Piotr Caban : msvcrt: Import trunc implementation from musl.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: f2c18726605315a93f733b583a61fb5417f4dde0
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=f2c18726605315a93f733b583...

Author: Piotr Caban 
Date:   Mon May 17 15:38:22 2021 +0200

msvcrt: Import trunc implementation from musl.

Signed-off-by: Piotr Caban 
Signed-off-by: Alexandre Julliard

---

configure             |  3 +--
 configure.ac          |  3 +--
 dlls/msvcrt/math.c    | 16 +++++++++++++++-
 dlls/msvcrt/unixlib.c | 13 -------------
 dlls/msvcrt/unixlib.h |  1 -
 include/config.h.in   |  3 ---
 6 files changed, 17 insertions(+), 22 deletions(-)

diff --git a/configure b/configure
index fe54e30321f..7c2e31de5af 100755
--- a/configure
+++ b/configure
@@ -19643,8 +19643,7 @@ for ac_func in \
    remquo \
    remquof \
    tgamma \
-	tgammaf \
-	trunc
+	tgammaf

do :
   as_ac_var=`$as_echo "ac_cv_func_$ac_func" | $as_tr_sh`
diff --git a/configure.ac b/configure.ac
index fb4ec181ea2..4c98c3e5597 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2683,8 +2683,7 @@ AC_CHECK_FUNCS(\
    remquo \
    remquof \
    tgamma \
-	tgammaf \
-	trunc
+	tgammaf
 )
 LIBS="$ac_save_LIBS"

diff --git a/dlls/msvcrt/math.c b/dlls/msvcrt/math.c
index 246f329ee95..f2caa81712b 100644
--- a/dlls/msvcrt/math.c
+++ b/dlls/msvcrt/math.c
@@ -4981,10 +4981,24 @@ __int64 CDECL llroundf(float x)

/*********************************************************************
  *      trunc (MSVCR120.@)
+ *
+ * Copied from musl: src/math/trunc.c
  */
 double CDECL trunc(double x)
 {
-    return unix_funcs->trunc(x);
+    union {double f; UINT64 i;} u = {x};
+    int e = (u.i >> 52 & 0x7ff) - 0x3ff + 12;
+    UINT64 m;
+
+    if (e >= 52 + 12)
+        return x;
+    if (e < 12)
+        e = 1;
+    m = -1ULL >> e;
+    if ((u.i & m) == 0)
+        return x;
+    u.i &= ~m;
+    return u.f;
 }

/*********************************************************************
diff --git a/dlls/msvcrt/unixlib.c b/dlls/msvcrt/unixlib.c
index e809d7353ff..d7e368d1b37 100644
--- a/dlls/msvcrt/unixlib.c
+++ b/dlls/msvcrt/unixlib.c
@@ -636,18 +636,6 @@ static double CDECL unix_tgamma(double x)
 #endif
 }

-/*********************************************************************
- *      trunc
- */
-static double CDECL unix_trunc(double x)
-{
-#ifdef HAVE_TRUNC
-    return trunc(x);
-#else
-    return (x > 0) ? floor(x) : ceil(x);
-#endif
-}
-
 /*********************************************************************
  *      tgammaf
  */
@@ -722,7 +710,6 @@ static const struct unix_funcs funcs =
     unix_tanhf,
     unix_tgamma,
     unix_tgammaf,
-    unix_trunc,
 };

NTSTATUS CDECL __wine_init_unix_lib( HMODULE module, DWORD reason, const void *ptr_in, void *ptr_out )
diff --git a/dlls/msvcrt/unixlib.h b/dlls/msvcrt/unixlib.h
index fd279cf5519..b8c18b1e2a5 100644
--- a/dlls/msvcrt/unixlib.h
+++ b/dlls/msvcrt/unixlib.h
@@ -82,7 +82,6 @@ struct unix_funcs
     float           (CDECL *tanhf)(float x);
     double          (CDECL *tgamma)(double x);
     float           (CDECL *tgammaf)(float x);
-    double          (CDECL *trunc)(double x);
 };

#endif /* __UNIXLIB_H */
diff --git a/include/config.h.in b/include/config.h.in
index 7fe9383a778..bf7fc0d4e9b 100644
--- a/include/config.h.in
+++ b/include/config.h.in
@@ -1010,9 +1010,6 @@
 /* Define to 1 if you have the <tiffio.h> header file. */
 #undef HAVE_TIFFIO_H

-/* Define to 1 if you have the `trunc' function. */
-#undef HAVE_TRUNC
-
 /* Define to 1 if you have the `udev' library (-ludev). */
 #undef HAVE_UDEV