From d9a5c8f38765812e93ffc9a28480423e6e81c95e Mon Sep 17 00:00:00 2001
From: Angus Gratton <angus@espressif.com>
Date: Thu, 16 May 2019 10:36:48 +0800
Subject: [PATCH] esp32: Use FPU for floating point divide, power, complex
 multiplications

* Linker was choosing ROM symbols for these, which use integer soft-float
  operations and are much slower.
* _divsf3() moved to IRAM to avoid regressions with any code that does
  integer float division in IRAM interrupt handlers (+88 bytes IRAM)
* Thanks to michal for reporting:
  https://esp32.com/viewtopic.php?f=14&t=10540&p=43367
---
 components/esp32/linker.lf                      | 1 +
 components/esp_rom/esp32/ld/esp32.rom.libgcc.ld | 4 ----
 2 files changed, 1 insertion(+), 4 deletions(-)

diff --git a/components/esp32/linker.lf b/components/esp32/linker.lf
index b7bb89f6e..db73d2dc9 100644
--- a/components/esp32/linker.lf
+++ b/components/esp32/linker.lf
@@ -7,6 +7,7 @@ entries:
 archive: libgcc.a
 entries:
     lib2funcs (noflash_text)
+    _divsf3 (noflash)
 
 [mapping:gcov]
 archive: libgcov.a
diff --git a/components/esp_rom/esp32/ld/esp32.rom.libgcc.ld b/components/esp_rom/esp32/ld/esp32.rom.libgcc.ld
index dfdbe2588..0bda115dc 100644
--- a/components/esp_rom/esp32/ld/esp32.rom.libgcc.ld
+++ b/components/esp_rom/esp32/ld/esp32.rom.libgcc.ld
@@ -24,8 +24,6 @@ __ctzsi2 = 0x4000c7f0;
 __divdc3 = 0x400645a4;
 __divdf3 = 0x40002954;
 __divdi3 = 0x4000ca84;
-__divsc3 = 0x4006429c;
-__divsf3 = 0x4000234c;
 __divsi3 = 0x4000c7b8;
 __eqdf2 = 0x400636a8;
 __eqsf2 = 0x40063374;
@@ -62,7 +60,6 @@ __modsi3 = 0x4000c7c0;
 __muldc3 = 0x40063c90;
 __muldf3 = 0x4006358c;
 __muldi3 = 0x4000c9fc;
-__mulsc3 = 0x40063944;
 __mulsf3 = 0x400632c8;
 __mulsi3 = 0x4000c7b0;
 __mulvdi3 = 0x40002d78;
@@ -80,7 +77,6 @@ __popcount_tab = 0x3ff96544;
 __popcountdi2 = 0x40002ef8;
 __popcountsi2 = 0x40002ed0;
 __powidf2 = 0x400638e4;
-__powisf2 = 0x4006389c;
 __subdf3 = 0x400026e4;
 __subsf3 = 0x400021d0;
 __subvdi3 = 0x40002d20;