diff options
Diffstat (limited to 'arch/powerpc/math-emu')
| -rw-r--r-- | arch/powerpc/math-emu/math_efp.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/arch/powerpc/math-emu/math_efp.c b/arch/powerpc/math-emu/math_efp.c index 59835c625dc6..ecdf35d8cb00 100644 --- a/arch/powerpc/math-emu/math_efp.c +++ b/arch/powerpc/math-emu/math_efp.c @@ -680,7 +680,8 @@ int speround_handler(struct pt_regs *regs) { union dw_union fgpr; int s_lo, s_hi; - unsigned long speinsn, type, fc; + int lo_inexact, hi_inexact; + unsigned long speinsn, type, fc, fptype; if (get_user(speinsn, (unsigned int __user *) regs->nip)) return -EFAULT; @@ -693,8 +694,12 @@ int speround_handler(struct pt_regs *regs) __FPU_FPSCR = mfspr(SPRN_SPEFSCR); pr_debug("speinsn:%08lx spefscr:%08lx\n", speinsn, __FPU_FPSCR); + fptype = (speinsn >> 5) & 0x7; + /* No need to round if the result is exact */ - if (!(__FPU_FPSCR & FP_EX_INEXACT)) + lo_inexact = __FPU_FPSCR & (SPEFSCR_FG | SPEFSCR_FX); + hi_inexact = __FPU_FPSCR & (SPEFSCR_FGH | SPEFSCR_FXH); + if (!(lo_inexact || (hi_inexact && fptype == VCT))) return 0; fc = (speinsn >> 21) & 0x1f; @@ -705,7 +710,7 @@ int speround_handler(struct pt_regs *regs) pr_debug("round fgpr: %08x %08x\n", fgpr.wp[0], fgpr.wp[1]); - switch ((speinsn >> 5) & 0x7) { + switch (fptype) { /* Since SPE instructions on E500 core can handle round to nearest * and round toward zero with IEEE-754 complied, we just need * to handle round toward +Inf and round toward -Inf by software. @@ -728,11 +733,15 @@ int speround_handler(struct pt_regs *regs) case VCT: if (FP_ROUNDMODE == FP_RND_PINF) { - if (!s_lo) fgpr.wp[1]++; /* Z_low > 0, choose Z1 */ - if (!s_hi) fgpr.wp[0]++; /* Z_high word > 0, choose Z1 */ + if (lo_inexact && !s_lo) + fgpr.wp[1]++; /* Z_low > 0, choose Z1 */ + if (hi_inexact && !s_hi) + fgpr.wp[0]++; /* Z_high word > 0, choose Z1 */ } else { /* round to -Inf */ - if (s_lo) fgpr.wp[1]++; /* Z_low < 0, choose Z2 */ - if (s_hi) fgpr.wp[0]++; /* Z_high < 0, choose Z2 */ + if (lo_inexact && s_lo) + fgpr.wp[1]++; /* Z_low < 0, choose Z2 */ + if (hi_inexact && s_hi) + fgpr.wp[0]++; /* Z_high < 0, choose Z2 */ } break; |