From: H.J. Lu <hongjiu.lu@intel.com>
Date: Wed, 18 Sep 2019 19:50:45 +0000 (+0000)
Subject: i386: Restore Skylake SImode hard register store cost
X-Git-Url: https://git.libre-soc.org/?a=commitdiff_plain;h=7706f2f312a87b0c8509cccc986d6372dcd2fbcf;p=gcc.git

i386: Restore Skylake SImode hard register store cost

On Skylake, we should move integer register to SSE register without
going through memory.  This patch restores Skylake SImode hard register
store cost to 6.

gcc/

	PR target/90878
	* config/i386/x86-tune-costs.h (skylake_cost): Restore SImode
	hard register store cost to 6.

gcc/testsuite/

	PR target/90878
	* gcc.target/i386/pr90878.c: New test.

From-SVN: r275906
---

diff --git a/gcc/ChangeLog b/gcc/ChangeLog
index d74b19f7109..0a20e8644db 100644
--- a/gcc/ChangeLog
+++ b/gcc/ChangeLog
@@ -1,3 +1,9 @@
+2019-09-18  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/90878
+	* config/i386/x86-tune-costs.h (skylake_cost): Restore SImode
+	hard register store cost to 6.
+
 2019-09-18  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/91446
diff --git a/gcc/config/i386/x86-tune-costs.h b/gcc/config/i386/x86-tune-costs.h
index 42c9c2530c9..8e6f4b5d3ea 100644
--- a/gcc/config/i386/x86-tune-costs.h
+++ b/gcc/config/i386/x86-tune-costs.h
@@ -1594,7 +1594,7 @@ struct processor_costs skylake_cost = {
   {4, 4, 4},				/* cost of loading integer registers
 					   in QImode, HImode and SImode.
 					   Relative to reg-reg move (2).  */
-  {6, 6, 3},				/* cost of storing integer registers */
+  {6, 6, 6},				/* cost of storing integer registers */
   2,					/* cost of reg,reg fld/fst */
   {6, 6, 8},				/* cost of loading fp registers
 					   in SFmode, DFmode and XFmode */
diff --git a/gcc/testsuite/ChangeLog b/gcc/testsuite/ChangeLog
index 8ea581d775e..48e91d9f8ca 100644
--- a/gcc/testsuite/ChangeLog
+++ b/gcc/testsuite/ChangeLog
@@ -1,3 +1,8 @@
+2019-09-18  H.J. Lu  <hongjiu.lu@intel.com>
+
+	PR target/90878
+	* gcc.target/i386/pr90878.c: New test.
+
 2019-09-18  H.J. Lu  <hongjiu.lu@intel.com>
 
 	PR target/91446
diff --git a/gcc/testsuite/gcc.target/i386/pr90878.c b/gcc/testsuite/gcc.target/i386/pr90878.c
new file mode 100644
index 00000000000..18dd64bdaa7
--- /dev/null
+++ b/gcc/testsuite/gcc.target/i386/pr90878.c
@@ -0,0 +1,25 @@
+/* { dg-do compile } */
+/* { dg-options "-O2 -march=skylake" } */
+
+union ieee754_float
+  {
+    float f;
+
+    struct
+      {
+	unsigned int mantissa:23;
+	unsigned int exponent:8;
+	unsigned int negative:1;
+      } ieee;
+};
+
+double
+foo (float f)
+{
+  union ieee754_float u;
+  u.f = f;
+  u.ieee.negative = 0;
+  return u.f;
+}
+
+/* { dg-final { scan-assembler-not "vcvtss2sd\[^\\n\]*\\\(%.sp\\\)" } } */