From 175da732ac18acaf16eff97a2b7711b25a2cb157 Mon Sep 17 00:00:00 2001
From: Clifford Wolf <clifford@clifford.at>
Date: Sat, 4 Aug 2018 20:16:43 +0200
Subject: Use faster model for ice40 predictDelay()

Signed-off-by: Clifford Wolf <clifford@clifford.at>
---
 ice40/delay.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

(limited to 'ice40')

diff --git a/ice40/delay.cc b/ice40/delay.cc
index 342b7f0b..1fa4256e 100644
--- a/ice40/delay.cc
+++ b/ice40/delay.cc
@@ -23,7 +23,7 @@
 
 NEXTPNR_NAMESPACE_BEGIN
 
-#define NUM_FUZZ_ROUTES 1000
+#define NUM_FUZZ_ROUTES 100000
 
 void ice40DelayFuzzerMain(Context *ctx)
 {
@@ -218,6 +218,10 @@ delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
     if (dx <= 1 && dy <= 1)
         return p.neighbourhood;
 
+#if 1
+    // Model #0
+    return (p.model0_offset + p.model0_norm1 * (dx + dy)) / 128;
+#else
     float norm1 = dx + dy;
 
     float dx2 = dx * dx;
@@ -240,6 +244,7 @@ delay_t Arch::predictDelay(const NetInfo *net_info, const PortRef &sink) const
     v /= 128;
 
     return v;
+#endif
 }
 
 NEXTPNR_NAMESPACE_END
-- 
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