> I'm not sure about this bit. Couldn't [snip cse.c code]
> simply be replaced by:
>
> /* We can't simplify extension ops unless we know the
> original mode. */
> if ((code == ZERO_EXTEND || code == SIGN_EXTEND)
> && mode_arg0 == VOIDmode)
> break;
>
> new = simplify_unary_operation (code, mode,
> const_arg0 ? const_arg0 : folded_arg0,
> mode_arg0);
> ?
>
> (Sorry if I'm repeating earlier discussion here.)
I think so -- I was just trying to resemble the existing code as much as
possible (stage3), but it's probably better to clean up instead. What
do you thing about the simplify-rtx.c part instead?
Paolo
2008-09-06 Paolo Bonzini <[EMAIL PROTECTED]>
* cse.c (fold_rtx): Let simplify_unary_operation handle CONSTs.
* explow.c (plus_constant): Don't exit early if c == 0, to allow
canonicalizing CONSTs.
* simplify-rtx.c (simplify_plus_minus): Likewise.
Index: cse.c
===================================================================
--- cse.c (revision 134435)
+++ cse.c (working copy)
@@ -3138,33 +3138,20 @@ fold_rtx (rtx x, rtx insn)
{
case RTX_UNARY:
{
- int is_const = 0;
-
/* We can't simplify extension ops unless we know the
original mode. */
if ((code == ZERO_EXTEND || code == SIGN_EXTEND)
&& mode_arg0 == VOIDmode)
break;
- /* If we had a CONST, strip it off and put it back later if we
- fold. */
+ /* If we had a CONST, strip it off and let simplify_unary_operation
+ put it back if it can simplify something. */
if (const_arg0 != 0 && GET_CODE (const_arg0) == CONST)
- is_const = 1, const_arg0 = XEXP (const_arg0, 0);
+ const_arg0 = XEXP (const_arg0, 0);
new = simplify_unary_operation (code, mode,
const_arg0 ? const_arg0 : folded_arg0,
mode_arg0);
- /* NEG of PLUS could be converted into MINUS, but that causes
- expressions of the form
- (CONST (MINUS (CONST_INT) (SYMBOL_REF)))
- which many ports mistakenly treat as LEGITIMATE_CONSTANT_P.
- 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);
}
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);
