this should increase performance and reduce code size on aarch64.
the compiled code was checked against using __builtin_* instead
of inline asm with gcc-6.2.0.
lrint is two instructions.
c with inline asm is used because it is safer than a pure asm
implementation, this prevents ll{rint,round} to be an alias
of l{rint,round} (because the types don't match) and depends
on gcc style inline asm support.
ceil, floor, round, trunc can either raise inexact on finite
non-integer inputs or not raise any exceptions. the new
implementation does not raise exceptions while the generic
c code does.
on aarch64, the underflow exception is signaled before rounding
(ieee 754 allows both before and after rounding, but it must be
consistent), the generic fma c code signals it after rounding
so using single instruction fixes a slight conformance issue too.
--- /dev/null
+#include <math.h>
+
+double ceil(double x)
+{
+ __asm__ ("frintp %d0, %d1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float ceilf(float x)
+{
+ __asm__ ("frintp %s0, %s1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+double fabs(double x)
+{
+ __asm__ ("fabs %d0, %d1" : "=w"(x) : "w"(x));
+ return x;
+}
+++ /dev/null
-.text
-.global fabs
-.type fabs,%function
-fabs:
- fabs d0, d0
- ret
--- /dev/null
+#include <math.h>
+
+float fabsf(float x)
+{
+ __asm__ ("fabs %s0, %s1" : "=w"(x) : "w"(x));
+ return x;
+}
+++ /dev/null
-.text
-.global fabsf
-.type fabsf,%function
-fabsf:
- fabs s0, s0
- ret
--- /dev/null
+#include <math.h>
+
+double floor(double x)
+{
+ __asm__ ("frintm %d0, %d1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float floorf(float x)
+{
+ __asm__ ("frintm %s0, %s1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+double fma(double x, double y, double z)
+{
+ __asm__ ("fmadd %d0, %d1, %d2, %d3" : "=w"(x) : "w"(x), "w"(y), "w"(z));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float fmaf(float x, float y, float z)
+{
+ __asm__ ("fmadd %s0, %s1, %s2, %s3" : "=w"(x) : "w"(x), "w"(y), "w"(z));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+double fmax(double x, double y)
+{
+ __asm__ ("fmaxnm %d0, %d1, %d2" : "=w"(x) : "w"(x), "w"(y));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float fmaxf(float x, float y)
+{
+ __asm__ ("fmaxnm %s0, %s1, %s2" : "=w"(x) : "w"(x), "w"(y));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+double fmin(double x, double y)
+{
+ __asm__ ("fminnm %d0, %d1, %d2" : "=w"(x) : "w"(x), "w"(y));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float fminf(float x, float y)
+{
+ __asm__ ("fminnm %s0, %s1, %s2" : "=w"(x) : "w"(x), "w"(y));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+long long llrint(double x)
+{
+ long long n;
+ __asm__ (
+ "frintx %d1, %d1\n"
+ "fcvtzs %x0, %d1\n" : "=r"(n), "+w"(x));
+ return n;
+}
--- /dev/null
+#include <math.h>
+
+long long llrintf(float x)
+{
+ long long n;
+ __asm__ (
+ "frintx %s1, %s1\n"
+ "fcvtzs %x0, %s1\n" : "=r"(n), "+w"(x));
+ return n;
+}
--- /dev/null
+#include <math.h>
+
+long long llround(double x)
+{
+ long long n;
+ __asm__ ("fcvtas %x0, %d1" : "=r"(n) : "w"(x));
+ return n;
+}
--- /dev/null
+#include <math.h>
+
+long long llroundf(float x)
+{
+ long long n;
+ __asm__ ("fcvtas %x0, %s1" : "=r"(n) : "w"(x));
+ return n;
+}
--- /dev/null
+#include <math.h>
+
+long lrint(double x)
+{
+ long n;
+ __asm__ (
+ "frintx %d1, %d1\n"
+ "fcvtzs %x0, %d1\n" : "=r"(n), "+w"(x));
+ return n;
+}
--- /dev/null
+#include <math.h>
+
+long lrintf(float x)
+{
+ long n;
+ __asm__ (
+ "frintx %s1, %s1\n"
+ "fcvtzs %x0, %s1\n" : "=r"(n), "+w"(x));
+ return n;
+}
--- /dev/null
+#include <math.h>
+
+long lround(double x)
+{
+ long n;
+ __asm__ ("fcvtas %x0, %d1" : "=r"(n) : "w"(x));
+ return n;
+}
--- /dev/null
+#include <math.h>
+
+long lroundf(float x)
+{
+ long n;
+ __asm__ ("fcvtas %x0, %s1" : "=r"(n) : "w"(x));
+ return n;
+}
--- /dev/null
+#include <math.h>
+
+double nearbyint(double x)
+{
+ __asm__ ("frinti %d0, %d1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float nearbyintf(float x)
+{
+ __asm__ ("frinti %s0, %s1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+double rint(double x)
+{
+ __asm__ ("frintx %d0, %d1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float rintf(float x)
+{
+ __asm__ ("frintx %s0, %s1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+double round(double x)
+{
+ __asm__ ("frinta %d0, %d1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float roundf(float x)
+{
+ __asm__ ("frinta %s0, %s1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+double sqrt(double x)
+{
+ __asm__ ("fsqrt %d0, %d1" : "=w"(x) : "w"(x));
+ return x;
+}
+++ /dev/null
-.text
-.global sqrt
-.type sqrt,%function
-sqrt:
- fsqrt d0, d0
- ret
--- /dev/null
+#include <math.h>
+
+float sqrtf(float x)
+{
+ __asm__ ("fsqrt %s0, %s1" : "=w"(x) : "w"(x));
+ return x;
+}
+++ /dev/null
-.text
-.global sqrtf
-.type sqrtf,%function
-sqrtf:
- fsqrt s0, s0
- ret
--- /dev/null
+#include <math.h>
+
+double trunc(double x)
+{
+ __asm__ ("frintz %d0, %d1" : "=w"(x) : "w"(x));
+ return x;
+}
--- /dev/null
+#include <math.h>
+
+float truncf(float x)
+{
+ __asm__ ("frintz %s0, %s1" : "=w"(x) : "w"(x));
+ return x;
+}