diff options
Diffstat (limited to 'arch/mips/math-emu/cp1emu.c')
| -rw-r--r-- | arch/mips/math-emu/cp1emu.c | 23 |
1 files changed, 12 insertions, 11 deletions
diff --git a/arch/mips/math-emu/cp1emu.c b/arch/mips/math-emu/cp1emu.c index a03bf00a1a9c..afb5a0bcf7a5 100644 --- a/arch/mips/math-emu/cp1emu.c +++ b/arch/mips/math-emu/cp1emu.c @@ -169,18 +169,19 @@ static int isBranchInstr(mips_instruction * i) /* * In the Linux kernel, we support selection of FPR format on the - * basis of the Status.FR bit. If an FPU is not present, the FR bit + * basis of the Status.FR bit. If an FPU is not present, the FR bit * is hardwired to zero, which would imply a 32-bit FPU even for - * 64-bit CPUs. For 64-bit kernels with no FPU we use TIF_32BIT_REGS - * as a proxy for the FR bit so that a 64-bit FPU is emulated. In any - * case, for a 32-bit kernel which uses the O32 MIPS ABI, only the - * even FPRs are used (Status.FR = 0). + * 64-bit CPUs so we rather look at TIF_32BIT_REGS. + * FPU emu is slow and bulky and optimizing this function offers fairly + * sizeable benefits so we try to be clever and make this function return + * a constant whenever possible, that is on 64-bit kernels without O32 + * compatibility enabled and on 32-bit kernels. */ static inline int cop1_64bit(struct pt_regs *xcp) { - if (cpu_has_fpu) - return xcp->cp0_status & ST0_FR; -#ifdef CONFIG_64BIT +#if defined(CONFIG_64BIT) && !defined(CONFIG_MIPS32_O32) + return 1; +#elif defined(CONFIG_64BIT) && defined(CONFIG_MIPS32_O32) return !test_thread_flag(TIF_32BIT_REGS); #else return 0; @@ -233,7 +234,7 @@ static int cop1Emulate(struct pt_regs *xcp, struct mips_fpu_struct *ctx, if (xcp->cp0_cause & CAUSEF_BD) { /* * The instruction to be emulated is in a branch delay slot - * which means that we have to emulate the branch instruction + * which means that we have to emulate the branch instruction * BEFORE we do the cop1 instruction. * * This branch could be a COP1 branch, but in that case we @@ -1334,8 +1335,8 @@ int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx, else { /* * The 'ieee754_csr' is an alias of - * ctx->fcr31. No need to copy ctx->fcr31 to - * ieee754_csr. But ieee754_csr.rm is ieee + * ctx->fcr31. No need to copy ctx->fcr31 to + * ieee754_csr. But ieee754_csr.rm is ieee * library modes. (not mips rounding mode) */ /* convert to ieee library modes */ |