diff options
| author | Andrew Cagney <cagney@redhat.com> | 1997-12-01 06:27:02 +0000 |
|---|---|---|
| committer | Andrew Cagney <cagney@redhat.com> | 1997-12-01 06:27:02 +0000 |
| commit | 70ee56c585016f0b3b24814af61c458e8c7def4f (patch) | |
| tree | 907dccf2f6595e455b9267470438fc170dd6bbdb /sim/d10v/simops.c | |
| parent | 664298e6dc699825f3cd1fe0f4f4ee5593cffd9f (diff) | |
| download | gdb-70ee56c585016f0b3b24814af61c458e8c7def4f.zip gdb-70ee56c585016f0b3b24814af61c458e8c7def4f.tar.gz gdb-70ee56c585016f0b3b24814af61c458e8c7def4f.tar.bz2 | |
Rework sim/common/sim-alu.h to differentiate between direcct
subtraction (involves borrow) and negated addition (involves carry).
Update d30v so that it uses this method. Add more tests.
Diffstat (limited to 'sim/d10v/simops.c')
| -rw-r--r-- | sim/d10v/simops.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/sim/d10v/simops.c b/sim/d10v/simops.c index df0f826..222d2d4 100644 --- a/sim/d10v/simops.c +++ b/sim/d10v/simops.c @@ -1931,23 +1931,23 @@ OP_5201 () void OP_4201 () { - int64 tmp; + signed64 tmp; int shift = SEXT3 (OP[2]); trace_input ("rachi", OP_REG_OUTPUT, OP_ACCUM, OP_CONSTANT3); State.F1 = State.F0; if (shift >=0) - tmp = SEXT44 (State.a[OP[1]]) << shift; + tmp = SEXT40 (State.a[OP[1]]) << shift; else - tmp = SEXT44 (State.a[OP[1]]) >> -shift; + tmp = SEXT40 (State.a[OP[1]]) >> -shift; tmp += 0x8000; - if (tmp > MAX32) + if (tmp > SEXT44 (SIGNED64 (0x0007fffffff))) { State.regs[OP[0]] = 0x7fff; State.F0 = 1; } - else if (tmp < 0xfff80000000LL) + else if (tmp < SEXT44 (SIGNED64 (0xfff80000000))) { State.regs[OP[0]] = 0x8000; State.F0 = 1; @@ -2480,8 +2480,10 @@ OP_1000 () trace_input ("sub2w", OP_DREG, OP_DREG, OP_VOID); a = (uint32)((State.regs[OP[0]] << 16) | State.regs[OP[0]+1]); b = (uint32)((State.regs[OP[1]] << 16) | State.regs[OP[1]+1]); - tmp = a-b; - State.C = (tmp > a); + /* see ../common/sim-alu.h for a more extensive discussion on how to + compute the carry/overflow bits */ + tmp = a - b; + State.C = (a < b); State.regs[OP[0]] = (tmp >> 16) & 0xffff; State.regs[OP[0]+1] = tmp & 0xffff; trace_output (OP_DREG); @@ -2577,14 +2579,17 @@ OP_17001002 () void OP_1 () { - uint16 tmp; + unsigned tmp; if (OP[1] == 0) OP[1] = 16; trace_input ("subi", OP_REG, OP_CONSTANT16, OP_VOID); - tmp = State.regs[OP[0]] - OP[1]; - State.C = (tmp > State.regs[OP[0]]); - State.regs[OP[0]] = tmp; + /* see ../common/sim-alu.h for a more extensive discussion on how to + compute the carry/overflow bits */ + tmp = ((unsigned)(unsigned16) State.regs[OP[0]] + + (unsigned)(unsigned16) ( - OP[1])); + State.C = (tmp >= (1 << 16)); + State.regs[OP[0]] = tmp; trace_output (OP_REG); } |