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[Qemu-devel] [PULL 12/15] hardfloat: implement float32/64 division
From: |
Alex Bennée |
Subject: |
[Qemu-devel] [PULL 12/15] hardfloat: implement float32/64 division |
Date: |
Fri, 14 Dec 2018 13:54:49 +0000 |
From: "Emilio G. Cota" <address@hidden>
Performance results for fp-bench:
1. Intel(R) Core(TM) i7-6700K CPU @ 4.00GHz
- before:
div-single: 34.84 MFlops
div-double: 34.04 MFlops
- after:
div-single: 275.23 MFlops
div-double: 216.38 MFlops
2. ARM Aarch64 A57 @ 2.4GHz
- before:
div-single: 9.33 MFlops
div-double: 9.30 MFlops
- after:
div-single: 51.55 MFlops
div-double: 15.09 MFlops
3. IBM POWER8E @ 2.1 GHz
- before:
div-single: 25.65 MFlops
div-double: 24.91 MFlops
- after:
div-single: 96.83 MFlops
div-double: 31.01 MFlops
Here setting 2FP64_USE_FP to 1 pays off for x86_64:
[1] 215.97 vs [0] 62.15 MFlops
Reviewed-by: Alex Bennée <address@hidden>
Signed-off-by: Emilio G. Cota <address@hidden>
Signed-off-by: Alex Bennée <address@hidden>
diff --git a/fpu/softfloat.c b/fpu/softfloat.c
index dad2ce2d9f..82294458fe 100644
--- a/fpu/softfloat.c
+++ b/fpu/softfloat.c
@@ -1628,7 +1628,8 @@ float16 float16_div(float16 a, float16 b, float_status
*status)
return float16_round_pack_canonical(pr, status);
}
-float32 float32_div(float32 a, float32 b, float_status *status)
+static float32 QEMU_SOFTFLOAT_ATTR
+soft_f32_div(float32 a, float32 b, float_status *status)
{
FloatParts pa = float32_unpack_canonical(a, status);
FloatParts pb = float32_unpack_canonical(b, status);
@@ -1637,7 +1638,8 @@ float32 float32_div(float32 a, float32 b, float_status
*status)
return float32_round_pack_canonical(pr, status);
}
-float64 float64_div(float64 a, float64 b, float_status *status)
+static float64 QEMU_SOFTFLOAT_ATTR
+soft_f64_div(float64 a, float64 b, float_status *status)
{
FloatParts pa = float64_unpack_canonical(a, status);
FloatParts pb = float64_unpack_canonical(b, status);
@@ -1646,6 +1648,64 @@ float64 float64_div(float64 a, float64 b, float_status
*status)
return float64_round_pack_canonical(pr, status);
}
+static float hard_f32_div(float a, float b)
+{
+ return a / b;
+}
+
+static double hard_f64_div(double a, double b)
+{
+ return a / b;
+}
+
+static bool f32_div_pre(union_float32 a, union_float32 b)
+{
+ if (QEMU_HARDFLOAT_2F32_USE_FP) {
+ return (fpclassify(a.h) == FP_NORMAL || fpclassify(a.h) == FP_ZERO) &&
+ fpclassify(b.h) == FP_NORMAL;
+ }
+ return float32_is_zero_or_normal(a.s) && float32_is_normal(b.s);
+}
+
+static bool f64_div_pre(union_float64 a, union_float64 b)
+{
+ if (QEMU_HARDFLOAT_2F64_USE_FP) {
+ return (fpclassify(a.h) == FP_NORMAL || fpclassify(a.h) == FP_ZERO) &&
+ fpclassify(b.h) == FP_NORMAL;
+ }
+ return float64_is_zero_or_normal(a.s) && float64_is_normal(b.s);
+}
+
+static bool f32_div_post(union_float32 a, union_float32 b)
+{
+ if (QEMU_HARDFLOAT_2F32_USE_FP) {
+ return fpclassify(a.h) != FP_ZERO;
+ }
+ return !float32_is_zero(a.s);
+}
+
+static bool f64_div_post(union_float64 a, union_float64 b)
+{
+ if (QEMU_HARDFLOAT_2F64_USE_FP) {
+ return fpclassify(a.h) != FP_ZERO;
+ }
+ return !float64_is_zero(a.s);
+}
+
+float32 QEMU_FLATTEN
+float32_div(float32 a, float32 b, float_status *s)
+{
+ return float32_gen2(a, b, s, hard_f32_div, soft_f32_div,
+ f32_div_pre, f32_div_post, NULL, NULL);
+}
+
+float64 QEMU_FLATTEN
+float64_div(float64 a, float64 b, float_status *s)
+{
+ return float64_gen2(a, b, s, hard_f64_div, soft_f64_div,
+ f64_div_pre, f64_div_post, NULL, NULL);
+}
+
/*
* Float to Float conversions
*
--
2.17.1
- [Qemu-devel] [PULL 05/15] target/tricore: use float32_is_denormal, (continued)
- [Qemu-devel] [PULL 05/15] target/tricore: use float32_is_denormal, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 10/15] hardfloat: implement float32/64 addition and subtraction, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 06/15] softfloat: rename canonicalize to sf_canonicalize, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 09/15] fpu: introduce hardfloat, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 08/15] tests/fp: add fp-bench, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 02/15] MAINTAINERS: update status of FPU emulation, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 11/15] hardfloat: implement float32/64 multiplication, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 13/15] hardfloat: implement float32/64 fused multiply-add, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 15/15] hardfloat: implement float32/64 comparison, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 14/15] hardfloat: implement float32/64 square root, Alex Bennée, 2018/12/14
- [Qemu-devel] [PULL 12/15] hardfloat: implement float32/64 division,
Alex Bennée <=
- Re: [Qemu-devel] [PULL 00/15] Hardfloat + softfloat maintainers update and gitdm, Peter Maydell, 2018/12/16