From 2dfabc86e656e835c67954c60e143ecd33e15817 Mon Sep 17 00:00:00 2001 From: "Emilio G. Cota" Date: Mon, 26 Mar 2018 14:54:25 -0400 Subject: hardfloat: implement float32/64 multiplication MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Performance results for fp-bench: 1. Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz - before: mul-single: 126.91 MFlops mul-double: 118.28 MFlops - after: mul-single: 258.02 MFlops mul-double: 197.96 MFlops 2. ARM Aarch64 A57 @ 2.4GHz - before: mul-single: 37.42 MFlops mul-double: 38.77 MFlops - after: mul-single: 73.41 MFlops mul-double: 76.93 MFlops 3. IBM POWER8E @ 2.1 GHz - before: mul-single: 58.40 MFlops mul-double: 59.33 MFlops - after: mul-single: 60.25 MFlops mul-double: 94.79 MFlops Reviewed-by: Alex Bennée Signed-off-by: Emilio G. Cota Signed-off-by: Alex Bennée --- fpu/softfloat.c | 54 ++++++++++++++++++++++++++++++++++++++++++++++++++++-- 1 file changed, 52 insertions(+), 2 deletions(-) (limited to 'fpu') diff --git a/fpu/softfloat.c b/fpu/softfloat.c index 08afa86..dad2ce2 100644 --- a/fpu/softfloat.c +++ b/fpu/softfloat.c @@ -1236,7 +1236,8 @@ float16 QEMU_FLATTEN float16_mul(float16 a, float16 b, float_status *status) return float16_round_pack_canonical(pr, status); } -float32 QEMU_FLATTEN float32_mul(float32 a, float32 b, float_status *status) +static float32 QEMU_SOFTFLOAT_ATTR +soft_f32_mul(float32 a, float32 b, float_status *status) { FloatParts pa = float32_unpack_canonical(a, status); FloatParts pb = float32_unpack_canonical(b, status); @@ -1245,7 +1246,8 @@ float32 QEMU_FLATTEN float32_mul(float32 a, float32 b, float_status *status) return float32_round_pack_canonical(pr, status); } -float64 QEMU_FLATTEN float64_mul(float64 a, float64 b, float_status *status) +static float64 QEMU_SOFTFLOAT_ATTR +soft_f64_mul(float64 a, float64 b, float_status *status) { FloatParts pa = float64_unpack_canonical(a, status); FloatParts pb = float64_unpack_canonical(b, status); @@ -1254,6 +1256,54 @@ float64 QEMU_FLATTEN float64_mul(float64 a, float64 b, float_status *status) return float64_round_pack_canonical(pr, status); } +static float hard_f32_mul(float a, float b) +{ + return a * b; +} + +static double hard_f64_mul(double a, double b) +{ + return a * b; +} + +static bool f32_mul_fast_test(union_float32 a, union_float32 b) +{ + return float32_is_zero(a.s) || float32_is_zero(b.s); +} + +static bool f64_mul_fast_test(union_float64 a, union_float64 b) +{ + return float64_is_zero(a.s) || float64_is_zero(b.s); +} + +static float32 f32_mul_fast_op(float32 a, float32 b, float_status *s) +{ + bool signbit = float32_is_neg(a) ^ float32_is_neg(b); + + return float32_set_sign(float32_zero, signbit); +} + +static float64 f64_mul_fast_op(float64 a, float64 b, float_status *s) +{ + bool signbit = float64_is_neg(a) ^ float64_is_neg(b); + + return float64_set_sign(float64_zero, signbit); +} + +float32 QEMU_FLATTEN +float32_mul(float32 a, float32 b, float_status *s) +{ + return float32_gen2(a, b, s, hard_f32_mul, soft_f32_mul, + f32_is_zon2, NULL, f32_mul_fast_test, f32_mul_fast_op); +} + +float64 QEMU_FLATTEN +float64_mul(float64 a, float64 b, float_status *s) +{ + return float64_gen2(a, b, s, hard_f64_mul, soft_f64_mul, + f64_is_zon2, NULL, f64_mul_fast_test, f64_mul_fast_op); +} + /* * Returns the result of multiplying the floating-point values `a' and * `b' then adding 'c', with no intermediate rounding step after the -- cgit v1.1