diff options
Diffstat (limited to 'target-alpha')
| -rw-r--r-- | target-alpha/helper.h | 1 | ||||
| -rw-r--r-- | target-alpha/int_helper.c | 51 | ||||
| -rw-r--r-- | target-alpha/translate.c | 7 |
3 files changed, 46 insertions, 13 deletions
diff --git a/target-alpha/helper.h b/target-alpha/helper.h index 42bb247e32..c3d8a3ee49 100644 --- a/target-alpha/helper.h +++ b/target-alpha/helper.h @@ -10,6 +10,7 @@ DEF_HELPER_FLAGS_1(cttz, TCG_CALL_NO_RWG_SE, i64, i64) DEF_HELPER_FLAGS_2(zap, TCG_CALL_NO_RWG_SE, i64, i64, i64) DEF_HELPER_FLAGS_2(zapnot, TCG_CALL_NO_RWG_SE, i64, i64, i64) +DEF_HELPER_FLAGS_1(cmpbe0, TCG_CALL_NO_RWG_SE, i64, i64) DEF_HELPER_FLAGS_2(cmpbge, TCG_CALL_NO_RWG_SE, i64, i64, i64) DEF_HELPER_FLAGS_2(minub8, TCG_CALL_NO_RWG_SE, i64, i64, i64) diff --git a/target-alpha/int_helper.c b/target-alpha/int_helper.c index 74f38cbe7b..d7f4774127 100644 --- a/target-alpha/int_helper.c +++ b/target-alpha/int_helper.c @@ -58,20 +58,47 @@ uint64_t helper_zap(uint64_t val, uint64_t mask) return helper_zapnot(val, ~mask); } -uint64_t helper_cmpbge(uint64_t op1, uint64_t op2) +uint64_t helper_cmpbe0(uint64_t a) { - uint8_t opa, opb, res; - int i; + uint64_t m = 0x7f7f7f7f7f7f7f7fULL; + uint64_t c = ~(((a & m) + m) | a | m); + /* a.......b.......c.......d.......e.......f.......g.......h....... */ + c |= c << 7; + /* ab......bc......cd......de......ef......fg......gh......h....... */ + c |= c << 14; + /* abcd....bcde....cdef....defg....efgh....fgh.....gh......h....... */ + c |= c << 28; + /* abcdefghbcdefgh.cdefgh..defgh...efgh....fgh.....gh......h....... */ + return c >> 56; +} - res = 0; - for (i = 0; i < 8; i++) { - opa = op1 >> (i * 8); - opb = op2 >> (i * 8); - if (opa >= opb) { - res |= 1 << i; - } - } - return res; +uint64_t helper_cmpbge(uint64_t a, uint64_t b) +{ + uint64_t mask = 0x00ff00ff00ff00ffULL; + uint64_t test = 0x0100010001000100ULL; + uint64_t al, ah, bl, bh, cl, ch; + + /* Separate the bytes to avoid false positives. */ + al = a & mask; + bl = b & mask; + ah = (a >> 8) & mask; + bh = (b >> 8) & mask; + + /* "Compare". If a byte in B is greater than a byte in A, + it will clear the test bit. */ + cl = ((al | test) - bl) & test; + ch = ((ah | test) - bh) & test; + + /* Fold all of the test bits into a contiguous set. */ + /* ch=.......a...............c...............e...............g........ */ + /* cl=.......b...............d...............f...............h........ */ + cl += ch << 1; + /* cl=......ab..............cd..............ef..............gh........ */ + cl |= cl << 14; + /* cl=......abcd............cdef............efgh............gh........ */ + cl |= cl << 28; + /* cl=......abcdefgh........cdefgh..........efgh............gh........ */ + return cl >> 50; } uint64_t helper_minub8(uint64_t op1, uint64_t op2) diff --git a/target-alpha/translate.c b/target-alpha/translate.c index 1fd9c3be96..206feb5746 100644 --- a/target-alpha/translate.c +++ b/target-alpha/translate.c @@ -1562,7 +1562,12 @@ static ExitStatus translate_one(DisasContext *ctx, uint32_t insn) break; case 0x0F: /* CMPBGE */ - gen_helper_cmpbge(vc, va, vb); + if (ra == 31) { + /* Special case 0 >= X as X == 0. */ + gen_helper_cmpbe0(vc, vb); + } else { + gen_helper_cmpbge(vc, va, vb); + } break; case 0x12: /* S8ADDL */ |