Fresh pull from upstream

[librecmc/librecmc.git] / toolchain / musl / patches / 055-fix-strtod-int-optimization-in-non-nearest-rounding-mode.patch

diff --git a/toolchain/musl/patches/055-fix-strtod-int-optimization-in-non-nearest-rounding-mode.patch b/toolchain/musl/patches/055-fix-strtod-int-optimization-in-non-nearest-rounding-mode.patch
new file mode 100644 (file)
index 0000000..1588b14
--- /dev/null
+++ b/toolchain/musl/patches/055-fix-strtod-int-optimization-in-non-nearest-rounding-mode.patch
@@ -0,0 +1,38 @@
+From 6ffdc4579ffb34f4aab69ab4c081badabc7c0a9a Mon Sep 17 00:00:00 2001
+From: Szabolcs Nagy <nsz@port70.net>
+Date: Sun, 4 Sep 2016 04:51:03 +0200
+Subject: fix strtod int optimization in non-nearest rounding mode
+
+the mid-sized integer optimization relies on lnz set up properly
+to mark the last non-zero decimal digit, but this was not done
+if the non-zero digit lied outside the KMAX digits of the base
+10^9 number representation.
+
+so if the fractional part was a very long list of zeros (>2048*9 on
+x86) followed by non-zero digits then the integer optimization could
+kick in discarding the tiny non-zero fraction which can mean wrong
+result on non-nearest rounding mode.
+
+strtof, strtod and strtold were all affected.
+---
+ src/internal/floatscan.c | 5 ++++-
+ 1 file changed, 4 insertions(+), 1 deletion(-)
+
+diff --git a/src/internal/floatscan.c b/src/internal/floatscan.c
+index 80305ee..ae09852 100644
+--- a/src/internal/floatscan.c
++++ b/src/internal/floatscan.c
+@@ -110,7 +110,10 @@ static long double decfloat(FILE *f, int c, int bits, int emin, int sign, int po
+                       gotdig=1;
+               } else {
+                       dc++;
+-                      if (c!='0') x[KMAX-4] |= 1;
++                      if (c!='0') {
++                              lnz = (KMAX-4)*9;
++                              x[KMAX-4] |= 1;
++                      }
+               }
+       }
+       if (!gotrad) lrp=dc;
+-- 
+cgit v0.11.2