musl: backport various post-1.1.15 fixes

[openwrt/openwrt.git] / toolchain / musl / patches / 051-fix-float-formatting-of-some-exact-halfway-cases.patch

diff --git a/toolchain/musl/patches/051-fix-float-formatting-of-some-exact-halfway-cases.patch b/toolchain/musl/patches/051-fix-float-formatting-of-some-exact-halfway-cases.patch
new file mode 100644 (file)
index 0000000..d01a163
--- /dev/null
+++ b/toolchain/musl/patches/051-fix-float-formatting-of-some-exact-halfway-cases.patch
@@ -0,0 +1,30 @@
+From 51ab6db4ed115d079d7131975e4adb074ba9ef9d Mon Sep 17 00:00:00 2001
+From: Szabolcs Nagy <nsz@port70.net>
+Date: Wed, 12 Oct 2016 00:49:59 +0200
+Subject: fix float formatting of some exact halfway cases
+
+in nearest rounding mode exact halfway cases were not following the
+round to even rule if the rounding happened at a base 1000000000 digit
+boundary of the internal representation and the previous digit was odd.
+
+e.g. printf("%.0f", 1.5) printed 1 instead of 2.
+---
+ src/stdio/vfprintf.c | 3 ++-
+ 1 file changed, 2 insertions(+), 1 deletion(-)
+
+diff --git a/src/stdio/vfprintf.c b/src/stdio/vfprintf.c
+index e2ab2dc..60da14d 100644
+--- a/src/stdio/vfprintf.c
++++ b/src/stdio/vfprintf.c
+@@ -345,7 +345,8 @@ static int fmt_fp(FILE *f, long double y, int w, int p, int fl, int t)
+               if (x || d+1!=z) {
+                       long double round = 2/LDBL_EPSILON;
+                       long double small;
+-                      if (*d/i & 1) round += 2;
++                      if ((*d/i & 1) || (i==1000000000 && d>a && (d[-1]&1)))
++                              round += 2;
+                       if (x<i/2) small=0x0.8p0;
+                       else if (x==i/2 && d+1==z) small=0x1.0p0;
+                       else small=0x1.8p0;
+-- 
+cgit v0.11.2