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Zen tuning part 5: Disable buldozer dispatch scheduling
- From: Jan Hubicka <hubicka at ucw dot cz>
- To: gcc-patches at gcc dot gnu dot org, Venkataramanan dot Kumar at amd dot com
- Date: Sun, 8 Oct 2017 12:58:49 +0200
- Subject: Zen tuning part 5: Disable buldozer dispatch scheduling
- Authentication-results: sourceware.org; auth=none
Hi,
at the moment we do dispatch scheduling which is trying to optimize for Buldrozer's
decoder. This does not make much sense as both decoders are significantly different.
Bootstrapped/regtested x86_64-linux, comitted.
Honza
* i386.c (has_dispatch): Disable for Ryzen.
Index: i386.c
===================================================================
--- i386.c (revision 253513)
+++ i386.c (working copy)
@@ -51798,8 +51801,9 @@ do_dispatch (rtx_insn *insn, int mode)
static bool
has_dispatch (rtx_insn *insn, int action)
{
+ /* Current implementation of dispatch scheduler models buldozer only. */
if ((TARGET_BDVER1 || TARGET_BDVER2 || TARGET_BDVER3
- || TARGET_BDVER4 || TARGET_ZNVER1) && flag_dispatch_scheduler)
+ || TARGET_BDVER4) && flag_dispatch_scheduler)
switch (action)
{
default: