From: Martin Liska <mliska@suse.cz>
Date: Mon, 1 Jun 2020 11:21:40 +0000 (+0200)
Subject: Tune memcpy and memset for Zen cores.
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=dc65aba7a4725d1b464c8c64a5f739ee910e8943;p=gcc.git

Tune memcpy and memset for Zen cores.

Based on the collected numbers in PR95435, I suggest the following
tuning changes:

gcc/ChangeLog:

	PR target/95435
	* config/i386/x86-tune-costs.h: Use libcall for large sizes for
	-m32. Start using libcall from 128+ bytes.
---

diff --git a/gcc/config/i386/x86-tune-costs.h b/gcc/config/i386/x86-tune-costs.h
index 1169178433f..3207404e514 100644
--- a/gcc/config/i386/x86-tune-costs.h
+++ b/gcc/config/i386/x86-tune-costs.h
@@ -1314,20 +1314,20 @@ static stringop_algs znver1_memcpy[2] = {
   /* 32-bit tuning.  */
   {libcall, {{6, loop, false},
 	     {14, unrolled_loop, false},
-	     {-1, rep_prefix_4_byte, false}}},
+	     {-1, libcall, false}}},
   /* 64-bit tuning.  */
   {libcall, {{16, loop, false},
-	     {8192, rep_prefix_8_byte, false},
+	     {128, rep_prefix_8_byte, false},
 	     {-1, libcall, false}}}};
 static stringop_algs znver1_memset[2] = {
   /* 32-bit tuning.  */
   {libcall, {{8, loop, false},
 	     {24, unrolled_loop, false},
-	     {2048, rep_prefix_4_byte, false},
+	     {128, rep_prefix_4_byte, false},
 	     {-1, libcall, false}}},
   /* 64-bit tuning.  */
   {libcall, {{48, unrolled_loop, false},
-	     {8192, rep_prefix_8_byte, false},
+	     {128, rep_prefix_8_byte, false},
 	     {-1, libcall, false}}}};
 struct processor_costs znver1_cost = {
   {
@@ -1460,7 +1460,7 @@ static stringop_algs znver2_memcpy[2] = {
   /* 32-bit tuning.  */
   {libcall, {{6, loop, false},
 	     {14, unrolled_loop, false},
-	     {-1, rep_prefix_4_byte, false}}},
+	     {-1, libcall, false}}},
   /* 64-bit tuning.  */
   {libcall, {{16, loop, false},
 	     {64, rep_prefix_4_byte, false},
@@ -1469,7 +1469,7 @@ static stringop_algs znver2_memset[2] = {
   /* 32-bit tuning.  */
   {libcall, {{8, loop, false},
 	     {24, unrolled_loop, false},
-	     {2048, rep_prefix_4_byte, false}
+	     {128, rep_prefix_4_byte, false},
 	     {-1, libcall, false}}},
   /* 64-bit tuning.  */
   {libcall, {{24, rep_prefix_4_byte, false},