[ARM] 3749/3: Correct VFP single/double conversion emulation
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>
diff --git a/arch/arm/vfp/vfpsingle.c b/arch/arm/vfp/vfpsingle.c
index dae2c2f..5bbd5d1 100644
--- a/arch/arm/vfp/vfpsingle.c
+++ b/arch/arm/vfp/vfpsingle.c
@@ -514,10 +514,6 @@
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:
@@ -1174,7 +1170,7 @@
{
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;
@@ -1184,10 +1180,22 @@
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,
@@ -1201,15 +1209,18 @@
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);
@@ -1227,7 +1238,7 @@
* 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);