>From 5f97370ff3e94bea812ec123a31d7482965a3b1b Mon Sep 17 00:00:00 2001
From: Szabolcs Nagy <nsz@port70.net>
Date: Wed, 24 Apr 2019 23:29:05 +0000
Subject: [PATCH] x86: optimize fp_arch.h

Use fp register constraint instead of volatile store when sse2 math is
available, and use memory constraint when only x87 fpu is available.
---
 arch/i386/fp_arch.h   | 31 +++++++++++++++++++++++++++++++
 arch/x32/fp_arch.h    | 25 +++++++++++++++++++++++++
 arch/x86_64/fp_arch.h | 25 +++++++++++++++++++++++++
 3 files changed, 81 insertions(+)
 create mode 100644 arch/i386/fp_arch.h
 create mode 100644 arch/x32/fp_arch.h
 create mode 100644 arch/x86_64/fp_arch.h

diff --git a/arch/i386/fp_arch.h b/arch/i386/fp_arch.h
new file mode 100644
index 00000000..b4019de2
--- /dev/null
+++ b/arch/i386/fp_arch.h
@@ -0,0 +1,31 @@
+#ifdef __SSE2_MATH__
+#define FP_BARRIER(x) __asm__ __volatile__ ("" : "+x"(x))
+#else
+#define FP_BARRIER(x) __asm__ __volatile__ ("" : "+m"(x))
+#endif
+
+#define fp_barrierf fp_barrierf
+static inline float fp_barrierf(float x)
+{
+	FP_BARRIER(x);
+	return x;
+}
+
+#define fp_barrier fp_barrier
+static inline double fp_barrier(double x)
+{
+	FP_BARRIER(x);
+	return x;
+}
+
+#define fp_force_evalf fp_force_evalf
+static inline void fp_force_evalf(float x)
+{
+	FP_BARRIER(x);
+}
+
+#define fp_force_eval fp_force_eval
+static inline void fp_force_eval(double x)
+{
+	FP_BARRIER(x);
+}
diff --git a/arch/x32/fp_arch.h b/arch/x32/fp_arch.h
new file mode 100644
index 00000000..ff9b8311
--- /dev/null
+++ b/arch/x32/fp_arch.h
@@ -0,0 +1,25 @@
+#define fp_barrierf fp_barrierf
+static inline float fp_barrierf(float x)
+{
+	__asm__ __volatile__ ("" : "+x"(x));
+	return x;
+}
+
+#define fp_barrier fp_barrier
+static inline double fp_barrier(double x)
+{
+	__asm__ __volatile__ ("" : "+x"(x));
+	return x;
+}
+
+#define fp_force_evalf fp_force_evalf
+static inline void fp_force_evalf(float x)
+{
+	__asm__ __volatile__ ("" : "+x"(x));
+}
+
+#define fp_force_eval fp_force_eval
+static inline void fp_force_eval(double x)
+{
+	__asm__ __volatile__ ("" : "+x"(x));
+}
diff --git a/arch/x86_64/fp_arch.h b/arch/x86_64/fp_arch.h
new file mode 100644
index 00000000..ff9b8311
--- /dev/null
+++ b/arch/x86_64/fp_arch.h
@@ -0,0 +1,25 @@
+#define fp_barrierf fp_barrierf
+static inline float fp_barrierf(float x)
+{
+	__asm__ __volatile__ ("" : "+x"(x));
+	return x;
+}
+
+#define fp_barrier fp_barrier
+static inline double fp_barrier(double x)
+{
+	__asm__ __volatile__ ("" : "+x"(x));
+	return x;
+}
+
+#define fp_force_evalf fp_force_evalf
+static inline void fp_force_evalf(float x)
+{
+	__asm__ __volatile__ ("" : "+x"(x));
+}
+
+#define fp_force_eval fp_force_eval
+static inline void fp_force_eval(double x)
+{
+	__asm__ __volatile__ ("" : "+x"(x));
+}
-- 
2.21.0