Piotr Caban : msvcrt: Import remquo implementation from musl.

[Alexandre Julliard]

Module: wine
Branch: master
Commit: c7fa4673769c42bfb1b44ebfc7c981b458784e5a
URL:    https://source.winehq.org/git/wine.git/?a=commit;h=c7fa4673769c42bfb1b44ebfc7c981b458784e5a

Author: Piotr Caban <piotr at codeweavers.com>
Date:   Tue May 18 19:09:00 2021 +0200

msvcrt: Import remquo implementation from musl.

Signed-off-by: Piotr Caban <piotr at codeweavers.com>
Signed-off-by: Alexandre Julliard <julliard at winehq.org>

---

 configure             |  1 -
 configure.ac          |  1 -
 dlls/msvcrt/math.c    | 81 +++++++++++++++++++++++++++++++++++++++++++++++++--
 dlls/msvcrt/unixlib.c | 14 ---------
 dlls/msvcrt/unixlib.h |  1 -
 include/config.h.in   |  3 --
 6 files changed, 78 insertions(+), 23 deletions(-)

diff --git a/configure b/configure
index ac738ca964b..b243f0280f5 100755
--- a/configure
+++ b/configure
@@ -19640,7 +19640,6 @@ for ac_func in \
 	log2f \
 	remainder \
 	remainderf \
-	remquo \
 	remquof \
 	tgamma \
 	tgammaf
diff --git a/configure.ac b/configure.ac
index 4c98c3e5597..8942a3eefc2 100644
--- a/configure.ac
+++ b/configure.ac
@@ -2680,7 +2680,6 @@ AC_CHECK_FUNCS(\
 	log2f \
 	remainder \
 	remainderf \
-	remquo \
 	remquof \
 	tgamma \
 	tgammaf
diff --git a/dlls/msvcrt/math.c b/dlls/msvcrt/math.c
index fab505abfb5..f4c5c69fc4b 100644
--- a/dlls/msvcrt/math.c
+++ b/dlls/msvcrt/math.c
@@ -5496,12 +5496,87 @@ float CDECL remainderf(float x, float y)
 
 /*********************************************************************
  *      remquo (MSVCR120.@)
+ *
+ * Copied from musl: src/math/remquo.c
  */
 double CDECL remquo(double x, double y, int *quo)
 {
-    if(!isfinite(x)) *_errno() = EDOM;
-    if(isnan(y) || y==0.0) *_errno() = EDOM;
-    return unix_funcs->remquo( x, y, quo );
+    UINT64 uxi = *(UINT64*)&x;
+    UINT64 uyi = *(UINT64*)&y;
+    int ex = uxi >> 52 & 0x7ff;
+    int ey = uyi >> 52 & 0x7ff;
+    int sx = uxi >> 63;
+    int sy = uyi >> 63;
+    UINT32 q;
+    UINT64 i;
+
+    *quo = 0;
+    if (y == 0 || isinf(x)) *_errno() = EDOM;
+    if (uyi << 1 == 0 || isnan(y) || ex == 0x7ff)
+        return (x * y) / (x * y);
+    if (uxi << 1 == 0)
+        return x;
+
+    /* normalize x and y */
+    if (!ex) {
+        for (i = uxi << 12; i >> 63 == 0; ex--, i <<= 1);
+        uxi <<= -ex + 1;
+    } else {
+        uxi &= -1ULL >> 12;
+        uxi |= 1ULL << 52;
+    }
+    if (!ey) {
+        for (i = uyi << 12; i >> 63 == 0; ey--, i <<= 1);
+        uyi <<= -ey + 1;
+    } else {
+        uyi &= -1ULL >> 12;
+        uyi |= 1ULL << 52;
+    }
+
+    q = 0;
+    if (ex < ey) {
+        if (ex+1 == ey)
+            goto end;
+        return x;
+    }
+
+    /* x mod y */
+    for (; ex > ey; ex--) {
+        i = uxi - uyi;
+        if (i >> 63 == 0) {
+            uxi = i;
+            q++;
+        }
+        uxi <<= 1;
+        q <<= 1;
+    }
+    i = uxi - uyi;
+    if (i >> 63 == 0) {
+        uxi = i;
+        q++;
+    }
+    if (uxi == 0)
+        ex = -60;
+    else
+        for (; uxi >> 52 == 0; uxi <<= 1, ex--);
+end:
+    /* scale result and decide between |x| and |x|-|y| */
+    if (ex > 0) {
+        uxi -= 1ULL << 52;
+        uxi |= (UINT64)ex << 52;
+    } else {
+        uxi >>= -ex + 1;
+    }
+    x = *(double*)&uxi;
+    if (sy)
+        y = -y;
+    if (ex == ey || (ex + 1 == ey && (2 * x > y || (2 * x == y && q % 2)))) {
+        x -= y;
+        q++;
+    }
+    q &= 0x7fffffff;
+    *quo = sx ^ sy ? -(int)q : (int)q;
+    return sx ? -x : x;
 }
 
 /*********************************************************************
diff --git a/dlls/msvcrt/unixlib.c b/dlls/msvcrt/unixlib.c
index 62c6a5ae189..05d8c2bd83a 100644
--- a/dlls/msvcrt/unixlib.c
+++ b/dlls/msvcrt/unixlib.c
@@ -501,19 +501,6 @@ static float CDECL unix_remainderf(float x, float y)
 #endif
 }
 
-/*********************************************************************
- *      remquo
- */
-static double CDECL unix_remquo(double x, double y, int *quo)
-{
-#ifdef HAVE_REMQUO
-    return remquo(x, y, quo);
-#else
-    FIXME( "not implemented\n" );
-    return 0;
-#endif
-}
-
 /*********************************************************************
  *      remquof
  */
@@ -662,7 +649,6 @@ static const struct unix_funcs funcs =
     unix_powf,
     unix_remainder,
     unix_remainderf,
-    unix_remquo,
     unix_remquof,
     unix_sin,
     unix_sinf,
diff --git a/dlls/msvcrt/unixlib.h b/dlls/msvcrt/unixlib.h
index 69f4e02f321..9f91c097d71 100644
--- a/dlls/msvcrt/unixlib.h
+++ b/dlls/msvcrt/unixlib.h
@@ -66,7 +66,6 @@ struct unix_funcs
     float           (CDECL *powf)(float x, float y);
     double          (CDECL *remainder)(double x, double y);
     float           (CDECL *remainderf)(float x, float y);
-    double          (CDECL *remquo)(double x, double y, int *quo);
     float           (CDECL *remquof)(float x, float y, int *quo);
     double          (CDECL *sin)(double x);
     float           (CDECL *sinf)(float x);
diff --git a/include/config.h.in b/include/config.h.in
index bf7fc0d4e9b..7d0c5e934e6 100644
--- a/include/config.h.in
+++ b/include/config.h.in
@@ -636,9 +636,6 @@
 /* Define to 1 if you have the `remainderf' function. */
 #undef HAVE_REMAINDERF
 
-/* Define to 1 if you have the `remquo' function. */
-#undef HAVE_REMQUO
-
 /* Define to 1 if you have the `remquof' function. */
 #undef HAVE_REMQUOF