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reload1.c (maybe_fix_stack_asms): New static function. 

* reload1.c (maybe_fix_stack_asms): New static function.
	(reload): Call it.

From-SVN: r23075
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Bernd Schmidt 1998-10-14 01:21:06 +00:00 committed by Jeff Law
parent 7609e7209a
commit 18a90182e3
2 changed files with 119 additions and 0 deletions
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3
gcc/ChangeLog
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@ -1,5 +1,8 @@
Tue Oct 13 22:12:11 1998 Bernd Schmidt <crux@pool.informatik.rwth-aachen.de>
* reload1.c (maybe_fix_stack_asms): New static function.
(reload): Call it.
* reload.h (compute_use_by_pseudos): Declare.
* reload1.c (spilled_pseudos, insns_need_reload): New variables.

116
gcc/reload1.c
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@ -357,6 +357,7 @@ static int num_labels;
struct hard_reg_n_uses { int regno; int uses; };
static void dump_needs PROTO((FILE *));
static void maybe_fix_stack_asms PROTO((void));
static int calculate_needs_all_insns PROTO((int));
static int calculate_needs PROTO((struct insn_chain *, rtx, int));
static int find_reload_regs PROTO((int, FILE *));
@ -868,6 +869,8 @@ reload (first, global, dumpfile)
order_regs_for_reload ();
maybe_fix_stack_asms ();
/* So far, no hard regs have been spilled. */
n_spills = 0;
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
@ -1280,6 +1283,119 @@ reload (first, global, dumpfile)
return failure;
}
/* Yet another special case. Unfortunately, reg-stack forces people to
write incorrect clobbers in asm statements. These clobbers must not
cause the register to appear in bad_spill_regs, otherwise we'll call
fatal_insn later. We clear the corresponding regnos in the live
register sets to avoid this.
The whole thing is rather sick, I'm afraid. */
static void
maybe_fix_stack_asms ()
{
#ifdef STACK_REGS
char *constraints[MAX_RECOG_OPERANDS];
enum machine_mode operand_mode[MAX_RECOG_OPERANDS];
struct insn_chain *chain;
for (chain = reload_insn_chain; chain != 0; chain = chain->next)
{
int i, noperands;
HARD_REG_SET clobbered, allowed;
rtx pat;
if (GET_RTX_CLASS (GET_CODE (chain->insn)) != 'i'
|| (noperands = asm_noperands (PATTERN (chain->insn))) < 0)
continue;
pat = PATTERN (chain->insn);
if (GET_CODE (pat) != PARALLEL)
continue;
CLEAR_HARD_REG_SET (clobbered);
CLEAR_HARD_REG_SET (allowed);
/* First, make a mask of all stack regs that are clobbered. */
for (i = 0; i < XVECLEN (pat, 0); i++)
{
rtx t = XVECEXP (pat, 0, i);
if (GET_CODE (t) == CLOBBER && STACK_REG_P (XEXP (t, 0)))
SET_HARD_REG_BIT (clobbered, REGNO (XEXP (t, 0)));
}
/* Get the operand values and constraints out of the insn. */
decode_asm_operands (pat, recog_operand, recog_operand_loc,
constraints, operand_mode);
/* For every operand, see what registers are allowed. */
for (i = 0; i < noperands; i++)
{
char *p = constraints[i];
/* For every alternative, we compute the class of registers allowed
for reloading in CLS, and merge its contents into the reg set
ALLOWED. */
int cls = (int) NO_REGS;
for (;;)
{
char c = *p++;
if (c == '\0' || c == ',' || c == '#')
{
/* End of one alternative - mark the regs in the current
class, and reset the class. */
IOR_HARD_REG_SET (allowed, reg_class_contents[cls]);
cls = NO_REGS;
if (c == '#')
do {
c = *p++;
} while (c != '\0' && c != ',');
if (c == '\0')
break;
continue;
}
switch (c)
{
case '=': case '+': case '*': case '%': case '?': case '!':
case '0': case '1': case '2': case '3': case '4': case 'm':
case '<': case '>': case 'V': case 'o': case '&': case 'E':
case 'F': case 's': case 'i': case 'n': case 'X': case 'I':
case 'J': case 'K': case 'L': case 'M': case 'N': case 'O':
case 'P':
#ifdef EXTRA_CONSTRAINT
case 'Q': case 'R': case 'S': case 'T': case 'U':
#endif
break;
case 'p':
cls = (int) reg_class_subunion[cls][(int) BASE_REG_CLASS];
break;
case 'g':
case 'r':
cls = (int) reg_class_subunion[cls][(int) GENERAL_REGS];
break;
default:
cls = (int) reg_class_subunion[cls][(int) REG_CLASS_FROM_LETTER (c)];
}
}
}
/* Those of the registers which are clobbered, but allowed by the
constraints, must be usable as reload registers. So clear them
out of the life information. */
AND_HARD_REG_SET (allowed, clobbered);
for (i = 0; i < FIRST_PSEUDO_REGISTER; i++)
if (TEST_HARD_REG_BIT (allowed, i))
{
CLEAR_REGNO_REG_SET (chain->live_before, i);
CLEAR_REGNO_REG_SET (chain->live_after, i);
}
}
#endif
}
/* Walk the insns of the current function, starting with FIRST, and collect
information about the need to do register elimination and the need to
perform reloads. */