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Fix performance regression with -mtune=atom
- From: Vladimir Yakovlev <vbyakovl23 at gmail dot com>
- To: gcc-patches at gcc dot gnu dot org
- Date: Fri, 30 Sep 2011 12:56:04 +0400
- Subject: Fix performance regression with -mtune=atom
This patch fixes performance regression with -mtune=atom. Changing
atom cost removes regression in several tests of EEMBC and spec2000.
Bootstrap amd make check Ok for both with and witout -mtune-atom.
OK for trunk?
2011-09-30 Yakovlev Vladimir vladimir.b.yakovlev@intel.com
* gcc/config/i386/i386.c (atom_cost): Changed cost for loading
QImode using movzbl.
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 7e89dbd..8a512a7 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -1672,7 +1672,7 @@ struct processor_costs atom_cost = {
COSTS_N_INSNS (1), /* cost of movzx */
8, /* "large" insn */
17, /* MOVE_RATIO */
- 2, /* cost for loading QImode using movzbl */
+ 4, /* cost for loading QImode
using movzbl */
{4, 4, 4}, /* cost of loading integer registers
in QImode, HImode and SImode.
Relative to reg-reg move (2). */