From a1812e2a46b61c431e5650e7aa38ac6cf1f0c934 Mon Sep 17 00:00:00 2001
From: wm4 <wm4@nowhere>
Date: Sat, 9 May 2020 17:53:53 +0200
Subject: build: add -fno-math-errno

glibc/gcc make certain math functions set errno by default. This is not
required by the standard, and makes everything complexer and slower
(well done glibc). It typically prevents inlining certain math functions
too, where the compiler can turn a function call to a single
instruction, such as observed with lrint().

So this has possibly some minor performance advantages, and no
disadvantages.
---
 waftools/detections/compiler.py | 1 +
 1 file changed, 1 insertion(+)

diff --git a/waftools/detections/compiler.py b/waftools/detections/compiler.py
index 399a606144..06baa98ac0 100644
--- a/waftools/detections/compiler.py
+++ b/waftools/detections/compiler.py
@@ -44,6 +44,7 @@ def __add_generic_flags__(ctx):
                                  "-Wno-format-truncation",
                                  "-Wimplicit-fallthrough",
                                  ])
+    __test_and_add_flags__(ctx, ["-fno-math-errno"])
 
 def __add_gcc_flags__(ctx):
     ctx.env.CFLAGS += ["-Wall", "-Wundef", "-Wmissing-prototypes", "-Wshadow",
-- 
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