math: move x87-family fmod functions to C with inline asm

diff --git a/src/math/i386/fmod.c b/src/math/i386/fmod.c
new file mode 100644 (file)
index 0000000..ea0c58d
--- /dev/null
+++ b/src/math/i386/fmod.c
@@ -0,0 +1,10 @@
+#include <math.h>
+
+double fmod(double x, double y)
+{
+       unsigned short fpsr;
+       // fprem does not introduce excess precision into x
+       do __asm__ ("fprem; fnstsw %%ax" : "+t"(x), "=a"(fpsr) : "u"(y));
+       while (fpsr & 0x400);
+       return x;
+}

diff --git a/src/math/i386/fmod.s b/src/math/i386/fmod.s
deleted file mode 100644 (file)
index 2113b3c..0000000
--- a/src/math/i386/fmod.s
+++ /dev/null
@@ -1,11 +0,0 @@
-.global fmod
-.type fmod,@function
-fmod:
-       fldl 12(%esp)
-       fldl 4(%esp)
-1:     fprem
-       fnstsw %ax
-       sahf
-       jp 1b
-       fstp %st(1)
-       ret

diff --git a/src/math/i386/fmodf.c b/src/math/i386/fmodf.c
new file mode 100644 (file)
index 0000000..90b56ab
--- /dev/null
+++ b/src/math/i386/fmodf.c
@@ -0,0 +1,10 @@
+#include <math.h>
+
+float fmodf(float x, float y)
+{
+       unsigned short fpsr;
+       // fprem does not introduce excess precision into x
+       do __asm__ ("fprem; fnstsw %%ax" : "+t"(x), "=a"(fpsr) : "u"(y));
+       while (fpsr & 0x400);
+       return x;
+}

diff --git a/src/math/i386/fmodf.s b/src/math/i386/fmodf.s
deleted file mode 100644 (file)
index e04e2a5..0000000
--- a/src/math/i386/fmodf.s
+++ /dev/null
@@ -1,11 +0,0 @@
-.global fmodf
-.type fmodf,@function
-fmodf:
-       flds 8(%esp)
-       flds 4(%esp)
-1:     fprem
-       fnstsw %ax
-       sahf
-       jp 1b
-       fstp %st(1)
-       ret

diff --git a/src/math/i386/fmodl.c b/src/math/i386/fmodl.c
new file mode 100644 (file)
index 0000000..3daeab0
--- /dev/null
+++ b/src/math/i386/fmodl.c
@@ -0,0 +1,9 @@
+#include <math.h>
+
+long double fmodl(long double x, long double y)
+{
+       unsigned short fpsr;
+       do __asm__ ("fprem; fnstsw %%ax" : "+t"(x), "=a"(fpsr) : "u"(y));
+       while (fpsr & 0x400);
+       return x;
+}

diff --git a/src/math/i386/fmodl.s b/src/math/i386/fmodl.s
deleted file mode 100644 (file)
index 0cb3fe9..0000000
--- a/src/math/i386/fmodl.s
+++ /dev/null
@@ -1,11 +0,0 @@
-.global fmodl
-.type fmodl,@function
-fmodl:
-       fldt 16(%esp)
-       fldt 4(%esp)
-1:     fprem
-       fnstsw %ax
-       sahf
-       jp 1b
-       fstp %st(1)
-       ret

diff --git a/src/math/x86_64/fmodl.c b/src/math/x86_64/fmodl.c
new file mode 100644 (file)
index 0000000..3daeab0
--- /dev/null
+++ b/src/math/x86_64/fmodl.c
@@ -0,0 +1,9 @@
+#include <math.h>
+
+long double fmodl(long double x, long double y)
+{
+       unsigned short fpsr;
+       do __asm__ ("fprem; fnstsw %%ax" : "+t"(x), "=a"(fpsr) : "u"(y));
+       while (fpsr & 0x400);
+       return x;
+}

diff --git a/src/math/x86_64/fmodl.s b/src/math/x86_64/fmodl.s
deleted file mode 100644 (file)
index ea07b40..0000000
--- a/src/math/x86_64/fmodl.s
+++ /dev/null
@@ -1,11 +0,0 @@
-.global fmodl
-.type fmodl,@function
-fmodl:
-       fldt 24(%rsp)
-       fldt 8(%rsp)
-1:     fprem
-       fnstsw %ax
-       testb $4,%ah
-       jnz 1b
-       fstp %st(1)
-       ret