From ae92ea149c30bb90082a627d30d663b3359a6e4c Mon Sep 17 00:00:00 2001
From: Ayke van Laethem <aykevanlaethem@gmail.com>
Date: Thu, 3 Dec 2020 20:37:08 +0100
Subject: [PATCH] esp32: enable the FPU

This allows working with float32 values, for example it allows
testdata/float.go to work correctly (assuming an Xtensa backend bug is
fixed, see https://github.com/espressif/llvm-project/issues/41).
---
 src/device/esp/esp32.S | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/src/device/esp/esp32.S b/src/device/esp/esp32.S
index f8fc6f93..1179a2da 100644
--- a/src/device/esp/esp32.S
+++ b/src/device/esp/esp32.S
@@ -42,6 +42,11 @@ call_start_cpu0:
     wsr.ps a2
     rsync
 
+    // Enable the FPU (coprocessor 0 so the lowest bit).
+    movi a2, 1
+    wsr.cpenable a2
+    rsync
+
     // Jump to the runtime start function written in Go.
     call4 main