Make FLT_ROUNDS correctly reflect the dynamic rounding mode.

11 files changed, 102 insertions, 9 deletions

diff --git a/lib/libc/amd64/gen/Makefile.inc b/lib/libc/amd64/gen/Makefile.inc
index 9f559e6..9cae7fa 100644
--- a/lib/libc/amd64/gen/Makefile.inc
+++ b/lib/libc/amd64/gen/Makefile.inc
@@ -4,5 +4,5 @@
 SRCS+=	_setjmp.S rfork_thread.S setjmp.S sigsetjmp.S \
 	fabs.S modf.S \
 	infinity.c ldexp.c makecontext.c signalcontext.c \
-	fpgetmask.c fpsetmask.c fpgetprec.c fpsetprec.c \
+	flt_rounds.c fpgetmask.c fpsetmask.c fpgetprec.c fpsetprec.c \
 	fpgetround.c fpsetround.c fpgetsticky.c fpsetsticky.c
diff --git a/lib/libc/amd64/gen/flt_rounds.c b/lib/libc/amd64/gen/flt_rounds.c
new file mode 100644
index 0000000..c0ce81f
--- /dev/null
+++ b/lib/libc/amd64/gen/flt_rounds.c
@@ -0,0 +1,26 @@
+/*
+ * Written by J.T. Conklin, Apr 10, 1995
+ * Public domain.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <float.h>
+
+static const int map[] = {
+	1,	/* round to nearest */
+	3,	/* round to zero */
+	2,	/* round to negative infinity */
+	0	/* round to positive infinity */
+};
+
+int
+__flt_rounds(void)
+{
+	int x;
+
+        /* Assume that the x87 and the SSE unit agree on the rounding mode. */
+	__asm("fnstcw %0" : "=m" (x));
+        return (map[(x >> 10) & 0x03]);
+}
diff --git a/lib/libc/i386/gen/Makefile.inc b/lib/libc/i386/gen/Makefile.inc
index fcfc9ec..7776387 100644
--- a/lib/libc/i386/gen/Makefile.inc
+++ b/lib/libc/i386/gen/Makefile.inc
@@ -2,5 +2,5 @@
 # $FreeBSD$
 
 SRCS+=	_ctx_start.S _setjmp.S alloca.S fabs.S \
-	infinity.c ldexp.c makecontext.c modf.S \
+	flt_rounds.c infinity.c ldexp.c makecontext.c modf.S \
 	rfork_thread.S setjmp.S signalcontext.c sigsetjmp.S
diff --git a/lib/libc/i386/gen/flt_rounds.c b/lib/libc/i386/gen/flt_rounds.c
new file mode 100644
index 0000000..16417ff
--- /dev/null
+++ b/lib/libc/i386/gen/flt_rounds.c
@@ -0,0 +1,25 @@
+/*
+ * Written by J.T. Conklin, Apr 10, 1995
+ * Public domain.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <float.h>
+
+static const int map[] = {
+	1,	/* round to nearest */
+	3,	/* round to zero */
+	2,	/* round to negative infinity */
+	0	/* round to positive infinity */
+};
+
+int
+__flt_rounds(void)
+{
+	int x;
+
+	__asm("fnstcw %0" : "=m" (x));
+        return (map[(x >> 10) & 0x03]);
+}
diff --git a/lib/libc/ia64/gen/Makefile.inc b/lib/libc/ia64/gen/Makefile.inc
index 30bb45e..f7dcd6a 100644
--- a/lib/libc/ia64/gen/Makefile.inc
+++ b/lib/libc/ia64/gen/Makefile.inc
@@ -2,7 +2,8 @@
 
 SRCS+=	__divdf3.S __divdi3.S __divsf3.S __divsi3.S __moddi3.S __modsi3.S \
 	__udivdi3.S __udivsi3.S __umoddi3.S __umodsi3.S _setjmp.S fabs.S \
-	fpgetmask.c fpgetround.c fpsetmask.c fpsetround.c infinity.c \
+	flt_rounds.c fpgetmask.c fpgetround.c fpsetmask.c \
+	fpsetround.c infinity.c \
 	ldexp.c makecontext.c modf.c setjmp.S signalcontext.c sigsetjmp.S
 
 # The following may go away if function _Unwind_FindTableEntry()
diff --git a/lib/libc/ia64/gen/flt_rounds.c b/lib/libc/ia64/gen/flt_rounds.c
new file mode 100644
index 0000000..d650965
--- /dev/null
+++ b/lib/libc/ia64/gen/flt_rounds.c
@@ -0,0 +1,25 @@
+/*
+ * Written by J.T. Conklin, Apr 10, 1995
+ * Public domain.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <float.h>
+
+static const int map[] = {
+	1,	/* round to nearest */
+	3,	/* round to zero */
+	2,	/* round to negative infinity */
+	0	/* round to positive infinity */
+};
+
+int
+__flt_rounds(void)
+{
+	int x;
+
+	__asm("mov %0=ar.fpsr" : "=r" (x));
+        return (map[(x >> 10) & 0x03]);
+}
diff --git a/sys/amd64/include/float.h b/sys/amd64/include/float.h
index 1608472..ea2df3c 100644
--- a/sys/amd64/include/float.h
+++ b/sys/amd64/include/float.h
@@ -35,8 +35,12 @@
 
 #include <sys/cdefs.h>
 
+__BEGIN_DECLS
+extern int __flt_rounds(void);
+__END_DECLS
+
 #define FLT_RADIX	2		/* b */
-#define FLT_ROUNDS	1		/* FP addition rounds to nearest */
+#define FLT_ROUNDS	__flt_rounds()
 #if __ISO_C_VISIBLE >= 1999
 #define	FLT_EVAL_METHOD	(-1)		/* i387 semantics are...interesting */
 #define	DECIMAL_DIG	21		/* max precision in decimal digits */
diff --git a/sys/arm/include/float.h b/sys/arm/include/float.h
index 2cbdcaf..21761ec 100644
--- a/sys/arm/include/float.h
+++ b/sys/arm/include/float.h
@@ -38,8 +38,8 @@
 #define _MACHINE_FLOAT_H_ 1
 
 #define FLT_RADIX	2		/* b */
-#define FLT_ROUNDS	1		/* FP addition rounds to nearest */
-#define	FLT_EVAL_METHOD	(-1)		/* i387 semantics are...interesting */
+#define FLT_ROUNDS	(-1)		/* indeterminate */
+#define	FLT_EVAL_METHOD	(-1)		/* XXX */
 #define	DECIMAL_DIG	21		/* max precision in decimal digits */
 
 #define FLT_MANT_DIG	24		/* p */
diff --git a/sys/i386/include/float.h b/sys/i386/include/float.h
index 1608472..ea2df3c 100644
--- a/sys/i386/include/float.h
+++ b/sys/i386/include/float.h
@@ -35,8 +35,12 @@
 
 #include <sys/cdefs.h>
 
+__BEGIN_DECLS
+extern int __flt_rounds(void);
+__END_DECLS
+
 #define FLT_RADIX	2		/* b */
-#define FLT_ROUNDS	1		/* FP addition rounds to nearest */
+#define FLT_ROUNDS	__flt_rounds()
 #if __ISO_C_VISIBLE >= 1999
 #define	FLT_EVAL_METHOD	(-1)		/* i387 semantics are...interesting */
 #define	DECIMAL_DIG	21		/* max precision in decimal digits */
diff --git a/sys/ia64/include/float.h b/sys/ia64/include/float.h
index ffd430b..21f1608 100644
--- a/sys/ia64/include/float.h
+++ b/sys/ia64/include/float.h
@@ -35,8 +35,12 @@
 
 #include <sys/cdefs.h>
 
+__BEGIN_DECLS
+extern int __flt_rounds(void);
+__END_DECLS
+
 #define FLT_RADIX	2		/* b */
-#define FLT_ROUNDS	1		/* FP addition rounds to nearest */
+#define FLT_ROUNDS	__flt_rounds()
 #if __ISO_C_VISIBLE >= 1999
 #define	FLT_EVAL_METHOD	0		/* no promotions */
 #define	DECIMAL_DIG	35		/* max precision in decimal digits */
diff --git a/sys/powerpc/include/float.h b/sys/powerpc/include/float.h
index 1d683f6..fff14f4 100644
--- a/sys/powerpc/include/float.h
+++ b/sys/powerpc/include/float.h
@@ -36,8 +36,12 @@
 
 #include <sys/cdefs.h>
 
+__BEGIN_DECLS
+extern int __flt_rounds(void);
+__END_DECLS
+
 #define FLT_RADIX	2		/* b */
-#define FLT_ROUNDS	1		/* FP addition rounds to nearest */
+#define FLT_ROUNDS	__flt_rounds()
 #if __ISO_C_VISIBLE >= 1999
 #define	FLT_EVAL_METHOD	1		/* operands promoted to double */
 #define	DECIMAL_DIG	35		/* max precision in decimal digits */