From 011da610ba6416df54feed46bcde1955211a2149 Mon Sep 17 00:00:00 2001 From: Peter Maydell Date: Thu, 16 Dec 2010 11:51:18 +0000 Subject: [PATCH] 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 Signed-off-by: Aurelien Jarno --- fpu/softfloat-specialize.h | 23 +++++++++++++++++++++++ 1 file changed, 23 insertions(+) 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