diff options
Diffstat (limited to 'gcc')
| -rw-r--r-- | gcc/ChangeLog | 20 | ||||
| -rw-r--r-- | gcc/config/i386/i386.c | 193 | ||||
| -rw-r--r-- | gcc/config/i386/i386.md | 54 |
3 files changed, 123 insertions, 144 deletions
diff --git a/gcc/ChangeLog b/gcc/ChangeLog index c708a02..1162cc1 100644 --- a/gcc/ChangeLog +++ b/gcc/ChangeLog @@ -1,3 +1,23 @@ +2000-02-04 Jan Hubicka <jh@suse.cz> + Richard Henderson <rth@cygnus.com> + + * i386.c (SAVE_REGS_FIRST): Remove. + (ix86_initial_elimination_offset): Handle only SAVE_REGS_FIRST mode. + (ix86_compute_frame_size): Likewise. + (ix86_expand_prologue): Likewise. Use pro_epilogue_adjust_stack. + (ix86_emit_restore_regs): Remove. + (ix86_emit_epilogue_esp_adjustment): Use pro_epilogue_adjust_stack + when a frame pointer is in use. + (ix86_expand_epilogue): Handle only SAVE_REGS_FIRST mode. Use mov + instead of pop to restore a register when profitable; emit leave + when profitable. + (ix86_attr_length_default): Handle pro_epilogue_adjust_stack + as a TYPE_LEA insn. + (ix86_adjust_cost): Handle pro_epilogue_adjust_stack as TYPE_ALU. + * i386.md (prologue_allocate_stack): Remove. + (epilogue_deallocate_stack): Remove. + (pro_epilogue_adjust_stack): New. + 2000-02-04 Richard Henderson <rth@cygnus.com> * function.c (diddle_return_value): Rework to use a callback function. diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c index 18fc2f3..93a89f1 100644 --- a/gcc/config/i386/i386.c +++ b/gcc/config/i386/i386.c @@ -41,16 +41,6 @@ Boston, MA 02111-1307, USA. */ #include "basic-block.h" #include "ggc.h" -/* True when we want to do pushes before allocating stack to get better - scheduling. - - Saving registers first is win in the most cases except for LEAVE - instruction. Macro is 0 iff we will use LEAVE. */ - -#define SAVED_REGS_FIRST \ - (!frame_pointer_needed || (!TARGET_USE_LEAVE && !optimize_size)) - - #ifdef EXTRA_CONSTRAINT /* If EXTRA_CONSTRAINT is defined, then the 'S' constraint in REG_CLASS_FROM_LETTER will no longer work, and various @@ -411,7 +401,6 @@ static HOST_WIDE_INT ix86_compute_frame_size PARAMS((HOST_WIDE_INT, int *, int *, int *)); static int ix86_nsaved_regs PARAMS((void)); static void ix86_emit_save_regs PARAMS((void)); -static void ix86_emit_restore_regs PARAMS((void)); static void ix86_emit_epilogue_esp_adjustment PARAMS((int)); struct ix86_address @@ -1705,16 +1694,13 @@ ix86_initial_elimination_offset (from, to) saved frame pointer if frame_pointer_needed <- HARD_FRAME_POINTER - [saved regs if SAVED_REGS_FIRST] + [saved regs] [padding1] \ | <- FRAME_POINTER [frame] > tsize | [padding2] / - - [saved regs if !SAVED_REGS_FIRST] - <- STACK_POINTER */ if (from == ARG_POINTER_REGNUM && to == HARD_FRAME_POINTER_REGNUM) @@ -1725,8 +1711,7 @@ ix86_initial_elimination_offset (from, to) && to == HARD_FRAME_POINTER_REGNUM) { ix86_compute_frame_size (get_frame_size (), &nregs, &padding1, (int *)0); - if (SAVED_REGS_FIRST) - padding1 += nregs * UNITS_PER_WORD; + padding1 += nregs * UNITS_PER_WORD; return -padding1; } else @@ -1743,10 +1728,8 @@ ix86_initial_elimination_offset (from, to) return tsize + nregs * UNITS_PER_WORD + frame_size; else if (from != FRAME_POINTER_REGNUM) abort (); - else if (SAVED_REGS_FIRST) - return tsize - padding1; else - return tsize + nregs * UNITS_PER_WORD - padding1; + return tsize - padding1; } } @@ -1788,13 +1771,10 @@ ix86_compute_frame_size (size, nregs_on_stack, rpadding1, rpadding2) if (stack_alignment_needed < 4) stack_alignment_needed = 4; - if (stack_alignment_needed > preferred_alignment) + if (stack_alignment_needed > PREFERRED_STACK_BOUNDARY / BITS_PER_UNIT) abort (); - if (SAVED_REGS_FIRST) - offset += nregs * UNITS_PER_WORD; - else - total_size += nregs * UNITS_PER_WORD; + offset += nregs * UNITS_PER_WORD; total_size += offset; @@ -1807,9 +1787,8 @@ ix86_compute_frame_size (size, nregs_on_stack, rpadding1, rpadding2) } /* Align stack boundary. */ - if (!current_function_is_leaf) - padding2 = ((total_size + preferred_alignment - 1) - & -preferred_alignment) - total_size; + padding2 = ((total_size + preferred_alignment - 1) + & -preferred_alignment) - total_size; } #endif @@ -1868,18 +1847,16 @@ ix86_expand_prologue () RTX_FRAME_RELATED_P (insn) = 1; } - if (SAVED_REGS_FIRST) - ix86_emit_save_regs (); + ix86_emit_save_regs (); if (tsize == 0) ; else if (! TARGET_STACK_PROBE || tsize < CHECK_STACK_LIMIT) { if (frame_pointer_needed) - insn = emit_insn (gen_prologue_allocate_stack (stack_pointer_rtx, - stack_pointer_rtx, - GEN_INT (-tsize), - hard_frame_pointer_rtx)); + insn = emit_insn (gen_pro_epilogue_adjust_stack + (stack_pointer_rtx, stack_pointer_rtx, + GEN_INT (-tsize), hard_frame_pointer_rtx)); else insn = emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx, GEN_INT (-tsize))); @@ -1903,9 +1880,6 @@ ix86_expand_prologue () CALL_INSN_FUNCTION_USAGE (insn)); } - if (!SAVED_REGS_FIRST) - ix86_emit_save_regs (); - #ifdef SUBTARGET_PROLOGUE SUBTARGET_PROLOGUE; #endif @@ -1920,25 +1894,6 @@ ix86_expand_prologue () emit_insn (gen_blockage ()); } -/* Emit code to pop all registers from stack. */ - -static void -ix86_emit_restore_regs () -{ - int pic_reg_used = flag_pic && (current_function_uses_pic_offset_table - || current_function_uses_const_pool); - int limit = (frame_pointer_needed - ? HARD_FRAME_POINTER_REGNUM : STACK_POINTER_REGNUM); - int regno; - - for (regno = 0; regno < limit; regno++) - if ((regs_ever_live[regno] && !call_used_regs[regno]) - || (regno == PIC_OFFSET_TABLE_REGNUM && pic_reg_used)) - { - emit_insn (gen_popsi1 (gen_rtx_REG (SImode, regno))); - } -} - /* Emit code to add TSIZE to esp value. Use POP instruction when profitable. */ @@ -1980,9 +1935,16 @@ ix86_emit_epilogue_esp_adjustment (tsize) } else { - /* If there is no frame pointer, we must still release the frame. */ - emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx, - GEN_INT (tsize))); + /* If a frame pointer is present, we must be sure to tie the sp + to the fp so that we don't mis-schedule. */ + if (frame_pointer_needed) + emit_insn (gen_pro_epilogue_adjust_stack (stack_pointer_rtx, + stack_pointer_rtx, + GEN_INT (tsize), + hard_frame_pointer_rtx)); + else + emit_insn (gen_addsi3 (stack_pointer_rtx, stack_pointer_rtx, + GEN_INT (tsize))); } } @@ -1991,60 +1953,36 @@ ix86_emit_epilogue_esp_adjustment (tsize) void ix86_expand_epilogue () { - int regno; int nregs; - int limit; + int regno; + int pic_reg_used = flag_pic && (current_function_uses_pic_offset_table || current_function_uses_const_pool); int sp_valid = !frame_pointer_needed || current_function_sp_is_unchanging; HOST_WIDE_INT offset; - HOST_WIDE_INT tsize = ix86_compute_frame_size (get_frame_size (), &nregs, (int *)0, - (int *)0); + HOST_WIDE_INT tsize = ix86_compute_frame_size (get_frame_size (), &nregs, + (int *)0, (int *)0); - /* SP is often unreliable so we may have to go off the frame pointer. */ - offset = -(tsize + nregs * UNITS_PER_WORD); + /* Calculate start of saved registers relative to ebp. */ + offset = -nregs * UNITS_PER_WORD; - if (SAVED_REGS_FIRST) +#ifdef FUNCTION_BLOCK_PROFILER_EXIT + if (profile_block_flag == 2) { - if (!sp_valid) - { - if (nregs) - emit_insn (gen_rtx_SET (VOIDmode, stack_pointer_rtx, - gen_rtx_PLUS (SImode, hard_frame_pointer_rtx, - GEN_INT (- nregs * UNITS_PER_WORD)))); - else - emit_insn (gen_epilogue_deallocate_stack (stack_pointer_rtx, - hard_frame_pointer_rtx)); - } - else if (tsize) - ix86_emit_epilogue_esp_adjustment (tsize); - ix86_emit_restore_regs (); + FUNCTION_BLOCK_PROFILER_EXIT; } +#endif /* If we're only restoring one register and sp is not valid then using a move instruction to restore the register since it's - less work than reloading sp and popping the register. Otherwise, - restore sp (if necessary) and pop the registers. */ - - else if (nregs > 1 || sp_valid) + less work than reloading sp and popping the register. */ + if (!sp_valid && nregs <= 1) { - if (!sp_valid) - { - rtx addr_offset; - addr_offset = adj_offsettable_operand (AT_BP (QImode), offset); - addr_offset = XEXP (addr_offset, 0); - - emit_insn (gen_rtx_SET (VOIDmode, stack_pointer_rtx, addr_offset)); - } + if (!frame_pointer_needed) + abort(); - ix86_emit_restore_regs (); - } - else - { - limit = (frame_pointer_needed - ? HARD_FRAME_POINTER_REGNUM : STACK_POINTER_REGNUM); - for (regno = 0; regno < limit; regno++) + for (regno = 0; regno < HARD_FRAME_POINTER_REGNUM; regno++) if ((regs_ever_live[regno] && ! call_used_regs[regno]) || (regno == PIC_OFFSET_TABLE_REGNUM && pic_reg_used)) { @@ -2052,30 +1990,40 @@ ix86_expand_epilogue () adj_offsettable_operand (AT_BP (Pmode), offset)); offset += 4; } - } - if (frame_pointer_needed) - { /* If not an i386, mov & pop is faster than "leave". */ if (TARGET_USE_LEAVE || optimize_size) emit_insn (gen_leave ()); else { - if (!SAVED_REGS_FIRST) - emit_insn (gen_epilogue_deallocate_stack (stack_pointer_rtx, - hard_frame_pointer_rtx)); + emit_insn (gen_pro_epilogue_adjust_stack (stack_pointer_rtx, + hard_frame_pointer_rtx, + const0_rtx, + hard_frame_pointer_rtx)); emit_insn (gen_popsi1 (hard_frame_pointer_rtx)); } } - else if (!SAVED_REGS_FIRST && tsize) - ix86_emit_epilogue_esp_adjustment (tsize); - -#ifdef FUNCTION_BLOCK_PROFILER_EXIT - if (profile_block_flag == 2) + else { - FUNCTION_BLOCK_PROFILER_EXIT; + /* First step is to deallocate the stack frame so that we can + pop the registers. */ + if (!sp_valid) + { + if (!frame_pointer_needed) + abort (); + emit_insn (gen_pro_epilogue_adjust_stack (stack_pointer_rtx, + hard_frame_pointer_rtx, + GEN_INT (offset), + hard_frame_pointer_rtx)); + } + else if (tsize) + ix86_emit_epilogue_esp_adjustment (tsize); + + for (regno = 0; regno < STACK_POINTER_REGNUM; regno++) + if ((regs_ever_live[regno] && !call_used_regs[regno]) + || (regno == PIC_OFFSET_TABLE_REGNUM && pic_reg_used)) + emit_insn (gen_popsi1 (gen_rtx_REG (SImode, regno))); } -#endif if (current_function_pops_args && current_function_args_size) { @@ -5853,14 +5801,14 @@ ix86_attr_length_default (insn) { /* Irritatingly, single_set doesn't work with REG_UNUSED present, as we'll get from running life_analysis during reg-stack when - not optimizing. */ + not optimizing. Not that it matters anyway, now that + pro_epilogue_adjust_stack uses lea, and is by design not + single_set. */ rtx set = PATTERN (insn); if (GET_CODE (set) == SET) ; else if (GET_CODE (set) == PARALLEL - && XVECLEN (set, 0) == 2 - && GET_CODE (XVECEXP (set, 0, 0)) == SET - && GET_CODE (XVECEXP (set, 0, 1)) == CLOBBER) + && GET_CODE (XVECEXP (set, 0, 0)) == SET) set = XVECEXP (set, 0, 0); else abort (); @@ -6011,18 +5959,17 @@ ix86_adjust_cost (insn, link, dep_insn, cost) if (dep_insn_code_number < 0 || recog_memoized (insn) < 0) return cost; - /* Prologue and epilogue allocators have false dependency on ebp. - This results in one cycle extra stall on Pentium prologue scheduling, so - handle this important case manually. */ + insn_type = get_attr_type (insn); + dep_insn_type = get_attr_type (dep_insn); - if ((dep_insn_code_number == CODE_FOR_prologue_allocate_stack - || dep_insn_code_number == CODE_FOR_epilogue_deallocate_stack) + /* Prologue and epilogue allocators can have a false dependency on ebp. + This results in one cycle extra stall on Pentium prologue scheduling, + so handle this important case manually. */ + if (dep_insn_code_number == CODE_FOR_pro_epilogue_adjust_stack + && dep_insn_type == TYPE_ALU && !reg_mentioned_p (stack_pointer_rtx, insn)) return 0; - insn_type = get_attr_type (insn); - dep_insn_type = get_attr_type (dep_insn); - switch (ix86_cpu) { case PROCESSOR_PENTIUM: diff --git a/gcc/config/i386/i386.md b/gcc/config/i386/i386.md index c5454d7..dc63bb18 100644 --- a/gcc/config/i386/i386.md +++ b/gcc/config/i386/i386.md @@ -8807,35 +8807,47 @@ ;; ;; in proper program order. -(define_insn "prologue_allocate_stack" - [(set (match_operand:SI 0 "register_operand" "=r") - (plus:SI (match_operand:SI 1 "register_operand" "0") - (match_operand:SI 2 "nonmemory_operand" "ri"))) - (set (match_operand:SI 3 "register_operand" "=r") +(define_insn "pro_epilogue_adjust_stack" + [(set (match_operand:SI 0 "register_operand" "=r,r") + (plus:SI (match_operand:SI 1 "register_operand" "0,r") + (match_operand:SI 2 "immediate_operand" "i,i"))) + (set (match_operand:SI 3 "register_operand" "+r,r") (match_dup 3)) (clobber (reg:CC 17))] "" "* { - if (GET_CODE (operands[2]) == CONST_INT - && (INTVAL (operands[2]) == 128 - || (INTVAL (operands[2]) < 0 - && INTVAL (operands[2]) != -128))) + switch (get_attr_type (insn)) { - operands[2] = GEN_INT (-INTVAL (operands[2])); - return \"sub{l}\\t{%2, %0|%0, %2}\"; + case TYPE_IMOV: + return \"mov{l}\\t{%1, %0|%0, %1}\"; + + case TYPE_ALU: + if (GET_CODE (operands[2]) == CONST_INT + && (INTVAL (operands[2]) == 128 + || (INTVAL (operands[2]) < 0 + && INTVAL (operands[2]) != -128))) + { + operands[2] = GEN_INT (-INTVAL (operands[2])); + return \"sub{l}\\t{%2, %0|%0, %2}\"; + } + return \"add{l}\\t{%2, %0|%0, %2}\"; + + case TYPE_LEA: + operands[2] = SET_SRC (XVECEXP (PATTERN (insn), 0, 0)); + return \"lea{l}\\t{%a2, %0|%0, %a2}\"; + + default: + abort (); } - return \"add{l}\\t{%2, %0|%0, %2}\"; }" - [(set_attr "type" "alu")]) - -(define_insn "epilogue_deallocate_stack" - [(set (match_operand:SI 0 "register_operand" "=r") - (match_operand:SI 1 "register_operand" "+r")) - (set (match_dup 1) (match_dup 1))] - "" - "mov{l}\\t{%1, %0|%0, %1}" - [(set_attr "type" "imov")]) + [(set (attr "type") + (cond [(eq_attr "alternative" "0") + (const_string "alu") + (match_operand:SI 2 "const0_operand" "") + (const_string "imov") + ] + (const_string "lea")))]) (define_insn "allocate_stack_worker" [(unspec:SI [(match_operand:SI 0 "register_operand" "a")] 3) |