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Extra arg for rtx_varies_p
- To: <gcc-patches at gcc dot gnu dot org>
- Subject: Extra arg for rtx_varies_p
- From: Bernd Schmidt <bernds at redhat dot com>
- Date: Mon, 1 Jan 2001 17:06:28 +0000 (GMT)
There's a hack in rtx_varies_p that makes us return 1 for pic_offset_table_rtx.
This is undesirable for alias analysis on ia64; it restricts scheduling of
loads. This patch adds an extra argument to rtx_varies_p which tells the
function whether it needs to apply this hack or not.
Bootstrapped in i686-linux; compiled SPECint95 on ia64.
Bernd
* alias.c (fixed_scalar_and_varying_struct): Adjust prototype of
arg VARIES_P. Call it with extra arg.
(true_dependence): Likewise.
* rtl.h (rtx_addr_can_trap_p): Declare.
(rtx_varies_p, rtx_addr_varies_p, true_dependence): Update
prototypes.
* rtlanal.c (rtx_addr_can_trap_p): No longer static.
(rtx_varies_p): Accept extra arg FOR_ALIAS; only disallow
pic offset table register if it's zero. All callers changed.
(rtx_addr_varies_p): Accept extra arg FOR_ALIAS; all callers changed.
Index: alias.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/alias.c,v
retrieving revision 1.108
diff -u -p -r1.108 alias.c
--- alias.c 2000/12/15 00:04:28 1.108
+++ alias.c 2001/01/01 16:59:55
@@ -101,7 +101,7 @@ static int insert_subset_children
static tree find_base_decl PARAMS ((tree));
static alias_set_entry get_alias_set_entry PARAMS ((HOST_WIDE_INT));
static rtx fixed_scalar_and_varying_struct_p PARAMS ((rtx, rtx, rtx, rtx,
- int (*) (rtx)));
+ int (*) (rtx, int)));
static int aliases_everything_p PARAMS ((rtx));
static int write_dependence_p PARAMS ((rtx, rtx, int));
static int nonlocal_mentioned_p PARAMS ((rtx));
@@ -1541,19 +1541,19 @@ static rtx
fixed_scalar_and_varying_struct_p (mem1, mem2, mem1_addr, mem2_addr, varies_p)
rtx mem1, mem2;
rtx mem1_addr, mem2_addr;
- int (*varies_p) PARAMS ((rtx));
+ int (*varies_p) PARAMS ((rtx, int));
{
if (! flag_strict_aliasing)
return NULL_RTX;
if (MEM_SCALAR_P (mem1) && MEM_IN_STRUCT_P (mem2)
- && !varies_p (mem1_addr) && varies_p (mem2_addr))
+ && !varies_p (mem1_addr, 1) && varies_p (mem2_addr, 1))
/* MEM1 is a scalar at a fixed address; MEM2 is a struct at a
varying address. */
return mem1;
if (MEM_IN_STRUCT_P (mem1) && MEM_SCALAR_P (mem2)
- && varies_p (mem1_addr) && !varies_p (mem2_addr))
+ && varies_p (mem1_addr, 1) && !varies_p (mem2_addr, 1))
/* MEM2 is a scalar at a fixed address; MEM1 is a struct at a
varying address. */
return mem2;
@@ -1583,7 +1583,7 @@ true_dependence (mem, mem_mode, x, varie
rtx mem;
enum machine_mode mem_mode;
rtx x;
- int (*varies) PARAMS ((rtx));
+ int (*varies) PARAMS ((rtx, int));
{
register rtx x_addr, mem_addr;
rtx base;
Index: cse.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/cse.c,v
retrieving revision 1.166
diff -u -p -r1.166 cse.c
--- cse.c 2000/11/24 11:36:27 1.166
+++ cse.c 2001/01/01 16:59:58
@@ -2745,7 +2745,7 @@ cse_rtx_varies_p (x)
return 0;
}
- return rtx_varies_p (x);
+ return rtx_varies_p (x, 0);
}
/* Canonicalize an expression:
Index: local-alloc.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/local-alloc.c,v
retrieving revision 1.75
diff -u -p -r1.75 local-alloc.c
--- local-alloc.c 2000/11/30 21:40:33 1.75
+++ local-alloc.c 2001/01/01 16:59:58
@@ -540,7 +540,7 @@ equiv_init_varies_p (x)
return 0;
case REG:
- return reg_equiv[REGNO (x)].replace == 0 && rtx_varies_p (x);
+ return reg_equiv[REGNO (x)].replace == 0 && rtx_varies_p (x, 0);
case ASM_OPERANDS:
if (MEM_VOLATILE_P (x))
@@ -604,7 +604,7 @@ equiv_init_movable_p (x, regno)
case REG:
return (reg_equiv[REGNO (x)].loop_depth >= reg_equiv[regno].loop_depth
&& reg_equiv[REGNO (x)].replace)
- || (REG_BASIC_BLOCK (REGNO (x)) < 0 && ! rtx_varies_p (x));
+ || (REG_BASIC_BLOCK (REGNO (x)) < 0 && ! rtx_varies_p (x, 0));
case UNSPEC_VOLATILE:
return 0;
@@ -933,7 +933,7 @@ update_equiv_regs ()
/* cse sometimes generates function invariants, but doesn't put a
REG_EQUAL note on the insn. Since this note would be redundant,
there's no point creating it earlier than here. */
- if (! note && ! rtx_varies_p (src))
+ if (! note && ! rtx_varies_p (src, 0))
REG_NOTES (insn)
= note = gen_rtx_EXPR_LIST (REG_EQUAL, src, REG_NOTES (insn));
@@ -944,7 +944,7 @@ update_equiv_regs ()
if (REG_N_SETS (regno) != 1
&& (! note
- || rtx_varies_p (XEXP (note, 0))
+ || rtx_varies_p (XEXP (note, 0), 0)
|| (reg_equiv[regno].replacement
&& ! rtx_equal_p (XEXP (note, 0),
reg_equiv[regno].replacement))))
@@ -958,7 +958,7 @@ update_equiv_regs ()
/* If this register is known to be equal to a constant, record that
it is always equivalent to the constant. */
- if (note && ! rtx_varies_p (XEXP (note, 0)))
+ if (note && ! rtx_varies_p (XEXP (note, 0), 0))
PUT_MODE (note, (enum machine_mode) REG_EQUIV);
/* If this insn introduces a "constant" register, decrease the priority
Index: reload.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/reload.c,v
retrieving revision 1.137
diff -u -p -r1.137 reload.c
--- reload.c 2000/12/22 01:24:14 1.137
+++ reload.c 2001/01/01 17:00:00
@@ -4431,7 +4431,7 @@ make_memloc (ad, regno)
/* If TEM might contain a pseudo, we must copy it to avoid
modifying it when we do the substitution for the reload. */
- if (rtx_varies_p (tem))
+ if (rtx_varies_p (tem, 0))
tem = copy_rtx (tem);
tem = gen_rtx_MEM (GET_MODE (ad), tem);
Index: rtl.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/rtl.h,v
retrieving revision 1.235
diff -u -p -r1.235 rtl.h
--- rtl.h 2000/12/29 17:35:57 1.235
+++ rtl.h 2001/01/01 17:00:01
@@ -1352,9 +1352,10 @@ extern void set_unique_reg_note
: NULL_RTX)
#define single_set_1(I) single_set_2 (I, PATTERN (I))
+extern int rtx_addr_can_trap_p PARAMS ((rtx));
extern int rtx_unstable_p PARAMS ((rtx));
-extern int rtx_varies_p PARAMS ((rtx));
-extern int rtx_addr_varies_p PARAMS ((rtx));
+extern int rtx_varies_p PARAMS ((rtx, int));
+extern int rtx_addr_varies_p PARAMS ((rtx, int));
extern HOST_WIDE_INT get_integer_term PARAMS ((rtx));
extern rtx get_related_value PARAMS ((rtx));
extern int reg_mentioned_p PARAMS ((rtx, rtx));
@@ -1986,7 +1987,7 @@ extern void fancy_abort PARAMS ((const c
/* In alias.c */
extern rtx canon_rtx PARAMS ((rtx));
extern int true_dependence PARAMS ((rtx, enum machine_mode, rtx,
- int (*)(rtx)));
+ int (*)(rtx, int)));
extern int read_dependence PARAMS ((rtx, rtx));
extern int anti_dependence PARAMS ((rtx, rtx));
extern int output_dependence PARAMS ((rtx, rtx));
Index: rtlanal.c
===================================================================
RCS file: /cvs/gcc/egcs/gcc/rtlanal.c,v
retrieving revision 1.77
diff -u -p -r1.77 rtlanal.c
--- rtlanal.c 2000/12/21 22:15:22 1.77
+++ rtlanal.c 2001/01/01 17:00:01
@@ -25,7 +25,6 @@ Boston, MA 02111-1307, USA. */
#include "toplev.h"
#include "rtl.h"
-static int rtx_addr_can_trap_p PARAMS ((rtx));
static void reg_set_p_1 PARAMS ((rtx, rtx, void *));
static void insn_dependent_p_1 PARAMS ((rtx, rtx, void *));
static void reg_set_last_1 PARAMS ((rtx, rtx, void *));
@@ -113,11 +112,14 @@ rtx_unstable_p (x)
/* Return 1 if X has a value that can vary even between two
executions of the program. 0 means X can be compared reliably
against certain constants or near-constants.
+ FOR_ALIAS is nonzero if we are called from alias analysis; if it is
+ zero, we are slightly more conservative.
The frame pointer and the arg pointer are considered constant. */
int
-rtx_varies_p (x)
+rtx_varies_p (x, for_alias)
rtx x;
+ int for_alias;
{
register RTX_CODE code = GET_CODE (x);
register int i;
@@ -126,7 +128,7 @@ rtx_varies_p (x)
switch (code)
{
case MEM:
- return ! RTX_UNCHANGING_P (x) || rtx_varies_p (XEXP (x, 0));
+ return ! RTX_UNCHANGING_P (x) || rtx_varies_p (XEXP (x, 0), for_alias);
case QUEUED:
return 1;
@@ -146,19 +148,22 @@ rtx_varies_p (x)
if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
|| x == arg_pointer_rtx)
return 0;
-#ifndef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
- /* ??? When call-clobbered, the value is stable modulo the restore
- that must happen after a call. This currently screws up local-alloc
- into believing that the restore is not needed. */
- if (x == pic_offset_table_rtx)
- return 0;
+ if (x == pic_offset_table_rtx
+#ifdef PIC_OFFSET_TABLE_REG_CALL_CLOBBERED
+ /* ??? When call-clobbered, the value is stable modulo the restore
+ that must happen after a call. This currently screws up
+ local-alloc into believing that the restore is not needed, so we
+ must return 0 only if we are called from alias analysis. */
+ && for_alias
#endif
+ )
+ return 0;
return 1;
case LO_SUM:
/* The operand 0 of a LO_SUM is considered constant
(in fact is it related specifically to operand 1). */
- return rtx_varies_p (XEXP (x, 1));
+ return rtx_varies_p (XEXP (x, 1), for_alias);
case ASM_OPERANDS:
if (MEM_VOLATILE_P (x))
@@ -174,14 +179,14 @@ rtx_varies_p (x)
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
if (fmt[i] == 'e')
{
- if (rtx_varies_p (XEXP (x, i)))
+ if (rtx_varies_p (XEXP (x, i), for_alias))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
- if (rtx_varies_p (XVECEXP (x, i, j)))
+ if (rtx_varies_p (XVECEXP (x, i, j), for_alias))
return 1;
}
@@ -190,7 +195,7 @@ rtx_varies_p (x)
/* Return 0 if the use of X as an address in a MEM can cause a trap. */
-static int
+int
rtx_addr_can_trap_p (x)
register rtx x;
{
@@ -236,11 +241,14 @@ rtx_addr_can_trap_p (x)
/* Return 1 if X refers to a memory location whose address
cannot be compared reliably with constant addresses,
- or if X refers to a BLKmode memory object. */
+ or if X refers to a BLKmode memory object.
+ FOR_ALIAS is nonzero if we are called from alias analysis; if it is
+ zero, we are slightly more conservative. */
int
-rtx_addr_varies_p (x)
+rtx_addr_varies_p (x, for_alias)
rtx x;
+ int for_alias;
{
register enum rtx_code code;
register int i;
@@ -251,20 +259,20 @@ rtx_addr_varies_p (x)
code = GET_CODE (x);
if (code == MEM)
- return GET_MODE (x) == BLKmode || rtx_varies_p (XEXP (x, 0));
+ return GET_MODE (x) == BLKmode || rtx_varies_p (XEXP (x, 0), for_alias);
fmt = GET_RTX_FORMAT (code);
for (i = GET_RTX_LENGTH (code) - 1; i >= 0; i--)
if (fmt[i] == 'e')
{
- if (rtx_addr_varies_p (XEXP (x, i)))
+ if (rtx_addr_varies_p (XEXP (x, i), for_alias))
return 1;
}
else if (fmt[i] == 'E')
{
int j;
for (j = 0; j < XVECLEN (x, i); j++)
- if (rtx_addr_varies_p (XVECEXP (x, i, j)))
+ if (rtx_addr_varies_p (XVECEXP (x, i, j), for_alias))
return 1;
}
return 0;
Index: config/a29k/a29k.h
===================================================================
RCS file: /cvs/gcc/egcs/gcc/config/a29k/a29k.h,v
retrieving revision 1.16
diff -u -p -r1.16 a29k.h
--- config/a29k/a29k.h 2000/11/02 23:29:07 1.16
+++ config/a29k/a29k.h 2001/01/01 17:00:03
@@ -995,7 +995,7 @@ extern const char *a29k_function_name;
&& ! (needs_regstack_p () && uses_local_reg_p (PATTERN (INSN))) \
&& (GET_CODE (PATTERN (INSN)) != SET \
|| GET_CODE (SET_SRC (PATTERN (INSN))) != MEM \
- || ! rtx_varies_p (XEXP (SET_SRC (PATTERN (INSN)), 0))))
+ || ! rtx_varies_p (XEXP (SET_SRC (PATTERN (INSN)), 0), 0)))
/* Output assembler code for a block containing the constant parts
of a trampoline, leaving space for the variable parts.