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[PATCH] PR target/72839: Increase MOVE_RATIO to 17 for Lakemont
- From: "H.J. Lu" <hongjiu dot lu at intel dot com>
- To: gcc-patches at gcc dot gnu dot org
- Cc: Uros Bizjak <ubizjak at gmail dot com>
- Date: Wed, 17 Aug 2016 11:26:36 -0700
- Subject: [PATCH] PR target/72839: Increase MOVE_RATIO to 17 for Lakemont
- Authentication-results: sourceware.org; auth=none
- Reply-to: "H.J. Lu" <hjl dot tools at gmail dot com>
Larger MOVE_RATIO will always make code faster. 17 is the number with
smaller code sizes for Lakemont.
Tested on x86-64. OK for trunk?
H.J.
---
gcc/
PR target/72839
* config/i386/i386.c (lakemont_cost): Set MOVE_RATIO to 17.
gcc/testsuite/
PR target/72839
* gcc.target/i386/pr72839.c: New test.
---
gcc/config/i386/i386.c | 2 +-
gcc/testsuite/gcc.target/i386/pr72839.c | 17 +++++++++++++++++
2 files changed, 18 insertions(+), 1 deletion(-)
create mode 100644 gcc/testsuite/gcc.target/i386/pr72839.c
diff --git a/gcc/config/i386/i386.c b/gcc/config/i386/i386.c
index 3805817..8fe3821 100644
--- a/gcc/config/i386/i386.c
+++ b/gcc/config/i386/i386.c
@@ -426,7 +426,7 @@ struct processor_costs lakemont_cost = {
COSTS_N_INSNS (3), /* cost of movsx */
COSTS_N_INSNS (2), /* cost of movzx */
8, /* "large" insn */
- 9, /* MOVE_RATIO */
+ 17, /* MOVE_RATIO */
6, /* cost for loading QImode using movzbl */
{2, 4, 2}, /* cost of loading integer registers
in QImode, HImode and SImode.
diff --git a/gcc/testsuite/gcc.target/i386/pr72839.c b/gcc/testsuite/gcc.target/i386/pr72839.c
new file mode 100644
index 0000000..ea724f7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr72839.c
@@ -0,0 +1,17 @@
+/* { dg-do compile } */
+/* { dg-require-effective-target ia32 } */
+/* { dg-options "-O2 -mtune=lakemont" } */
+
+extern char *strcpy (char *, const char *);
+
+void
+foo (char *s)
+{
+ strcpy (s,
+ "12345678123456781234567812345678123456781234567812345678"
+ "1234567");
+}
+
+/* { dg-final { scan-assembler-times "movl\[ \\t\]+\\$\[0-9\]+, \[0-9\]*\\(%\[^,\]+\\)" 16 } } */
+/* { dg-final { scan-assembler-not "rep movsl" } } */
+/* { dg-final { scan-assembler-not "rep movsb" } } */
--
2.7.4