Paolo Bonzini wrote:
> Hans-Peter Nilsson wrote:
>>> Date: Fri, 5 Sep 2008 14:57:00 +0200
>>> From: Hans-Peter Nilsson <[EMAIL PROTECTED]>
>>> Maybe as part of a change from target macro to target hook, with
>>> LEGITIMATE_CONSTANT_P as a default would fit, even at this
>>> stage?
>> Sorry, I mean CONSTANT_P, not LEGITIMATE_CONSTANT_P. Or maybe a
>> new macro or hook
>
> What about replacing the problematic uses of gen_rtx_CONST with
> "plus_constant (x, 0)"? plus_constant knows when to make a CONST rtx.
>
> There are just a handful of places where this would be needed: instead
> of the check after the wrong comment in cse.c, and everywhere
> gen_rtx_CONST is used in simplify-rtx.c.
Here is a prototype patch, untested.
Paolo
2008-09-06 Paolo Bonzini <[EMAIL PROTECTED]>
* explow.c (plus_constant): Don't exit early if c == 0, to allow
canonicalizing CONSTs.
* cse.c (fold_rtx): Use plus_constant instead of wrapping with CONST.
* simplify-rtx.c (simplify_plus_minus): Likewise.
Index: cse.c
===================================================================
--- cse.c (revision 134435)
+++ cse.c (working copy)
@@ -3161,10 +3161,8 @@ fold_rtx (rtx x, rtx insn)
FIXME: those ports should be fixed. */
if (new != 0 && is_const
&& GET_CODE (new) == PLUS
- && (GET_CODE (XEXP (new, 0)) == SYMBOL_REF
- || GET_CODE (XEXP (new, 0)) == LABEL_REF)
&& GET_CODE (XEXP (new, 1)) == CONST_INT)
- new = gen_rtx_CONST (mode, new);
+ new = plus_constant (XEXP (new, 0), XEXP (new, 1));
+ else
+ new = plus_constant (new, 0);
}
break;
Index: simplify-rtx.c
===================================================================
--- simplify-rtx.c (revision 140055)
+++ simplify-rtx.c (working copy)
@@ -3625,7 +3625,7 @@ simplify_plus_minus (enum rtx_code code,
tem = simplify_binary_operation (ncode, mode, tem_lhs,
tem_rhs);
if (tem && !CONSTANT_P (tem))
- tem = gen_rtx_CONST (GET_MODE (tem), tem);
+ tem = plus_constant (tem, 0);
}
else
tem = simplify_binary_operation (ncode, mode, lhs, rhs);
@@ -3690,7 +3690,7 @@ simplify_plus_minus (enum rtx_code code,
&& GET_CODE (ops[i].op) == GET_CODE (ops[i - 1].op))
{
ops[i - 1].op = gen_rtx_MINUS (mode, ops[i - 1].op, ops[i].op);
- ops[i - 1].op = gen_rtx_CONST (mode, ops[i - 1].op);
+ ops[i - 1].op = plus_constant (ops[i - 1].op, 0);
if (i < n_ops - 1)
ops[i] = ops[i + 1];
n_ops--;
@@ -5247,7 +5247,7 @@ simplify_subreg (enum machine_mode outer
&& GET_MODE_BITSIZE (innermode) >= (2 * GET_MODE_BITSIZE (outermode))
&& GET_CODE (XEXP (op, 1)) == CONST_INT
&& (INTVAL (XEXP (op, 1)) & (GET_MODE_BITSIZE (outermode) - 1)) == 0
- && INTVAL (XEXP (op, 1)) < GET_MODE_BITSIZE (innermode)
+ && INTVAL (XEXP (op, 1)) < GET_MODE_BITSIZE (innermode)
&& byte == subreg_lowpart_offset (outermode, innermode))
{
int shifted_bytes = INTVAL (XEXP (op, 1)) / BITS_PER_UNIT;
Index: explow.c
===================================================================
--- explow.c (revision 134435)
+++ explow.c (working copy)
@@ -83,9 +83,6 @@ plus_constant (rtx x, HOST_WIDE_INT c)
rtx tem;
int all_constant = 0;
- if (c == 0)
- return x;
-
restart:
code = GET_CODE (x);
