)])]) + [(const_int 1) + (if_then_else (eq_attr "mcu_mega" "yes") + (const_int 2) + (const_int 1)) + (const_int 1) + (if_then_else (eq_attr "mcu_mega" "yes") + (const_int 2) + (const_int 1))])]) (define_insn "nop" [(const_int 0)] @@ -3237,8 +3234,15 @@ (define_expand "epilogue" [(const_int 0)] "" - " { - expand_epilogue (); + expand_epilogue (false /* sibcall_p */); DONE; - }") + }) + +(define_expand "sibcall_epilogue" + [(const_int 0)] + "" + { + expand_epilogue (true /* sibcall_p */); + DONE; + }) -- 2.7.4