1da177e4c3
Initial git repository build. I'm not bothering with the full history, even though we have it. We can create a separate "historical" git archive of that later if we want to, and in the meantime it's about 3.2GB when imported into git - space that would just make the early git days unnecessarily complicated, when we don't have a lot of good infrastructure for it. Let it rip!
194 lines
6.1 KiB
C
194 lines
6.1 KiB
C
#ifndef __ASM_ALPHA_FPU_H
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#define __ASM_ALPHA_FPU_H
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/*
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* Alpha floating-point control register defines:
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*/
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#define FPCR_DNOD (1UL<<47) /* denorm INV trap disable */
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#define FPCR_DNZ (1UL<<48) /* denorms to zero */
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#define FPCR_INVD (1UL<<49) /* invalid op disable (opt.) */
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#define FPCR_DZED (1UL<<50) /* division by zero disable (opt.) */
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#define FPCR_OVFD (1UL<<51) /* overflow disable (optional) */
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#define FPCR_INV (1UL<<52) /* invalid operation */
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#define FPCR_DZE (1UL<<53) /* division by zero */
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#define FPCR_OVF (1UL<<54) /* overflow */
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#define FPCR_UNF (1UL<<55) /* underflow */
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#define FPCR_INE (1UL<<56) /* inexact */
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#define FPCR_IOV (1UL<<57) /* integer overflow */
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#define FPCR_UNDZ (1UL<<60) /* underflow to zero (opt.) */
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#define FPCR_UNFD (1UL<<61) /* underflow disable (opt.) */
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#define FPCR_INED (1UL<<62) /* inexact disable (opt.) */
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#define FPCR_SUM (1UL<<63) /* summary bit */
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#define FPCR_DYN_SHIFT 58 /* first dynamic rounding mode bit */
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#define FPCR_DYN_CHOPPED (0x0UL << FPCR_DYN_SHIFT) /* towards 0 */
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#define FPCR_DYN_MINUS (0x1UL << FPCR_DYN_SHIFT) /* towards -INF */
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#define FPCR_DYN_NORMAL (0x2UL << FPCR_DYN_SHIFT) /* towards nearest */
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#define FPCR_DYN_PLUS (0x3UL << FPCR_DYN_SHIFT) /* towards +INF */
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#define FPCR_DYN_MASK (0x3UL << FPCR_DYN_SHIFT)
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#define FPCR_MASK 0xffff800000000000L
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/*
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* IEEE trap enables are implemented in software. These per-thread
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* bits are stored in the "ieee_state" field of "struct thread_info".
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* Thus, the bits are defined so as not to conflict with the
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* floating-point enable bit (which is architected). On top of that,
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* we want to make these bits compatible with OSF/1 so
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* ieee_set_fp_control() etc. can be implemented easily and
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* compatibly. The corresponding definitions are in
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* /usr/include/machine/fpu.h under OSF/1.
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*/
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#define IEEE_TRAP_ENABLE_INV (1UL<<1) /* invalid op */
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#define IEEE_TRAP_ENABLE_DZE (1UL<<2) /* division by zero */
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#define IEEE_TRAP_ENABLE_OVF (1UL<<3) /* overflow */
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#define IEEE_TRAP_ENABLE_UNF (1UL<<4) /* underflow */
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#define IEEE_TRAP_ENABLE_INE (1UL<<5) /* inexact */
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#define IEEE_TRAP_ENABLE_DNO (1UL<<6) /* denorm */
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#define IEEE_TRAP_ENABLE_MASK (IEEE_TRAP_ENABLE_INV | IEEE_TRAP_ENABLE_DZE |\
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IEEE_TRAP_ENABLE_OVF | IEEE_TRAP_ENABLE_UNF |\
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IEEE_TRAP_ENABLE_INE | IEEE_TRAP_ENABLE_DNO)
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/* Denorm and Underflow flushing */
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#define IEEE_MAP_DMZ (1UL<<12) /* Map denorm inputs to zero */
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#define IEEE_MAP_UMZ (1UL<<13) /* Map underflowed outputs to zero */
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#define IEEE_MAP_MASK (IEEE_MAP_DMZ | IEEE_MAP_UMZ)
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/* status bits coming from fpcr: */
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#define IEEE_STATUS_INV (1UL<<17)
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#define IEEE_STATUS_DZE (1UL<<18)
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#define IEEE_STATUS_OVF (1UL<<19)
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#define IEEE_STATUS_UNF (1UL<<20)
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#define IEEE_STATUS_INE (1UL<<21)
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#define IEEE_STATUS_DNO (1UL<<22)
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#define IEEE_STATUS_MASK (IEEE_STATUS_INV | IEEE_STATUS_DZE | \
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IEEE_STATUS_OVF | IEEE_STATUS_UNF | \
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IEEE_STATUS_INE | IEEE_STATUS_DNO)
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#define IEEE_SW_MASK (IEEE_TRAP_ENABLE_MASK | \
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IEEE_STATUS_MASK | IEEE_MAP_MASK)
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#define IEEE_CURRENT_RM_SHIFT 32
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#define IEEE_CURRENT_RM_MASK (3UL<<IEEE_CURRENT_RM_SHIFT)
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#define IEEE_STATUS_TO_EXCSUM_SHIFT 16
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#define IEEE_INHERIT (1UL<<63) /* inherit on thread create? */
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/*
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* Convert the software IEEE trap enable and status bits into the
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* hardware fpcr format.
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*
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* Digital Unix engineers receive my thanks for not defining the
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* software bits identical to the hardware bits. The chip designers
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* receive my thanks for making all the not-implemented fpcr bits
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* RAZ forcing us to use system calls to read/write this value.
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*/
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static inline unsigned long
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ieee_swcr_to_fpcr(unsigned long sw)
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{
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unsigned long fp;
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fp = (sw & IEEE_STATUS_MASK) << 35;
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fp |= (sw & IEEE_MAP_DMZ) << 36;
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fp |= (sw & IEEE_STATUS_MASK ? FPCR_SUM : 0);
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fp |= (~sw & (IEEE_TRAP_ENABLE_INV
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| IEEE_TRAP_ENABLE_DZE
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| IEEE_TRAP_ENABLE_OVF)) << 48;
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fp |= (~sw & (IEEE_TRAP_ENABLE_UNF | IEEE_TRAP_ENABLE_INE)) << 57;
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fp |= (sw & IEEE_MAP_UMZ ? FPCR_UNDZ | FPCR_UNFD : 0);
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fp |= (~sw & IEEE_TRAP_ENABLE_DNO) << 41;
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return fp;
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}
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static inline unsigned long
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ieee_fpcr_to_swcr(unsigned long fp)
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{
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unsigned long sw;
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sw = (fp >> 35) & IEEE_STATUS_MASK;
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sw |= (fp >> 36) & IEEE_MAP_DMZ;
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sw |= (~fp >> 48) & (IEEE_TRAP_ENABLE_INV
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| IEEE_TRAP_ENABLE_DZE
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| IEEE_TRAP_ENABLE_OVF);
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sw |= (~fp >> 57) & (IEEE_TRAP_ENABLE_UNF | IEEE_TRAP_ENABLE_INE);
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sw |= (fp >> 47) & IEEE_MAP_UMZ;
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sw |= (~fp >> 41) & IEEE_TRAP_ENABLE_DNO;
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return sw;
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}
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#ifdef __KERNEL__
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/* The following two functions don't need trapb/excb instructions
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around the mf_fpcr/mt_fpcr instructions because (a) the kernel
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never generates arithmetic faults and (b) call_pal instructions
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are implied trap barriers. */
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static inline unsigned long
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rdfpcr(void)
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{
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unsigned long tmp, ret;
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#if defined(__alpha_cix__) || defined(__alpha_fix__)
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__asm__ __volatile__ (
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"ftoit $f0,%0\n\t"
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"mf_fpcr $f0\n\t"
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"ftoit $f0,%1\n\t"
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"itoft %0,$f0"
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: "=r"(tmp), "=r"(ret));
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#else
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__asm__ __volatile__ (
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"stt $f0,%0\n\t"
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"mf_fpcr $f0\n\t"
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"stt $f0,%1\n\t"
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"ldt $f0,%0"
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: "=m"(tmp), "=m"(ret));
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#endif
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return ret;
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}
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static inline void
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wrfpcr(unsigned long val)
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{
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unsigned long tmp;
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#if defined(__alpha_cix__) || defined(__alpha_fix__)
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__asm__ __volatile__ (
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"ftoit $f0,%0\n\t"
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"itoft %1,$f0\n\t"
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"mt_fpcr $f0\n\t"
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"itoft %0,$f0"
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: "=&r"(tmp) : "r"(val));
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#else
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__asm__ __volatile__ (
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"stt $f0,%0\n\t"
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"ldt $f0,%1\n\t"
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"mt_fpcr $f0\n\t"
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"ldt $f0,%0"
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: "=m"(tmp) : "m"(val));
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#endif
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}
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static inline unsigned long
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swcr_update_status(unsigned long swcr, unsigned long fpcr)
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{
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/* EV6 implements most of the bits in hardware. Collect
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the acrued exception bits from the real fpcr. */
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if (implver() == IMPLVER_EV6) {
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swcr &= ~IEEE_STATUS_MASK;
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swcr |= (fpcr >> 35) & IEEE_STATUS_MASK;
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}
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return swcr;
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}
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extern unsigned long alpha_read_fp_reg (unsigned long reg);
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extern void alpha_write_fp_reg (unsigned long reg, unsigned long val);
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extern unsigned long alpha_read_fp_reg_s (unsigned long reg);
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extern void alpha_write_fp_reg_s (unsigned long reg, unsigned long val);
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#endif /* __KERNEL__ */
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#endif /* __ASM_ALPHA_FPU_H */
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