diff options
| author | Carl Shaw <carl.shaw@st.com> | 2008-09-05 16:36:19 +0900 |
|---|---|---|
| committer | Paul Mundt <lethal@linux-sh.org> | 2008-09-08 10:35:05 +0900 |
| commit | b6ad1e8c3f76fcc5dee506d5e79e752d296ff745 (patch) | |
| tree | c626da55bdfc3e19419856e086a5cad1dc4829c4 /arch/sh/kernel/cpu/sh4/fpu.c | |
| parent | f040ddaf4cfd28f25ea9d6a42d3c734d5c3f6798 (diff) | |
sh: Subnormal double to float conversion
This patch adds support for the SH4 to convert a subnormal double
into a float by catching the FPE and implementing the FCNVDS
instruction in software.
Signed-off-by: Carl Shaw <carl.shaw@st.com>
Signed-off-by: Paul Mundt <lethal@linux-sh.org>
Diffstat (limited to 'arch/sh/kernel/cpu/sh4/fpu.c')
| -rw-r--r-- | arch/sh/kernel/cpu/sh4/fpu.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/arch/sh/kernel/cpu/sh4/fpu.c b/arch/sh/kernel/cpu/sh4/fpu.c index 2d452f67fb8..2780917c008 100644 --- a/arch/sh/kernel/cpu/sh4/fpu.c +++ b/arch/sh/kernel/cpu/sh4/fpu.c @@ -36,7 +36,7 @@ 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); - +extern unsigned long int float64_to_float32(unsigned long long a); static unsigned int fpu_exception_flags; /* @@ -417,6 +417,29 @@ static int ieee_fpe_handler(struct pt_regs *regs) regs->pc = nextpc; return 1; + } else if ((finsn & 0xf0bd) == 0xf0bd) { + /* fcnvds - double to single precision convert */ + struct task_struct *tsk = current; + int m; + unsigned int hx; + + m = (finsn >> 9) & 0x7; + hx = tsk->thread.fpu.hard.fp_regs[m]; + + if ((tsk->thread.fpu.hard.fpscr & FPSCR_CAUSE_ERROR) + && ((hx & 0x7fffffff) < 0x00100000)) { + /* subnormal double to float conversion */ + long long llx; + + llx = ((long long)tsk->thread.fpu.hard.fp_regs[m] << 32) + | tsk->thread.fpu.hard.fp_regs[m + 1]; + + tsk->thread.fpu.hard.fpul = float64_to_float32(llx); + } else + return 0; + + regs->pc = nextpc; + return 1; } return 0; |