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author Patrick Mackinlay <pmackinlay@hotmail.com>2019-02-18 17:09:01 +0700
committer Patrick Mackinlay <pmackinlay@hotmail.com>2019-02-18 17:09:01 +0700
commit4ada281e4c75650b656ee24738c4f27de5f7b498 (patch)
tree5f5731f39132d2b9b94b0d72a4bd7b8427e9a446
parent12c73111219b52f83bcb4cbb899df375c5115dd8 (diff)
mips3: trivial changes (nw)
* use the new 64x64 multiply helpers * make sure unordered exceptions are generated by abs.fmt * correct an unimportant drc flag
-rw-r--r--src/devices/cpu/mips/mips3.cpp38
-rw-r--r--src/devices/cpu/mips/mips3fe.cpp4
-rw-r--r--src/devices/cpu/mips/r4000.cpp51
3 files changed, 13 insertions, 80 deletions
diff --git a/src/devices/cpu/mips/mips3.cpp b/src/devices/cpu/mips/mips3.cpp
index df9ff7f96ba..178d81fadbd 100644
--- a/src/devices/cpu/mips/mips3.cpp
+++ b/src/devices/cpu/mips/mips3.cpp
@@ -3530,47 +3530,13 @@ void mips3_device::handle_special(uint32_t op)
m_core->icount -= 35;
break;
case 0x1c: /* DMULT */
- {
- uint64_t a_hi = (uint32_t)(RSVAL64 >> 32);
- uint64_t b_hi = (uint32_t)(RTVAL64 >> 32);
- uint64_t a_lo = (uint32_t)RSVAL64;
- uint64_t b_lo = (uint32_t)RTVAL64;
- uint64_t p1 = a_lo * b_lo;
- uint64_t p2 = a_hi * b_lo;
- uint64_t p3 = a_lo * b_hi;
- uint64_t p4 = a_hi * b_hi;
- uint64_t carry = (uint32_t)(((p1 >> 32) + (uint32_t)p2 + (uint32_t)p3) >> 32);
-
- LOVAL64 = p1 + (p2 << 32) + (p3 << 32);
- HIVAL64 = p4 + (p2 >> 32) + (p3 >> 32) + carry;
-
- // Adjust for sign
- if (RSVAL64 < 0)
- HIVAL64 -= RTVAL64;
- if (RTVAL64 < 0)
- HIVAL64 -= RSVAL64;
-
+ LOVAL64 = mul_64x64(RSVAL64, RTVAL64, reinterpret_cast<s64 *>(&HIVAL64));
m_core->icount -= 7;
break;
- }
case 0x1d: /* DMULTU */
- {
- uint64_t a_hi = (uint32_t)(RSVAL64 >> 32);
- uint64_t b_hi = (uint32_t)(RTVAL64 >> 32);
- uint64_t a_lo = (uint32_t)RSVAL64;
- uint64_t b_lo = (uint32_t)RTVAL64;
- uint64_t p1 = a_lo * b_lo;
- uint64_t p2 = a_hi * b_lo;
- uint64_t p3 = a_lo * b_hi;
- uint64_t p4 = a_hi * b_hi;
- uint64_t carry = (uint32_t)(((p1 >> 32) + (uint32_t)p2 + (uint32_t)p3) >> 32);
-
- LOVAL64 = p1 + (p2 << 32) + (p3 << 32);
- HIVAL64 = p4 + (p2 >> 32) + (p3 >> 32) + carry;
-
+ LOVAL64 = mulu_64x64(RSVAL64, RTVAL64, &HIVAL64);
m_core->icount -= 7;
break;
- }
case 0x1e: /* DDIV */
if (RTVAL64)
{
diff --git a/src/devices/cpu/mips/mips3fe.cpp b/src/devices/cpu/mips/mips3fe.cpp
index ff0c59797d9..77b72c9b48b 100644
--- a/src/devices/cpu/mips/mips3fe.cpp
+++ b/src/devices/cpu/mips/mips3fe.cpp
@@ -316,13 +316,13 @@ bool mips3_frontend::describe_special(uint32_t op, opcode_desc &desc)
return true;
case 0x10: // MFHI
- desc.regin[0] |= REGFLAG_HI;
+ desc.regin[2] |= REGFLAG_HI;
desc.regout[0] |= REGFLAG_R(RDREG);
return true;
case 0x11: // MTHI
desc.regin[0] |= REGFLAG_R(RSREG);
- desc.regout[0] |= REGFLAG_HI;
+ desc.regout[2] |= REGFLAG_HI;
return true;
case 0x12: // MFLO
diff --git a/src/devices/cpu/mips/r4000.cpp b/src/devices/cpu/mips/r4000.cpp
index 7aedc9054e1..ca95b107c65 100644
--- a/src/devices/cpu/mips/r4000.cpp
+++ b/src/devices/cpu/mips/r4000.cpp
@@ -486,48 +486,12 @@ void r4000_base_device::cpu_execute(u32 const op)
m_icount -= 35;
break;
case 0x1c: // DMULT
- {
- u64 const a_hi = u32(m_r[RSREG] >> 32);
- u64 const b_hi = u32(m_r[RTREG] >> 32);
- u64 const a_lo = u32(m_r[RSREG]);
- u64 const b_lo = u32(m_r[RTREG]);
-
- u64 const p1 = a_lo * b_lo;
- u64 const p2 = a_hi * b_lo;
- u64 const p3 = a_lo * b_hi;
- u64 const p4 = a_hi * b_hi;
- u64 const carry = u32(((p1 >> 32) + u32(p2) + u32(p3)) >> 32);
-
- m_lo = p1 + (p2 << 32) + (p3 << 32);
- m_hi = p4 + (p2 >> 32) + (p3 >> 32) + carry;
-
- // adjust for sign
- if (s64(m_r[RSREG]) < 0)
- m_hi -= m_r[RTREG];
- if (s64(m_r[RTREG]) < 0)
- m_hi -= m_r[RSREG];
-
- m_icount -= 7;
- }
+ m_lo = mul_64x64(m_r[RSREG], m_r[RTREG], reinterpret_cast<s64 *>(&m_hi));
+ m_icount -= 7;
break;
case 0x1d: // DMULTU
- {
- u64 const a_hi = u32(m_r[RSREG] >> 32);
- u64 const b_hi = u32(m_r[RTREG] >> 32);
- u64 const a_lo = u32(m_r[RSREG]);
- u64 const b_lo = u32(m_r[RTREG]);
-
- u64 const p1 = a_lo * b_lo;
- u64 const p2 = a_hi * b_lo;
- u64 const p3 = a_lo * b_hi;
- u64 const p4 = a_hi * b_hi;
- u64 const carry = u32(((p1 >> 32) + u32(p2) + u32(p3)) >> 32);
-
- m_lo = p1 + (p2 << 32) + (p3 << 32);
- m_hi = p4 + (p2 >> 32) + (p3 >> 32) + carry;
-
- m_icount -= 7;
- }
+ m_lo = mulu_64x64(m_r[RSREG], m_r[RTREG], &m_hi);
+ m_icount -= 7;
break;
case 0x1e: // DDIV
if (m_r[RTREG])
@@ -1797,7 +1761,7 @@ void r4000_base_device::cp1_execute(u32 const op)
if (f32_lt(float32_t{ u32(m_f[FSREG]) }, float32_t{ 0 }))
cp1_set(FDREG, f32_mul(float32_t{ u32(m_f[FSREG]) }, i32_to_f32(-1)).v);
else
- m_f[FDREG] = m_f[FSREG];
+ cp1_set(FDREG, m_f[FSREG]);
}
break;
case 0x06: // MOV.S
@@ -2085,7 +2049,7 @@ void r4000_base_device::cp1_execute(u32 const op)
if (f64_lt(float64_t{ m_f[FSREG] }, float64_t{ 0 }))
cp1_set(FDREG, f64_mul(float64_t{ m_f[FSREG] }, i32_to_f64(-1)).v);
else
- m_f[FDREG] = m_f[FSREG];
+ cp1_set(FDREG, m_f[FSREG]);
}
break;
case 0x06: // MOV.D
@@ -2808,6 +2772,9 @@ void r4000_base_device::address_error(int intention, u64 const address)
m_cp0[CP0_BadVAddr] = address;
cpu_exception((intention & TRANSLATE_WRITE) ? EXCEPTION_ADES : EXCEPTION_ADEL);
+
+ // address errors shouldn't typically occur, so a breakpoint is handy
+ machine().debug_break();
}
}