[bib] cse cleanup wrt address classification
Richard Henderson
rth@twiddle.net
Mon Oct 7 04:01:00 GMT 2002
This is the cse patch that depends on the i960 patch
I posted earlier this evening.
It has built and tested successfully on i686, i960,
alpha, sparc, but I still didn't put it on mainline.
Not yet anyway.
r~
* cse.c (fixed_base_plus_p): Turn FIXED_BASE_PLUS_P into a
function; cleanup PLUS case by using recursion. Update all users.
(NONZERO_BASE_PLUS_P): Remove.
(find_comparison_args): Use rtx_addr_can_trap_p instead.
(fold_rtx): Use nonzero_address_p.
* rtl.h (nonzero_address_p): Declare.
* rtlanal.c (rtx_varies_p): Handle ADDRESSOF.
(rtx_addr_can_trap_p): Likewise.
(nonzero_address_p): New.
* simplify-rtx.c (NONZERO_BASE_PLUS_P): Remove.
(simplify_relational_operation): Use nonzero_address_p.
Index: cse.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/cse.c,v
retrieving revision 1.238
diff -u -p -r1.238 cse.c
--- cse.c 1 Oct 2002 12:19:36 -0000 1.238
+++ cse.c 7 Oct 2002 08:58:02 -0000
@@ -582,55 +582,7 @@ struct cse_basic_block_data
} path[PATHLENGTH];
};
-/* Nonzero if X has the form (PLUS frame-pointer integer). We check for
- virtual regs here because the simplify_*_operation routines are called
- by integrate.c, which is called before virtual register instantiation.
-
- ?!? FIXED_BASE_PLUS_P and NONZERO_BASE_PLUS_P need to move into
- a header file so that their definitions can be shared with the
- simplification routines in simplify-rtx.c. Until then, do not
- change these macros without also changing the copy in simplify-rtx.c. */
-
-#define FIXED_BASE_PLUS_P(X) \
- ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \
- || ((X) == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])\
- || (X) == virtual_stack_vars_rtx \
- || (X) == virtual_incoming_args_rtx \
- || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \
- && (XEXP (X, 0) == frame_pointer_rtx \
- || XEXP (X, 0) == hard_frame_pointer_rtx \
- || ((X) == arg_pointer_rtx \
- && fixed_regs[ARG_POINTER_REGNUM]) \
- || XEXP (X, 0) == virtual_stack_vars_rtx \
- || XEXP (X, 0) == virtual_incoming_args_rtx)) \
- || GET_CODE (X) == ADDRESSOF)
-
-/* Similar, but also allows reference to the stack pointer.
-
- This used to include FIXED_BASE_PLUS_P, however, we can't assume that
- arg_pointer_rtx by itself is nonzero, because on at least one machine,
- the i960, the arg pointer is zero when it is unused. */
-
-#define NONZERO_BASE_PLUS_P(X) \
- ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \
- || (X) == virtual_stack_vars_rtx \
- || (X) == virtual_incoming_args_rtx \
- || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \
- && (XEXP (X, 0) == frame_pointer_rtx \
- || XEXP (X, 0) == hard_frame_pointer_rtx \
- || ((X) == arg_pointer_rtx \
- && fixed_regs[ARG_POINTER_REGNUM]) \
- || XEXP (X, 0) == virtual_stack_vars_rtx \
- || XEXP (X, 0) == virtual_incoming_args_rtx)) \
- || (X) == stack_pointer_rtx \
- || (X) == virtual_stack_dynamic_rtx \
- || (X) == virtual_outgoing_args_rtx \
- || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \
- && (XEXP (X, 0) == stack_pointer_rtx \
- || XEXP (X, 0) == virtual_stack_dynamic_rtx \
- || XEXP (X, 0) == virtual_outgoing_args_rtx)) \
- || GET_CODE (X) == ADDRESSOF)
-
+static bool fixed_base_plus_p PARAMS ((rtx x));
static int notreg_cost PARAMS ((rtx, enum rtx_code));
static int approx_reg_cost_1 PARAMS ((rtx *, void *));
static int approx_reg_cost PARAMS ((rtx));
@@ -693,6 +645,39 @@ static bool insn_live_p PARAMS ((rtx, i
static bool set_live_p PARAMS ((rtx, rtx, int *));
static bool dead_libcall_p PARAMS ((rtx, int *));
+/* Nonzero if X has the form (PLUS frame-pointer integer). We check for
+ virtual regs here because the simplify_*_operation routines are called
+ by integrate.c, which is called before virtual register instantiation. */
+
+static bool
+fixed_base_plus_p (x)
+ rtx x;
+{
+ switch (GET_CODE (x))
+ {
+ case REG:
+ if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx)
+ return true;
+ if (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM])
+ return true;
+ if (REGNO (x) >= FIRST_VIRTUAL_REGISTER
+ && REGNO (x) <= LAST_VIRTUAL_REGISTER)
+ return true;
+ return false;
+
+ case PLUS:
+ if (GET_CODE (XEXP (x, 1)) != CONST_INT)
+ return false;
+ return fixed_base_plus_p (XEXP (x, 0));
+
+ case ADDRESSOF:
+ return true;
+
+ default:
+ return false;
+ }
+}
+
/* Dump the expressions in the equivalence class indicated by CLASSP.
This function is used only for debugging. */
void
@@ -1597,7 +1582,7 @@ insert (x, classp, hash, mode)
|| (GET_CODE (x) == REG
&& RTX_UNCHANGING_P (x)
&& REGNO (x) >= FIRST_PSEUDO_REGISTER)
- || FIXED_BASE_PLUS_P (x));
+ || fixed_base_plus_p (x));
if (table[hash])
table[hash]->prev_same_hash = elt;
@@ -2359,10 +2344,9 @@ canon_hash (x, mode)
do_not_record = 1;
return 0;
}
- if (! RTX_UNCHANGING_P (x) || FIXED_BASE_PLUS_P (XEXP (x, 0)))
- {
- hash_arg_in_memory = 1;
- }
+ if (! RTX_UNCHANGING_P (x) || fixed_base_plus_p (XEXP (x, 0)))
+ hash_arg_in_memory = 1;
+
/* Now that we have already found this special case,
might as well speed it up as much as possible. */
hash += (unsigned) MEM;
@@ -2380,7 +2364,7 @@ canon_hash (x, mode)
hash += (unsigned) USE;
x = XEXP (x, 0);
- if (! RTX_UNCHANGING_P (x) || FIXED_BASE_PLUS_P (XEXP (x, 0)))
+ if (! RTX_UNCHANGING_P (x) || fixed_base_plus_p (XEXP (x, 0)))
hash_arg_in_memory = 1;
/* Now that we have already found this special case,
@@ -3257,9 +3241,10 @@ find_comparison_args (code, parg1, parg2
break;
}
- /* If this is fp + constant, the equivalent is a better operand since
- it may let us predict the value of the comparison. */
- else if (NONZERO_BASE_PLUS_P (p->exp))
+ /* If this non-trapping address, e.g. fp + constant, the
+ equivalent is a better operand since it may let us predict
+ the value of the comparison. */
+ else if (!rtx_addr_can_trap_p (p->exp))
{
arg1 = p->exp;
continue;
@@ -3960,17 +3945,10 @@ fold_rtx (x, insn)
comparison. */
if (const_arg0 == 0 || const_arg1 == 0)
{
- /* Is FOLDED_ARG0 frame-pointer plus a constant? Or
- non-explicit constant? These aren't zero, but we
- don't know their sign. */
+ /* Some addresses are known to be nonzero. We don't know
+ their sign, but equality comparisons are known. */
if (const_arg1 == const0_rtx
- && (NONZERO_BASE_PLUS_P (folded_arg0)
-#if 0 /* Sad to say, on sysvr4, #pragma weak can make a symbol address
- come out as 0. */
- || GET_CODE (folded_arg0) == SYMBOL_REF
-#endif
- || GET_CODE (folded_arg0) == LABEL_REF
- || GET_CODE (folded_arg0) == CONST))
+ && nonzero_address_p (folded_arg0))
{
if (code == EQ)
return false_rtx;
@@ -6164,7 +6142,7 @@ cse_insn (insn, libcall_insn)
elt->in_memory = (GET_CODE (sets[i].inner_dest) == MEM
&& (! RTX_UNCHANGING_P (sets[i].inner_dest)
- || FIXED_BASE_PLUS_P (XEXP (sets[i].inner_dest,
+ || fixed_base_plus_p (XEXP (sets[i].inner_dest,
0))));
/* If we have (set (subreg:m1 (reg:m2 foo) 0) (bar:m1)), M1 is no
Index: rtl.h
===================================================================
RCS file: /cvs/gcc/gcc/gcc/rtl.h,v
retrieving revision 1.372
diff -u -p -r1.372 rtl.h
--- rtl.h 30 Sep 2002 19:35:17 -0000 1.372
+++ rtl.h 7 Oct 2002 08:58:03 -0000
@@ -1576,6 +1576,7 @@ extern rtx set_unique_reg_note PARAMS (
#define single_set_1(I) single_set_2 (I, PATTERN (I))
extern int rtx_addr_can_trap_p PARAMS ((rtx));
+extern bool nonzero_address_p PARAMS ((rtx));
extern int rtx_unstable_p PARAMS ((rtx));
extern int rtx_varies_p PARAMS ((rtx, int));
extern int rtx_addr_varies_p PARAMS ((rtx, int));
Index: rtlanal.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/rtlanal.c,v
retrieving revision 1.140
diff -u -p -r1.140 rtlanal.c
--- rtlanal.c 26 Sep 2002 22:25:14 -0000 1.140
+++ rtlanal.c 7 Oct 2002 08:58:04 -0000
@@ -153,6 +153,10 @@ rtx_varies_p (x, for_alias)
case LABEL_REF:
return 0;
+ case ADDRESSOF:
+ /* This will resolve to some offset from the frame pointer. */
+ return 0;
+
case REG:
/* Note that we have to test for the actual rtx used for the frame
and arg pointers and not just the register number in case we have
@@ -225,6 +229,10 @@ rtx_addr_can_trap_p (x)
case LABEL_REF:
return 0;
+ case ADDRESSOF:
+ /* This will resolve to some offset from the frame pointer. */
+ return 0;
+
case REG:
/* As in rtx_varies_p, we have to use the actual rtx, not reg number. */
if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
@@ -267,6 +275,90 @@ rtx_addr_can_trap_p (x)
/* If it isn't one of the case above, it can cause a trap. */
return 1;
+}
+
+/* Return true if X is an address that is known to not be zero. */
+
+bool
+nonzero_address_p (x)
+ rtx x;
+{
+ enum rtx_code code = GET_CODE (x);
+
+ switch (code)
+ {
+ case SYMBOL_REF:
+ return !SYMBOL_REF_WEAK (x);
+
+ case LABEL_REF:
+ return true;
+
+ case ADDRESSOF:
+ /* This will resolve to some offset from the frame pointer. */
+ return true;
+
+ case REG:
+ /* As in rtx_varies_p, we have to use the actual rtx, not reg number. */
+ if (x == frame_pointer_rtx || x == hard_frame_pointer_rtx
+ || x == stack_pointer_rtx
+ || (x == arg_pointer_rtx && fixed_regs[ARG_POINTER_REGNUM]))
+ return true;
+ /* All of the virtual frame registers are stack references. */
+ if (REGNO (x) >= FIRST_VIRTUAL_REGISTER
+ && REGNO (x) <= LAST_VIRTUAL_REGISTER)
+ return true;
+ return false;
+
+ case CONST:
+ return nonzero_address_p (XEXP (x, 0));
+
+ case PLUS:
+ if (GET_CODE (XEXP (x, 1)) == CONST_INT)
+ {
+ /* Pointers aren't allowed to wrap. If we've got a register
+ that is known to be a pointer, and a positive offset, then
+ the composite can't be zero. */
+ if (INTVAL (XEXP (x, 1)) > 0
+ && REG_P (XEXP (x, 0))
+ && REG_POINTER (XEXP (x, 0)))
+ return true;
+
+ return nonzero_address_p (XEXP (x, 0));
+ }
+ /* Handle PIC references. */
+ else if (XEXP (x, 0) == pic_offset_table_rtx
+ && CONSTANT_P (XEXP (x, 1)))
+ return true;
+ return false;
+
+ case PRE_MODIFY:
+ /* Similar to the above; allow positive offsets. Further, since
+ auto-inc is only allowed in memories, the register must be a
+ pointer. */
+ if (GET_CODE (XEXP (x, 1)) == CONST_INT
+ && INTVAL (XEXP (x, 1)) > 0)
+ return true;
+ return nonzero_address_p (XEXP (x, 0));
+
+ case PRE_INC:
+ /* Similarly. Further, the offset is always positive. */
+ return true;
+
+ case PRE_DEC:
+ case POST_DEC:
+ case POST_INC:
+ case POST_MODIFY:
+ return nonzero_address_p (XEXP (x, 0));
+
+ case LO_SUM:
+ return nonzero_address_p (XEXP (x, 1));
+
+ default:
+ break;
+ }
+
+ /* If it isn't one of the case above, might be zero. */
+ return false;
}
/* Return 1 if X refers to a memory location whose address
Index: simplify-rtx.c
===================================================================
RCS file: /cvs/gcc/gcc/gcc/simplify-rtx.c,v
retrieving revision 1.122
diff -u -p -r1.122 simplify-rtx.c
--- simplify-rtx.c 27 Sep 2002 12:48:02 -0000 1.122
+++ simplify-rtx.c 7 Oct 2002 08:58:04 -0000
@@ -39,41 +39,6 @@ Software Foundation, 59 Temple Place - S
/* Simplification and canonicalization of RTL. */
-/* Nonzero if X has the form (PLUS frame-pointer integer). We check for
- virtual regs here because the simplify_*_operation routines are called
- by integrate.c, which is called before virtual register instantiation.
-
- ?!? NONZERO_BASE_PLUS_P needs to move into
- a header file so that their definitions can be shared with the
- simplification routines in simplify-rtx.c. Until then, do not
- change this macro without also changing the copy in simplify-rtx.c. */
-
-/* Allows reference to the stack pointer.
-
- This used to include FIXED_BASE_PLUS_P, however, we can't assume that
- arg_pointer_rtx by itself is nonzero, because on at least one machine,
- the i960, the arg pointer is zero when it is unused. */
-
-#define NONZERO_BASE_PLUS_P(X) \
- ((X) == frame_pointer_rtx || (X) == hard_frame_pointer_rtx \
- || (X) == virtual_stack_vars_rtx \
- || (X) == virtual_incoming_args_rtx \
- || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \
- && (XEXP (X, 0) == frame_pointer_rtx \
- || XEXP (X, 0) == hard_frame_pointer_rtx \
- || ((X) == arg_pointer_rtx \
- && fixed_regs[ARG_POINTER_REGNUM]) \
- || XEXP (X, 0) == virtual_stack_vars_rtx \
- || XEXP (X, 0) == virtual_incoming_args_rtx)) \
- || (X) == stack_pointer_rtx \
- || (X) == virtual_stack_dynamic_rtx \
- || (X) == virtual_outgoing_args_rtx \
- || (GET_CODE (X) == PLUS && GET_CODE (XEXP (X, 1)) == CONST_INT \
- && (XEXP (X, 0) == stack_pointer_rtx \
- || XEXP (X, 0) == virtual_stack_dynamic_rtx \
- || XEXP (X, 0) == virtual_outgoing_args_rtx)) \
- || GET_CODE (X) == ADDRESSOF)
-
/* Much code operates on (low, high) pairs; the low value is an
unsigned wide int, the high value a signed wide int. We
occasionally need to sign extend from low to high as if low were a
@@ -2022,25 +1987,12 @@ simplify_relational_operation (code, mod
switch (code)
{
case EQ:
- /* References to the frame plus a constant or labels cannot
- be zero, but a SYMBOL_REF can due to #pragma weak. */
- if (((NONZERO_BASE_PLUS_P (op0) && trueop1 == const0_rtx)
- || GET_CODE (trueop0) == LABEL_REF)
-#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
- /* On some machines, the ap reg can be 0 sometimes. */
- && op0 != arg_pointer_rtx
-#endif
- )
+ if (trueop1 == const0_rtx && nonzero_address_p (op0))
return const0_rtx;
break;
case NE:
- if (((NONZERO_BASE_PLUS_P (op0) && trueop1 == const0_rtx)
- || GET_CODE (trueop0) == LABEL_REF)
-#if FRAME_POINTER_REGNUM != ARG_POINTER_REGNUM
- && op0 != arg_pointer_rtx
-#endif
- )
+ if (trueop1 == const0_rtx && nonzero_address_p (op0))
return const_true_rtx;
break;
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