From: Jan Hubicka <jh@suse.cz>
Date: Tue, 30 Jul 2019 08:10:22 +0000 (+0200)
Subject: backport: i386.c (ix86_option_override_internal): Default PARAM_AVOID_FMA_MAX_BITS... 
X-Git-Tag: releases/gcc-9.2.0~97
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=c2db11bbb9bac5b81552bdeb13f7008fceff35c2;p=thirdparty%2Fgcc.git

backport: i386.c (ix86_option_override_internal): Default PARAM_AVOID_FMA_MAX_BITS to 256 for znver2.


	Backport from mainline
	2019-07-23  Jan Hubicka  <hubicka@ucw.cz>

	* config/i386/i386.c (ix86_option_override_internal): Default
	PARAM_AVOID_FMA_MAX_BITS to 256 for znver2.
	* config/i386/x86-tune.def (X86_TUNE_AVOID_256FMA_CHAINS): Set
	for ZNVER2.

From-SVN: r273901
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index c70358bf4ac5..d6fd8f5a054f 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,13 @@
+2019-07-30  Jan Hubicka  <jh@suse.cz>
+
+	Backport from mainline
+	2019-07-23  Jan Hubicka  <hubicka@ucw.cz>
+
+	* config/i386/i386.c (ix86_option_override_internal): Default
+	PARAM_AVOID_FMA_MAX_BITS to 256 for znver2.
+	* config/i386/x86-tune.def (X86_TUNE_AVOID_256FMA_CHAINS): Set
+	for ZNVER2.
+
 2019-07-30  Jan Hubicka  <jh@suse.cz>
 
 	Backport from mainline
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 9288fc4b17c1..83b6708da020 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -4817,7 +4817,11 @@ ix86_option_override_internal (bool main_args_p,
     opts->x_flag_cf_protection
       = (cf_protection_level) (opts->x_flag_cf_protection | CF_SET);
 
-  if (ix86_tune_features [X86_TUNE_AVOID_128FMA_CHAINS])
+  if (ix86_tune_features [X86_TUNE_AVOID_256FMA_CHAINS])
+    maybe_set_param_value (PARAM_AVOID_FMA_MAX_BITS, 256,
+			   opts->x_param_values,
+			   opts_set->x_param_values);
+  else if (ix86_tune_features [X86_TUNE_AVOID_128FMA_CHAINS])
     maybe_set_param_value (PARAM_AVOID_FMA_MAX_BITS, 128,
 			   opts->x_param_values,
 			   opts_set->x_param_values);
diff --git a/gcc/config/i386/x86-tune.def b/gcc/config/i386/x86-tune.def
index 01e49867dfbd..fd59a842658b 100644
--- a/gcc/config/i386/x86-tune.def
+++ b/gcc/config/i386/x86-tune.def
@@ -431,6 +431,10 @@ DEF_TUNE (X86_TUNE_USE_GATHER, "use_gather",
    smaller FMA chain.  */
 DEF_TUNE (X86_TUNE_AVOID_128FMA_CHAINS, "avoid_fma_chains", m_ZNVER)
 
+/* X86_TUNE_AVOID_256FMA_CHAINS: Avoid creating loops with tight 256bit or
+   smaller FMA chain.  */
+DEF_TUNE (X86_TUNE_AVOID_256FMA_CHAINS, "avoid_fma256_chains", m_ZNVER2)
+
 /*****************************************************************************/
 /* AVX instruction selection tuning (some of SSE flags affects AVX, too)     */
 /*****************************************************************************/