[PATCH v3 0/2] MR8347: musl: Don't use __builtin_rint in clang builds.

[Piotr Caban (＠piotr)]

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=58381

--
  v3: musl: Optimize rint when floating point operations use 53-bit precision.
      musl: Don't use __builtin_rint in clang builds.

https://gitlab.winehq.org/wine/wine/-/merge_requests/8347

[PATCH v3 1/2] musl: Don't use __builtin_rint in clang builds.

[Piotr Caban]

From: Piotr Caban

Wine-Bug: https://bugs.winehq.org/show_bug.cgi?id=58381
---
 libs/musl/src/math/rint.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libs/musl/src/math/rint.c b/libs/musl/src/math/rint.c
index 61df07485b8..7ecf9d8625c 100644
--- a/libs/musl/src/math/rint.c
+++ b/libs/musl/src/math/rint.c
@@ -7,7 +7,7 @@ static const float_t toint = 1 / FLT_EPSILON;

double __cdecl rint(double x)
 {
-#if defined(__GNUC__) || defined(__clang__)
+#if defined(__GNUC__) && !defined(__clang__)
     return __builtin_rint(x);
 #else
     union {double f; uint64_t i;} u = {x};

[PATCH v3 2/2] musl: Optimize rint when floating point operations use 53-bit precision.

[Piotr Caban]

From: Piotr Caban

---
 libs/musl/src/math/rint.c | 22 +++++++++++++++++++---
 1 file changed, 19 insertions(+), 3 deletions(-)

diff --git a/libs/musl/src/math/rint.c b/libs/musl/src/math/rint.c
index 7ecf9d8625c..d9857272747 100644
--- a/libs/musl/src/math/rint.c
+++ b/libs/musl/src/math/rint.c
@@ -3,12 +3,28 @@
 #include <stdint.h>
 #include "libm.h"

-static const float_t toint = 1 / FLT_EPSILON;
+static const float_t tointf = 1 / FLT_EPSILON;
+static const double_t toint = 1 / DBL_EPSILON;

double __cdecl rint(double x)
 {
 #if defined(__GNUC__) && !defined(__clang__)
     return __builtin_rint(x);
+#elif defined(__SSE_MATH__)
+    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 = x - toint + toint;
+    else
+        y = x + toint - toint;
+    if (y == 0)
+        return s ? -0.0 : 0;
+    return y;
 #else
     union {double f; uint64_t i;} u = {x};
     int e = (u.i >> 52 & 0x7ff) - 0x3ff;
@@ -32,7 +48,7 @@ double __cdecl rint(double x)
         else f = 0.0;

f = (even ? -0.0 : -1.0) + f;
-        f = fp_barrierf(f - toint) + toint;
+        f = fp_barrierf(f - tointf) + tointf;
         if (f == (even ? 0.0 : -1.0)) z = y;
         else z = floor(x);
     }
@@ -46,7 +62,7 @@ double __cdecl rint(double x)
         else f = 0.0;

f = (even ? 0.0 : 1.0) + f;
-        f = fp_barrierf(f + toint) - toint;
+        f = fp_barrierf(f + tointf) - tointf;
         if (f == (even ? 0.0 : 1.0)) z = y;
         else z = ceil(x);
     }