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[Qemu-devel] [PULL 2/7] softfloat: add float128_is_{normal, denormal}
From: |
Alex Bennée |
Subject: |
[Qemu-devel] [PULL 2/7] softfloat: add float128_is_{normal, denormal} |
Date: |
Tue, 26 Feb 2019 14:11:56 +0000 |
From: David Hildenbrand <address@hidden>
Needed on s390x, to test for the data class of a number. So it will
gain soon a user.
A number is considered normal if the exponent is neither 0 nor all 1's.
That can be checked by adding 1 to the exponent, and comparing against
>= 2 after dropping an eventual overflow into the sign bit.
While at it, convert the other floatXX_is_normal functions to use a
similar, less error prone calculation, as suggested by Richard H.
Signed-off-by: David Hildenbrand <address@hidden>
Reviewed-by: Richard Henderson <address@hidden>
Signed-off-by: Alex Bennée <address@hidden>
diff --git a/include/fpu/softfloat.h b/include/fpu/softfloat.h
index 38a5e99cf3..3ff5215b81 100644
--- a/include/fpu/softfloat.h
+++ b/include/fpu/softfloat.h
@@ -466,7 +466,7 @@ static inline int float32_is_zero_or_denormal(float32 a)
static inline bool float32_is_normal(float32 a)
{
- return ((float32_val(a) + 0x00800000) & 0x7fffffff) >= 0x01000000;
+ return (((float32_val(a) >> 23) + 1) & 0xff) >= 2;
}
static inline bool float32_is_denormal(float32 a)
@@ -622,7 +622,7 @@ static inline int float64_is_zero_or_denormal(float64 a)
static inline bool float64_is_normal(float64 a)
{
- return ((float64_val(a) + (1ULL << 52)) & -1ULL >> 1) >= 1ULL << 53;
+ return (((float64_val(a) >> 52) + 1) & 0x7ff) >= 2;
}
static inline bool float64_is_denormal(float64 a)
@@ -940,6 +940,16 @@ static inline int float128_is_zero_or_denormal(float128 a)
return (a.high & 0x7fff000000000000LL) == 0;
}
+static inline bool float128_is_normal(float128 a)
+{
+ return (((a.high >> 48) + 1) & 0x7fff) >= 2;
+}
+
+static inline bool float128_is_denormal(float128 a)
+{
+ return float128_is_zero_or_denormal(a) && !float128_is_zero(a);
+}
+
static inline int float128_is_any_nan(float128 a)
{
return ((a.high >> 48) & 0x7fff) == 0x7fff &&
--
2.20.1
- [Qemu-devel] [PULL 0/7] softfloat updates, mostly for s390x, Alex Bennée, 2019/02/26
- [Qemu-devel] [PULL 6/7] softfloat: Support float_round_to_odd more places, Alex Bennée, 2019/02/26
- [Qemu-devel] [PULL 3/7] softfloat: Implement float128_to_uint32, Alex Bennée, 2019/02/26
- [Qemu-devel] [PULL 1/7] tests: Ignore fp test outputs, Alex Bennée, 2019/02/26
- [Qemu-devel] [PULL 7/7] tests/Makefile.include: test all rounding modes of softfloat, Alex Bennée, 2019/02/26
- [Qemu-devel] [PULL 2/7] softfloat: add float128_is_{normal, denormal},
Alex Bennée <=
- [Qemu-devel] [PULL 4/7] tests/fp: add wrapping for f128_to_ui32, Alex Bennée, 2019/02/26
- [Qemu-devel] [PULL 5/7] tests/fp: enable f128_to_ui[32/64] tests in float-to-uint, Alex Bennée, 2019/02/26
- Re: [Qemu-devel] [PULL 0/7] softfloat updates, mostly for s390x, Peter Maydell, 2019/02/28