From: Peter Maydell <peter.maydell@linaro.org>
To: qemu-devel@nongnu.org
Cc: patches@linaro.org
Subject: [Qemu-devel] [PATCH 2/2] target-arm: use make_float32() to make constant floats for VRSQRTS
Date: Mon, 14 Mar 2011 12:32:28 +0000 [thread overview]
Message-ID: <1300105948-26961-3-git-send-email-peter.maydell@linaro.org> (raw)
In-Reply-To: <1300105948-26961-1-git-send-email-peter.maydell@linaro.org>
The preferred way to create a constant floating point value is to use
make_float32() rather than doing a runtime int32_to_float32().
Convert the code in the VRSQRTS helper to work this way.
Signed-off-by: Peter Maydell <peter.maydell@linaro.org>
---
target-arm/helper.c | 11 +++++------
1 files changed, 5 insertions(+), 6 deletions(-)
diff --git a/target-arm/helper.c b/target-arm/helper.c
index c01a5a2..c3238d3 100644
--- a/target-arm/helper.c
+++ b/target-arm/helper.c
@@ -2708,6 +2708,8 @@ uint32_t HELPER(vfp_fcvt_f32_to_f16)(float32 a, CPUState *env)
}
#define float32_two make_float32(0x40000000)
+#define float32_three make_float32(0x40400000)
+#define float32_one_point_five makefloat32(0x3fc00000)
float32 HELPER(recps_f32)(float32 a, float32 b, CPUState *env)
{
@@ -2722,16 +2724,13 @@ float32 HELPER(recps_f32)(float32 a, float32 b, CPUState *env)
float32 HELPER(rsqrts_f32)(float32 a, float32 b, CPUState *env)
{
float_status *s = &env->vfp.standard_fp_status;
- float32 two = int32_to_float32(2, s);
- float32 three = int32_to_float32(3, s);
float32 product;
if ((float32_is_infinity(a) && float32_is_zero_or_denormal(b)) ||
(float32_is_infinity(b) && float32_is_zero_or_denormal(a))) {
- product = float32_zero;
- } else {
- product = float32_mul(a, b, s);
+ return float32_one_point_five;
}
- return float32_div(float32_sub(three, product, s), two, s);
+ product = float32_mul(a, b, s);
+ return float32_div(float32_sub(float32_three, product, s), float32_two, s);
}
/* NEON helpers. */
--
1.7.1
prev parent reply other threads:[~2011-03-14 12:32 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-03-14 12:32 [Qemu-devel] [PATCH 0/2] Fix VRECPS edge cases handling Peter Maydell
2011-03-14 12:32 ` [Qemu-devel] [PATCH 1/2] target-arm: " Peter Maydell
2011-03-14 12:32 ` Peter Maydell [this message]
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