/* Register to Stack convert for GNU compiler.
Copyright (C) 1992, 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
- 2001, 2002, 2003, 2004, 2005, 2006, 2007
+ 2001, 2002, 2003, 2004, 2005, 2006, 2007, 2008
Free Software Foundation, Inc.
This file is part of GCC.
#include "output.h"
#include "basic-block.h"
#include "cfglayout.h"
-#include "varray.h"
#include "reload.h"
#include "ggc.h"
#include "timevar.h"
static rtx *get_true_reg (rtx *);
static int check_asm_stack_operands (rtx);
-static int get_asm_operand_n_inputs (rtx);
+static void get_asm_operands_in_out (rtx, int *, int *);
static rtx stack_result (tree);
static void replace_reg (rtx *, int);
static void remove_regno_note (rtx, enum reg_note, unsigned int);
preprocess_constraints ();
- n_inputs = get_asm_operand_n_inputs (body);
- n_outputs = recog_data.n_operands - n_inputs;
+ get_asm_operands_in_out (body, &n_outputs, &n_inputs);
if (alt < 0)
{
N_INPUTS and N_OUTPUTS are pointers to ints into which the results are
placed. */
-static int
-get_asm_operand_n_inputs (rtx body)
+static void
+get_asm_operands_in_out (rtx body, int *pout, int *pin)
{
- switch (GET_CODE (body))
- {
- case SET:
- gcc_assert (GET_CODE (SET_SRC (body)) == ASM_OPERANDS);
- return ASM_OPERANDS_INPUT_LENGTH (SET_SRC (body));
-
- case ASM_OPERANDS:
- return ASM_OPERANDS_INPUT_LENGTH (body);
-
- case PARALLEL:
- return get_asm_operand_n_inputs (XVECEXP (body, 0, 0));
-
- default:
- gcc_unreachable ();
- }
+ rtx asmop = extract_asm_operands (body);
+
+ *pin = ASM_OPERANDS_INPUT_LENGTH (asmop);
+ *pout = (recog_data.n_operands
+ - ASM_OPERANDS_INPUT_LENGTH (asmop)
+ - ASM_OPERANDS_LABEL_LENGTH (asmop));
}
/* If current function returns its result in an fp stack register,
static void
remove_regno_note (rtx insn, enum reg_note note, unsigned int regno)
{
- rtx *note_link, this;
+ rtx *note_link, this_rtx;
note_link = ®_NOTES (insn);
- for (this = *note_link; this; this = XEXP (this, 1))
- if (REG_NOTE_KIND (this) == note
- && REG_P (XEXP (this, 0)) && REGNO (XEXP (this, 0)) == regno)
+ for (this_rtx = *note_link; this_rtx; this_rtx = XEXP (this_rtx, 1))
+ if (REG_NOTE_KIND (this_rtx) == note
+ && REG_P (XEXP (this_rtx, 0)) && REGNO (XEXP (this_rtx, 0)) == regno)
{
- *note_link = XEXP (this, 1);
+ *note_link = XEXP (this_rtx, 1);
return;
}
else
- note_link = &XEXP (this, 1);
+ note_link = &XEXP (this_rtx, 1);
gcc_unreachable ();
}
else
pop_insn = emit_insn_before (pop_rtx, insn);
- REG_NOTES (pop_insn)
- = gen_rtx_EXPR_LIST (REG_DEAD, FP_MODE_REG (FIRST_STACK_REG, DFmode),
- REG_NOTES (pop_insn));
+ add_reg_note (pop_insn, REG_DEAD, FP_MODE_REG (FIRST_STACK_REG, DFmode));
regstack->reg[regstack->top - (hard_regno - FIRST_STACK_REG)]
= regstack->reg[regstack->top];
push_rtx = gen_movxf (top_stack_reg, top_stack_reg);
emit_insn_before (push_rtx, insn);
- REG_NOTES (insn) = gen_rtx_EXPR_LIST (REG_DEAD, top_stack_reg,
- REG_NOTES (insn));
+ add_reg_note (insn, REG_DEAD, top_stack_reg);
}
replace_reg (psrc, FIRST_STACK_REG);
}
}
\f
+/* Substitute new registers in LOC, which is part of a debug insn.
+ REGSTACK is the current register layout. */
+
+static int
+subst_stack_regs_in_debug_insn (rtx *loc, void *data)
+{
+ rtx *tloc = get_true_reg (loc);
+ stack regstack = (stack)data;
+ int hard_regno;
+
+ if (!STACK_REG_P (*tloc))
+ return 0;
+
+ if (tloc != loc)
+ return 0;
+
+ hard_regno = get_hard_regnum (regstack, *loc);
+ gcc_assert (hard_regno >= FIRST_STACK_REG);
+
+ replace_reg (loc, hard_regno);
+
+ return -1;
+}
+
/* Substitute new registers in PAT, which is part of INSN. REGSTACK
is the current register layout. Return whether a control flow insn
was deleted in the process. */
/* Uninitialized USE might happen for functions returning uninitialized
value. We will properly initialize the USE on the edge to EXIT_BLOCK,
so it is safe to ignore the use here. This is consistent with behavior
- of dataflow analyzer that ignores USE too. (This also imply that
+ of dataflow analyzer that ignores USE too. (This also imply that
forcibly initializing the register to NaN here would lead to ICE later,
since the REG_DEAD notes are not issued.) */
break;
+ case VAR_LOCATION:
+ gcc_unreachable ();
+
case CLOBBER:
{
rtx note;
if (pat != PATTERN (insn))
{
- /* The fix_truncdi_1 pattern wants to be able to allocate
- its own scratch register. It does this by clobbering
- an fp reg so that it is assured of an empty reg-stack
- register. If the register is live, kill it now.
- Remove the DEAD/UNUSED note so we don't try to kill it
- later too. */
+ /* The fix_truncdi_1 pattern wants to be able to
+ allocate its own scratch register. It does this by
+ clobbering an fp reg so that it is assured of an
+ empty reg-stack register. If the register is live,
+ kill it now. Remove the DEAD/UNUSED note so we
+ don't try to kill it later too.
+
+ In reality the UNUSED note can be absent in some
+ complicated cases when the register is reused for
+ partially set variable. */
if (note)
emit_pop_insn (insn, regstack, *dest, EMIT_BEFORE);
else
- {
- note = find_reg_note (insn, REG_UNUSED, *dest);
- gcc_assert (note);
- }
- remove_note (insn, note);
+ note = find_reg_note (insn, REG_UNUSED, *dest);
+ if (note)
+ remove_note (insn, note);
replace_reg (dest, FIRST_STACK_REG + 1);
}
else
else
{
/* Both operands are REG. If neither operand is already
- at the top of stack, choose to make the one that is the dest
- the new top of stack. */
+ at the top of stack, choose to make the one that is the
+ dest the new top of stack. */
int src1_hard_regnum, src2_hard_regnum;
src1_hard_regnum = get_hard_regnum (regstack, *src1);
src2_hard_regnum = get_hard_regnum (regstack, *src2);
- gcc_assert (src1_hard_regnum != -1);
- gcc_assert (src2_hard_regnum != -1);
+
+ /* If the source is not live, this is yet another case of
+ uninitialized variables. Load up a NaN instead. */
+ if (src1_hard_regnum == -1)
+ {
+ rtx pat2 = gen_rtx_CLOBBER (VOIDmode, *src1);
+ rtx insn2 = emit_insn_before (pat2, insn);
+ control_flow_insn_deleted
+ |= move_nan_for_stack_reg (insn2, regstack, *src1);
+ }
+ if (src2_hard_regnum == -1)
+ {
+ rtx pat2 = gen_rtx_CLOBBER (VOIDmode, *src2);
+ rtx insn2 = emit_insn_before (pat2, insn);
+ control_flow_insn_deleted
+ |= move_nan_for_stack_reg (insn2, regstack, *src2);
+ }
if (src1_hard_regnum != FIRST_STACK_REG
&& src2_hard_regnum != FIRST_STACK_REG)
preprocess_constraints ();
- n_inputs = get_asm_operand_n_inputs (body);
- n_outputs = recog_data.n_operands - n_inputs;
+ get_asm_operands_in_out (body, &n_outputs, &n_inputs);
gcc_assert (alt >= 0);
is no longer needed once this has executed. */
static void
-change_stack (rtx insn, stack old, stack new, enum emit_where where)
+change_stack (rtx insn, stack old, stack new_stack, enum emit_where where)
{
int reg;
int update_end = 0;
&& starting_stack_p
&& where == EMIT_BEFORE)
{
- BLOCK_INFO (current_block)->stack_in = *new;
+ BLOCK_INFO (current_block)->stack_in = *new_stack;
starting_stack_p = false;
- *old = *new;
+ *old = *new_stack;
return;
}
/* Initialize partially dead variables. */
for (i = FIRST_STACK_REG; i < LAST_STACK_REG + 1; i++)
- if (TEST_HARD_REG_BIT (new->reg_set, i)
+ if (TEST_HARD_REG_BIT (new_stack->reg_set, i)
&& !TEST_HARD_REG_BIT (old->reg_set, i))
{
old->reg[++old->top] = i;
/* If the destination block's stack already has a specified layout
and contains two or more registers, use a more intelligent algorithm
to pop registers that minimizes the number number of fxchs below. */
- if (new->top > 0)
+ if (new_stack->top > 0)
{
bool slots[REG_STACK_SIZE];
int pops[REG_STACK_SIZE];
int next, dest, topsrc;
/* First pass to determine the free slots. */
- for (reg = 0; reg <= new->top; reg++)
- slots[reg] = TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]);
+ for (reg = 0; reg <= new_stack->top; reg++)
+ slots[reg] = TEST_HARD_REG_BIT (new_stack->reg_set, old->reg[reg]);
/* Second pass to allocate preferred slots. */
topsrc = -1;
- for (reg = old->top; reg > new->top; reg--)
- if (TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]))
+ for (reg = old->top; reg > new_stack->top; reg--)
+ if (TEST_HARD_REG_BIT (new_stack->reg_set, old->reg[reg]))
{
dest = -1;
- for (next = 0; next <= new->top; next++)
- if (!slots[next] && new->reg[next] == old->reg[reg])
+ for (next = 0; next <= new_stack->top; next++)
+ if (!slots[next] && new_stack->reg[next] == old->reg[reg])
{
/* If this is a preference for the new top of stack, record
the fact by remembering it's old->reg in topsrc. */
- if (next == new->top)
+ if (next == new_stack->top)
topsrc = reg;
slots[next] = true;
dest = next;
slot is still unallocated, in which case we should place the
top of stack there. */
if (topsrc != -1)
- for (reg = 0; reg < new->top; reg++)
+ for (reg = 0; reg < new_stack->top; reg++)
if (!slots[reg])
{
pops[topsrc] = reg;
- slots[new->top] = false;
+ slots[new_stack->top] = false;
slots[reg] = true;
break;
}
/* Third pass allocates remaining slots and emits pop insns. */
- next = new->top;
- for (reg = old->top; reg > new->top; reg--)
+ next = new_stack->top;
+ for (reg = old->top; reg > new_stack->top; reg--)
{
dest = pops[reg];
if (dest == -1)
live = 0;
for (reg = 0; reg <= old->top; reg++)
- if (TEST_HARD_REG_BIT (new->reg_set, old->reg[reg]))
+ if (TEST_HARD_REG_BIT (new_stack->reg_set, old->reg[reg]))
live++;
next = live;
while (old->top >= live)
- if (TEST_HARD_REG_BIT (new->reg_set, old->reg[old->top]))
+ if (TEST_HARD_REG_BIT (new_stack->reg_set, old->reg[old->top]))
{
- while (TEST_HARD_REG_BIT (new->reg_set, old->reg[next]))
+ while (TEST_HARD_REG_BIT (new_stack->reg_set, old->reg[next]))
next--;
emit_pop_insn (insn, old, FP_MODE_REG (old->reg[next], DFmode),
EMIT_BEFORE);
EMIT_BEFORE);
}
- if (new->top == -2)
+ if (new_stack->top == -2)
{
/* If the new block has never been processed, then it can inherit
the old stack order. */
- new->top = old->top;
- memcpy (new->reg, old->reg, sizeof (new->reg));
+ new_stack->top = old->top;
+ memcpy (new_stack->reg, old->reg, sizeof (new_stack->reg));
}
else
{
/* By now, the only difference should be the order of the stack,
not their depth or liveliness. */
- gcc_assert (hard_reg_set_equal_p (old->reg_set, new->reg_set));
- gcc_assert (old->top == new->top);
+ gcc_assert (hard_reg_set_equal_p (old->reg_set, new_stack->reg_set));
+ gcc_assert (old->top == new_stack->top);
- /* If the stack is not empty (new->top != -1), loop here emitting
+ /* If the stack is not empty (new_stack->top != -1), loop here emitting
swaps until the stack is correct.
The worst case number of swaps emitted is N + 2, where N is the
other regs. But since we never swap any other reg away from
its correct slot, this algorithm will converge. */
- if (new->top != -1)
+ if (new_stack->top != -1)
do
{
/* Swap the reg at top of stack into the position it is
supposed to be in, until the correct top of stack appears. */
- while (old->reg[old->top] != new->reg[new->top])
+ while (old->reg[old->top] != new_stack->reg[new_stack->top])
{
- for (reg = new->top; reg >= 0; reg--)
- if (new->reg[reg] == old->reg[old->top])
+ for (reg = new_stack->top; reg >= 0; reg--)
+ if (new_stack->reg[reg] == old->reg[old->top])
break;
gcc_assert (reg != -1);
incorrect reg to the top of stack, and let the while loop
above fix it. */
- for (reg = new->top; reg >= 0; reg--)
- if (new->reg[reg] != old->reg[reg])
+ for (reg = new_stack->top; reg >= 0; reg--)
+ if (new_stack->reg[reg] != old->reg[reg])
{
emit_swap_insn (insn, old,
FP_MODE_REG (old->reg[reg], DFmode));
/* At this point there must be no differences. */
for (reg = old->top; reg >= 0; reg--)
- gcc_assert (old->reg[reg] == new->reg[reg]);
+ gcc_assert (old->reg[reg] == new_stack->reg[reg]);
}
if (update_end)
int reg;
rtx insn, next;
bool control_flow_insn_deleted = false;
+ int debug_insns_with_starting_stack = 0;
any_malformed_asm = false;
/* Don't bother processing unless there is a stack reg
mentioned or if it's a CALL_INSN. */
- if (stack_regs_mentioned (insn)
- || CALL_P (insn))
+ if (DEBUG_INSN_P (insn))
+ {
+ if (starting_stack_p)
+ debug_insns_with_starting_stack++;
+ else
+ {
+ for_each_rtx (&PATTERN (insn), subst_stack_regs_in_debug_insn,
+ ®stack);
+
+ /* Nothing must ever die at a debug insn. If something
+ is referenced in it that becomes dead, it should have
+ died before and the reference in the debug insn
+ should have been removed so as to avoid changing code
+ generation. */
+ gcc_assert (!find_reg_note (insn, REG_DEAD, NULL));
+ }
+ }
+ else if (stack_regs_mentioned (insn)
+ || CALL_P (insn))
{
if (dump_file)
{
}
while (next);
+ if (debug_insns_with_starting_stack)
+ {
+ /* Since it's the first non-debug instruction that determines
+ the stack requirements of the current basic block, we refrain
+ from updating debug insns before it in the loop above, and
+ fix them up here. */
+ for (insn = BB_HEAD (block); debug_insns_with_starting_stack;
+ insn = NEXT_INSN (insn))
+ {
+ if (!DEBUG_INSN_P (insn))
+ continue;
+
+ debug_insns_with_starting_stack--;
+ for_each_rtx (&PATTERN (insn), subst_stack_regs_in_debug_insn,
+ &bi->stack_in);
+ }
+ }
+
if (dump_file)
{
fprintf (dump_file, "Expected live registers [");
control_flow_insn_deleted |= subst_stack_regs (insn, ®stack);
}
}
-
+
/* Amongst the insns possibly deleted during the substitution process above,
might have been the only trapping insn in the block. We purge the now
possibly dead EH edges here to avoid an ICE from fixup_abnormal_edges,
/* Something failed if the stack lives don't match. If we had malformed
asms, we zapped the instruction itself, but that didn't produce the
same pattern of register kills as before. */
-
+
gcc_assert (hard_reg_set_equal_p (regstack.reg_set, bi->out_reg_set)
|| any_malformed_asm);
bi->stack_out = regstack;
/* We process the blocks in a top-down manner, in a way such that one block
is only processed after all its predecessors. The number of predecessors
- of every block has already been computed. */
+ of every block has already been computed. */
stack = XNEWVEC (basic_block, n_basic_blocks);
sp = stack;
??? We can't load from constant memory in PIC mode, because
we're inserting these instructions before the prologue and
the PIC register hasn't been set up. In that case, fall back
- on zero, which we can get from `ldz'. */
+ on zero, which we can get from `fldz'. */
if ((flag_pic && !TARGET_64BIT)
|| ix86_cmodel == CM_LARGE || ix86_cmodel == CM_LARGE_PIC)
not_a_num = CONST0_RTX (SFmode);
else
{
- not_a_num = gen_lowpart (SFmode, GEN_INT (0x7fc00000));
+ REAL_VALUE_TYPE r;
+
+ real_nan (&r, "", 1, SFmode);
+ not_a_num = CONST_DOUBLE_FROM_REAL_VALUE (r, SFmode);
not_a_num = force_const_mem (SFmode, not_a_num);
}
max_uid = get_max_uid ();
stack_regs_mentioned_data = VEC_alloc (char, heap, max_uid + 1);
memset (VEC_address (char, stack_regs_mentioned_data),
- 0, sizeof (char) * max_uid + 1);
+ 0, sizeof (char) * (max_uid + 1));
convert_regs ();
{
{
RTL_PASS,
- NULL, /* name */
+ "*stack_regs", /* name */
gate_handle_stack_regs, /* gate */
NULL, /* execute */
NULL, /* sub */
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