On 07/23/2016 02:14 PM, Nikunj A Dadhania wrote:
Adding following instructions:
moduw: Modulo Unsigned Word
modsw: Modulo Signed Word
Signed-off-by: Nikunj A Dadhania <nik...@linux.vnet.ibm.com>
---
target-ppc/helper.h | 2 ++
target-ppc/int_helper.c | 15 +++++++++++++++
target-ppc/translate.c | 19 +++++++++++++++++++
3 files changed, 36 insertions(+)
diff --git a/target-ppc/helper.h b/target-ppc/helper.h
index 1f5cfd0..76072fd 100644
--- a/target-ppc/helper.h
+++ b/target-ppc/helper.h
@@ -41,6 +41,8 @@ DEF_HELPER_FLAGS_1(cntlzw, TCG_CALL_NO_RWG_SE, tl, tl)
DEF_HELPER_FLAGS_1(popcntb, TCG_CALL_NO_RWG_SE, tl, tl)
DEF_HELPER_FLAGS_1(popcntw, TCG_CALL_NO_RWG_SE, tl, tl)
DEF_HELPER_FLAGS_2(cmpb, TCG_CALL_NO_RWG_SE, tl, tl, tl)
+DEF_HELPER_FLAGS_2(modsw, TCG_CALL_NO_RWG_SE, i32, i32, i32)
+DEF_HELPER_FLAGS_2(moduw, TCG_CALL_NO_RWG_SE, i32, i32, i32)
DEF_HELPER_3(sraw, tl, env, tl, tl)
#if defined(TARGET_PPC64)
DEF_HELPER_FLAGS_1(cntlzd, TCG_CALL_NO_RWG_SE, tl, tl)
diff --git a/target-ppc/int_helper.c b/target-ppc/int_helper.c
index 7445376..631e0b4 100644
--- a/target-ppc/int_helper.c
+++ b/target-ppc/int_helper.c
@@ -139,6 +139,21 @@ uint64_t helper_divde(CPUPPCState *env, uint64_t rau,
uint64_t rbu, uint32_t oe)
#endif
+uint32_t helper_modsw(uint32_t rau, uint32_t rbu)
+{
+ int32_t ra = (int32_t) rau;
+ int32_t rb = (int32_t) rbu;
+
+ if ((rb == 0) || (ra == INT32_MIN && rb == -1)) {
+ return 0;
+ }
+ return ra % rb;
+}
+
+uint32_t helper_moduw(uint32_t ra, uint32_t rb)
+{
+ return rb ? ra % rb : 0;
+}
I think, like you, I got distracted by the current div implementation in ppc.
I've just re-read the spec and seen the "undefined" language. Which of course
gives us much more freedom.
With this freedom, we can do the division inline, without branches. Please see
target-mips/translate.c, gen_r6_muldiv.
Basically, we check for the offending cases and modify the divisor prior to the
division. For unsigned:
a / (b == 0 ? 1 : b)
For signed:
a / ((a == INT_MAX & b == -1) | (b == 0) ? : b)
r~
