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MIPS: math-emu: Switch to using the MIPS rounding modes.

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Previously math-emu was using the IEEE-754 constants internally.  These
were differing by having the constants for rounding to +/- infinity
switched, so a conversion was necessary.  This would be entirely
avoidable if the MIPS constants were used throughout, so get rid of
the bloat.

Signed-off-by: Ralf Baechle <ralf@linux-mips.org>
This commit is contained in:
Ralf Baechle
2014-04-30 11:21:55 +02:00
parent aef3fb76aa
commit 56a6473339
15 changed files with 63 additions and 91 deletions
Download Patch File Download Diff File Expand all files Collapse all files

35
arch/mips/math-emu/cp1emu.c
View File

@@ -67,21 +67,6 @@ static int fpux_emu(struct pt_regs *,
/* Determine rounding mode from the RM bits of the FCSR */
#define modeindex(v) ((v) & FPU_CSR_RM)
/* Convert MIPS rounding mode (0..3) to IEEE library modes. */
static const unsigned char ieee_rm[4] = {
[FPU_CSR_RN] = IEEE754_RN,
[FPU_CSR_RZ] = IEEE754_RZ,
[FPU_CSR_RU] = IEEE754_RU,
[FPU_CSR_RD] = IEEE754_RD,
};
/* Convert IEEE library modes to MIPS rounding mode (0..3). */
static const unsigned char mips_rm[4] = {
[IEEE754_RN] = FPU_CSR_RN,
[IEEE754_RZ] = FPU_CSR_RZ,
[IEEE754_RD] = FPU_CSR_RD,
[IEEE754_RU] = FPU_CSR_RU,
};
/* convert condition code register number to csr bit */
static const unsigned int fpucondbit[8] = {
FPU_CSR_COND0,
@@ -907,8 +892,7 @@ emul:
/* cop control register rd -> gpr[rt] */
if (MIPSInst_RD(ir) == FPCREG_CSR) {
value = ctx->fcr31;
value = (value & ~FPU_CSR_RM) |
mips_rm[modeindex(value)];
value = (value & ~FPU_CSR_RM) | modeindex(value);
pr_debug("%p gpr[%d]<-csr=%08x\n",
(void *) (xcp->cp0_epc),
MIPSInst_RT(ir), value);
@@ -939,9 +923,8 @@ emul:
* Don't write reserved bits,
* and convert to ieee library modes
*/
ctx->fcr31 = (value &
~(FPU_CSR_RSVD | FPU_CSR_RM)) |
ieee_rm[modeindex(value)];
ctx->fcr31 = (value & ~(FPU_CSR_RSVD | FPU_CSR_RM)) |
modeindex(value);
}
if ((ctx->fcr31 >> 5) & ctx->fcr31 & FPU_CSR_ALL_E) {
return SIGFPE;
@@ -1515,7 +1498,7 @@ copcsr:
oldrm = ieee754_csr.rm;
SPFROMREG(fs, MIPSInst_FS(ir));
ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
rv.w = ieee754sp_tint(fs);
ieee754_csr.rm = oldrm;
rfmt = w_fmt;
@@ -1539,7 +1522,7 @@ copcsr:
oldrm = ieee754_csr.rm;
SPFROMREG(fs, MIPSInst_FS(ir));
ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
rv.l = ieee754sp_tlong(fs);
ieee754_csr.rm = oldrm;
rfmt = l_fmt;
@@ -1692,7 +1675,7 @@ dcopuop:
oldrm = ieee754_csr.rm;
DPFROMREG(fs, MIPSInst_FS(ir));
ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
rv.w = ieee754dp_tint(fs);
ieee754_csr.rm = oldrm;
rfmt = w_fmt;
@@ -1716,7 +1699,7 @@ dcopuop:
oldrm = ieee754_csr.rm;
DPFROMREG(fs, MIPSInst_FS(ir));
ieee754_csr.rm = ieee_rm[modeindex(MIPSInst_FUNC(ir))];
ieee754_csr.rm = modeindex(MIPSInst_FUNC(ir));
rv.l = ieee754dp_tlong(fs);
ieee754_csr.rm = oldrm;
rfmt = l_fmt;
@@ -1926,11 +1909,7 @@ int fpu_emulator_cop1Handler(struct pt_regs *xcp, struct mips_fpu_struct *ctx,
* ieee754_csr. But ieee754_csr.rm is ieee
* library modes. (not mips rounding mode)
*/
/* convert to ieee library modes */
ieee754_csr.rm = ieee_rm[ieee754_csr.rm];
sig = cop1Emulate(xcp, ctx, dec_insn, fault_addr);
/* revert to mips rounding mode */
ieee754_csr.rm = mips_rm[ieee754_csr.rm];
}
if (has_fpu)