Clean up <machine/ieeefp.h> and make sure the rounding mode bits match the

hardware.  Implement fp[gs]etround(3) and fp[gs]etsticky(3) and tweak
the fp[gs]etmask(3) implementation to provide the right weak symbols.
This implementation deliberately ignores the additional
"round to nearest, away from zero" as this interface is derived from
i386-specific code and the i387 FPU doesn't implement such a rounding
mode.  This is a legacy API and code should use <fenv.h> instead.

ok drahn@

diff --git a/lib/libc/arch/riscv64/gen/fpgetmask.c b/lib/libc/arch/riscv64/gen/fpgetmask.c
index 6e94f99..4d8fac9 100644 (file)
--- a/lib/libc/arch/riscv64/gen/fpgetmask.c
+++ b/lib/libc/arch/riscv64/gen/fpgetmask.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: fpgetmask.c,v 1.1 2021/04/28 08:22:56 kettenis Exp $  */
+/*     $OpenBSD: fpgetmask.c,v 1.2 2021/04/29 17:19:18 kettenis Exp $  */
 /*
  * Copyright (c) 2018 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -17,10 +17,9 @@
 
 #include <ieeefp.h>
 
-__weak_alias(_fpgetmask,fpgetmask);
-
 fp_except
 fpgetmask(void)
 {
        return 0;
 }
+DEF_WEAK(fpgetmask);

diff --git a/lib/libc/arch/riscv64/gen/fpgetround.c b/lib/libc/arch/riscv64/gen/fpgetround.c
new file mode 100644 (file)
index 0000000..6d2351f
--- /dev/null
+++ b/lib/libc/arch/riscv64/gen/fpgetround.c
@@ -0,0 +1,29 @@
+/*     $OpenBSD: fpgetround.c,v 1.1 2021/04/29 17:19:18 kettenis Exp $ */
+/*
+ * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <ieeefp.h>
+
+fp_rnd
+fpgetround(void)
+{
+       uint32_t frm;
+
+       __asm volatile ("frrm %0" : "=r"(frm));
+       return frm & 0x3;
+}
+DEF_WEAK(fpgetround);

diff --git a/lib/libc/arch/riscv64/gen/fpgetsticky.c b/lib/libc/arch/riscv64/gen/fpgetsticky.c
new file mode 100644 (file)
index 0000000..81a14b0
--- /dev/null
+++ b/lib/libc/arch/riscv64/gen/fpgetsticky.c
@@ -0,0 +1,29 @@
+/*     $OpenBSD: fpgetsticky.c,v 1.1 2021/04/29 17:19:18 kettenis Exp $        */
+/*
+ * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <ieeefp.h>
+
+fp_except
+fpgetsticky(void)
+{
+       uint32_t fflags;
+
+       __asm volatile ("frflags %0" : "=r"(fflags));
+       return fflags;
+}
+DEF_WEAK(fpgetsticky);

diff --git a/lib/libc/arch/riscv64/gen/fpsetmask.c b/lib/libc/arch/riscv64/gen/fpsetmask.c
index 03485db..d4b1edd 100644 (file)
--- a/lib/libc/arch/riscv64/gen/fpsetmask.c
+++ b/lib/libc/arch/riscv64/gen/fpsetmask.c
@@ -1,4 +1,4 @@
-/*     $OpenBSD: fpsetmask.c,v 1.1 2021/04/28 08:22:56 kettenis Exp $  */
+/*     $OpenBSD: fpsetmask.c,v 1.2 2021/04/29 17:19:18 kettenis Exp $  */
 /*
  * Copyright (c) 2018 Mark Kettenis <kettenis@openbsd.org>
  *
@@ -17,10 +17,9 @@
 
 #include <ieeefp.h>
 
-__weak_alias(_fpsetmask,fpsetmask);
-
 fp_except
 fpsetmask(fp_except mask)
 {
        return 0;
 }
+DEF_WEAK(fpsetmask);

diff --git a/lib/libc/arch/riscv64/gen/fpsetround.c b/lib/libc/arch/riscv64/gen/fpsetround.c
new file mode 100644 (file)
index 0000000..e9e26b3
--- /dev/null
+++ b/lib/libc/arch/riscv64/gen/fpsetround.c
@@ -0,0 +1,31 @@
+/*     $OpenBSD: fpsetround.c,v 1.1 2021/04/29 17:19:18 kettenis Exp $ */
+/*
+ * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <ieeefp.h>
+
+fp_rnd
+fpsetround(fp_rnd rnd_dir)
+{
+       uint32_t frm;
+
+       __asm volatile ("fsrm %0, %1" : "=r"(frm) : "r"(rnd_dir));
+
+       /* Truncating to 2 bits means both RNE and RMM become FP_RN. */
+       return frm & 0x3;
+}
+DEF_WEAK(fpsetround);

diff --git a/lib/libc/arch/riscv64/gen/fpsetsticky.c b/lib/libc/arch/riscv64/gen/fpsetsticky.c
new file mode 100644 (file)
index 0000000..a7069c3
--- /dev/null
+++ b/lib/libc/arch/riscv64/gen/fpsetsticky.c
@@ -0,0 +1,29 @@
+/*     $OpenBSD: fpsetsticky.c,v 1.1 2021/04/29 17:19:18 kettenis Exp $        */
+/*
+ * Copyright (c) 2021 Mark Kettenis <kettenis@openbsd.org>
+ *
+ * Permission to use, copy, modify, and distribute this software for any
+ * purpose with or without fee is hereby granted, provided that the above
+ * copyright notice and this permission notice appear in all copies.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
+ * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
+ * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
+ * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
+ * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
+ * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
+ * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
+ */
+
+#include <sys/types.h>
+#include <ieeefp.h>
+
+fp_except
+fpsetsticky(fp_except sticky)
+{
+       uint32_t fflags;
+
+       __asm volatile ("fsflags %0, %1" : "=r"(fflags) : "r"(sticky));
+       return fflags;
+}
+DEF_WEAK(fpsetsticky);

diff --git a/sys/arch/riscv64/include/ieeefp.h b/sys/arch/riscv64/include/ieeefp.h
index 3cd1684..f64ce9d 100644 (file)
--- a/sys/arch/riscv64/include/ieeefp.h
+++ b/sys/arch/riscv64/include/ieeefp.h
@@ -1,5 +1,4 @@
-/*     $OpenBSD: ieeefp.h,v 1.1 2021/04/23 02:42:16 drahn Exp $        */
-/*     $NetBSD: ieeefp.h,v 1.1 2001/01/10 19:02:06 bjh21 Exp $ */
+/*     $OpenBSD: ieeefp.h,v 1.2 2021/04/29 17:19:18 kettenis Exp $     */
 
 /*
  * Based on ieeefp.h written by J.T. Conklin, Apr 28, 1995
@@ -9,34 +8,18 @@
 #ifndef _MACHINE_IEEEFP_H_
 #define _MACHINE_IEEEFP_H_
 
-/* FP exception codes */
-
-#define FP_EXCEPT_INV  0
-#define FP_EXCEPT_DZ   1
-#define FP_EXCEPT_OFL  2
-#define FP_EXCEPT_UFL  3
-#define FP_EXCEPT_IMP  4
-
-/* Exception type (used by fpsetmask() et al.) */
-
 typedef int fp_except;
-
-/* Bit defines for fp_except */
-
-#define        FP_X_INV        (1 << FP_EXCEPT_INV)    /* invalid operation exception */
-#define        FP_X_DZ         (1 << FP_EXCEPT_DZ)     /* divide-by-zero exception */
-#define        FP_X_OFL        (1 << FP_EXCEPT_OFL)    /* overflow exception */
-#define        FP_X_UFL        (1 << FP_EXCEPT_UFL)    /* underflow exception */
-#define        FP_X_IMP        (1 << FP_EXCEPT_IMP)    /* imprecise (loss of precision; "inexact") */
-#define FP_X_MASK      0x1f
-
-/* Rounding modes */
+#define FP_X_INV       0x10    /* invalid operation exception */
+#define FP_X_DZ                0x08    /* divide-by-zero exception */
+#define FP_X_OFL       0x04    /* overflow exception */
+#define FP_X_UFL       0x02    /* underflow exception */
+#define FP_X_IMP       0x01    /* imprecise (loss of precision) */
 
 typedef enum {
     FP_RN=0,                   /* round to nearest representable number */
-    FP_RP=1,                   /* round toward positive infinity */
+    FP_RZ=1                    /* round to zero (truncate) */
     FP_RM=2,                   /* round toward negative infinity */
-    FP_RZ=3                    /* round to zero (truncate) */
+    FP_RP=3,                   /* round toward positive infinity */
 } fp_rnd;
 
 #endif /* _MACHINE_IEEEFP_H_ */