sh: Support denormalization on SH-4 FPU.
authorStuart Menefy <stuart.menefy@st.com>
Fri, 30 Nov 2007 09:42:27 +0000 (18:42 +0900)
committerPaul Mundt <lethal@linux-sh.org>
Mon, 28 Jan 2008 04:18:59 +0000 (13:18 +0900)
Signed-off-by: Stuart Menefy <stuart.menefy@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
arch/sh/kernel/cpu/sh4/Makefile
arch/sh/kernel/cpu/sh4/fpu.c
arch/sh/kernel/cpu/sh4/softfloat.c [new file with mode: 0644]
include/asm-sh/cpu-sh4/fpu.h [new file with mode: 0644]

index dadd6bffc128436fe50050c6296b35e15d7c81f2..d608557c7a3f7246dee6797d2c1836230a29a8ff 100644 (file)
@@ -5,7 +5,7 @@
 obj-y  := probe.o common.o
 common-y       += $(addprefix ../sh3/, entry.o ex.o)
 
-obj-$(CONFIG_SH_FPU)                   += fpu.o
+obj-$(CONFIG_SH_FPU)                   += fpu.o softfloat.o
 obj-$(CONFIG_SH_STORE_QUEUES)          += sq.o
 
 # CPU subtype setup
index e624180b44678dac405ef728951491322080bf00..817f9939cda69242bd88032ffb6e18dd8262d2eb 100644 (file)
@@ -1,7 +1,4 @@
-/* $Id: fpu.c,v 1.4 2004/01/13 05:52:11 kkojima Exp $
- *
- * linux/arch/sh/kernel/fpu.c
- *
+/*
  * Save/restore floating point context for signal handlers.
  *
  * This file is subject to the terms and conditions of the GNU General Public
@@ -9,15 +6,16 @@
  * for more details.
  *
  * Copyright (C) 1999, 2000  Kaz Kojima & Niibe Yutaka
+ * Copyright (C) 2006  ST Microelectronics Ltd. (denorm support)
  *
- * FIXME! These routines can be optimized in big endian case.
+ * FIXME! These routines have not been tested for big endian case.
  */
-
 #include <linux/sched.h>
 #include <linux/signal.h>
+#include <linux/io.h>
+#include <asm/cpu/fpu.h>
 #include <asm/processor.h>
 #include <asm/system.h>
-#include <asm/io.h>
 
 /* The PR (precision) bit in the FP Status Register must be clear when
  * an frchg instruction is executed, otherwise the instruction is undefined.
  */
 
 #define FPSCR_RCHG 0x00000000
+extern unsigned long long float64_div(unsigned long long a,
+                                     unsigned long long b);
+extern unsigned long int float32_div(unsigned long int a, unsigned long int b);
+extern unsigned long long float64_mul(unsigned long long a,
+                                     unsigned long long b);
+extern unsigned long int float32_mul(unsigned long int a, unsigned long int b);
+extern unsigned long long float64_add(unsigned long long a,
+                                     unsigned long long b);
+extern unsigned long int float32_add(unsigned long int a, unsigned long int b);
+extern unsigned long long float64_sub(unsigned long long a,
+                                     unsigned long long b);
+extern unsigned long int float32_sub(unsigned long int a, unsigned long int b);
 
+static unsigned int fpu_exception_flags;
 
 /*
  * Save FPU registers onto task structure.
  * Assume called with FPU enabled (SR.FD=0).
  */
-void
-save_fpu(struct task_struct *tsk, struct pt_regs *regs)
+void save_fpu(struct task_struct *tsk, struct pt_regs *regs)
 {
        unsigned long dummy;
 
        clear_tsk_thread_flag(tsk, TIF_USEDFPU);
        enable_fpu();
-       asm volatile("sts.l     fpul, @-%0\n\t"
-                    "sts.l     fpscr, @-%0\n\t"
-                    "lds       %2, fpscr\n\t"
-                    "frchg\n\t"
-                    "fmov.s    fr15, @-%0\n\t"
-                    "fmov.s    fr14, @-%0\n\t"
-                    "fmov.s    fr13, @-%0\n\t"
-                    "fmov.s    fr12, @-%0\n\t"
-                    "fmov.s    fr11, @-%0\n\t"
-                    "fmov.s    fr10, @-%0\n\t"
-                    "fmov.s    fr9, @-%0\n\t"
-                    "fmov.s    fr8, @-%0\n\t"
-                    "fmov.s    fr7, @-%0\n\t"
-                    "fmov.s    fr6, @-%0\n\t"
-                    "fmov.s    fr5, @-%0\n\t"
-                    "fmov.s    fr4, @-%0\n\t"
-                    "fmov.s    fr3, @-%0\n\t"
-                    "fmov.s    fr2, @-%0\n\t"
-                    "fmov.s    fr1, @-%0\n\t"
-                    "fmov.s    fr0, @-%0\n\t"
-                    "frchg\n\t"
-                    "fmov.s    fr15, @-%0\n\t"
-                    "fmov.s    fr14, @-%0\n\t"
-                    "fmov.s    fr13, @-%0\n\t"
-                    "fmov.s    fr12, @-%0\n\t"
-                    "fmov.s    fr11, @-%0\n\t"
-                    "fmov.s    fr10, @-%0\n\t"
-                    "fmov.s    fr9, @-%0\n\t"
-                    "fmov.s    fr8, @-%0\n\t"
-                    "fmov.s    fr7, @-%0\n\t"
-                    "fmov.s    fr6, @-%0\n\t"
-                    "fmov.s    fr5, @-%0\n\t"
-                    "fmov.s    fr4, @-%0\n\t"
-                    "fmov.s    fr3, @-%0\n\t"
-                    "fmov.s    fr2, @-%0\n\t"
-                    "fmov.s    fr1, @-%0\n\t"
-                    "fmov.s    fr0, @-%0\n\t"
-                    "lds       %3, fpscr\n\t"
-                    : "=r" (dummy)
-                    : "0" ((char *)(&tsk->thread.fpu.hard.status)),
-                      "r" (FPSCR_RCHG),
-                      "r" (FPSCR_INIT)
-                    : "memory");
+       asm volatile ("sts.l    fpul, @-%0\n\t"
+                     "sts.l    fpscr, @-%0\n\t"
+                     "lds      %2, fpscr\n\t"
+                     "frchg\n\t"
+                     "fmov.s   fr15, @-%0\n\t"
+                     "fmov.s   fr14, @-%0\n\t"
+                     "fmov.s   fr13, @-%0\n\t"
+                     "fmov.s   fr12, @-%0\n\t"
+                     "fmov.s   fr11, @-%0\n\t"
+                     "fmov.s   fr10, @-%0\n\t"
+                     "fmov.s   fr9, @-%0\n\t"
+                     "fmov.s   fr8, @-%0\n\t"
+                     "fmov.s   fr7, @-%0\n\t"
+                     "fmov.s   fr6, @-%0\n\t"
+                     "fmov.s   fr5, @-%0\n\t"
+                     "fmov.s   fr4, @-%0\n\t"
+                     "fmov.s   fr3, @-%0\n\t"
+                     "fmov.s   fr2, @-%0\n\t"
+                     "fmov.s   fr1, @-%0\n\t"
+                     "fmov.s   fr0, @-%0\n\t"
+                     "frchg\n\t"
+                     "fmov.s   fr15, @-%0\n\t"
+                     "fmov.s   fr14, @-%0\n\t"
+                     "fmov.s   fr13, @-%0\n\t"
+                     "fmov.s   fr12, @-%0\n\t"
+                     "fmov.s   fr11, @-%0\n\t"
+                     "fmov.s   fr10, @-%0\n\t"
+                     "fmov.s   fr9, @-%0\n\t"
+                     "fmov.s   fr8, @-%0\n\t"
+                     "fmov.s   fr7, @-%0\n\t"
+                     "fmov.s   fr6, @-%0\n\t"
+                     "fmov.s   fr5, @-%0\n\t"
+                     "fmov.s   fr4, @-%0\n\t"
+                     "fmov.s   fr3, @-%0\n\t"
+                     "fmov.s   fr2, @-%0\n\t"
+                     "fmov.s   fr1, @-%0\n\t"
+                     "fmov.s   fr0, @-%0\n\t"
+                     "lds      %3, fpscr\n\t":"=r" (dummy)
+                     :"0"((char *)(&tsk->thread.fpu.hard.status)),
+                     "r"(FPSCR_RCHG), "r"(FPSCR_INIT)
+                     :"memory");
 
        disable_fpu();
        release_fpu(regs);
 }
 
-static void
-restore_fpu(struct task_struct *tsk)
+static void restore_fpu(struct task_struct *tsk)
 {
        unsigned long dummy;
 
        enable_fpu();
-       asm volatile("lds       %2, fpscr\n\t"
-                    "fmov.s    @%0+, fr0\n\t"
-                    "fmov.s    @%0+, fr1\n\t"
-                    "fmov.s    @%0+, fr2\n\t"
-                    "fmov.s    @%0+, fr3\n\t"
-                    "fmov.s    @%0+, fr4\n\t"
-                    "fmov.s    @%0+, fr5\n\t"
-                    "fmov.s    @%0+, fr6\n\t"
-                    "fmov.s    @%0+, fr7\n\t"
-                    "fmov.s    @%0+, fr8\n\t"
-                    "fmov.s    @%0+, fr9\n\t"
-                    "fmov.s    @%0+, fr10\n\t"
-                    "fmov.s    @%0+, fr11\n\t"
-                    "fmov.s    @%0+, fr12\n\t"
-                    "fmov.s    @%0+, fr13\n\t"
-                    "fmov.s    @%0+, fr14\n\t"
-                    "fmov.s    @%0+, fr15\n\t"
-                    "frchg\n\t"
-                    "fmov.s    @%0+, fr0\n\t"
-                    "fmov.s    @%0+, fr1\n\t"
-                    "fmov.s    @%0+, fr2\n\t"
-                    "fmov.s    @%0+, fr3\n\t"
-                    "fmov.s    @%0+, fr4\n\t"
-                    "fmov.s    @%0+, fr5\n\t"
-                    "fmov.s    @%0+, fr6\n\t"
-                    "fmov.s    @%0+, fr7\n\t"
-                    "fmov.s    @%0+, fr8\n\t"
-                    "fmov.s    @%0+, fr9\n\t"
-                    "fmov.s    @%0+, fr10\n\t"
-                    "fmov.s    @%0+, fr11\n\t"
-                    "fmov.s    @%0+, fr12\n\t"
-                    "fmov.s    @%0+, fr13\n\t"
-                    "fmov.s    @%0+, fr14\n\t"
-                    "fmov.s    @%0+, fr15\n\t"
-                    "frchg\n\t"
-                    "lds.l     @%0+, fpscr\n\t"
-                    "lds.l     @%0+, fpul\n\t"
-                    "=r" (dummy)
-                    : "0" (&tsk->thread.fpu), "r" (FPSCR_RCHG)
-                    "memory");
+       asm volatile ("lds      %2, fpscr\n\t"
+                     "fmov.s   @%0+, fr0\n\t"
+                     "fmov.s   @%0+, fr1\n\t"
+                     "fmov.s   @%0+, fr2\n\t"
+                     "fmov.s   @%0+, fr3\n\t"
+                     "fmov.s   @%0+, fr4\n\t"
+                     "fmov.s   @%0+, fr5\n\t"
+                     "fmov.s   @%0+, fr6\n\t"
+                     "fmov.s   @%0+, fr7\n\t"
+                     "fmov.s   @%0+, fr8\n\t"
+                     "fmov.s   @%0+, fr9\n\t"
+                     "fmov.s   @%0+, fr10\n\t"
+                     "fmov.s   @%0+, fr11\n\t"
+                     "fmov.s   @%0+, fr12\n\t"
+                     "fmov.s   @%0+, fr13\n\t"
+                     "fmov.s   @%0+, fr14\n\t"
+                     "fmov.s   @%0+, fr15\n\t"
+                     "frchg\n\t"
+                     "fmov.s   @%0+, fr0\n\t"
+                     "fmov.s   @%0+, fr1\n\t"
+                     "fmov.s   @%0+, fr2\n\t"
+                     "fmov.s   @%0+, fr3\n\t"
+                     "fmov.s   @%0+, fr4\n\t"
+                     "fmov.s   @%0+, fr5\n\t"
+                     "fmov.s   @%0+, fr6\n\t"
+                     "fmov.s   @%0+, fr7\n\t"
+                     "fmov.s   @%0+, fr8\n\t"
+                     "fmov.s   @%0+, fr9\n\t"
+                     "fmov.s   @%0+, fr10\n\t"
+                     "fmov.s   @%0+, fr11\n\t"
+                     "fmov.s   @%0+, fr12\n\t"
+                     "fmov.s   @%0+, fr13\n\t"
+                     "fmov.s   @%0+, fr14\n\t"
+                     "fmov.s   @%0+, fr15\n\t"
+                     "frchg\n\t"
+                     "lds.l    @%0+, fpscr\n\t"
+                     "lds.l    @%0+, fpul\n\t"
+                     :"=r" (dummy)
+                     :"0"(&tsk->thread.fpu), "r"(FPSCR_RCHG)
+                     :"memory");
        disable_fpu();
 }
 
@@ -141,61 +148,59 @@ restore_fpu(struct task_struct *tsk)
  * double precision represents signaling NANS.
  */
 
-static void
-fpu_init(void)
+static void fpu_init(void)
 {
        enable_fpu();
-       asm volatile("lds       %0, fpul\n\t"
-                    "lds       %1, fpscr\n\t"
-                    "fsts      fpul, fr0\n\t"
-                    "fsts      fpul, fr1\n\t"
-                    "fsts      fpul, fr2\n\t"
-                    "fsts      fpul, fr3\n\t"
-                    "fsts      fpul, fr4\n\t"
-                    "fsts      fpul, fr5\n\t"
-                    "fsts      fpul, fr6\n\t"
-                    "fsts      fpul, fr7\n\t"
-                    "fsts      fpul, fr8\n\t"
-                    "fsts      fpul, fr9\n\t"
-                    "fsts      fpul, fr10\n\t"
-                    "fsts      fpul, fr11\n\t"
-                    "fsts      fpul, fr12\n\t"
-                    "fsts      fpul, fr13\n\t"
-                    "fsts      fpul, fr14\n\t"
-                    "fsts      fpul, fr15\n\t"
-                    "frchg\n\t"
-                    "fsts      fpul, fr0\n\t"
-                    "fsts      fpul, fr1\n\t"
-                    "fsts      fpul, fr2\n\t"
-                    "fsts      fpul, fr3\n\t"
-                    "fsts      fpul, fr4\n\t"
-                    "fsts      fpul, fr5\n\t"
-                    "fsts      fpul, fr6\n\t"
-                    "fsts      fpul, fr7\n\t"
-                    "fsts      fpul, fr8\n\t"
-                    "fsts      fpul, fr9\n\t"
-                    "fsts      fpul, fr10\n\t"
-                    "fsts      fpul, fr11\n\t"
-                    "fsts      fpul, fr12\n\t"
-                    "fsts      fpul, fr13\n\t"
-                    "fsts      fpul, fr14\n\t"
-                    "fsts      fpul, fr15\n\t"
-                    "frchg\n\t"
-                    "lds       %2, fpscr\n\t"
-                    : /* no output */
-                    : "r" (0), "r" (FPSCR_RCHG), "r" (FPSCR_INIT));
+       asm volatile (  "lds    %0, fpul\n\t"
+                       "lds    %1, fpscr\n\t"
+                       "fsts   fpul, fr0\n\t"
+                       "fsts   fpul, fr1\n\t"
+                       "fsts   fpul, fr2\n\t"
+                       "fsts   fpul, fr3\n\t"
+                       "fsts   fpul, fr4\n\t"
+                       "fsts   fpul, fr5\n\t"
+                       "fsts   fpul, fr6\n\t"
+                       "fsts   fpul, fr7\n\t"
+                       "fsts   fpul, fr8\n\t"
+                       "fsts   fpul, fr9\n\t"
+                       "fsts   fpul, fr10\n\t"
+                       "fsts   fpul, fr11\n\t"
+                       "fsts   fpul, fr12\n\t"
+                       "fsts   fpul, fr13\n\t"
+                       "fsts   fpul, fr14\n\t"
+                       "fsts   fpul, fr15\n\t"
+                       "frchg\n\t"
+                       "fsts   fpul, fr0\n\t"
+                       "fsts   fpul, fr1\n\t"
+                       "fsts   fpul, fr2\n\t"
+                       "fsts   fpul, fr3\n\t"
+                       "fsts   fpul, fr4\n\t"
+                       "fsts   fpul, fr5\n\t"
+                       "fsts   fpul, fr6\n\t"
+                       "fsts   fpul, fr7\n\t"
+                       "fsts   fpul, fr8\n\t"
+                       "fsts   fpul, fr9\n\t"
+                       "fsts   fpul, fr10\n\t"
+                       "fsts   fpul, fr11\n\t"
+                       "fsts   fpul, fr12\n\t"
+                       "fsts   fpul, fr13\n\t"
+                       "fsts   fpul, fr14\n\t"
+                       "fsts   fpul, fr15\n\t"
+                       "frchg\n\t"
+                       "lds    %2, fpscr\n\t"
+                       :       /* no output */
+                       :"r" (0), "r"(FPSCR_RCHG), "r"(FPSCR_INIT));
        disable_fpu();
 }
 
 /**
- *     denormal_to_double - Given denormalized float number,
- *                          store double float
+ *      denormal_to_double - Given denormalized float number,
+ *                           store double float
  *
- *     @fpu: Pointer to sh_fpu_hard structure
- *     @n: Index to FP register
+ *      @fpu: Pointer to sh_fpu_hard structure
+ *      @n: Index to FP register
  */
-static void
-denormal_to_double (struct sh_fpu_hard_struct *fpu, int n)
+static void denormal_to_double(struct sh_fpu_hard_struct *fpu, int n)
 {
        unsigned long du, dl;
        unsigned long x = fpu->fpul;
@@ -212,7 +217,7 @@ denormal_to_double (struct sh_fpu_hard_struct *fpu, int n)
                dl = x << 29;
 
                fpu->fp_regs[n] = du;
-               fpu->fp_regs[n+1] = dl;
+               fpu->fp_regs[n + 1] = dl;
        }
 }
 
@@ -223,67 +228,191 @@ denormal_to_double (struct sh_fpu_hard_struct *fpu, int n)
  *
  *     Returns 1 when it's handled (should not cause exception).
  */
-static int
-ieee_fpe_handler (struct pt_regs *regs)
+static int ieee_fpe_handler(struct pt_regs *regs)
 {
-       unsigned short insn = *(unsigned short *) regs->pc;
+       unsigned short insn = *(unsigned short *)regs->pc;
        unsigned short finsn;
        unsigned long nextpc;
        int nib[4] = {
                (insn >> 12) & 0xf,
                (insn >> 8) & 0xf,
                (insn >> 4) & 0xf,
-               insn & 0xf};
-
-       if (nib[0] == 0xb ||
-           (nib[0] == 0x4 && nib[2] == 0x0 && nib[3] == 0xb)) /* bsr & jsr */
-               regs->pr = regs->pc + 4;
-       if (nib[0] == 0xa || nib[0] == 0xb) { /* bra & bsr */
-               nextpc = regs->pc + 4 + ((short) ((insn & 0xfff) << 4) >> 3);
-               finsn = *(unsigned short *) (regs->pc + 2);
-       } else if (nib[0] == 0x8 && nib[1] == 0xd) { /* bt/s */
+               insn & 0xf
+       };
+
+       if (nib[0] == 0xb || (nib[0] == 0x4 && nib[2] == 0x0 && nib[3] == 0xb))
+               regs->pr = regs->pc + 4;  /* bsr & jsr */
+
+       if (nib[0] == 0xa || nib[0] == 0xb) {
+               /* bra & bsr */
+               nextpc = regs->pc + 4 + ((short)((insn & 0xfff) << 4) >> 3);
+               finsn = *(unsigned short *)(regs->pc + 2);
+       } else if (nib[0] == 0x8 && nib[1] == 0xd) {
+               /* bt/s */
                if (regs->sr & 1)
-                       nextpc = regs->pc + 4 + ((char) (insn & 0xff) << 1);
+                       nextpc = regs->pc + 4 + ((char)(insn & 0xff) << 1);
                else
                        nextpc = regs->pc + 4;
-               finsn = *(unsigned short *) (regs->pc + 2);
-       } else if (nib[0] == 0x8 && nib[1] == 0xf) { /* bf/s */
+               finsn = *(unsigned short *)(regs->pc + 2);
+       } else if (nib[0] == 0x8 && nib[1] == 0xf) {
+               /* bf/s */
                if (regs->sr & 1)
                        nextpc = regs->pc + 4;
                else
-                       nextpc = regs->pc + 4 + ((char) (insn & 0xff) << 1);
-               finsn = *(unsigned short *) (regs->pc + 2);
+                       nextpc = regs->pc + 4 + ((char)(insn & 0xff) << 1);
+               finsn = *(unsigned short *)(regs->pc + 2);
        } else if (nib[0] == 0x4 && nib[3] == 0xb &&
-                (nib[2] == 0x0 || nib[2] == 0x2)) { /* jmp & jsr */
+                  (nib[2] == 0x0 || nib[2] == 0x2)) {
+               /* jmp & jsr */
                nextpc = regs->regs[nib[1]];
-               finsn = *(unsigned short *) (regs->pc + 2);
+               finsn = *(unsigned short *)(regs->pc + 2);
        } else if (nib[0] == 0x0 && nib[3] == 0x3 &&
-                (nib[2] == 0x0 || nib[2] == 0x2)) { /* braf & bsrf */
+                  (nib[2] == 0x0 || nib[2] == 0x2)) {
+               /* braf & bsrf */
                nextpc = regs->pc + 4 + regs->regs[nib[1]];
-               finsn = *(unsigned short *) (regs->pc + 2);
-       } else if (insn == 0x000b) { /* rts */
+               finsn = *(unsigned short *)(regs->pc + 2);
+       } else if (insn == 0x000b) {
+               /* rts */
                nextpc = regs->pr;
-               finsn = *(unsigned short *) (regs->pc + 2);
+               finsn = *(unsigned short *)(regs->pc + 2);
        } else {
                nextpc = regs->pc + instruction_size(insn);
                finsn = insn;
        }
 
-       if ((finsn & 0xf1ff) == 0xf0ad) { /* fcnvsd */
+       if ((finsn & 0xf1ff) == 0xf0ad) {
+               /* fcnvsd */
                struct task_struct *tsk = current;
 
                save_fpu(tsk, regs);
-               if ((tsk->thread.fpu.hard.fpscr & (1 << 17))) {
+               if ((tsk->thread.fpu.hard.fpscr & FPSCR_CAUSE_ERROR))
                        /* FPU error */
-                       denormal_to_double (&tsk->thread.fpu.hard,
-                                           (finsn >> 8) & 0xf);
-                       tsk->thread.fpu.hard.fpscr &=
-                               ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
-                       grab_fpu(regs);
-                       restore_fpu(tsk);
-                       set_tsk_thread_flag(tsk, TIF_USEDFPU);
+                       denormal_to_double(&tsk->thread.fpu.hard,
+                                          (finsn >> 8) & 0xf);
+               else
+                       return 0;
+
+               regs->pc = nextpc;
+               return 1;
+       } else if ((finsn & 0xf00f) == 0xf002) {
+               /* fmul */
+               struct task_struct *tsk = current;
+               int fpscr;
+               int n, m, prec;
+               unsigned int hx, hy;
+
+               n = (finsn >> 8) & 0xf;
+               m = (finsn >> 4) & 0xf;
+               hx = tsk->thread.fpu.hard.fp_regs[n];
+               hy = tsk->thread.fpu.hard.fp_regs[m];
+               fpscr = tsk->thread.fpu.hard.fpscr;
+               prec = fpscr & FPSCR_DBL_PRECISION;
+
+               if ((fpscr & FPSCR_CAUSE_ERROR)
+                   && (prec && ((hx & 0x7fffffff) < 0x00100000
+                                || (hy & 0x7fffffff) < 0x00100000))) {
+                       long long llx, lly;
+
+                       /* FPU error because of denormal (doubles) */
+                       llx = ((long long)hx << 32)
+                           | tsk->thread.fpu.hard.fp_regs[n + 1];
+                       lly = ((long long)hy << 32)
+                           | tsk->thread.fpu.hard.fp_regs[m + 1];
+                       llx = float64_mul(llx, lly);
+                       tsk->thread.fpu.hard.fp_regs[n] = llx >> 32;
+                       tsk->thread.fpu.hard.fp_regs[n + 1] = llx & 0xffffffff;
+               } else if ((fpscr & FPSCR_CAUSE_ERROR)
+                          && (!prec && ((hx & 0x7fffffff) < 0x00800000
+                                        || (hy & 0x7fffffff) < 0x00800000))) {
+                       /* FPU error because of denormal (floats) */
+                       hx = float32_mul(hx, hy);
+                       tsk->thread.fpu.hard.fp_regs[n] = hx;
+               } else
+                       return 0;
+
+               regs->pc = nextpc;
+               return 1;
+       } else if ((finsn & 0xf00e) == 0xf000) {
+               /* fadd, fsub */
+               struct task_struct *tsk = current;
+               int fpscr;
+               int n, m, prec;
+               unsigned int hx, hy;
+
+               n = (finsn >> 8) & 0xf;
+               m = (finsn >> 4) & 0xf;
+               hx = tsk->thread.fpu.hard.fp_regs[n];
+               hy = tsk->thread.fpu.hard.fp_regs[m];
+               fpscr = tsk->thread.fpu.hard.fpscr;
+               prec = fpscr & FPSCR_DBL_PRECISION;
+
+               if ((fpscr & FPSCR_CAUSE_ERROR)
+                   && (prec && ((hx & 0x7fffffff) < 0x00100000
+                                || (hy & 0x7fffffff) < 0x00100000))) {
+                       long long llx, lly;
+
+                       /* FPU error because of denormal (doubles) */
+                       llx = ((long long)hx << 32)
+                           | tsk->thread.fpu.hard.fp_regs[n + 1];
+                       lly = ((long long)hy << 32)
+                           | tsk->thread.fpu.hard.fp_regs[m + 1];
+                       if ((finsn & 0xf00f) == 0xf000)
+                               llx = float64_add(llx, lly);
+                       else
+                               llx = float64_sub(llx, lly);
+                       tsk->thread.fpu.hard.fp_regs[n] = llx >> 32;
+                       tsk->thread.fpu.hard.fp_regs[n + 1] = llx & 0xffffffff;
+               } else if ((fpscr & FPSCR_CAUSE_ERROR)
+                          && (!prec && ((hx & 0x7fffffff) < 0x00800000
+                                        || (hy & 0x7fffffff) < 0x00800000))) {
+                       /* FPU error because of denormal (floats) */
+                       if ((finsn & 0xf00f) == 0xf000)
+                               hx = float32_add(hx, hy);
+                       else
+                               hx = float32_sub(hx, hy);
+                       tsk->thread.fpu.hard.fp_regs[n] = hx;
+               } else
+                       return 0;
+
+               regs->pc = nextpc;
+               return 1;
+       } else if ((finsn & 0xf003) == 0xf003) {
+               /* fdiv */
+               struct task_struct *tsk = current;
+               int fpscr;
+               int n, m, prec;
+               unsigned int hx, hy;
+
+               n = (finsn >> 8) & 0xf;
+               m = (finsn >> 4) & 0xf;
+               hx = tsk->thread.fpu.hard.fp_regs[n];
+               hy = tsk->thread.fpu.hard.fp_regs[m];
+               fpscr = tsk->thread.fpu.hard.fpscr;
+               prec = fpscr & FPSCR_DBL_PRECISION;
+
+               if ((fpscr & FPSCR_CAUSE_ERROR)
+                   && (prec && ((hx & 0x7fffffff) < 0x00100000
+                                || (hy & 0x7fffffff) < 0x00100000))) {
+                       long long llx, lly;
+
+                       /* FPU error because of denormal (doubles) */
+                       llx = ((long long)hx << 32)
+                           | tsk->thread.fpu.hard.fp_regs[n + 1];
+                       lly = ((long long)hy << 32)
+                           | tsk->thread.fpu.hard.fp_regs[m + 1];
+
+                       llx = float64_div(llx, lly);
+
+                       tsk->thread.fpu.hard.fp_regs[n] = llx >> 32;
+                       tsk->thread.fpu.hard.fp_regs[n + 1] = llx & 0xffffffff;
+               } else if ((fpscr & FPSCR_CAUSE_ERROR)
+                          && (!prec && ((hx & 0x7fffffff) < 0x00800000
+                                        || (hy & 0x7fffffff) < 0x00800000))) {
+                       /* FPU error because of denormal (floats) */
+                       hx = float32_div(hx, hy);
+                       tsk->thread.fpu.hard.fp_regs[n] = hx;
                } else
-                       force_sig(SIGFPE, tsk);
+                       return 0;
 
                regs->pc = nextpc;
                return 1;
@@ -292,16 +421,41 @@ ieee_fpe_handler (struct pt_regs *regs)
        return 0;
 }
 
+void float_raise(unsigned int flags)
+{
+       fpu_exception_flags |= flags;
+}
+
+int float_rounding_mode(void)
+{
+       struct task_struct *tsk = current;
+       int roundingMode = FPSCR_ROUNDING_MODE(tsk->thread.fpu.hard.fpscr);
+       return roundingMode;
+}
+
 BUILD_TRAP_HANDLER(fpu_error)
 {
        struct task_struct *tsk = current;
        TRAP_HANDLER_DECL;
 
-       if (ieee_fpe_handler(regs))
-               return;
-
-       regs->pc += 2;
        save_fpu(tsk, regs);
+       fpu_exception_flags = 0;
+       if (ieee_fpe_handler(regs)) {
+               tsk->thread.fpu.hard.fpscr &=
+                   ~(FPSCR_CAUSE_MASK | FPSCR_FLAG_MASK);
+               tsk->thread.fpu.hard.fpscr |= fpu_exception_flags;
+               /* Set the FPSCR flag as well as cause bits - simply
+                * replicate the cause */
+               tsk->thread.fpu.hard.fpscr |= (fpu_exception_flags >> 10);
+               grab_fpu(regs);
+               restore_fpu(tsk);
+               set_tsk_thread_flag(tsk, TIF_USEDFPU);
+               if ((((tsk->thread.fpu.hard.fpscr & FPSCR_ENABLE_MASK) >> 7) &
+                    (fpu_exception_flags >> 2)) == 0) {
+                       return;
+               }
+       }
+
        force_sig(SIGFPE, tsk);
 }
 
@@ -319,7 +473,7 @@ BUILD_TRAP_HANDLER(fpu_state_restore)
        if (used_math()) {
                /* Using the FPU again.  */
                restore_fpu(tsk);
-       } else  {
+       } else {
                /* First time FPU user.  */
                fpu_init();
                set_used_math();
diff --git a/arch/sh/kernel/cpu/sh4/softfloat.c b/arch/sh/kernel/cpu/sh4/softfloat.c
new file mode 100644 (file)
index 0000000..7b2d337
--- /dev/null
@@ -0,0 +1,892 @@
+/*
+ * Floating point emulation support for subnormalised numbers on SH4
+ * architecture This file is derived from the SoftFloat IEC/IEEE
+ * Floating-point Arithmetic Package, Release 2 the original license of
+ * which is reproduced below.
+ *
+ * ========================================================================
+ *
+ * This C source file is part of the SoftFloat IEC/IEEE Floating-point
+ * Arithmetic Package, Release 2.
+ *
+ * Written by John R. Hauser.  This work was made possible in part by the
+ * International Computer Science Institute, located at Suite 600, 1947 Center
+ * Street, Berkeley, California 94704.  Funding was partially provided by the
+ * National Science Foundation under grant MIP-9311980.  The original version
+ * of this code was written as part of a project to build a fixed-point vector
+ * processor in collaboration with the University of California at Berkeley,
+ * overseen by Profs. Nelson Morgan and John Wawrzynek.  More information
+ * is available through the web page `http://HTTP.CS.Berkeley.EDU/~jhauser/
+ * arithmetic/softfloat.html'.
+ *
+ * THIS SOFTWARE IS DISTRIBUTED AS IS, FOR FREE.  Although reasonable effort
+ * has been made to avoid it, THIS SOFTWARE MAY CONTAIN FAULTS THAT WILL AT
+ * TIMES RESULT IN INCORRECT BEHAVIOR.  USE OF THIS SOFTWARE IS RESTRICTED TO
+ * PERSONS AND ORGANIZATIONS WHO CAN AND WILL TAKE FULL RESPONSIBILITY FOR ANY
+ * AND ALL LOSSES, COSTS, OR OTHER PROBLEMS ARISING FROM ITS USE.
+ *
+ * Derivative works are acceptable, even for commercial purposes, so long as
+ * (1) they include prominent notice that the work is derivative, and (2) they
+ * include prominent notice akin to these three paragraphs for those parts of
+ * this code that are retained.
+ *
+ * ========================================================================
+ *
+ * SH4 modifications by Ismail Dhaoui <ismail.dhaoui@st.com>
+ * and Kamel Khelifi <kamel.khelifi@st.com>
+ */
+#include <linux/kernel.h>
+#include <asm/cpu/fpu.h>
+
+#define LIT64( a ) a##LL
+
+typedef char flag;
+typedef unsigned char uint8;
+typedef signed char int8;
+typedef int uint16;
+typedef int int16;
+typedef unsigned int uint32;
+typedef signed int int32;
+
+typedef unsigned long long int bits64;
+typedef signed long long int sbits64;
+
+typedef unsigned char bits8;
+typedef signed char sbits8;
+typedef unsigned short int bits16;
+typedef signed short int sbits16;
+typedef unsigned int bits32;
+typedef signed int sbits32;
+
+typedef unsigned long long int uint64;
+typedef signed long long int int64;
+
+typedef unsigned long int float32;
+typedef unsigned long long float64;
+
+extern void float_raise(unsigned int flags);   /* in fpu.c */
+extern int float_rounding_mode(void);  /* in fpu.c */
+
+inline bits64 extractFloat64Frac(float64 a);
+inline flag extractFloat64Sign(float64 a);
+inline int16 extractFloat64Exp(float64 a);
+inline int16 extractFloat32Exp(float32 a);
+inline flag extractFloat32Sign(float32 a);
+inline bits32 extractFloat32Frac(float32 a);
+inline float64 packFloat64(flag zSign, int16 zExp, bits64 zSig);
+inline void shift64RightJamming(bits64 a, int16 count, bits64 * zPtr);
+inline float32 packFloat32(flag zSign, int16 zExp, bits32 zSig);
+inline void shift32RightJamming(bits32 a, int16 count, bits32 * zPtr);
+float64 float64_sub(float64 a, float64 b);
+float32 float32_sub(float32 a, float32 b);
+float32 float32_add(float32 a, float32 b);
+float64 float64_add(float64 a, float64 b);
+float64 float64_div(float64 a, float64 b);
+float32 float32_div(float32 a, float32 b);
+float32 float32_mul(float32 a, float32 b);
+float64 float64_mul(float64 a, float64 b);
+inline void add128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
+                  bits64 * z1Ptr);
+inline void sub128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
+                  bits64 * z1Ptr);
+inline void mul64To128(bits64 a, bits64 b, bits64 * z0Ptr, bits64 * z1Ptr);
+
+static int8 countLeadingZeros32(bits32 a);
+static int8 countLeadingZeros64(bits64 a);
+static float64 normalizeRoundAndPackFloat64(flag zSign, int16 zExp,
+                                           bits64 zSig);
+static float64 subFloat64Sigs(float64 a, float64 b, flag zSign);
+static float64 addFloat64Sigs(float64 a, float64 b, flag zSign);
+static float32 roundAndPackFloat32(flag zSign, int16 zExp, bits32 zSig);
+static float32 normalizeRoundAndPackFloat32(flag zSign, int16 zExp,
+                                           bits32 zSig);
+static float64 roundAndPackFloat64(flag zSign, int16 zExp, bits64 zSig);
+static float32 subFloat32Sigs(float32 a, float32 b, flag zSign);
+static float32 addFloat32Sigs(float32 a, float32 b, flag zSign);
+static void normalizeFloat64Subnormal(bits64 aSig, int16 * zExpPtr,
+                                     bits64 * zSigPtr);
+static bits64 estimateDiv128To64(bits64 a0, bits64 a1, bits64 b);
+static void normalizeFloat32Subnormal(bits32 aSig, int16 * zExpPtr,
+                                     bits32 * zSigPtr);
+
+inline bits64 extractFloat64Frac(float64 a)
+{
+       return a & LIT64(0x000FFFFFFFFFFFFF);
+}
+
+inline flag extractFloat64Sign(float64 a)
+{
+       return a >> 63;
+}
+
+inline int16 extractFloat64Exp(float64 a)
+{
+       return (a >> 52) & 0x7FF;
+}
+
+inline int16 extractFloat32Exp(float32 a)
+{
+       return (a >> 23) & 0xFF;
+}
+
+inline flag extractFloat32Sign(float32 a)
+{
+       return a >> 31;
+}
+
+inline bits32 extractFloat32Frac(float32 a)
+{
+       return a & 0x007FFFFF;
+}
+
+inline float64 packFloat64(flag zSign, int16 zExp, bits64 zSig)
+{
+       return (((bits64) zSign) << 63) + (((bits64) zExp) << 52) + zSig;
+}
+
+inline void shift64RightJamming(bits64 a, int16 count, bits64 * zPtr)
+{
+       bits64 z;
+
+       if (count == 0) {
+               z = a;
+       } else if (count < 64) {
+               z = (a >> count) | ((a << ((-count) & 63)) != 0);
+       } else {
+               z = (a != 0);
+       }
+       *zPtr = z;
+}
+
+static int8 countLeadingZeros32(bits32 a)
+{
+       static const int8 countLeadingZerosHigh[] = {
+               8, 7, 6, 6, 5, 5, 5, 5, 4, 4, 4, 4, 4, 4, 4, 4,
+               3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3, 3,
+               2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+               2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2, 2,
+               1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+               1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+               1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+               1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1, 1,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0,
+               0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
+       };
+       int8 shiftCount;
+
+       shiftCount = 0;
+       if (a < 0x10000) {
+               shiftCount += 16;
+               a <<= 16;
+       }
+       if (a < 0x1000000) {
+               shiftCount += 8;
+               a <<= 8;
+       }
+       shiftCount += countLeadingZerosHigh[a >> 24];
+       return shiftCount;
+
+}
+
+static int8 countLeadingZeros64(bits64 a)
+{
+       int8 shiftCount;
+
+       shiftCount = 0;
+       if (a < ((bits64) 1) << 32) {
+               shiftCount += 32;
+       } else {
+               a >>= 32;
+       }
+       shiftCount += countLeadingZeros32(a);
+       return shiftCount;
+
+}
+
+static float64 normalizeRoundAndPackFloat64(flag zSign, int16 zExp, bits64 zSig)
+{
+       int8 shiftCount;
+
+       shiftCount = countLeadingZeros64(zSig) - 1;
+       return roundAndPackFloat64(zSign, zExp - shiftCount,
+                                  zSig << shiftCount);
+
+}
+
+static float64 subFloat64Sigs(float64 a, float64 b, flag zSign)
+{
+       int16 aExp, bExp, zExp;
+       bits64 aSig, bSig, zSig;
+       int16 expDiff;
+
+       aSig = extractFloat64Frac(a);
+       aExp = extractFloat64Exp(a);
+       bSig = extractFloat64Frac(b);
+       bExp = extractFloat64Exp(b);
+       expDiff = aExp - bExp;
+       aSig <<= 10;
+       bSig <<= 10;
+       if (0 < expDiff)
+               goto aExpBigger;
+       if (expDiff < 0)
+               goto bExpBigger;
+       if (aExp == 0) {
+               aExp = 1;
+               bExp = 1;
+       }
+       if (bSig < aSig)
+               goto aBigger;
+       if (aSig < bSig)
+               goto bBigger;
+       return packFloat64(float_rounding_mode() == FPSCR_RM_ZERO, 0, 0);
+      bExpBigger:
+       if (bExp == 0x7FF) {
+               return packFloat64(zSign ^ 1, 0x7FF, 0);
+       }
+       if (aExp == 0) {
+               ++expDiff;
+       } else {
+               aSig |= LIT64(0x4000000000000000);
+       }
+       shift64RightJamming(aSig, -expDiff, &aSig);
+       bSig |= LIT64(0x4000000000000000);
+      bBigger:
+       zSig = bSig - aSig;
+       zExp = bExp;
+       zSign ^= 1;
+       goto normalizeRoundAndPack;
+      aExpBigger:
+       if (aExp == 0x7FF) {
+               return a;
+       }
+       if (bExp == 0) {
+               --expDiff;
+       } else {
+               bSig |= LIT64(0x4000000000000000);
+       }
+       shift64RightJamming(bSig, expDiff, &bSig);
+       aSig |= LIT64(0x4000000000000000);
+      aBigger:
+       zSig = aSig - bSig;
+       zExp = aExp;
+      normalizeRoundAndPack:
+       --zExp;
+       return normalizeRoundAndPackFloat64(zSign, zExp, zSig);
+
+}
+static float64 addFloat64Sigs(float64 a, float64 b, flag zSign)
+{
+       int16 aExp, bExp, zExp;
+       bits64 aSig, bSig, zSig;
+       int16 expDiff;
+
+       aSig = extractFloat64Frac(a);
+       aExp = extractFloat64Exp(a);
+       bSig = extractFloat64Frac(b);
+       bExp = extractFloat64Exp(b);
+       expDiff = aExp - bExp;
+       aSig <<= 9;
+       bSig <<= 9;
+       if (0 < expDiff) {
+               if (aExp == 0x7FF) {
+                       return a;
+               }
+               if (bExp == 0) {
+                       --expDiff;
+               } else {
+                       bSig |= LIT64(0x2000000000000000);
+               }
+               shift64RightJamming(bSig, expDiff, &bSig);
+               zExp = aExp;
+       } else if (expDiff < 0) {
+               if (bExp == 0x7FF) {
+                       return packFloat64(zSign, 0x7FF, 0);
+               }
+               if (aExp == 0) {
+                       ++expDiff;
+               } else {
+                       aSig |= LIT64(0x2000000000000000);
+               }
+               shift64RightJamming(aSig, -expDiff, &aSig);
+               zExp = bExp;
+       } else {
+               if (aExp == 0x7FF) {
+                       return a;
+               }
+               if (aExp == 0)
+                       return packFloat64(zSign, 0, (aSig + bSig) >> 9);
+               zSig = LIT64(0x4000000000000000) + aSig + bSig;
+               zExp = aExp;
+               goto roundAndPack;
+       }
+       aSig |= LIT64(0x2000000000000000);
+       zSig = (aSig + bSig) << 1;
+       --zExp;
+       if ((sbits64) zSig < 0) {
+               zSig = aSig + bSig;
+               ++zExp;
+       }
+      roundAndPack:
+       return roundAndPackFloat64(zSign, zExp, zSig);
+
+}
+
+inline float32 packFloat32(flag zSign, int16 zExp, bits32 zSig)
+{
+       return (((bits32) zSign) << 31) + (((bits32) zExp) << 23) + zSig;
+}
+
+inline void shift32RightJamming(bits32 a, int16 count, bits32 * zPtr)
+{
+       bits32 z;
+       if (count == 0) {
+               z = a;
+       } else if (count < 32) {
+               z = (a >> count) | ((a << ((-count) & 31)) != 0);
+       } else {
+               z = (a != 0);
+       }
+       *zPtr = z;
+}
+
+static float32 roundAndPackFloat32(flag zSign, int16 zExp, bits32 zSig)
+{
+       flag roundNearestEven;
+       int8 roundIncrement, roundBits;
+       flag isTiny;
+
+       /* SH4 has only 2 rounding modes - round to nearest and round to zero */
+       roundNearestEven = (float_rounding_mode() == FPSCR_RM_NEAREST);
+       roundIncrement = 0x40;
+       if (!roundNearestEven) {
+               roundIncrement = 0;
+       }
+       roundBits = zSig & 0x7F;
+       if (0xFD <= (bits16) zExp) {
+               if ((0xFD < zExp)
+                   || ((zExp == 0xFD)
+                       && ((sbits32) (zSig + roundIncrement) < 0))
+                   ) {
+                       float_raise(FPSCR_CAUSE_OVERFLOW | FPSCR_CAUSE_INEXACT);
+                       return packFloat32(zSign, 0xFF,
+                                          0) - (roundIncrement == 0);
+               }
+               if (zExp < 0) {
+                       isTiny = (zExp < -1)
+                           || (zSig + roundIncrement < 0x80000000);
+                       shift32RightJamming(zSig, -zExp, &zSig);
+                       zExp = 0;
+                       roundBits = zSig & 0x7F;
+                       if (isTiny && roundBits)
+                               float_raise(FPSCR_CAUSE_UNDERFLOW);
+               }
+       }
+       if (roundBits)
+               float_raise(FPSCR_CAUSE_INEXACT);
+       zSig = (zSig + roundIncrement) >> 7;
+       zSig &= ~(((roundBits ^ 0x40) == 0) & roundNearestEven);
+       if (zSig == 0)
+               zExp = 0;
+       return packFloat32(zSign, zExp, zSig);
+
+}
+
+static float32 normalizeRoundAndPackFloat32(flag zSign, int16 zExp, bits32 zSig)
+{
+       int8 shiftCount;
+
+       shiftCount = countLeadingZeros32(zSig) - 1;
+       return roundAndPackFloat32(zSign, zExp - shiftCount,
+                                  zSig << shiftCount);
+}
+
+static float64 roundAndPackFloat64(flag zSign, int16 zExp, bits64 zSig)
+{
+       flag roundNearestEven;
+       int16 roundIncrement, roundBits;
+       flag isTiny;
+
+       /* SH4 has only 2 rounding modes - round to nearest and round to zero */
+       roundNearestEven = (float_rounding_mode() == FPSCR_RM_NEAREST);
+       roundIncrement = 0x200;
+       if (!roundNearestEven) {
+               roundIncrement = 0;
+       }
+       roundBits = zSig & 0x3FF;
+       if (0x7FD <= (bits16) zExp) {
+               if ((0x7FD < zExp)
+                   || ((zExp == 0x7FD)
+                       && ((sbits64) (zSig + roundIncrement) < 0))
+                   ) {
+                       float_raise(FPSCR_CAUSE_OVERFLOW | FPSCR_CAUSE_INEXACT);
+                       return packFloat64(zSign, 0x7FF,
+                                          0) - (roundIncrement == 0);
+               }
+               if (zExp < 0) {
+                       isTiny = (zExp < -1)
+                           || (zSig + roundIncrement <
+                               LIT64(0x8000000000000000));
+                       shift64RightJamming(zSig, -zExp, &zSig);
+                       zExp = 0;
+                       roundBits = zSig & 0x3FF;
+                       if (isTiny && roundBits)
+                               float_raise(FPSCR_CAUSE_UNDERFLOW);
+               }
+       }
+       if (roundBits)
+               float_raise(FPSCR_CAUSE_INEXACT);
+       zSig = (zSig + roundIncrement) >> 10;
+       zSig &= ~(((roundBits ^ 0x200) == 0) & roundNearestEven);
+       if (zSig == 0)
+               zExp = 0;
+       return packFloat64(zSign, zExp, zSig);
+
+}
+
+static float32 subFloat32Sigs(float32 a, float32 b, flag zSign)
+{
+       int16 aExp, bExp, zExp;
+       bits32 aSig, bSig, zSig;
+       int16 expDiff;
+
+       aSig = extractFloat32Frac(a);
+       aExp = extractFloat32Exp(a);
+       bSig = extractFloat32Frac(b);
+       bExp = extractFloat32Exp(b);
+       expDiff = aExp - bExp;
+       aSig <<= 7;
+       bSig <<= 7;
+       if (0 < expDiff)
+               goto aExpBigger;
+       if (expDiff < 0)
+               goto bExpBigger;
+       if (aExp == 0) {
+               aExp = 1;
+               bExp = 1;
+       }
+       if (bSig < aSig)
+               goto aBigger;
+       if (aSig < bSig)
+               goto bBigger;
+       return packFloat32(float_rounding_mode() == FPSCR_RM_ZERO, 0, 0);
+      bExpBigger:
+       if (bExp == 0xFF) {
+               return packFloat32(zSign ^ 1, 0xFF, 0);
+       }
+       if (aExp == 0) {
+               ++expDiff;
+       } else {
+               aSig |= 0x40000000;
+       }
+       shift32RightJamming(aSig, -expDiff, &aSig);
+       bSig |= 0x40000000;
+      bBigger:
+       zSig = bSig - aSig;
+       zExp = bExp;
+       zSign ^= 1;
+       goto normalizeRoundAndPack;
+      aExpBigger:
+       if (aExp == 0xFF) {
+               return a;
+       }
+       if (bExp == 0) {
+               --expDiff;
+       } else {
+               bSig |= 0x40000000;
+       }
+       shift32RightJamming(bSig, expDiff, &bSig);
+       aSig |= 0x40000000;
+      aBigger:
+       zSig = aSig - bSig;
+       zExp = aExp;
+      normalizeRoundAndPack:
+       --zExp;
+       return normalizeRoundAndPackFloat32(zSign, zExp, zSig);
+
+}
+
+static float32 addFloat32Sigs(float32 a, float32 b, flag zSign)
+{
+       int16 aExp, bExp, zExp;
+       bits32 aSig, bSig, zSig;
+       int16 expDiff;
+
+       aSig = extractFloat32Frac(a);
+       aExp = extractFloat32Exp(a);
+       bSig = extractFloat32Frac(b);
+       bExp = extractFloat32Exp(b);
+       expDiff = aExp - bExp;
+       aSig <<= 6;
+       bSig <<= 6;
+       if (0 < expDiff) {
+               if (aExp == 0xFF) {
+                       return a;
+               }
+               if (bExp == 0) {
+                       --expDiff;
+               } else {
+                       bSig |= 0x20000000;
+               }
+               shift32RightJamming(bSig, expDiff, &bSig);
+               zExp = aExp;
+       } else if (expDiff < 0) {
+               if (bExp == 0xFF) {
+                       return packFloat32(zSign, 0xFF, 0);
+               }
+               if (aExp == 0) {
+                       ++expDiff;
+               } else {
+                       aSig |= 0x20000000;
+               }
+               shift32RightJamming(aSig, -expDiff, &aSig);
+               zExp = bExp;
+       } else {
+               if (aExp == 0xFF) {
+                       return a;
+               }
+               if (aExp == 0)
+                       return packFloat32(zSign, 0, (aSig + bSig) >> 6);
+               zSig = 0x40000000 + aSig + bSig;
+               zExp = aExp;
+               goto roundAndPack;
+       }
+       aSig |= 0x20000000;
+       zSig = (aSig + bSig) << 1;
+       --zExp;
+       if ((sbits32) zSig < 0) {
+               zSig = aSig + bSig;
+               ++zExp;
+       }
+      roundAndPack:
+       return roundAndPackFloat32(zSign, zExp, zSig);
+
+}
+
+float64 float64_sub(float64 a, float64 b)
+{
+       flag aSign, bSign;
+
+       aSign = extractFloat64Sign(a);
+       bSign = extractFloat64Sign(b);
+       if (aSign == bSign) {
+               return subFloat64Sigs(a, b, aSign);
+       } else {
+               return addFloat64Sigs(a, b, aSign);
+       }
+
+}
+
+float32 float32_sub(float32 a, float32 b)
+{
+       flag aSign, bSign;
+
+       aSign = extractFloat32Sign(a);
+       bSign = extractFloat32Sign(b);
+       if (aSign == bSign) {
+               return subFloat32Sigs(a, b, aSign);
+       } else {
+               return addFloat32Sigs(a, b, aSign);
+       }
+
+}
+
+float32 float32_add(float32 a, float32 b)
+{
+       flag aSign, bSign;
+
+       aSign = extractFloat32Sign(a);
+       bSign = extractFloat32Sign(b);
+       if (aSign == bSign) {
+               return addFloat32Sigs(a, b, aSign);
+       } else {
+               return subFloat32Sigs(a, b, aSign);
+       }
+
+}
+
+float64 float64_add(float64 a, float64 b)
+{
+       flag aSign, bSign;
+
+       aSign = extractFloat64Sign(a);
+       bSign = extractFloat64Sign(b);
+       if (aSign == bSign) {
+               return addFloat64Sigs(a, b, aSign);
+       } else {
+               return subFloat64Sigs(a, b, aSign);
+       }
+}
+
+static void
+normalizeFloat64Subnormal(bits64 aSig, int16 * zExpPtr, bits64 * zSigPtr)
+{
+       int8 shiftCount;
+
+       shiftCount = countLeadingZeros64(aSig) - 11;
+       *zSigPtr = aSig << shiftCount;
+       *zExpPtr = 1 - shiftCount;
+}
+
+inline void add128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
+                  bits64 * z1Ptr)
+{
+       bits64 z1;
+
+       z1 = a1 + b1;
+       *z1Ptr = z1;
+       *z0Ptr = a0 + b0 + (z1 < a1);
+}
+
+inline void
+sub128(bits64 a0, bits64 a1, bits64 b0, bits64 b1, bits64 * z0Ptr,
+       bits64 * z1Ptr)
+{
+       *z1Ptr = a1 - b1;
+       *z0Ptr = a0 - b0 - (a1 < b1);
+}
+
+static bits64 estimateDiv128To64(bits64 a0, bits64 a1, bits64 b)
+{
+       bits64 b0, b1;
+       bits64 rem0, rem1, term0, term1;
+       bits64 z;
+       if (b <= a0)
+               return LIT64(0xFFFFFFFFFFFFFFFF);
+       b0 = b >> 32;
+       z = (b0 << 32 <= a0) ? LIT64(0xFFFFFFFF00000000) : (a0 / b0) << 32;
+       mul64To128(b, z, &term0, &term1);
+       sub128(a0, a1, term0, term1, &rem0, &rem1);
+       while (((sbits64) rem0) < 0) {
+               z -= LIT64(0x100000000);
+               b1 = b << 32;
+               add128(rem0, rem1, b0, b1, &rem0, &rem1);
+       }
+       rem0 = (rem0 << 32) | (rem1 >> 32);
+       z |= (b0 << 32 <= rem0) ? 0xFFFFFFFF : rem0 / b0;
+       return z;
+}
+
+inline void mul64To128(bits64 a, bits64 b, bits64 * z0Ptr, bits64 * z1Ptr)
+{
+       bits32 aHigh, aLow, bHigh, bLow;
+       bits64 z0, zMiddleA, zMiddleB, z1;
+
+       aLow = a;
+       aHigh = a >> 32;
+       bLow = b;
+       bHigh = b >> 32;
+       z1 = ((bits64) aLow) * bLow;
+       zMiddleA = ((bits64) aLow) * bHigh;
+       zMiddleB = ((bits64) aHigh) * bLow;
+       z0 = ((bits64) aHigh) * bHigh;
+       zMiddleA += zMiddleB;
+       z0 += (((bits64) (zMiddleA < zMiddleB)) << 32) + (zMiddleA >> 32);
+       zMiddleA <<= 32;
+       z1 += zMiddleA;
+       z0 += (z1 < zMiddleA);
+       *z1Ptr = z1;
+       *z0Ptr = z0;
+
+}
+
+static void normalizeFloat32Subnormal(bits32 aSig, int16 * zExpPtr,
+                                     bits32 * zSigPtr)
+{
+       int8 shiftCount;
+
+       shiftCount = countLeadingZeros32(aSig) - 8;
+       *zSigPtr = aSig << shiftCount;
+       *zExpPtr = 1 - shiftCount;
+
+}
+
+float64 float64_div(float64 a, float64 b)
+{
+       flag aSign, bSign, zSign;
+       int16 aExp, bExp, zExp;
+       bits64 aSig, bSig, zSig;
+       bits64 rem0, rem1;
+       bits64 term0, term1;
+
+       aSig = extractFloat64Frac(a);
+       aExp = extractFloat64Exp(a);
+       aSign = extractFloat64Sign(a);
+       bSig = extractFloat64Frac(b);
+       bExp = extractFloat64Exp(b);
+       bSign = extractFloat64Sign(b);
+       zSign = aSign ^ bSign;
+       if (aExp == 0x7FF) {
+               if (bExp == 0x7FF) {
+               }
+               return packFloat64(zSign, 0x7FF, 0);
+       }
+       if (bExp == 0x7FF) {
+               return packFloat64(zSign, 0, 0);
+       }
+       if (bExp == 0) {
+               if (bSig == 0) {
+                       if ((aExp | aSig) == 0) {
+                               float_raise(FPSCR_CAUSE_INVALID);
+                       }
+                       return packFloat64(zSign, 0x7FF, 0);
+               }
+               normalizeFloat64Subnormal(bSig, &bExp, &bSig);
+       }
+       if (aExp == 0) {
+               if (aSig == 0)
+                       return packFloat64(zSign, 0, 0);
+               normalizeFloat64Subnormal(aSig, &aExp, &aSig);
+       }
+       zExp = aExp - bExp + 0x3FD;
+       aSig = (aSig | LIT64(0x0010000000000000)) << 10;
+       bSig = (bSig | LIT64(0x0010000000000000)) << 11;
+       if (bSig <= (aSig + aSig)) {
+               aSig >>= 1;
+               ++zExp;
+       }
+       zSig = estimateDiv128To64(aSig, 0, bSig);
+       if ((zSig & 0x1FF) <= 2) {
+               mul64To128(bSig, zSig, &term0, &term1);
+               sub128(aSig, 0, term0, term1, &rem0, &rem1);
+               while ((sbits64) rem0 < 0) {
+                       --zSig;
+                       add128(rem0, rem1, 0, bSig, &rem0, &rem1);
+               }
+               zSig |= (rem1 != 0);
+       }
+       return roundAndPackFloat64(zSign, zExp, zSig);
+
+}
+
+float32 float32_div(float32 a, float32 b)
+{
+       flag aSign, bSign, zSign;
+       int16 aExp, bExp, zExp;
+       bits32 aSig, bSig, zSig;
+
+       aSig = extractFloat32Frac(a);
+       aExp = extractFloat32Exp(a);
+       aSign = extractFloat32Sign(a);
+       bSig = extractFloat32Frac(b);
+       bExp = extractFloat32Exp(b);
+       bSign = extractFloat32Sign(b);
+       zSign = aSign ^ bSign;
+       if (aExp == 0xFF) {
+               if (bExp == 0xFF) {
+               }
+               return packFloat32(zSign, 0xFF, 0);
+       }
+       if (bExp == 0xFF) {
+               return packFloat32(zSign, 0, 0);
+       }
+       if (bExp == 0) {
+               if (bSig == 0) {
+                       return packFloat32(zSign, 0xFF, 0);
+               }
+               normalizeFloat32Subnormal(bSig, &bExp, &bSig);
+       }
+       if (aExp == 0) {
+               if (aSig == 0)
+                       return packFloat32(zSign, 0, 0);
+               normalizeFloat32Subnormal(aSig, &aExp, &aSig);
+       }
+       zExp = aExp - bExp + 0x7D;
+       aSig = (aSig | 0x00800000) << 7;
+       bSig = (bSig | 0x00800000) << 8;
+       if (bSig <= (aSig + aSig)) {
+               aSig >>= 1;
+               ++zExp;
+       }
+       zSig = (((bits64) aSig) << 32) / bSig;
+       if ((zSig & 0x3F) == 0) {
+               zSig |= (((bits64) bSig) * zSig != ((bits64) aSig) << 32);
+       }
+       return roundAndPackFloat32(zSign, zExp, zSig);
+
+}
+
+float32 float32_mul(float32 a, float32 b)
+{
+       char aSign, bSign, zSign;
+       int aExp, bExp, zExp;
+       unsigned int aSig, bSig;
+       unsigned long long zSig64;
+       unsigned int zSig;
+
+       aSig = extractFloat32Frac(a);
+       aExp = extractFloat32Exp(a);
+       aSign = extractFloat32Sign(a);
+       bSig = extractFloat32Frac(b);
+       bExp = extractFloat32Exp(b);
+       bSign = extractFloat32Sign(b);
+       zSign = aSign ^ bSign;
+       if (aExp == 0) {
+               if (aSig == 0)
+                       return packFloat32(zSign, 0, 0);
+               normalizeFloat32Subnormal(aSig, &aExp, &aSig);
+       }
+       if (bExp == 0) {
+               if (bSig == 0)
+                       return packFloat32(zSign, 0, 0);
+               normalizeFloat32Subnormal(bSig, &bExp, &bSig);
+       }
+       if ((bExp == 0xff && bSig == 0) || (aExp == 0xff && aSig == 0))
+               return roundAndPackFloat32(zSign, 0xff, 0);
+
+       zExp = aExp + bExp - 0x7F;
+       aSig = (aSig | 0x00800000) << 7;
+       bSig = (bSig | 0x00800000) << 8;
+       shift64RightJamming(((unsigned long long)aSig) * bSig, 32, &zSig64);
+       zSig = zSig64;
+       if (0 <= (signed int)(zSig << 1)) {
+               zSig <<= 1;
+               --zExp;
+       }
+       return roundAndPackFloat32(zSign, zExp, zSig);
+
+}
+
+float64 float64_mul(float64 a, float64 b)
+{
+       char aSign, bSign, zSign;
+       int aExp, bExp, zExp;
+       unsigned long long int aSig, bSig, zSig0, zSig1;
+
+       aSig = extractFloat64Frac(a);
+       aExp = extractFloat64Exp(a);
+       aSign = extractFloat64Sign(a);
+       bSig = extractFloat64Frac(b);
+       bExp = extractFloat64Exp(b);
+       bSign = extractFloat64Sign(b);
+       zSign = aSign ^ bSign;
+
+       if (aExp == 0) {
+               if (aSig == 0)
+                       return packFloat64(zSign, 0, 0);
+               normalizeFloat64Subnormal(aSig, &aExp, &aSig);
+       }
+       if (bExp == 0) {
+               if (bSig == 0)
+                       return packFloat64(zSign, 0, 0);
+               normalizeFloat64Subnormal(bSig, &bExp, &bSig);
+       }
+       if ((aExp == 0x7ff && aSig == 0) || (bExp == 0x7ff && bSig == 0))
+               return roundAndPackFloat64(zSign, 0x7ff, 0);
+
+       zExp = aExp + bExp - 0x3FF;
+       aSig = (aSig | 0x0010000000000000LL) << 10;
+       bSig = (bSig | 0x0010000000000000LL) << 11;
+       mul64To128(aSig, bSig, &zSig0, &zSig1);
+       zSig0 |= (zSig1 != 0);
+       if (0 <= (signed long long int)(zSig0 << 1)) {
+               zSig0 <<= 1;
+               --zExp;
+       }
+       return roundAndPackFloat64(zSign, zExp, zSig0);
+}
diff --git a/include/asm-sh/cpu-sh4/fpu.h b/include/asm-sh/cpu-sh4/fpu.h
new file mode 100644 (file)
index 0000000..febef73
--- /dev/null
@@ -0,0 +1,32 @@
+/*
+ * linux/arch/sh/kernel/cpu/sh4/sh4_fpu.h
+ *
+ * Copyright (C) 2006 STMicroelectronics Limited
+ * Author: Carl Shaw <carl.shaw@st.com>
+ *
+ * May be copied or modified under the terms of the GNU General Public
+ * License Version 2.  See linux/COPYING for more information.
+ *
+ * Definitions for SH4 FPU operations
+ */
+
+#ifndef __CPU_SH4_FPU_H
+#define __CPU_SH4_FPU_H
+
+#define FPSCR_ENABLE_MASK      0x00000f80UL
+
+#define FPSCR_FMOV_DOUBLE      (1<<1)
+
+#define FPSCR_CAUSE_INEXACT    (1<<12)
+#define FPSCR_CAUSE_UNDERFLOW  (1<<13)
+#define FPSCR_CAUSE_OVERFLOW   (1<<14)
+#define FPSCR_CAUSE_DIVZERO    (1<<15)
+#define FPSCR_CAUSE_INVALID    (1<<16)
+#define FPSCR_CAUSE_ERROR      (1<<17)
+
+#define FPSCR_DBL_PRECISION    (1<<19)
+#define FPSCR_ROUNDING_MODE(x) ((x >> 20) & 3)
+#define FPSCR_RM_NEAREST       (0)
+#define FPSCR_RM_ZERO          (1)
+
+#endif