aboutsummaryrefslogtreecommitdiff
path: root/fpu
diff options
context:
space:
mode:
authorPeter Maydell <peter.maydell@linaro.org>2010-12-16 11:51:18 +0000
committerAurelien Jarno <aurelien@aurel32.net>2011-01-02 23:59:03 +0100
commit011da610ba6416df54feed46bcde1955211a2149 (patch)
tree41544bf6f962d2e0375b859765f840a1986f036a /fpu
parent354f211b1a49a7387929e22d6e63849fcba48f8a (diff)
downloadqemu-arm-011da610ba6416df54feed46bcde1955211a2149.tar.gz
target-arm: Implement correct NaN propagation rules
Implement the correct NaN propagation rules for ARM targets by providing an appropriate pickNaN function. Signed-off-by: Peter Maydell <peter.maydell@linaro.org> Signed-off-by: Aurelien Jarno <aurelien@aurel32.net>
Diffstat (limited to 'fpu')
-rw-r--r--fpu/softfloat-specialize.h23
1 files changed, 23 insertions, 0 deletions
diff --git a/fpu/softfloat-specialize.h b/fpu/softfloat-specialize.h
index 8dcf469ee6..f43f2d0ace 100644
--- a/fpu/softfloat-specialize.h
+++ b/fpu/softfloat-specialize.h
@@ -168,6 +168,28 @@ static float32 commonNaNToFloat32( commonNaNT a )
| tie-break rule.
*----------------------------------------------------------------------------*/
+#if defined(TARGET_ARM)
+static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
+ flag aIsLargerSignificand)
+{
+ /* ARM mandated NaN propagation rules: take the first of:
+ * 1. A if it is signaling
+ * 2. B if it is signaling
+ * 3. A (quiet)
+ * 4. B (quiet)
+ * A signaling NaN is always quietened before returning it.
+ */
+ if (aIsSNaN) {
+ return 0;
+ } else if (bIsSNaN) {
+ return 1;
+ } else if (aIsQNaN) {
+ return 0;
+ } else {
+ return 1;
+ }
+}
+#else
static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
flag aIsLargerSignificand)
{
@@ -197,6 +219,7 @@ static int pickNaN(flag aIsQNaN, flag aIsSNaN, flag bIsQNaN, flag bIsSNaN,
return 1;
}
}
+#endif
/*----------------------------------------------------------------------------
| Takes two single-precision floating-point values `a' and `b', one of which