MIPS: math-emu: Switch to using the MIPS rounding modes.
authorRalf Baechle <ralf@linux-mips.org>
Wed, 30 Apr 2014 09:21:55 +0000 (11:21 +0200)
committerRalf Baechle <ralf@linux-mips.org>
Fri, 23 May 2014 13:12:38 +0000 (15:12 +0200)
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>
15 files changed:
arch/mips/math-emu/cp1emu.c
arch/mips/math-emu/dp_add.c
arch/mips/math-emu/dp_sqrt.c
arch/mips/math-emu/dp_sub.c
arch/mips/math-emu/dp_tint.c
arch/mips/math-emu/dp_tlong.c
arch/mips/math-emu/ieee754.h
arch/mips/math-emu/ieee754dp.c
arch/mips/math-emu/ieee754sp.c
arch/mips/math-emu/sp_add.c
arch/mips/math-emu/sp_fdp.c
arch/mips/math-emu/sp_sqrt.c
arch/mips/math-emu/sp_sub.c
arch/mips/math-emu/sp_tint.c
arch/mips/math-emu/sp_tlong.c

index b31ce6cdb6b947fe64f2070a397a8a693f88fba7..03e233223af72221c96effc3a5a3835f2e9623dc 100644 (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)
index 9c98b96f728771083d8e7d9cef9573e55e649576..7f64577df98492a9c721e237f15122933b8f26b2 100644 (file)
@@ -91,7 +91,7 @@ union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y)
                if (xs == ys)
                        return x;
                else
-                       return ieee754dp_zero(ieee754_csr.rm == IEEE754_RD);
+                       return ieee754dp_zero(ieee754_csr.rm == FPU_CSR_RD);
 
        case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
        case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
@@ -168,7 +168,7 @@ union ieee754dp ieee754dp_add(union ieee754dp x, union ieee754dp y)
                        xs = ys;
                }
                if (xm == 0)
-                       return ieee754dp_zero(ieee754_csr.rm == IEEE754_RD);
+                       return ieee754dp_zero(ieee754_csr.rm == FPU_CSR_RD);
 
                /*
                 * Normalize to rounding precision.
index 0384c094b1aa8036be1b184bcb791e5a4f23cfaf..041bbb6124bbde5ec679e7a855f147bf02c24b23 100644 (file)
@@ -80,7 +80,7 @@ union ieee754dp ieee754dp_sqrt(union ieee754dp x)
        oldcsr = ieee754_csr;
        ieee754_csr.mx &= ~IEEE754_INEXACT;
        ieee754_csr.sx &= ~IEEE754_INEXACT;
-       ieee754_csr.rm = IEEE754_RN;
+       ieee754_csr.rm = FPU_CSR_RN;
 
        /* adjust exponent to prevent overflow */
        scalx = 0;
@@ -122,7 +122,7 @@ union ieee754dp ieee754dp_sqrt(union ieee754dp x)
        /* twiddle last bit to force y correctly rounded */
 
        /* set RZ, clear INEX flag */
-       ieee754_csr.rm = IEEE754_RZ;
+       ieee754_csr.rm = FPU_CSR_RZ;
        ieee754_csr.sx &= ~IEEE754_INEXACT;
 
        /* t=x/y; ...chopped quotient, possibly inexact */
@@ -139,10 +139,10 @@ union ieee754dp ieee754dp_sqrt(union ieee754dp x)
                oldcsr.sx |= IEEE754_INEXACT;
 
                switch (oldcsr.rm) {
-               case IEEE754_RU:
+               case FPU_CSR_RU:
                        y.bits += 1;
                        /* drop through */
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        t.bits += 1;
                        break;
                }
index d502984df7ccd1419b566e2360dd1ce57a519242..7a174029043a674348619f65de6d5433dd25b283 100644 (file)
@@ -91,7 +91,7 @@ union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y)
                if (xs != ys)
                        return x;
                else
-                       return ieee754dp_zero(ieee754_csr.rm == IEEE754_RD);
+                       return ieee754dp_zero(ieee754_csr.rm == FPU_CSR_RD);
 
        case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
        case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
@@ -171,7 +171,7 @@ union ieee754dp ieee754dp_sub(union ieee754dp x, union ieee754dp y)
                        xs = ys;
                }
                if (xm == 0) {
-                       if (ieee754_csr.rm == IEEE754_RD)
+                       if (ieee754_csr.rm == FPU_CSR_RD)
                                return ieee754dp_zero(1);       /* round negative inf. => sign = -1 */
                        else
                                return ieee754dp_zero(0);       /* other round modes   => sign = 1 */
index 972dba0baca0eb7e3ee5385343205e3bfc305072..6ffc336c530e3e11c48c1dcb8ab9eb50224b7ff4 100644 (file)
@@ -74,17 +74,17 @@ int ieee754dp_tint(union ieee754dp x)
                   to be zero */
                odd = (xm & 0x1) != 0x0;
                switch (ieee754_csr.rm) {
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        if (round && (sticky || odd))
                                xm++;
                        break;
-               case IEEE754_RZ:
+               case FPU_CSR_RZ:
                        break;
-               case IEEE754_RU:        /* toward +Infinity */
+               case FPU_CSR_RU:        /* toward +Infinity */
                        if ((round || sticky) && !xs)
                                xm++;
                        break;
-               case IEEE754_RD:        /* toward -Infinity */
+               case FPU_CSR_RD:        /* toward -Infinity */
                        if ((round || sticky) && xs)
                                xm++;
                        break;
index afaf953e576db8bab5ad6dd2449a578ab4bd6a78..9cdc145b75e012d75a22f146c1e3c3b5c65a4e7f 100644 (file)
@@ -79,17 +79,17 @@ s64 ieee754dp_tlong(union ieee754dp x)
                }
                odd = (xm & 0x1) != 0x0;
                switch (ieee754_csr.rm) {
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        if (round && (sticky || odd))
                                xm++;
                        break;
-               case IEEE754_RZ:
+               case FPU_CSR_RZ:
                        break;
-               case IEEE754_RU:        /* toward +Infinity */
+               case FPU_CSR_RU:        /* toward +Infinity */
                        if ((round || sticky) && !xs)
                                xm++;
                        break;
-               case IEEE754_RD:        /* toward -Infinity */
+               case FPU_CSR_RD:        /* toward -Infinity */
                        if ((round || sticky) && xs)
                                xm++;
                        break;
index 2fa939c612f6d0c725c9cd820544e4dd8eb04909..43c4fb522ac2d4d609211b93a75830f231207ad8 100644 (file)
@@ -126,13 +126,6 @@ enum {
 #define IEEE754_CGT    0x04
 #define IEEE754_CUN    0x08
 
-/* rounding mode
-*/
-#define IEEE754_RN     0       /* round to nearest */
-#define IEEE754_RZ     1       /* round toward zero  */
-#define IEEE754_RD     2       /* round toward -Infinity */
-#define IEEE754_RU     3       /* round toward +Infinity */
-
 /* "normal" comparisons
 */
 static inline int ieee754sp_eq(union ieee754sp x, union ieee754sp y)
index 087a6f38b1490465a2a8ba35721c0a5144cd04c5..fd134675fc2e847444070e2f26213ee642477396 100644 (file)
@@ -67,17 +67,17 @@ static u64 ieee754dp_get_rounding(int sn, u64 xm)
         */
        if (xm & (DP_MBIT(3) - 1)) {
                switch (ieee754_csr.rm) {
-               case IEEE754_RZ:
+               case FPU_CSR_RZ:
                        break;
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        xm += 0x3 + ((xm >> 3) & 1);
                        /* xm += (xm&0x8)?0x4:0x3 */
                        break;
-               case IEEE754_RU:        /* toward +Infinity */
+               case FPU_CSR_RU:        /* toward +Infinity */
                        if (!sn)        /* ?? */
                                xm += 0x8;
                        break;
-               case IEEE754_RD:        /* toward -Infinity */
+               case FPU_CSR_RD:        /* toward -Infinity */
                        if (sn) /* ?? */
                                xm += 0x8;
                        break;
@@ -108,15 +108,15 @@ union ieee754dp ieee754dp_format(int sn, int xe, u64 xm)
                        ieee754_setcx(IEEE754_INEXACT);
 
                        switch(ieee754_csr.rm) {
-                       case IEEE754_RN:
-                       case IEEE754_RZ:
+                       case FPU_CSR_RN:
+                       case FPU_CSR_RZ:
                                return ieee754dp_zero(sn);
-                       case IEEE754_RU:    /* toward +Infinity */
+                       case FPU_CSR_RU:    /* toward +Infinity */
                                if (sn == 0)
                                        return ieee754dp_min(0);
                                else
                                        return ieee754dp_zero(1);
-                       case IEEE754_RD:    /* toward -Infinity */
+                       case FPU_CSR_RD:    /* toward -Infinity */
                                if (sn == 0)
                                        return ieee754dp_zero(0);
                                else
@@ -172,16 +172,16 @@ union ieee754dp ieee754dp_format(int sn, int xe, u64 xm)
                ieee754_setcx(IEEE754_INEXACT);
                /* -O can be table indexed by (rm,sn) */
                switch (ieee754_csr.rm) {
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        return ieee754dp_inf(sn);
-               case IEEE754_RZ:
+               case FPU_CSR_RZ:
                        return ieee754dp_max(sn);
-               case IEEE754_RU:        /* toward +Infinity */
+               case FPU_CSR_RU:        /* toward +Infinity */
                        if (sn == 0)
                                return ieee754dp_inf(0);
                        else
                                return ieee754dp_max(1);
-               case IEEE754_RD:        /* toward -Infinity */
+               case FPU_CSR_RD:        /* toward -Infinity */
                        if (sn == 0)
                                return ieee754dp_max(0);
                        else
index e4cec15845b91bfd200965d23f01244033349931..d348efe914454725bcbcafa3bf54d300dd59a43c 100644 (file)
@@ -67,17 +67,17 @@ static unsigned ieee754sp_get_rounding(int sn, unsigned xm)
         */
        if (xm & (SP_MBIT(3) - 1)) {
                switch (ieee754_csr.rm) {
-               case IEEE754_RZ:
+               case FPU_CSR_RZ:
                        break;
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        xm += 0x3 + ((xm >> 3) & 1);
                        /* xm += (xm&0x8)?0x4:0x3 */
                        break;
-               case IEEE754_RU:        /* toward +Infinity */
+               case FPU_CSR_RU:        /* toward +Infinity */
                        if (!sn)        /* ?? */
                                xm += 0x8;
                        break;
-               case IEEE754_RD:        /* toward -Infinity */
+               case FPU_CSR_RD:        /* toward -Infinity */
                        if (sn) /* ?? */
                                xm += 0x8;
                        break;
@@ -108,15 +108,15 @@ union ieee754sp ieee754sp_format(int sn, int xe, unsigned xm)
                        ieee754_setcx(IEEE754_INEXACT);
 
                        switch(ieee754_csr.rm) {
-                       case IEEE754_RN:
-                       case IEEE754_RZ:
+                       case FPU_CSR_RN:
+                       case FPU_CSR_RZ:
                                return ieee754sp_zero(sn);
-                       case IEEE754_RU:      /* toward +Infinity */
+                       case FPU_CSR_RU:      /* toward +Infinity */
                                if (sn == 0)
                                        return ieee754sp_min(0);
                                else
                                        return ieee754sp_zero(1);
-                       case IEEE754_RD:      /* toward -Infinity */
+                       case FPU_CSR_RD:      /* toward -Infinity */
                                if (sn == 0)
                                        return ieee754sp_zero(0);
                                else
@@ -170,16 +170,16 @@ union ieee754sp ieee754sp_format(int sn, int xe, unsigned xm)
                ieee754_setcx(IEEE754_INEXACT);
                /* -O can be table indexed by (rm,sn) */
                switch (ieee754_csr.rm) {
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        return ieee754sp_inf(sn);
-               case IEEE754_RZ:
+               case FPU_CSR_RZ:
                        return ieee754sp_max(sn);
-               case IEEE754_RU:        /* toward +Infinity */
+               case FPU_CSR_RU:        /* toward +Infinity */
                        if (sn == 0)
                                return ieee754sp_inf(0);
                        else
                                return ieee754sp_max(1);
-               case IEEE754_RD:        /* toward -Infinity */
+               case FPU_CSR_RD:        /* toward -Infinity */
                        if (sn == 0)
                                return ieee754sp_max(0);
                        else
index a0bc95cea1cc61491255c960b074e99decbaa73f..2d84d460cb677e0841f59be14598dd9a6c6b2ceb 100644 (file)
@@ -91,7 +91,7 @@ union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y)
                if (xs == ys)
                        return x;
                else
-                       return ieee754sp_zero(ieee754_csr.rm == IEEE754_RD);
+                       return ieee754sp_zero(ieee754_csr.rm == FPU_CSR_RD);
 
        case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
        case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
@@ -165,7 +165,7 @@ union ieee754sp ieee754sp_add(union ieee754sp x, union ieee754sp y)
                        xs = ys;
                }
                if (xm == 0)
-                       return ieee754sp_zero(ieee754_csr.rm == IEEE754_RD);
+                       return ieee754sp_zero(ieee754_csr.rm == FPU_CSR_RD);
 
                /*
                 * Normalize in extended single precision
index 90b9ec45e984298a16e02441974ee88ae64a4cc8..1b266fb16973093016a96eb5c77197eebfc390ef 100644 (file)
@@ -57,8 +57,8 @@ union ieee754sp ieee754sp_fdp(union ieee754dp x)
                /* can't possibly be sp representable */
                ieee754_setcx(IEEE754_UNDERFLOW);
                ieee754_setcx(IEEE754_INEXACT);
-               if ((ieee754_csr.rm == IEEE754_RU && !xs) ||
-                               (ieee754_csr.rm == IEEE754_RD && xs))
+               if ((ieee754_csr.rm == FPU_CSR_RU && !xs) ||
+                               (ieee754_csr.rm == FPU_CSR_RD && xs))
                        return ieee754sp_mind(xs);
                return ieee754sp_zero(xs);
 
index 94f5befa1d7080ddc38c43e22b015978a3d0b5cc..b7c098a86f951013f74d5d3838fef5ae014cbd9b 100644 (file)
@@ -100,10 +100,10 @@ union ieee754sp ieee754sp_sqrt(union ieee754sp x)
        if (ix != 0) {
                ieee754_setcx(IEEE754_INEXACT);
                switch (ieee754_csr.rm) {
-               case IEEE754_RU:
+               case FPU_CSR_RU:
                        q += 2;
                        break;
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        q += (q & 1);
                        break;
                }
index e813f4fee78475f358dff11be6dc1d3ad6b507e4..8592e49032b876d9e4eb1921e9385b05814e5e19 100644 (file)
@@ -91,7 +91,7 @@ union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y)
                if (xs != ys)
                        return x;
                else
-                       return ieee754sp_zero(ieee754_csr.rm == IEEE754_RD);
+                       return ieee754sp_zero(ieee754_csr.rm == FPU_CSR_RD);
 
        case CLPAIR(IEEE754_CLASS_NORM, IEEE754_CLASS_ZERO):
        case CLPAIR(IEEE754_CLASS_DNORM, IEEE754_CLASS_ZERO):
@@ -165,7 +165,7 @@ union ieee754sp ieee754sp_sub(union ieee754sp x, union ieee754sp y)
                        xs = ys;
                }
                if (xm == 0) {
-                       if (ieee754_csr.rm == IEEE754_RD)
+                       if (ieee754_csr.rm == FPU_CSR_RD)
                                return ieee754sp_zero(1);       /* round negative inf. => sign = -1 */
                        else
                                return ieee754sp_zero(0);       /* other round modes   => sign = 1 */
index e1dee56ebc541cb8c2e24bf061d2ff15a9bb94ec..091299a317980b6bf0cfd84f0958b1f271d2bf9d 100644 (file)
@@ -79,17 +79,17 @@ int ieee754sp_tint(union ieee754sp x)
                }
                odd = (xm & 0x1) != 0x0;
                switch (ieee754_csr.rm) {
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        if (round && (sticky || odd))
                                xm++;
                        break;
-               case IEEE754_RZ:
+               case FPU_CSR_RZ:
                        break;
-               case IEEE754_RU:        /* toward +Infinity */
+               case FPU_CSR_RU:        /* toward +Infinity */
                        if ((round || sticky) && !xs)
                                xm++;
                        break;
-               case IEEE754_RD:        /* toward -Infinity */
+               case FPU_CSR_RD:        /* toward -Infinity */
                        if ((round || sticky) && xs)
                                xm++;
                        break;
index 67eff6ba9e18d71b44ead610b7e52f4833953f6e..9f3c742c1cea6ac264d1d4d66ef56b6916f675cb 100644 (file)
@@ -76,17 +76,17 @@ s64 ieee754sp_tlong(union ieee754sp x)
                }
                odd = (xm & 0x1) != 0x0;
                switch (ieee754_csr.rm) {
-               case IEEE754_RN:
+               case FPU_CSR_RN:
                        if (round && (sticky || odd))
                                xm++;
                        break;
-               case IEEE754_RZ:
+               case FPU_CSR_RZ:
                        break;
-               case IEEE754_RU:        /* toward +Infinity */
+               case FPU_CSR_RU:        /* toward +Infinity */
                        if ((round || sticky) && !xs)
                                xm++;
                        break;
-               case IEEE754_RD:        /* toward -Infinity */
+               case FPU_CSR_RD:        /* toward -Infinity */
                        if ((round || sticky) && xs)
                                xm++;
                        break;