Skip to content

Commit

Permalink
[ARM] 3749/3: Correct VFP single/double conversion emulation
Browse files Browse the repository at this point in the history 
Patch from Daniel Jacobowitz

The fcvtsd/fcvtds emulation was left behind when the numbering of double
precision registers was changed from 0-30 to 0-15.  Both conversion
instructions were writing their results to the wrong register.  Also,
the conversion instructions should stop after the first element even
if a vector length is specified.

Signed-off-by: Daniel Jacobowitz <dan@codesourcery.com>
Signed-off-by: Russell King <rmk+kernel@arm.linux.org.uk>
  • Loading branch information
Daniel Jacobowitz authored and Russell King committed Aug 27, 2006
1 parent 7c6f251 commit c29ecac
Show file tree
Hide file tree
Showing 2 changed files with 43 additions and 18 deletions.
28 changes: 21 additions & 7 deletions arch/arm/vfp/vfpdouble.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1127,7 +1127,7 @@ u32 vfp_double_cpdo(u32 inst, u32 fpscr)
{
u32 op = inst & FOP_MASK;
u32 exceptions = 0;
unsigned int dd = vfp_get_dd(inst);
unsigned int dest;
unsigned int dn = vfp_get_dn(inst);
unsigned int dm = vfp_get_dm(inst);
unsigned int vecitr, veclen, vecstride;
Expand All @@ -1136,11 +1136,21 @@ u32 vfp_double_cpdo(u32 inst, u32 fpscr)
veclen = fpscr & FPSCR_LENGTH_MASK;
vecstride = (1 + ((fpscr & FPSCR_STRIDE_MASK) == FPSCR_STRIDE_MASK)) * 2;

/*
* fcvtds takes an sN register number as destination, not dN.
* It also always operates on scalars.
*/
if ((inst & FEXT_MASK) == FEXT_FCVT) {
veclen = 0;
dest = vfp_get_sd(inst);
} else
dest = vfp_get_dd(inst);

/*
* If destination bank is zero, vector length is always '1'.
* ARM DDI0100F C5.1.3, C5.3.2.
*/
if (FREG_BANK(dd) == 0)
if (FREG_BANK(dest) == 0)
veclen = 0;

pr_debug("VFP: vecstride=%u veclen=%u\n", vecstride,
Expand All @@ -1153,16 +1163,20 @@ u32 vfp_double_cpdo(u32 inst, u32 fpscr)
for (vecitr = 0; vecitr <= veclen; vecitr += 1 << FPSCR_LENGTH_BIT) {
u32 except;

if (op == FOP_EXT)
if (op == FOP_EXT && (inst & FEXT_MASK) == FEXT_FCVT)
pr_debug("VFP: itr%d (s%u) = op[%u] (d%u)\n",
vecitr >> FPSCR_LENGTH_BIT,
dest, dn, dm);
else if (op == FOP_EXT)
pr_debug("VFP: itr%d (d%u) = op[%u] (d%u)\n",
vecitr >> FPSCR_LENGTH_BIT,
dd, dn, dm);
dest, dn, dm);
else
pr_debug("VFP: itr%d (d%u) = (d%u) op[%u] (d%u)\n",
vecitr >> FPSCR_LENGTH_BIT,
dd, dn, FOP_TO_IDX(op), dm);
dest, dn, FOP_TO_IDX(op), dm);

except = fop(dd, dn, dm, fpscr);
except = fop(dest, dn, dm, fpscr);
pr_debug("VFP: itr%d: exceptions=%08x\n",
vecitr >> FPSCR_LENGTH_BIT, except);

Expand All @@ -1180,7 +1194,7 @@ u32 vfp_double_cpdo(u32 inst, u32 fpscr)
* we encounter an exception. We continue.
*/

dd = FREG_BANK(dd) + ((FREG_IDX(dd) + vecstride) & 6);
dest = FREG_BANK(dest) + ((FREG_IDX(dest) + vecstride) & 6);
dn = FREG_BANK(dn) + ((FREG_IDX(dn) + vecstride) & 6);
if (FREG_BANK(dm) != 0)
dm = FREG_BANK(dm) + ((FREG_IDX(dm) + vecstride) & 6);
Expand Down
33 changes: 22 additions & 11 deletions arch/arm/vfp/vfpsingle.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -514,10 +514,6 @@ static u32 vfp_single_fcvtd(int dd, int unused, s32 m, u32 fpscr)
else
vdd.exponent = vsm.exponent + (1023 - 127);

/*
* Technically, if bit 0 of dd is set, this is an invalid
* instruction. However, we ignore this for efficiency.
*/
return vfp_double_normaliseround(dd, &vdd, fpscr, exceptions, "fcvtd");

pack_nan:
Expand Down Expand Up @@ -1174,7 +1170,7 @@ u32 vfp_single_cpdo(u32 inst, u32 fpscr)
{
u32 op = inst & FOP_MASK;
u32 exceptions = 0;
unsigned int sd = vfp_get_sd(inst);
unsigned int dest;
unsigned int sn = vfp_get_sn(inst);
unsigned int sm = vfp_get_sm(inst);
unsigned int vecitr, veclen, vecstride;
Expand All @@ -1183,11 +1179,23 @@ u32 vfp_single_cpdo(u32 inst, u32 fpscr)
veclen = fpscr & FPSCR_LENGTH_MASK;
vecstride = 1 + ((fpscr & FPSCR_STRIDE_MASK) == FPSCR_STRIDE_MASK);

/*
* fcvtsd takes a dN register number as destination, not sN.
* Technically, if bit 0 of dd is set, this is an invalid
* instruction. However, we ignore this for efficiency.
* It also only operates on scalars.
*/
if ((inst & FEXT_MASK) == FEXT_FCVT) {
veclen = 0;
dest = vfp_get_dd(inst);
} else
dest = vfp_get_sd(inst);

/*
* If destination bank is zero, vector length is always '1'.
* ARM DDI0100F C5.1.3, C5.3.2.
*/
if (FREG_BANK(sd) == 0)
if (FREG_BANK(dest) == 0)
veclen = 0;

pr_debug("VFP: vecstride=%u veclen=%u\n", vecstride,
Expand All @@ -1201,15 +1209,18 @@ u32 vfp_single_cpdo(u32 inst, u32 fpscr)
s32 m = vfp_get_float(sm);
u32 except;

if (op == FOP_EXT)
if (op == FOP_EXT && (inst & FEXT_MASK) == FEXT_FCVT)
pr_debug("VFP: itr%d (d%u) = op[%u] (s%u=%08x)\n",
vecitr >> FPSCR_LENGTH_BIT, dest, sn, sm, m);
else if (op == FOP_EXT)
pr_debug("VFP: itr%d (s%u) = op[%u] (s%u=%08x)\n",
vecitr >> FPSCR_LENGTH_BIT, sd, sn, sm, m);
vecitr >> FPSCR_LENGTH_BIT, dest, sn, sm, m);
else
pr_debug("VFP: itr%d (s%u) = (s%u) op[%u] (s%u=%08x)\n",
vecitr >> FPSCR_LENGTH_BIT, sd, sn,
vecitr >> FPSCR_LENGTH_BIT, dest, sn,
FOP_TO_IDX(op), sm, m);

except = fop(sd, sn, m, fpscr);
except = fop(dest, sn, m, fpscr);
pr_debug("VFP: itr%d: exceptions=%08x\n",
vecitr >> FPSCR_LENGTH_BIT, except);

Expand All @@ -1227,7 +1238,7 @@ u32 vfp_single_cpdo(u32 inst, u32 fpscr)
* we encounter an exception. We continue.
*/

sd = FREG_BANK(sd) + ((FREG_IDX(sd) + vecstride) & 7);
dest = FREG_BANK(dest) + ((FREG_IDX(dest) + vecstride) & 7);
sn = FREG_BANK(sn) + ((FREG_IDX(sn) + vecstride) & 7);
if (FREG_BANK(sm) != 0)
sm = FREG_BANK(sm) + ((FREG_IDX(sm) + vecstride) & 7);
Expand Down

0 comments on commit c29ecac

Please sign in to comment.