From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from [140.186.70.92] (port=37345 helo=eggs.gnu.org) by lists.gnu.org with esmtp (Exim 4.43) id 1PGbod-0005Rs-ED for qemu-devel@nongnu.org; Thu, 11 Nov 2010 13:24:11 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1PGbob-0000fK-07 for qemu-devel@nongnu.org; Thu, 11 Nov 2010 13:24:07 -0500 Received: from mnementh.archaic.org.uk ([81.2.115.146]:46369) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1PGboa-0000e5-Fg for qemu-devel@nongnu.org; Thu, 11 Nov 2010 13:24:04 -0500 Received: from pm215 by mnementh.archaic.org.uk with local (Exim 4.69) (envelope-from ) id 1PGboY-0007VM-U7 for qemu-devel@nongnu.org; Thu, 11 Nov 2010 18:24:02 +0000 From: Peter Maydell Date: Thu, 11 Nov 2010 18:23:58 +0000 Message-Id: <1289499842-28818-5-git-send-email-peter.maydell@linaro.org> In-Reply-To: <1289499842-28818-1-git-send-email-peter.maydell@linaro.org> References: <1289499842-28818-1-git-send-email-peter.maydell@linaro.org> Subject: [Qemu-devel] [PATCH 4/8] ARM: Return correct result for float-to-integer conversion of NaN List-Id: qemu-devel.nongnu.org List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: qemu-devel@nongnu.org The ARM architecture mandates that converting a NaN value to integer gives zero. This isn't the behaviour of the SoftFloat library, so NaNs must be special-cased. Signed-off-by: Peter Maydell --- target-arm/helper.c | 44 ++++++++++++++++++++++++++++++++++++++++++++ 1 files changed, 44 insertions(+), 0 deletions(-) diff --git a/target-arm/helper.c b/target-arm/helper.c index 996d40d..72ba314 100644 --- a/target-arm/helper.c +++ b/target-arm/helper.c @@ -2445,43 +2445,84 @@ float64 VFP_HELPER(sito, d)(float32 x, CPUState *env) } /* Float to integer conversion. */ + +/* Helper routines to identify NaNs. Note that softfloat's + * floatxx_is_nan() actually only returns true for quiet NaNs. + * A NaN has an exponent field all 1s and a fraction field + * anything except all zeros. Conveniently we can detect this + * by masking out the sign bit and doing an unsigned comparison. + */ +static int float32_is_any_nan(float32 x) +{ + return ((float32_val(x) & ~(1 << 31)) > 0x7f800000UL); +} + +static int float64_is_any_nan(float64 x) +{ + return ((float64_val(x) & ~(1ULL << 63)) > 0x7ff0000000000000ULL); +} + float32 VFP_HELPER(toui, s)(float32 x, CPUState *env) { + if (float32_is_any_nan(x)) { + return float32_zero; + } return vfp_itos(float32_to_uint32(x, &env->vfp.fp_status)); } float32 VFP_HELPER(toui, d)(float64 x, CPUState *env) { + if (float64_is_any_nan(x)) { + return float32_zero; + } return vfp_itos(float64_to_uint32(x, &env->vfp.fp_status)); } float32 VFP_HELPER(tosi, s)(float32 x, CPUState *env) { + if (float32_is_any_nan(x)) { + return float32_zero; + } return vfp_itos(float32_to_int32(x, &env->vfp.fp_status)); } float32 VFP_HELPER(tosi, d)(float64 x, CPUState *env) { + if (float64_is_any_nan(x)) { + return float32_zero; + } return vfp_itos(float64_to_int32(x, &env->vfp.fp_status)); } float32 VFP_HELPER(touiz, s)(float32 x, CPUState *env) { + if (float32_is_any_nan(x)) { + return float32_zero; + } return vfp_itos(float32_to_uint32_round_to_zero(x, &env->vfp.fp_status)); } float32 VFP_HELPER(touiz, d)(float64 x, CPUState *env) { + if (float64_is_any_nan(x)) { + return float32_zero; + } return vfp_itos(float64_to_uint32_round_to_zero(x, &env->vfp.fp_status)); } float32 VFP_HELPER(tosiz, s)(float32 x, CPUState *env) { + if (float32_is_any_nan(x)) { + return float32_zero; + } return vfp_itos(float32_to_int32_round_to_zero(x, &env->vfp.fp_status)); } float32 VFP_HELPER(tosiz, d)(float64 x, CPUState *env) { + if (float64_is_any_nan(x)) { + return float32_zero; + } return vfp_itos(float64_to_int32_round_to_zero(x, &env->vfp.fp_status)); } @@ -2508,6 +2549,9 @@ ftype VFP_HELPER(name##to, p)(ftype x, uint32_t shift, CPUState *env) \ ftype VFP_HELPER(to##name, p)(ftype x, uint32_t shift, CPUState *env) \ { \ ftype tmp; \ + if (ftype##_is_any_nan(x)) { \ + return ftype##_zero; \ + } \ tmp = ftype##_scalbn(x, shift, &env->vfp.fp_status); \ return vfp_ito##p((itype)ftype##_to_##sign##int32_round_to_zero(tmp, \ &env->vfp.fp_status)); \ -- 1.7.1