system/musl: more complex fixes

2 files changed, 84 insertions, 3 deletions

diff --git a/system/musl/APKBUILD b/system/musl/APKBUILD
index 5b80c8dda..47e1b4e0a 100644
--- a/system/musl/APKBUILD
+++ b/system/musl/APKBUILD
@@ -1,9 +1,9 @@
 # Contributor: William Pitcock <nenolod@dereferenced.org>
-# Maintainer: Timo Teräs <timo.teras@iki.fi>
+# Maintainer: A. Wilcox <awilfox@adelielinux.org>
 pkgname=musl
 pkgver=1.1.19
-pkgrel=4
-pkgdesc="the musl c library (libc) implementation"
+pkgrel=5
+pkgdesc="System library (libc) implementation"
 url="http://www.musl-libc.org/"
 arch="all"
 options="!check"
@@ -28,6 +28,7 @@ source="http://www.musl-libc.org/releases/musl-$pkgver.tar.gz
 
 	2000-pthread-internals-increase-DEFAULT_GUARD_SIZE-to-2-p.patch
 	complex-math.patch
+	complex-math2.patch
 	handle-aux-at_base.patch
 
 	ldconfig
@@ -159,6 +160,7 @@ d0d0817a4e1d57b74cb442a3bf8d8efe39a23a387275b75cba1b2fa354d8a7dc2fd843b5b67584aa
 6f5f9b5fb5eba638b0d98c68c280dbcc2bdae58d94d9f6966f5de55f6dd5d7f3cdddd9ca758e8861e30841b80ba616a945fb2b885a31481707d578293b187ff0  0007-abort-raise-SIGABRT-again-if-signal-is-ignored.patch
 2c8e1dde1834238097b2ee8a7bfb53471a0d9cff4a5e38b55f048b567deff1cdd47c170d0578a67b1a039f95a6c5fbb8cff369c75b6a3e4d7ed171e8e86ebb8c  2000-pthread-internals-increase-DEFAULT_GUARD_SIZE-to-2-p.patch
 8909dc260968770ace8f3ffdc04c6c7d20933ff115b4fa3e512fb7460860a8216c73ca7a7ad54f59cb5988ef011f02bf18aa13cc2287cc64ffdb8db84ef69d47  complex-math.patch
+c34ae0c8c2b05d82bc6bd341ceb29041f6e1a1d2c7b2f4f289ab620288bfb1e1ddabc4cb2fc85220c1fbe735874c38a9b00af636644584c7cd1e895d54564a22  complex-math2.patch
 6a7ff16d95b5d1be77e0a0fbb245491817db192176496a57b22ab037637d97a185ea0b0d19da687da66c2a2f5578e4343d230f399d49fe377d8f008410974238  handle-aux-at_base.patch
 8d3a2d5315fc56fee7da9abb8b89bb38c6046c33d154c10d168fb35bfde6b0cf9f13042a3bceee34daf091bc409d699223735dcf19f382eeee1f6be34154f26f  ldconfig
 062bb49fa54839010acd4af113e20f7263dde1c8a2ca359b5fb2661ef9ed9d84a0f7c3bc10c25dcfa10bb3c5a4874588dff636ac43d5dbb3d748d75400756d0b  __stack_chk_fail_local.c
diff --git a/system/musl/complex-math2.patch b/system/musl/complex-math2.patch
new file mode 100644
index 000000000..49f5c3acd
--- /dev/null
+++ b/system/musl/complex-math2.patch
@@ -0,0 +1,79 @@
+From 10e4bd3780050e75b72aac5d85c31816419bb17d Mon Sep 17 00:00:00 2001
+From: Rich Felker <dalias@aerifal.cx>
+Date: Wed, 11 Apr 2018 15:05:22 -0400
+Subject: [PATCH 1/2] fix incorrect results for catan with some inputs
+MIME-Version: 1.0
+Content-Type: text/plain; charset=UTF-8
+Content-Transfer-Encoding: 8bit
+
+the catan implementation from OpenBSD includes a FIXME-annotated
+"overflow" branch that produces a meaningless and incorrect
+large-magnitude result. it was reachable via three paths,
+corresponding to gotos removed by this commit, in order:
+
+1. pure imaginary argument with imaginary component greater than 1 in
+   magnitude. this case does not seem at all exceptional and is
+   handled (at least with the quality currently expected from our
+   complex math functions) by the existing non-exceptional code path.
+
+2. arguments on the unit circle, including the pure-real argument 1.0.
+   these are not exceptional except for ±i, which should produce
+   results with infinite imaginary component and which lead to
+   computation of atan2(±0,0) in the existing non-exceptional code
+   path. such calls to atan2() however are well-defined by POSIX.
+
+3. the specific argument +i. this route should be unreachable due to
+   the above (2), but subtle rounding effects might have made it
+   possible in rare cases. continuing on the non-exceptional code path
+   in this case would lead to computing the (real) log of an infinite
+   argument, then producing a NAN when multiplying it by I.
+
+for now, remove the exceptional code paths entirely. replace the
+multiplication by I with construction of a complex number using the
+CMPLX macro so that the NAN issue (3) prevented cannot arise.
+
+with these changes, catan should give reasonably correct results for
+real arguments, and should no longer give completely-wrong results for
+pure-imaginary arguments outside the interval (-i,+i).
+---
+ src/complex/catan.c | 14 +-------------
+ 1 file changed, 1 insertion(+), 13 deletions(-)
+
+diff --git a/src/complex/catan.c b/src/complex/catan.c
+index 39ce6cf2..7dc2afeb 100644
+--- a/src/complex/catan.c
++++ b/src/complex/catan.c
+@@ -91,29 +91,17 @@ double complex catan(double complex z)
+ 	x = creal(z);
+ 	y = cimag(z);
+ 
+-	if (x == 0.0 && y > 1.0)
+-		goto ovrf;
+-
+ 	x2 = x * x;
+ 	a = 1.0 - x2 - (y * y);
+-	if (a == 0.0)
+-		goto ovrf;
+ 
+ 	t = 0.5 * atan2(2.0 * x, a);
+ 	w = _redupi(t);
+ 
+ 	t = y - 1.0;
+ 	a = x2 + (t * t);
+-	if (a == 0.0)
+-		goto ovrf;
+ 
+ 	t = y + 1.0;
+ 	a = (x2 + t * t)/a;
+-	w = w + (0.25 * log(a)) * I;
+-	return w;
+-
+-ovrf:
+-	// FIXME
+-	w = MAXNUM + MAXNUM * I;
++	w = CMPLX(w, 0.25 * log(a));
+ 	return w;
+ }
+-- 
+2.15.0
+