As in other parts of libm, mark a few constants as volatile to prevent

spurious optimizations. gcc doesn't support FENV_ACCESS, so when it
folds constants, it assumes that the rounding mode is always the
default and floating point exceptions never matter.

6 files changed, 20 insertions, 12 deletions

diff --git a/lib/msun/src/e_acos.c b/lib/msun/src/e_acos.c
index 78fd582..5b1b85a 100644
--- a/lib/msun/src/e_acos.c
+++ b/lib/msun/src/e_acos.c
@@ -44,8 +44,10 @@ __FBSDID("$FreeBSD$");
 static const double
 one=  1.00000000000000000000e+00, /* 0x3FF00000, 0x00000000 */
 pi =  3.14159265358979311600e+00, /* 0x400921FB, 0x54442D18 */
-pio2_hi =  1.57079632679489655800e+00, /* 0x3FF921FB, 0x54442D18 */
-pio2_lo =  6.12323399573676603587e-17, /* 0x3C91A626, 0x33145C07 */
+pio2_hi =  1.57079632679489655800e+00; /* 0x3FF921FB, 0x54442D18 */
+static volatile double
+pio2_lo =  6.12323399573676603587e-17; /* 0x3C91A626, 0x33145C07 */
+static const double
 pS0 =  1.66666666666666657415e-01, /* 0x3FC55555, 0x55555555 */
 pS1 = -3.25565818622400915405e-01, /* 0xBFD4D612, 0x03EB6F7D */
 pS2 =  2.01212532134862925881e-01, /* 0x3FC9C155, 0x0E884455 */
diff --git a/lib/msun/src/e_acosf.c b/lib/msun/src/e_acosf.c
index 7a9d0d5..7fbf3b2 100644
--- a/lib/msun/src/e_acosf.c
+++ b/lib/msun/src/e_acosf.c
@@ -22,8 +22,10 @@ __FBSDID("$FreeBSD$");
 static const float
 one =  1.0000000000e+00, /* 0x3F800000 */
 pi =  3.1415925026e+00, /* 0x40490fda */
-pio2_hi =  1.5707962513e+00, /* 0x3fc90fda */
-pio2_lo =  7.5497894159e-08, /* 0x33a22168 */
+pio2_hi =  1.5707962513e+00; /* 0x3fc90fda */
+static volatile float
+pio2_lo =  7.5497894159e-08; /* 0x33a22168 */
+static const float
 pS0 =  1.6666667163e-01, /* 0x3e2aaaab */
 pS1 = -3.2556581497e-01, /* 0xbea6b090 */
 pS2 =  2.0121252537e-01, /* 0x3e4e0aa8 */
diff --git a/lib/msun/src/e_atan2.c b/lib/msun/src/e_atan2.c
index 37c62c1..ba0b618 100644
--- a/lib/msun/src/e_atan2.c
+++ b/lib/msun/src/e_atan2.c
@@ -45,12 +45,14 @@ __FBSDID("$FreeBSD$");
 #include "math.h"
 #include "math_private.h"
 
+static volatile double
+tiny  = 1.0e-300;
 static const double
-tiny  = 1.0e-300,
 zero  = 0.0,
 pi_o_4  = 7.8539816339744827900E-01, /* 0x3FE921FB, 0x54442D18 */
 pi_o_2  = 1.5707963267948965580E+00, /* 0x3FF921FB, 0x54442D18 */
-pi      = 3.1415926535897931160E+00, /* 0x400921FB, 0x54442D18 */
+pi      = 3.1415926535897931160E+00; /* 0x400921FB, 0x54442D18 */
+static volatile double
 pi_lo   = 1.2246467991473531772E-16; /* 0x3CA1A626, 0x33145C07 */
 
 double
diff --git a/lib/msun/src/e_atan2f.c b/lib/msun/src/e_atan2f.c
index b6d336d..55435b4 100644
--- a/lib/msun/src/e_atan2f.c
+++ b/lib/msun/src/e_atan2f.c
@@ -19,12 +19,14 @@ __FBSDID("$FreeBSD$");
 #include "math.h"
 #include "math_private.h"
 
+static volatile float
+tiny  = 1.0e-30;
 static const float
-tiny  = 1.0e-30,
 zero  = 0.0,
 pi_o_4  = 7.8539818525e-01, /* 0x3f490fdb */
 pi_o_2  = 1.5707963705e+00, /* 0x3fc90fdb */
-pi      = 3.1415927410e+00, /* 0x40490fdb */
+pi      = 3.1415927410e+00; /* 0x40490fdb */
+static volatile float
 pi_lo   = -8.7422776573e-08; /* 0xb3bbbd2e */
 
 float
diff --git a/lib/msun/src/s_atan.c b/lib/msun/src/s_atan.c
index 4b0ab89..01e7bea 100644
--- a/lib/msun/src/s_atan.c
+++ b/lib/msun/src/s_atan.c
@@ -82,8 +82,8 @@ atan(double x)
 	    if(ix>0x7ff00000||
 		(ix==0x7ff00000&&(low!=0)))
 		return x+x;		/* NaN */
-	    if(hx>0) return  atanhi[3]+atanlo[3];
-	    else     return -atanhi[3]-atanlo[3];
+	    if(hx>0) return  atanhi[3]+*(volatile double *)&atanlo[3];
+	    else     return -atanhi[3]-*(volatile double *)&atanlo[3];
 	} if (ix < 0x3fdc0000) {	/* |x| < 0.4375 */
 	    if (ix < 0x3e200000) {	/* |x| < 2^-29 */
 		if(huge+x>one) return x;	/* raise inexact */
diff --git a/lib/msun/src/s_atanf.c b/lib/msun/src/s_atanf.c
index 7990c64..8221b42 100644
--- a/lib/msun/src/s_atanf.c
+++ b/lib/msun/src/s_atanf.c
@@ -62,8 +62,8 @@ atanf(float x)
 	if(ix>=0x50800000) {	/* if |x| >= 2^34 */
 	    if(ix>0x7f800000)
 		return x+x;		/* NaN */
-	    if(hx>0) return  atanhi[3]+atanlo[3];
-	    else     return -atanhi[3]-atanlo[3];
+	    if(hx>0) return  atanhi[3]+*(volatile float *)&atanlo[3];
+	    else     return -atanhi[3]-*(volatile float *)&atanlo[3];
 	} if (ix < 0x3ee00000) {	/* |x| < 0.4375 */
 	    if (ix < 0x31000000) {	/* |x| < 2^-29 */
 		if(huge+x>one) return x;	/* raise inexact */