According to the ISA, for instruction DENBCD:
"If an invalid BCD digit or sign code is detected in the source
operand, an invalid-operation exception (VXCVI) occurs."
In the Invalid Operation Exception section, there is the situation:
"When Invalid Operation Exception is disabled (VE=0) and Invalid
Operation occurs (...) If the operation is an (...) or format the
target FPR is set to a Quiet NaN". This was not being done in
QEMU.
This patch sets the result to QNaN when the instruction DENBCD causes
an Invalid Operation Exception.
Signed-off-by: Víctor Colombo <victor.colombo@eldorado.org.br>
---
target/ppc/dfp_helper.c | 26 ++++++++++++++++++++++++--
1 file changed, 24 insertions(+), 2 deletions(-)
diff --git a/target/ppc/dfp_helper.c b/target/ppc/dfp_helper.c
index be7aa5357a..cc024316d5 100644
--- a/target/ppc/dfp_helper.c
+++ b/target/ppc/dfp_helper.c
@@ -1147,6 +1147,26 @@ static inline uint8_t dfp_get_bcd_digit_128(ppc_vsr_t
*t, unsigned n)
return t->VsrD((n & 0x10) ? 0 : 1) >> ((n << 2) & 63) & 15;
}
+static inline void dfp_invalid_op_vxcvi_64(struct PPC_DFP *dfp)
+{
+ /* TODO: fpscr is incorrectly not being saved to env */
+ dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FPSCR_VE);
+ if ((dfp->env->fpscr & FP_VE) == 0) {
+ dfp->vt.VsrD(1) = 0x7c00000000000000; /* QNaN */
+ }
+}
+
+
+static inline void dfp_invalid_op_vxcvi_128(struct PPC_DFP *dfp)
+{
+ /* TODO: fpscr is incorrectly not being saved to env */
+ dfp_set_FPSCR_flag(dfp, FP_VX | FP_VXCVI, FPSCR_VE);
+ if ((dfp->env->fpscr & FP_VE) == 0) {
+ dfp->vt.VsrD(0) = 0x7c00000000000000; /* QNaN */
+ dfp->vt.VsrD(1) = 0x0;
+ }
+}
+
#define DFP_HELPER_ENBCD(op, size) \
void helper_##op(CPUPPCState *env, ppc_fprp_t *t, ppc_fprp_t *b, \
uint32_t s) \
@@ -1173,7 +1193,8 @@ void helper_##op(CPUPPCState *env, ppc_fprp_t *t,
ppc_fprp_t *b, \
sgn = 0; \
break; \
default: \
- dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE); \
+ dfp_invalid_op_vxcvi_##size(&dfp); \
+ set_dfp##size(t, &dfp.vt); \
return; \
} \
} \
@@ -1183,7 +1204,8 @@ void helper_##op(CPUPPCState *env, ppc_fprp_t *t,
ppc_fprp_t *b, \
digits[(size) / 4 - n] = dfp_get_bcd_digit_##size(&dfp.vb, \
offset++); \
if (digits[(size) / 4 - n] > 10) { \
- dfp_set_FPSCR_flag(&dfp, FP_VX | FP_VXCVI, FPSCR_VE); \
+ dfp_invalid_op_vxcvi_##size(&dfp); \
+ set_dfp##size(t, &dfp.vt); \
return; \
} else { \
nonzero |= (digits[(size) / 4 - n] > 0); \