From: H.J. Lu <hjl.tools@gmail.com>
Date: Fri, 15 Jan 2016 13:22:59 +0000 (-0800)
Subject: Call math_opt_barrier inside if
X-Git-Tag: glibc-2.23~58
X-Git-Url: http://git.ipfire.org/cgi-bin/gitweb.cgi?a=commitdiff_plain;h=09245377dac2c013155500ac0b3b05850813e3f8;p=thirdparty%2Fglibc.git

Call math_opt_barrier inside if

Since floating-point operation may trigger floating-point exceptions,
we call math_opt_barrier inside if to prevent code motion.

	[BZ #19465]
	* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Call math_opt_barrier
	inside if.
	* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Likewise.
	* sysdeps/ieee754/ldbl-96/s_fma.c (__fma): Likewise.
	* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Likewise.
---

diff --git a/ChangeLog b/ChangeLog
index c874d89c2ae..8e13d279079 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,12 @@
+2016-01-15  H.J. Lu  <hongjiu.lu@intel.com>
+
+	[BZ #19465]
+	* sysdeps/ieee754/dbl-64/s_fma.c (__fma): Call math_opt_barrier
+	inside if.
+	* sysdeps/ieee754/ldbl-128/s_fmal.c (__fmal): Likewise.
+	* sysdeps/ieee754/ldbl-96/s_fma.c (__fma): Likewise.
+	* sysdeps/ieee754/ldbl-96/s_fmal.c (__fmal): Likewise.
+
 2016-01-14  H.J. Lu  <hongjiu.lu@intel.com>
 
 	[BZ #19466]
diff --git a/sysdeps/ieee754/dbl-64/s_fma.c b/sysdeps/ieee754/dbl-64/s_fma.c
index bc3677d0c5f..a3492434e45 100644
--- a/sysdeps/ieee754/dbl-64/s_fma.c
+++ b/sysdeps/ieee754/dbl-64/s_fma.c
@@ -175,7 +175,10 @@ __fma (double x, double y, double z)
 
   /* Ensure correct sign of exact 0 + 0.  */
   if (__glibc_unlikely ((x == 0 || y == 0) && z == 0))
-    return x * y + z;
+    {
+      x = math_opt_barrier (x);
+      return x * y + z;
+    }
 
   fenv_t env;
   libc_feholdexcept_setround (&env, FE_TONEAREST);
diff --git a/sysdeps/ieee754/ldbl-128/s_fmal.c b/sysdeps/ieee754/ldbl-128/s_fmal.c
index ac30027af9e..728949c9168 100644
--- a/sysdeps/ieee754/ldbl-128/s_fmal.c
+++ b/sysdeps/ieee754/ldbl-128/s_fmal.c
@@ -179,7 +179,10 @@ __fmal (long double x, long double y, long double z)
 
   /* Ensure correct sign of exact 0 + 0.  */
   if (__glibc_unlikely ((x == 0 || y == 0) && z == 0))
-    return x * y + z;
+    {
+      x = math_opt_barrier (x);
+      return x * y + z;
+    }
 
   fenv_t env;
   feholdexcept (&env);
diff --git a/sysdeps/ieee754/ldbl-96/s_fma.c b/sysdeps/ieee754/ldbl-96/s_fma.c
index 5fbdda7ea9e..ab45bcfce21 100644
--- a/sysdeps/ieee754/ldbl-96/s_fma.c
+++ b/sysdeps/ieee754/ldbl-96/s_fma.c
@@ -41,7 +41,10 @@ __fma (double x, double y, double z)
 
   /* Ensure correct sign of exact 0 + 0.  */
   if (__glibc_unlikely ((x == 0 || y == 0) && z == 0))
-    return x * y + z;
+    {
+      x = math_opt_barrier (x);
+      return x * y + z;
+    }
 
   fenv_t env;
   feholdexcept (&env);
diff --git a/sysdeps/ieee754/ldbl-96/s_fmal.c b/sysdeps/ieee754/ldbl-96/s_fmal.c
index 57774cf6863..f1467fda3da 100644
--- a/sysdeps/ieee754/ldbl-96/s_fmal.c
+++ b/sysdeps/ieee754/ldbl-96/s_fmal.c
@@ -177,7 +177,10 @@ __fmal (long double x, long double y, long double z)
 
   /* Ensure correct sign of exact 0 + 0.  */
   if (__glibc_unlikely ((x == 0 || y == 0) && z == 0))
-    return x * y + z;
+    {
+      x = math_opt_barrier (x);
+      return x * y + z;
+    }
 
   fenv_t env;
   feholdexcept (&env);