[PATCH v5 0/3] MR8242: libs/musl: Force built-in rint for i386.

[Daniel Lehman (＠dlehman25)]

https://gitlab.winehq.org/wine/wine/-/merge_requests/7748#note_105461

huge thanks to @bernhardu for narrowing it down.  does this work for you?

--
  v5: msvcrt: Use rint() from the bundled musl library.
      musl: Use __builtin_rint if available.
      musl: Reimplement rint so it doesn't depend on floating point operations precision.

https://gitlab.winehq.org/wine/wine/-/merge_requests/8242

[PATCH v5 1/3] musl: Reimplement rint so it doesn't depend on floating point operations precision.

[Piotr Caban]

From: Piotr Caban

---
 libs/musl/src/math/rint.c | 63 ++++++++++++++++++++++++++-------------
 1 file changed, 43 insertions(+), 20 deletions(-)

diff --git a/libs/musl/src/math/rint.c b/libs/musl/src/math/rint.c
index ad35201b266..b9e3cbb0ec2 100644
--- a/libs/musl/src/math/rint.c
+++ b/libs/musl/src/math/rint.c
@@ -3,27 +3,50 @@
 #include <stdint.h>
 #include "libm.h"

-#if FLT_EVAL_METHOD==0 || FLT_EVAL_METHOD==1
-#define EPS DBL_EPSILON
-#elif FLT_EVAL_METHOD==2
-#define EPS LDBL_EPSILON
-#endif
-static const double_t toint = 1/EPS;
+static const float_t toint = 1 / FLT_EPSILON;

double __cdecl rint(double x)
 {
-	union {double f; uint64_t i;} u = {x};
-	int e = u.i>>52 & 0x7ff;
-	int s = u.i>>63;
-	double_t y;
-
-	if (e >= 0x3ff+52)
-		return x;
-	if (s)
-		y = fp_barrier(x - toint) + toint;
-	else
-		y = fp_barrier(x + toint) - toint;
-	if (y == 0)
-		return s ? -0.0 : 0;
-	return y;
+    union {double f; uint64_t i;} u = {x};
+    int e = (u.i >> 52 & 0x7ff) - 0x3ff;
+    int s = u.i>>63;
+    double_t y, z;
+    float_t f;
+    int even;
+
+    if (e >= 52)
+        return x;
+
+    even = e <= -1 ? 1 : !((u.i >> (52 - e)) % 2);
+
+    if (s)
+    {
+        y = ceil(x);
+        z = x - y;
+        if (z < -0.5) f = -0.75;
+        else if (z == -0.5) f = -0.5;
+        else if (z != 0.0) f = -0.25;
+        else f = 0.0;
+
+        f = (even ? -0.0 : -1.0) + f;
+        f = fp_barrierf(f - toint) + toint;
+        if (f == (even ? 0.0 : -1.0)) z = y;
+        else z = floor(x);
+    }
+    else
+    {
+        y = floor(x);
+        z = x - y;
+        if (z > 0.5) f = 0.75;
+        else if (z == 0.5) f = 0.5;
+        else if (z != 0.0) f = 0.25;
+        else f = 0.0;
+
+        f = (even ? 0.0 : 1.0) + f;
+        f = fp_barrierf(f + toint) - toint;
+        if (f == (even ? 0.0 : 1.0)) z = y;
+        else z = ceil(x);
+    }
+
+    return z;
 }

[PATCH v5 2/3] musl: Use __builtin_rint if available.

[Piotr Caban]

From: Piotr Caban

---
 libs/musl/src/math/rint.c | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/libs/musl/src/math/rint.c b/libs/musl/src/math/rint.c
index b9e3cbb0ec2..61df07485b8 100644
--- a/libs/musl/src/math/rint.c
+++ b/libs/musl/src/math/rint.c
@@ -7,6 +7,9 @@ static const float_t toint = 1 / FLT_EPSILON;

double __cdecl rint(double x)
 {
+#if defined(__GNUC__) || defined(__clang__)
+    return __builtin_rint(x);
+#else
     union {double f; uint64_t i;} u = {x};
     int e = (u.i >> 52 & 0x7ff) - 0x3ff;
     int s = u.i>>63;
@@ -49,4 +52,5 @@ double __cdecl rint(double x)
     }

return z;
+#endif
 }

[PATCH v5 3/3] msvcrt: Use rint() from the bundled musl library.

[Piotr Caban]

From: Piotr Caban

---
 dlls/msvcr120/msvcr120.spec |  4 ++--
 dlls/msvcrt/math.c          | 23 +++--------------------
 dlls/ucrtbase/ucrtbase.spec |  8 ++++----
 3 files changed, 9 insertions(+), 26 deletions(-)

diff --git a/dlls/msvcr120/msvcr120.spec b/dlls/msvcr120/msvcr120.spec
index 56b26852ce1..4305bc7bada 100644
--- a/dlls/msvcr120/msvcr120.spec
+++ b/dlls/msvcr120/msvcr120.spec
@@ -2334,9 +2334,9 @@
 @ cdecl remquol(double double ptr) remquo
 @ cdecl rename(str str)
 @ cdecl rewind(ptr)
-@ cdecl rint(double) MSVCRT_rint
+@ cdecl rint(double)
 @ cdecl rintf(float)
-@ cdecl rintl(double) MSVCRT_rint
+@ cdecl rintl(double) rint
 @ cdecl round(double)
 @ cdecl roundf(float)
 @ cdecl roundl(double) round
diff --git a/dlls/msvcrt/math.c b/dlls/msvcrt/math.c
index 682010e3aa5..512fe503fe0 100644
--- a/dlls/msvcrt/math.c
+++ b/dlls/msvcrt/math.c
@@ -1621,23 +1621,6 @@ int CDECL _isnan(double num)

#if _MSVCR_VER>=120

-/*********************************************************************
- *      rint (MSVCR120.@)
- */
-double CDECL MSVCRT_rint(double x)
-{
-    unsigned cw;
-    double y;
-
-    cw = _controlfp(0, 0);
-    if ((cw & _MCW_PC) != _PC_53)
-        _controlfp(_PC_53, _MCW_PC);
-    y = rint(x);
-    if ((cw & _MCW_PC) != _PC_53)
-        _controlfp(cw, _MCW_PC);
-    return y;
-}
-
 /*********************************************************************
  *		_nearbyint (MSVCR120.@)
  *
@@ -1656,7 +1639,7 @@ double CDECL nearbyint(double x)
         cw |= _EM_INEXACT;
         _setfp(&cw, _EM_INEXACT, NULL, 0);
     }
-    x = MSVCRT_rint(x);
+    x = rint(x);
     if (update_cw || update_sw)
     {
         sw = 0;
@@ -2603,7 +2586,7 @@ __msvcrt_long CDECL lrint(double x)
 {
     double d;

-    d = MSVCRT_rint(x);
+    d = rint(x);
     if ((d < 0 && d != (double)(__msvcrt_long)d)
             || (d >= 0 && d != (double)(__msvcrt_ulong)d)) {
         *_errno() = EDOM;
@@ -2635,7 +2618,7 @@ __int64 CDECL llrint(double x)
 {
     double d;

-    d = MSVCRT_rint(x);
+    d = rint(x);
     if ((d < 0 && d != (double)(__int64)d)
             || (d >= 0 && d != (double)(unsigned __int64)d)) {
         *_errno() = EDOM;
diff --git a/dlls/ucrtbase/ucrtbase.spec b/dlls/ucrtbase/ucrtbase.spec
index 230f5ceb1d7..9f026b351d1 100644
--- a/dlls/ucrtbase/ucrtbase.spec
+++ b/dlls/ucrtbase/ucrtbase.spec
@@ -1758,9 +1758,9 @@
 @ cdecl _o_remquol(double double ptr) remquo
 @ cdecl _o_rename(str str) rename
 @ cdecl _o_rewind(ptr) rewind
-@ cdecl _o_rint(double) MSVCRT_rint
+@ cdecl _o_rint(double) rint
 @ cdecl _o_rintf(float) rintf
-@ cdecl _o_rintl(double) MSVCRT_rint
+@ cdecl _o_rintl(double) rint
 @ cdecl _o_round(double) round
 @ cdecl _o_roundf(float) roundf
 @ cdecl _o_roundl(double) round
@@ -2472,9 +2472,9 @@
 @ cdecl rename(str str)
 @ cdecl -arch=i386 rewind(ptr) rewind_preserve_stack
 @ cdecl -arch=!i386 rewind(ptr)
-@ cdecl rint(double) MSVCRT_rint
+@ cdecl rint(double)
 @ cdecl rintf(float)
-@ cdecl rintl(double) MSVCRT_rint
+@ cdecl rintl(double) rint
 @ cdecl round(double)
 @ cdecl roundf(float)
 @ cdecl roundl(double) round

[PATCH v5 0/3] MR8242: libs/musl: Force built-in rint for i386. - approved

[Piotr Caban (＠piotr)]

This merge request was approved by Piotr Caban.