This patch adds the Divide Doubleword Extended instructions.
The implementation builds on the unsigned helper provided in
the previous patch.
V2: Updated to use the host-utils 128 bit divide.
Signed-off-by: Tom Musta <tommu...@gmail.com>
---
include/qemu/host-utils.h | 14 ++++++++++++++
target-ppc/helper.h | 1 +
target-ppc/int_helper.c | 23 +++++++++++++++++++++++
target-ppc/translate.c | 4 ++++
util/host-utils.c | 37 +++++++++++++++++++++++++++++++++++++
5 files changed, 79 insertions(+), 0 deletions(-)
diff --git a/include/qemu/host-utils.h b/include/qemu/host-utils.h
index 0ca187d..39fe018 100644
--- a/include/qemu/host-utils.h
+++ b/include/qemu/host-utils.h
@@ -57,10 +57,24 @@ static inline int divu128(uint64_t *plow, uint64_t *phigh,
uint64_t divisor)
return result > UINT64_MAX;
}
}
+
+static inline int divs128(int64_t *plow, int64_t *phigh, int64_t divisor)
+{
+ if (divisor == 0) {
+ return 1;
+ } else {
+ __int128_t dividend = ((__int128_t)*phigh << 64) | *plow;
+ __int128_t result = dividend / divisor;
+ *plow = result;
+ *phigh = dividend % divisor;
+ return (result > INT64_MAX) | (result < INT64_MIN);
+ }
+}
#else
void muls64(uint64_t *phigh, uint64_t *plow, int64_t a, int64_t b);
void mulu64(uint64_t *phigh, uint64_t *plow, uint64_t a, uint64_t b);
int divu128(uint64_t *plow, uint64_t *phigh, uint64_t divisor);
+int divs128(int64_t *plow, int64_t *phigh, int64_t divisor);
#endif
/**
diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index 3eff4df..4359009 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -32,6 +32,7 @@ DEF_HELPER_5(lscbx, tl, env, tl, i32, i32, i32)
#if defined(TARGET_PPC64)
DEF_HELPER_3(mulldo, i64, env, i64, i64)
DEF_HELPER_4(divdeu, i64, env, i64, i64, i32)
+DEF_HELPER_4(divde, i64, env, i64, i64, i32)
#endif
DEF_HELPER_FLAGS_1(cntlzw, TCG_CALL_NO_RWG_SE, tl, tl)
diff --git a/target-ppc/int_helper.c b/target-ppc/int_helper.c
index d6dcac9..9b289e7 100644
--- a/target-ppc/int_helper.c
+++ b/target-ppc/int_helper.c
@@ -65,6 +65,29 @@ uint64_t helper_divdeu(CPUPPCState *env, uint64_t ra,
uint64_t rb, uint32_t oe)
return rt;
}
+uint64_t helper_divde(CPUPPCState *env, uint64_t rau, uint64_t rbu, uint32_t
oe)
+{
+ int64_t rt = 0;
+ int64_t ra = (int64_t)rau;
+ int64_t rb = (int64_t)rbu;
+ int overflow = divs128(&rt, &ra, rb);
+
+ if (unlikely(overflow)) {
+ rt = 0; /* Undefined */
+ }
+
+ if (oe) {
+
+ if (unlikely(overflow)) {
+ env->so = env->ov = 1;
+ } else {
+ env->ov = 0;
+ }
+ }
+
+ return rt;
+}
+
#endif
diff --git a/target-ppc/translate.c b/target-ppc/translate.c
index 7a51c6d..b274a15 100644
--- a/target-ppc/translate.c
+++ b/target-ppc/translate.c
@@ -1048,6 +1048,8 @@ static void gen_##name(DisasContext *ctx)
\
GEN_DIVDE(divdeu, divdeu, 0);
GEN_DIVDE(divdeuo, divdeu, 1);
+GEN_DIVDE(divde, divde, 0);
+GEN_DIVDE(divdeo, divde, 1);
#endif
@@ -9613,6 +9615,8 @@ GEN_INT_ARITH_DIVD(divdo, 0x1F, 1, 1),
GEN_HANDLER_E(divdeu, 0x1F, 0x09, 0x0C, 0x00000000, PPC_NONE, PPC2_ISA206),
GEN_HANDLER_E(divdeuo, 0x1F, 0x09, 0x1C, 0x00000000, PPC_NONE, PPC2_ISA206),
+GEN_HANDLER_E(divde, 0x1F, 0x09, 0x0D, 0x00000000, PPC_NONE, PPC2_ISA206),
+GEN_HANDLER_E(divdeo, 0x1F, 0x09, 0x1D, 0x00000000, PPC_NONE, PPC2_ISA206),
#undef GEN_INT_ARITH_MUL_HELPER
#define GEN_INT_ARITH_MUL_HELPER(name, opc3) \
diff --git a/util/host-utils.c b/util/host-utils.c
index b6f7a6e..140e25c 100644
--- a/util/host-utils.c
+++ b/util/host-utils.c
@@ -124,4 +124,41 @@ int divu128(uint64_t *plow, uint64_t *phigh, uint64_t
divisor)
return 0;
}
}
+
+int divs128(int64_t *plow, int64_t *phigh, int64_t divisor)
+{
+ int sgn_dvdnd = *phigh < 0;
+ int sgn_divsr = divisor < 0;
+ int overflow = 0;
+
+ if (sgn_dvdnd) {
+ *plow = ~(*plow);
+ *phigh = ~(*phigh);
+ if (*plow == (int64_t)-1) {
+ *plow = 0;
+ (*phigh)++;
+ } else {
+ (*plow)++;
+ }
+ }
+
+ if (sgn_divsr) {
+ divisor = 0 - divisor;
+ }
+
+ overflow = divu128((uint64_t *)plow, (uint64_t *)phigh, (uint64_t)divisor);
+
+ if (sgn_dvdnd ^ sgn_divsr) {
+ *plow = 0 - *plow;
+ }
+
+ if (!overflow) {
+ if ((*plow < 0) ^ (sgn_dvdnd ^ sgn_divsr)) {
+ overflow = 1;
+ }
+ }
+
+ return overflow;
+}
+
#endif /* !CONFIG_INT128 */
--
1.7.1
