From 8d551c988e96ac4cfe462e6b34d513bba2da572f Mon Sep 17 00:00:00 2001 From: Tom Musta Date: Tue, 7 Jan 2014 17:17:51 +0000 Subject: [PATCH] softfloat: Fix float64_to_uint32 The float64_to_uint32 has several flaws: - for numbers between 2**32 and 2**64, the inexact exception flag may get incorrectly set. In this case, only the invalid flag should be set. test pattern: 425F81378DC0CD1F / 0x1.f81378dc0cd1fp+38 - for numbers between 2**63 and 2**64, incorrect results may be produced: test pattern: 43EAAF73F1F0B8BD / 0x1.aaf73f1f0b8bdp+63 This patch re-implements float64_to_uint32 to re-use the float64_to_uint64 routine (instead of float64_to_int64). For the saturation case, we ignore any flags which the conversion routine has set and raise only the invalid flag. This contribution can be licensed under either the softfloat-2a or -2b license. Signed-off-by: Tom Musta Message-id: 1387397961-4894-5-git-send-email-tommusta@gmail.com Signed-off-by: Peter Maydell Reviewed-by: Richard Henderson --- fpu/softfloat.c | 15 +++++++-------- 1 file changed, 7 insertions(+), 8 deletions(-) diff --git a/fpu/softfloat.c b/fpu/softfloat.c index f782c24..e68a87b 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -6650,19 +6650,18 @@ uint_fast16_t float32_to_uint16_round_to_zero(float32 a STATUS_PARAM) uint32 float64_to_uint32( float64 a STATUS_PARAM ) { - int64_t v; + uint64_t v; uint32 res; + int old_exc_flags = get_float_exception_flags(status); - v = float64_to_int64(a STATUS_VAR); - if (v < 0) { - res = 0; - float_raise( float_flag_invalid STATUS_VAR); - } else if (v > 0xffffffff) { + v = float64_to_uint64(a STATUS_VAR); + if (v > 0xffffffff) { res = 0xffffffff; - float_raise( float_flag_invalid STATUS_VAR); } else { - res = v; + return v; } + set_float_exception_flags(old_exc_flags, status); + float_raise(float_flag_invalid STATUS_VAR); return res; } -- 2.7.4