From b7ca416f49abaa58b45bad5be31b9e58cf306481 Mon Sep 17 00:00:00 2001
From: Andrew Pinski <pinskia@physics.uc.edu>
Date: Thu, 25 Nov 2004 23:10:27 +0000
Subject: [PATCH] parts of PR rtl-opt/18463, rtl-opt/17647
2004-11-25 Andrew Pinski <pinskia@physics.uc.edu>
parts of PR rtl-opt/18463, rtl-opt/17647
* cse.c (canon_for_address): New function.
(find_best_addr): Call canon_for_address before getting the
address's cost when checking if we should take that address.
From-SVN: r91308
---
gcc/ChangeLog | 7 +++++++
gcc/cse.c | 56 +++++++++++++++++++++++++++++++++++++++++++++++++++
2 files changed, 63 insertions(+)
diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index 316ca15473ee..54fe27c5da37 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,10 @@
+2004-11-25 Andrew Pinski <pinskia@physics.uc.edu>
+
+ parts of PR rtl-opt/18463, rtl-opt/17647
+ * cse.c (canon_for_address): New function.
+ (find_best_addr): Call canon_for_address before getting the
+ address's cost when checking if we should take that address.
+
2004-11-25 Kazu Hirata <kazu@cs.umass.edu>
* tree-phinodes.c (add_phi_arg): Take "tree" instead of
diff --git a/gcc/cse.c b/gcc/cse.c
index 0858b0252b8f..9ea5297caaff 100644
--- a/gcc/cse.c
+++ b/gcc/cse.c
@@ -761,6 +761,57 @@ approx_reg_cost (rtx x)
return cost;
}
+/* Returns a canonical version of X for the address, from the point of view,
+ that all multiplications are repesented as MULT instead of the multiply
+ by a power of 2 being repesented as ASHIFT. */
+
+static rtx
+canon_for_address (rtx x)
+{
+ enum rtx_code code;
+ enum machine_mode mode;
+ rtx new = 0;
+ int i;
+ const char *fmt;
+
+ if (!x)
+ return x;
+
+ code = GET_CODE (x);
+ mode = GET_MODE (x);
+
+ switch (code)
+ {
+ case ASHIFT:
+ if (GET_CODE (XEXP (x, 1)) == CONST_INT
+ && INTVAL (XEXP (x, 1)) < GET_MODE_BITSIZE (mode)
+ && INTVAL (XEXP (x, 1)) >= 0)
+ {
+ new = canon_for_address (XEXP (x, 0));
+ new = gen_rtx_MULT (mode, new,
+ gen_int_mode ((HOST_WIDE_INT) 1
+ << INTVAL (XEXP (x, 1)),
+ mode));
+ }
+ break;
+ default:
+ break;
+
+ }
+ if (new)
+ return new;
+
+ /* Now recursively process each operand of this operation. */
+ fmt = GET_RTX_FORMAT (code);
+ for (i = 0; i < GET_RTX_LENGTH (code); i++)
+ if (fmt[i] == 'e')
+ {
+ new = canon_for_address (XEXP (x, i));
+ XEXP (x, i) = new;
+ }
+ return x;
+}
+
/* Return a negative value if an rtx A, whose costs are given by COST_A
and REGCOST_A, is more desirable than an rtx B.
Return a positive value if A is less desirable, or 0 if the two are
@@ -2933,6 +2984,11 @@ find_best_addr (rtx insn, rtx *loc, enum machine_mode mode)
rtx new = simplify_gen_binary (GET_CODE (*loc), Pmode,
p->exp, op1);
int new_cost;
+
+ /* Get the canonical version of the address so we can accept
+ more. */
+ new = canon_for_address (new);
+
new_cost = address_cost (new, mode);
if (new_cost < best_addr_cost
--
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